Effect of spinal cord stimulation on myocardial perfusion reserve in patients with refractory angina pectoris.

PubMed

Saraste, Antti; Ukkonen, Heikki; Varis, Antti; Vasankari, Tuija; Tunturi, Satu; Taittonen, Markku; Rautakorpi, Pirkka; Luotolahti, Matti; Airaksinen, K E Juhani; Knuuti, Juhani

2015-04-01

Epidural spinal cord stimulation (SCS) provides symptom relief in refractory angina pectoris, but its mechanism of action remains incompletely understood. We studied effects of short-term SCS therapy on myocardial ischaemia tolerance, myocardial perfusion reserve (MPR), and endothelium-mediated vasodilatation induced by cold pressor test (CPT) in patients with refractory angina pectoris. We prospectively recruited 18 patients with refractory angina pectoris and studied them after implantation of SCS device at baseline before starting the therapy and after 3 weeks of continuous SCS therapy. Myocardial ischaemia was evaluated by dobutamine stress echocardiography. Global and regional myocardial blood flow (MBF) were measured using positron emission tomography and (15)O-water at rest, during adenosine stress, and in response to CPT. Systemic haemodynamics were comparable before and after 3 weeks of SCS at rest, during adenosine stress and during CPT. Appearance of angina pectoris induced by dobutamine stress was delayed after SCS therapy. Global MPR increased (P = 0.02) from 1.7 ± 0.6 at baseline to 2.0 ± 0.6 after 3-week SCS therapy. This was associated with a significant reduction in global MBF at rest and increase in MBF induced by adenosine in the ischaemic regions. Global MBF response to CPT was improved after SCS (0.27 ± 0.20 vs. 0.40 ± 0.15, P = 0.03). Short-term SCS therapy improved myocardial ischaemia tolerance, absolute MPR, and endothelium-mediated vasomotor function in refractory angina pectoris, indicating that this therapy can alleviate myocardial perfusion abnormalities in advanced CAD. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Serial Sampling of High-Sensitivity Cardiac Troponin T May Not Be Required for Prediction of Acute Myocardial Infarction Diagnosis in Chest Pain Patients with Highly Abnormal Concentrations at Presentation.

PubMed

Mueller-Hennessen, Matthias; Mueller, Christian; Giannitsis, Evangelos; Biener, Moritz; Vafaie, Mehrshad; deFilippi, Christopher R; Christ, Michael; Ordóñez-Llanos, Jorge; Panteghini, Mauro; Plebani, Mario; Verschuren, Franck; Melki, Dina; French, John K; Christenson, Robert H; Body, Richard; McCord, James; Dinkel, Carina; Katus, Hugo A; Lindahl, Bertil

2017-02-01

Guidelines for diagnosing acute myocardial infarction (AMI) recommend adding kinetic changes to the initial cardiac troponin (cTn) blood concentration to improve AMI diagnosis. We hypothesized that kinetic changes may not be required in patients presenting with highly abnormal cTn. Patients presenting with suspected AMI to the emergency department were enrolled in a prospective diagnostic study. We assessed the positive predictive value (PPV) of initial high-sensitivity cardiac troponin T (hs-cTnT) blood concentrations alone and in combination with kinetic changes for AMI. Predefined relative changes (δ change of ≥20%) and absolute changes (Δ change ≥9.2 ng/L) within different time intervals (1 h, 2 h, and 4-14 h after presentation) were assessed. The final diagnosis was adjudicated by 2 independent cardiologists. Among 1282 patients, 213 (16.6%) patients had a final diagnosis of AMI. For AMI prediction, PPVs increased from 48.8% for an initial hs-cTnT >14 ng/L to 87.2% for >60 ng/L, whereas PPVs remained unchanged for higher hs-cTnT concentrations at baseline (87.1% for both >80 ng/L and >100 ng/L). With addition of 20% relative Δ change, PPVs were not further improved in patients with baseline hs-cTnT >80 ng/L using the 1-h (84.0%) and 2-h (88.9%) intervals, and only minimally when extending the interval to 4-14 h (91.2% for >80 ng/L and 90.4% for >100 ng/L, respectively). Similar findings were observed when applying absolute changes. In chest pain patients with highly abnormal hs-cTnT concentrations at presentation, subsequent blood draws may not be required, as they do not provide incremental diagnostic value for prediction of AMI diagnosis. © 2016 American Association for Clinical Chemistry.

Reduced dose measurement of absolute myocardial blood flow using dynamic SPECT imaging in a porcine model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Timmins, Rachel; Klein, Ran; Petryk, Julia

Purpose: Absolute myocardial blood flow (MBF) and myocardial flow reserve (MFR) measurements provide important additional information over traditional relative perfusion imaging. Recent advances in camera technology have made this possible with single-photon emission tomography (SPECT). Low dose protocols are desirable to reduce the patient radiation risk; however, increased noise may reduce the accuracy of MBF measurements. The authors studied the effect of reducing dose on the accuracy of dynamic SPECT MBF measurements. Methods: Nineteen 30–40 kg pigs were injected with 370 + 1110 MBq of Tc-99m sestamibi or tetrofosmin or 37 + 111 MBq of Tl-201 at rest + stress.more » Microspheres were injected simultaneously to measure MBF. The pigs were imaged in list-mode for 11 min starting at the time of injection using a Discovery NM 530c camera (GE Healthcare). Each list file was modified so that 3/4, 1/2, 1/4, 1/8, 1/16, and 1/32 of the original counts were included in the projections. Modified projections were reconstructed with CT-based attenuation correction and an energy window-based scatter correction and analyzed with FlowQuant kinetic modeling software using a 1-compartment model. A modified Renkin-Crone extraction function was used to convert the tracer uptake rate K1 to MBF values. The SPECT results were compared to those from microspheres. Results: Correlation between SPECT and microsphere MBF values for the full injected activity was r ≥ 0.75 for all 3 tracers and did not significantly degrade over all count levels. The mean MBF and MFR and the standard errors in the estimates were not significantly worse than the full-count data at 1/4-counts (Tc99m-tracers) and 1/2-counts (Tl-201). Conclusions: Dynamic SPECT measurement of MBF and MFR in pigs can be performed with 1/4 (Tc99m-tracers) or 1/2 (Tl-201) of the standard injected activity without significantly reducing accuracy and precision.« less

A Comparison of Theory-Based and Experimentally Determined Myocardial Signal Intensity Correction Methods in First-Pass Perfusion Magnetic Resonance Imaging.

PubMed

Fluckiger, Jacob U; Benefield, Brandon C; Bakhos, Lara; Harris, Kathleen R; Lee, Daniel C

2015-01-01

To evaluate the impact of correcting myocardial signal saturation on the accuracy of absolute myocardial blood flow (MBF) measurements. We performed 15 dual bolus first-pass perfusion studies in 7 dogs during global coronary vasodilation and variable degrees of coronary artery stenosis. We compared microsphere MBF to MBF calculated from uncorrected and corrected MRI signal. Four correction methods were tested, two theoretical methods (Th1 and Th2) and two empirical methods (Em1 and Em2). The correlations with microsphere MBF (n = 90 segments) were: uncorrected (y = 0.47x + 1.1, r = 0.70), Th1 (y = 0.53x + 1.0, r = 0.71), Th2 (y = 0.62x + 0.86, r = 0.73), Em1 (y = 0.82x + 0.86, r = 0.77), and Em2 (y = 0.72x + 0.84, r = 0.75). All corrected methods were not significantly different from microspheres, while uncorrected MBF values were significantly lower. For the top 50% of microsphere MBF values, flows were significantly underestimated by uncorrected SI (31%), Th1 (25%), and Th2 (19%), while Em1 (1%), and Em2 (9%) were similar to microsphere MBF. Myocardial signal saturation should be corrected prior to flow modeling to avoid underestimation of MBF by MR perfusion imaging.

Detection of CD34/CXCR4+ stem cells in peripheral blood of patients following acute myocardial infarction.

PubMed

Abdallah, Khaled Omar; Saleh, Rasha Mamdouh; Al-Shawarby, Laila Abd Al-Aala; Amer, Hanaa Ahmed; Mostafa, Sara

2014-01-01

Bone marrow harbors a population of tissue-committed stem cells that are CD34+/CXCR4+. These potential cardiac progenitors which express cardiac and endothelial markers may contribute to cardiac regeneration. The ability of injured myocardium to recruit extracardiac stem cells after injury would be beneficial to aid in myocardial repair and regeneration. The aim of this study was to answer the question whether acute myocardial infarction (AMI) related stress may trigger the increase of CD34/CXCR4+ stem cells number in peripheral blood in response to myocardial ischemic injury which might be accompanied with increased release of this population of stem cells in peripheral blood as well as to correlate this phenomenon with other clinical and laboratory parameters such as diabetes, chest pain, smoking, streptokinase administration and elevated cardiac enzymes. The study was conducted on 25 newly diagnosed AMI patients who attended the emergency department of National Heart Institute. They were compared to a control group of 25 apparently healthy sex and age matched individuals. The percentage of CD34+ cells as well as percentage of cells coexpressing CD34/CXCR4+ and their expression intensity were assessed by Flowcytometery. These parameters were correlated to other laboratory and clinical data. The absolute CD34+ as well as the CD34/CXCR4+ cell counts were significantly higher in patients upon admission in comparison to control group (P < 0.01). While CD34 expression was significantly higher in patients compared to control group, CXCR4 expression on CD34+ cells was significantly lower in patients than control group (P < 0.05). Diabetes, duration of chest pain and streptokinase administration had no significant effect on CD34/CXCR4+ number or the expression intensity of both markers (p > 0.05). Otherwise, CXCR4 intensity was lower in non-smoker than smoker patients (P < 0.05). Patients admitted with normal cardiac enzymes, including Creatine Kinase (CK) and Creatine Kinase MB fraction (CK-MB) activity, showed no significant difference in CD34/CXCR4+ number or the expression intensity of CD34 marker in comparison to those admitted with high levels of enzymes (P > 0.05). However, the expression intensity of CXCR4 was significantly low in patients admitted with elevated cardiac enzymes (P < 0.05). In conclusion, there is a pool of CD34/CXCR4+ stem cells circulating in large number in peripheral blood of AMI patients post infarction together with low CXCR4 expression on these cells which are likely to contribute to myocardial repair following the acute ischemic injury.

Relationship between regional myocardial blood flow and thallium-201 distribution in the presence of coronary artery stenosis and dipyridamole-induced vasodilation.

PubMed Central

Mays, A E; Cobb, F R

1984-01-01

This study assesses the relationship between the distribution of thallium-201 and myocardial blood flow during coronary vasodilation induced by intravenous dipyridamole in canine models of partial and complete coronary artery stenosis. 10 dogs were chronically instrumented with catheters in the left atrium and aorta and with a balloon occluder and electromagnetic flow probe on the proximal left circumflex coronary artery. Regional myocardial blood flow was measured during control conditions with radioisotope-labeled microspheres, and the phasic reactive hyperemic response to a 20-s transient occlusion was then recorded. Dipyridamole was then infused intravenously until phasic coronary blood flow increased to match peak hyperemic values. The left circumflex coronary artery was either partially occluded to reduce phasic blood flow to control values (group 1) or it was completely occluded (group 2), and thallium-201 and a second microsphere label were injected. 5 min later, the animals were sacrificed, the left ventricle was sectioned into 1-2-g samples, and thallium-201 activity and regional myocardial blood flow were measured. Curvilinear regression analyses between thallium-201 localization and myocardial blood flow during dipyridamole infusion demonstrated a slightly better fit to a second- as compared with a first-order model, indicating a slight roll-off of thallium activity as myocardial blood flow increases. During the dipyridamole infusion, the increases in phasic blood flow, the distributions of regional myocardial blood flow, and the relationships between thallium-201 localization and regional blood flow were comparable to values previously observed in exercising dogs with similar occlusions. These data provide basic validation that supports the use of intravenous dipyridamole and thallium-201 as an alternative to exercise stress and thallium-201 for evaluating the effects of coronary occlusive lesions on the distribution of regional myocardial blood flow. PMID:6715540

Noninvasive quantification of myocardial blood flow in humans. A direct comparison of the [13N]ammonia and the [15O]water techniques.

PubMed

Nitzsche, E U; Choi, Y; Czernin, J; Hoh, C K; Huang, S C; Schelbert, H R

1996-06-01

[13N]Ammonia has been validated in dog studies as a myocardial blood flow tracer. Estimates of myocardial blood flow by [13N]ammonia were highly linearly correlated to those by the microsphere and blood sample techniques. However, estimates of myocardial blood flow with [13N]ammonia in humans have not yet been compared with those by an independent technique. This study therefore tested the hypothesis that the [13N]ammonia positron emission tomographic technique in humans gives estimates of myocardial blood flow comparable to those obtained with the [15O]water technique. A total of 30 pairs of positron emission tomographic flow measurements were performed in 30 healthy volunteers; 15 volunteers were studied at rest and 15 during adenosine-induced hypermia. Estimates of average and of regional myocardial blood flow by the [13N]ammonia and the [15O]water approaches correlated well (y = 0.02 + 1.02x, r = .99, P < .001 SEE = 0.023 for average and y = 0.06 + 1.00x, r = .97, P < .001, SEE = 0.025 for regional values) over a flow range of 0.45 to 4.74 mL.min-1.g-1. At rest, mean myocardial blood flow was 0.64 +/- 0.09 mL.min-1.g-1 for [13N]ammonia and 0.66 +/- 0.12 mL.min-1.g-1 for [15O]water (P = NS). For adenosine-induced hyperemia, mean myocardial blood flow was 2.63 +/- 0.75 mL.min-1.g-1 for [13N]ammonia and 2.73 +/- 0.77 mL.min-1.g-1 for [15O]water (P = NS). The coefficient of variation as an index of the observed heterogeneity of myocardial blood flow averaged, for [13N]ammonia, 9 +/- 4% at rest and 12 +/- 7% during stress and, for [15O]water, 14 +/- 11% at rest and 16 +/- 9% during stress. The coefficients of variation for [15O]water were significantly higher than those for [13N]ammonia (P = .004 at rest and P = .03 during stress). The two approaches yield comparable estimates of myocardial blood flow in humans, which supports the validity of the [13N]ammonia method in human myocardium previously shown only in animals. However, the [15O]water approach reveals a greater heterogeneity (presumably method-related), which might limit the accuracy of sectorial myocardial blood flow estimates in humans.

Regional myocardial extraction of a radioiodinated branched chain fatty acid during right ventricular pressure overload due to acute pulmonary hypertension

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurford, W.; Lowenstein, E.; Zapol, W.

1985-05-01

To determine whether branched chain fatty acid extraction is reduced during right ventricular (RV) dysfunction due to acute pulmonary artery hypertension, studies were done in 6 anesthetized dogs. Regional branched chain fatty acid extraction was measured by comparing the myocardial uptake of I-125 labeled 15-(p-(iodophenyl))-3-methylpentadecanoic acid (I-PDA) to myocardial blood flow. Acute pulmonary hypertension was induced by incremental intravenous injection of 100 micron diameter glass beads into six pentobarbital anesthetized, mechanically ventilated dogs. Myocardial blood flow was measured by radiolabeled microspheres both under baseline conditions and during pulmonary hypertension. Mean RV pressure rose from 12 +- 2 (mean +- SEM)more » to 30 +-3mmHg resulting in a 225 +- 16% increase in RV stroke work. RV ejection fraction, as assessed by gated blood pool scans fell from 39 +- 2 to 18 +- 2%. Left ventricular (LV) pressures, stroke work and ejection fraction were unchanged. Myocardial blood flow increased 132 + 59% in the RV free wall and 67 +- 22% in the RV septum. LV blood flow was unchanged. Despite increased RV work and myocardial blood flow, no differences were noted in the branched chain fatty acid extraction ratios among LV or RV free walls or septum. The authors conclude that early RV dysfunction associated with pulmonary artery hypertension is not due to inadequate myocardial blood flow or branched chain fatty acid extraction.« less

Effects of graded doses of epinephrine on regional myocardial blood flow during cardiopulmonary resuscitation in swine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, C.G.; Werman, H.A.; Davis, E.A.

1987-02-01

Although epinephrine has been shown to improve myocardial blood flow during cardiopulmonary resuscitation (CPR), the effects of standard as well as larger doses of epinephrine on regional myocardial blood flow have not been examined. In this study we compared the effects of various doses of epinephrine on regional myocardial blood flow after a 10 min arrest in a swine preparation. Fifteen swine weighing greater than 15 kg each were instrumented for regional myocardial blood flow measurements with tracer microspheres. Regional blood flow was measured during normal sinus rhythm. After 10 min of ventricular fibrillation, CPR was begun and regional myocardialmore » blood flow was determined. Animals were then randomly assigned to receive 0.02, 0.2, or 2.0 mg/kg epinephrine by peripheral injection. One minute after drug administration, regional myocardial blood flow measurements were repeated. The adjusted regional myocardial blood flows (ml/min/100 g) for animals given 0.02, 0.2, and 2.0 mg/kg epinephrine, respectively, were as follows: left atrium, 0.9, 67.4, and 58.8; right atrium, 0.3, 46.2, and 38.5; right ventricle, 0.7, 82.3, and 66.9; right interventricular septum, 1.7, 125.5, and 99.1; left interventricular septum, 2.8, 182.8, 109.5; mesointerventricular septum, 16.8, 142.2, and 79.2; left ventricular epicardium, 19.2, 98.5 and 108.7; left ventricular mesocardium, 22.8, 135.0, and 115.8; and left ventricular endocardium, 2.5, 176.1, and 132.9). All comparisons between the groups receiving 0.02 and 0.2 mg/kg epinephrine were statistically significant (p less than .05).« less

Acute Effect of Hookah Smoking on the Human Coronary Microcirculation

PubMed Central

Nelson, Michael D.; Rezk-Hanna, Mary; Rader, Florian; Mason, O’Neil R.; Tang, Xiu; Shidban, Sarah; Rosenberry, Ryan; Benowitz, Neal L.; Tashkin, Donald P.; Elashoff, Robert M.; Lindner, Jonathan R.; Victor, Ronald G.

2017-01-01

Hookah (water pipe) smoking is a major new understudied epidemic affecting youth. Because burning charcoal is used to heat the tobacco product, hookah smoke delivers not only nicotine but also large amounts of charcoal combustion products, including carbon-rich nanoparticles that constitute putative coronary vasoconstrictor stimuli and carbon monoxide, a known coronary vasodilator. We used myocardial contrast echocardiography perfusion imaging with intravenous lipid shelled microbubbles in young adult hookah smokers to determine the net effect of smoking hookah on myocardial blood flow. In 9 hookah smokers (age 27 – 5 years, mean – SD), we measured myocardial blood flow velocity (β), myocardial blood volume (A), myocardial blood flow (A × β) as well as myocardial oxygen consumption (MVO2) before and immediately after 30 minutes of ad lib hookah smoking. Myocardial blood flow did not decrease with hookah smoking but rather increased acutely (88 – 10 to 120 – 19 a.u./s, mean – SE, p = 0.02), matching a mild increase in MVO2 (6.5 – 0.3 to 7.6 – 0.4 ml·minute−1, p <0.001). This was manifested primarily by increased myocardial blood flow velocity (0.7 – 0.1 to 0.9 – 0.1 second−1, p = 0.01) with unchanged myocardial blood volume (133 – 7 to 137 – 7 a.u., p = ns), the same pattern of coronary microvascular response seen with a low-dose β-adrenergic agonist. Indeed, with hookah, the increased MVO2 was accompanied by decreased heart rate variability, an indirect index of adrenergic overactivity, and eliminated by β-adrenergic blockade (i.v. propranolol). In conclusion, nanoparticle-enriched hookah smoke either is not an acute coronary vasoconstrictor stimulus or its vasoconstrictor effect is too weak to overcome the physiologic dilation of coronary microvessels matching mild cardiac β-adrenergic stimulation. PMID:27067622

The effects of compound danshen dripping pills and human umbilical cord blood mononuclear cell transplant after acute myocardial infarction.

PubMed

Jun, Yi; Chunju, Yuan; Qi, Ai; Liuxia, Deng; Guolong, Yu

2014-04-01

The low frequency of survival of stem cells implanted in the myocardium after acute myocardial infarction may be caused by inflammation and oxidative stress in the myocardial microenvironment. We evaluated the effects of a traditional Chinese medicine, Compound Danshen Dripping Pills, on the cardiac microenvironment and cardiac function when used alone or in combination with human umbilical cord blood mononuclear cell transplant after acute myocardial infarction. After surgically induced acute myocardial infarction, rabbits were treated with Compound Danshen Dripping Pills alone or in combination with human umbilical cord blood mononuclear cell transplant. Evaluation included histology, measurement of left ventricular ejection fraction and fractional shortening, leukocyte count, count of green fluorescent protein positive cells, superoxide dismutase activity, and malondialdehyde content. Combination treatment with Compound Danshen Dripping Pills and human umbilical cord blood mononuclear cell transplant significantly increased the survival of implanted cells, inhibited cardiac cell apoptosis, decreased oxidative stress, decreased the inflammatory response, and improved cardiac function. Rabbits treated with either Compound Danshen Dripping Pills or human umbilical cord blood mononuclear cells alone had improvement in these effects compared with untreated control rabbits. Combination therapy with Compound Danshen Dripping Pills and human umbilical cord blood mononuclear cells may improve cardiac function and morphology after acute myocardial infarction.

Myocardial uptake and kinetic properties of technetium-99m-Q3 in dogs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerson, M.C.; Millard, R.W.; McGoron, A.J.

1994-10-01

We postulated that {sup 99m}Tc-Q3, a cationic imaging agent, produces myocardial activity related to myocardial blood flow during myocardial ischemia and pharmacologic coronary artery vasodilation, and shows little or no myocardial redistribution over 4 hr after intravenous injection. In six Group 1 dogs, the chest was opened, the left circumflex coronary artery was acutely ligated, and dipyridamole (0.32, 0.56 or 0.84 mg/kg) was infused into the right atrium, followed by 10 mCi of {sup 99m}Tc-Q3. Myocardial blood flow was measured by radiolabeled microspheres. The animals were euthanized and 357 myocardial samples were assayed in a well counter for {sup 99m}Tcmore » activity. One week later, radiolabeled microsphere activity was counted and myocardial blood flow calculated. In nine Group 2 dogs, a variable occluder was placed around the left circumflex coronary artery and an ischemic level of circumflex blood flow was maintained constant over 4 hr as measured by an ultrasonic flow meter. Dipyridamole (0.56 mg/kg) was then infused into the right atrium followed by 10mCi of {sup 99m}Tc-Q3. Gamma camera images were acquired at 5, 15, 30, 60, 120 and 240 min following k{sup 99m}Tc-Q3 injection. Microsphere blood flow and endocardial biopsies (n - 6 dogs) were performed at 30, 60, 120 and 240 min following {sup 99m}TcQ3 injection. 31 refs., 9 figs., 1 tab.« less

Reproducibility and Accuracy of Quantitative Myocardial Blood Flow Using 82Rb-PET: Comparison with 13N-Ammonia

PubMed Central

Fakhri, Georges El

2011-01-01

82Rb cardiac PET allows the assessment of myocardial perfusion using a column generator in clinics that lack a cyclotron. We and others have previously shown that quantitation of myocardial blood flow (MBF) and coronary flow reserve (CFR) is feasible using dynamic 82Rb PET and factor and compartment analyses. The aim of the present work was to determine the intra- and inter-observer variability of MBF estimation using 82Rb PET as well as the reproducibility of our generalized factor + compartment analyses methodology to estimate MBF and assess its accuracy by comparing, in the same subjects, 82Rb estimates of MBF to those obtained using 13N-ammonia. Methods Twenty-two subjects were included in the reproducibility and twenty subjects in the validation study. Patients were injected with 60±5mCi of 82Rb and imaged dynamically for 6 minutes at rest and during dipyridamole stress Left and right ventricular (LV+RV) time-activity curves were estimated by GFADS and used as input to a 2-compartment kinetic analysis that estimates parametric maps of myocardial tissue extraction (K1) and egress (k2), as well as LV+RV contributions (fv,rv). Results Our results show excellent reproducibility of the quantitative dynamic approach itself with coefficients of repeatability of 1.7% for estimation of MBF at rest, 1.4% for MBF at peak stress and 2.8% for CFR estimation. The inter-observer reproducibility between the four observers that participated in this study was also very good with correlation coefficients greater than 0.87 between any two given observers when estimating coronary flow reserve. The reproducibility of MBF in repeated 82Rb studies was good at rest and excellent at peak stress (r2=0.835). Furthermore, the slope of the correlation line was very close to 1 when estimating stress MBF and CFR in repeated 82Rb studies. The correlation between myocardial flow estimates obtained at rest and during peak stress in 82Rb and 13N-ammonia studies was very good at rest (r2=0.843) and stress (r2=0.761). The Bland-Altman plots show no significant presence of proportional error at rest or stress, nor a dependence of the variations on the amplitude of the myocardial blood flow at rest or stress. A small systematic overestimation of 13N-ammonia MBF was observed with 82Rb at rest (0.129 ml/g/min) and the opposite, i.e., underestimation, at stress (0.22 ml/g/min). Conclusions Our results show that absolute quantitation of myocardial bloof flow is reproducible and accurate with 82Rb dynamic cardiac PET as compared to 13N-ammonia. The reproducibility of the quantitation approach itself was very good as well as inter-observer reproducibility. PMID:19525467

SPECT Myocardial Blood Flow Quantitation Concludes Equivocal Myocardial Perfusion SPECT Studies to Increase Diagnostic Benefits.

PubMed

Chen, Lung-Ching; Lin, Chih-Yuan; Chen, Ing-Jou; Ku, Chi-Tai; Chen, Yen-Kung; Hsu, Bailing

2016-01-01

Recently, myocardial blood flow quantitation with dynamic SPECT/CT has been reported to enhance the detection of coronary artery disease in human. This advance has created important clinical applications to coronary artery disease diagnosis and management for areas where myocardial perfusion PET tracers are not available. We present 2 clinical cases that undergone a combined test of 1-day rest/dipyridamole-stress dynamic SPECT and ECG-gated myocardial perfusion SPECT scans using an integrated imaging protocol and demonstrate that flow parameters are capable to conclude equivocal myocardial perfusion SPECT studies, therefore increasing diagnostic benefits to add value in making clinical decisions.

Usefulness of rCBF analysis in diagnosing Parkinson's disease: supplemental role with MIBG myocardial scintigraphy.

PubMed

Nagamachi, Shigeki; Wakamatsu, Hideyuki; Kiyohara, Shogo; Fujita, Seigo; Futami, Shigemi; Tamura, Shozo; Nakazato, Masamitsu; Yamashita, Syuichi; Arita, Hideo; Nishii, Ryuichi; Kawai, Keiichi

2008-08-01

(123)I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy is a useful tool for differentiating idiopathic Parkinson's disease (PD) from parkinsonism (PS) caused by other disorders. However, cardiac MIBG uptake is affected by various causes. Alternatively, hypoperfusion in the occipital lobe of PD is reported recently. The objective is to clarify the correlation between regional cerebral blood flow (rCBF) alteration and cardiac MIBG uptake in PD. In addition, we examined whether additional brain perfusion analysis improved the differential diagnostic ability for PD from PS when compared with MIBG scintigraphy alone. Forty-nine patients with PD (27 mild groups: Hoehn and Yahr stages I, II; 22 severe groups: Hoehn and Yahr stages III, IV) and 28 patients with PS participated. We compared absolute rCBF values between PD and PS. In addition, we determined correlation between MIBG parameters and each rCBF value. Finally, we compared the diagnostic ability for the differentiation of PD from PS between two diagnostic criteria, each MIBG index abnormality alone [heart-to-mediastinum ratio, H/M (E) < 1.9, H/E (D) < 1.7, washout rate > 40%] and each MIBG index abnormality or occipital lobe hypoperfusion (<36 ml/100 g per min). Absolute rCBF value of occipital lobe was significantly lower in severe PD as compared with PS or mild PD. In the correlation analysis, rCBF of occipital lobe correlated positively with MIBG parameters (H/M). Regarding the diagnostic ability, sensitivity improved by accounting for occipital hypoperfusion as compared with MIBG indices alone. In contrast, neither specificity nor accuracy improved by adding occipital lobe analysis. MIBG parameters (H/M) correlated positively with occipital hypoperfusion in PD. In the differential diagnosis between PD and PS, although its usefulness might be limited, analysis of rCBF in the occipital lobe added to (123)I-MIBG myocardial imaging can be recommended.

Cardiovascular pharmacology of quazodine (MJ-1988), with particular reference to effects of myocardial blood flow and metabolic heat production.

PubMed

Parratt, J R; Winslow, E

1971-06-01

1. The effects of intravenous infusions of quazodine (6,7-dimethoxy-4-ethylquinazoline; MJ-1988) on myocardial blood flow, myocardial metabolic heat production and on general haemodynamics have been studied in cats anaesthetized with sodium pentobarbitone.2. Quazodine (0.25 and 0.5 (mg/kg)/min for 10 min) decreased diastolic blood pressure, peripheral vascular resistance, systolic ejection time and left ventricular end-diastolic pressure. Heart rate, cardiac effort, output and external work and left ventricular dP/dt were markedly increased. These changes are indicative of increased myocardial contractility and peripheral vasodilatation.3. In a dose of (1.0 mg/kg)/min, quazodine had a more marked hypotensive effect, systolic pressure being significantly reduced, and had less effect on left ventricular dP/dt and cardiac effort. Calculated external cardiac work was slightly reduced and there were very occasional nodal arrhythmias.4. Changes in heart rate, aortic dP/dt and diastolic blood pressure induced by quazodine were unaffected by the previous administration of the beta-adrenoceptor blocking agent alprenolol in a dose (1.0 mg/kg) which abolished the effects of isoprenaline.5. In all doses, quazodine markedly increased local blood flow (by 70-540%) around an implanted myocardial heated thermocouple recorder. ;Corrected temperature', an index of local myocardial metabolic heat production, was almost unchanged and it is suggested that increased myocardial contractility, occurring with unchanged metabolic heat production and oxygen consumption, probably results from a concomitant decrease in intramural wall tension.

Myocardial Blood Flow Distribution during Ischemia-Induced Coronary Vasodilation in the Unanesthetized Dog

PubMed Central

Bache, Robert J.; Cobb, Frederick R.; Greenfield, Joseph C.

1974-01-01

This study was designed to determine whether coronary vasodilation distal to a flow-limiting coronary artery stenosis could result in redistribution of myocardial blood flow to produce subendocardial underperfusion. Studies were performed in 10 awake dogs chronically prepared with electromagnetic flow-meters and hydraulic occluders on the left circumflex coronary artery. Regional myocardial blood flow was measured using radionuclide-labeled microspheres, 7-10 μm in diameter, injected into the left atrium. A 5-s coronary artery occlusion was followed by reactive hyperemia with excess inflow of arterial blood effecting 375±20% repayment of the blood flow debt incurred during occlusion. When, after a 5-s occlusion, the occluder was only partially released to hold arterial inflow to the preocclusion level for 20 s before complete release, the delayed reactive hyperemia was augmented (mean blood flow repayment = 610±45%, P < 0.01). This augmentation of the reactive hyperemia suggested that ischemia was continuing during the interval of coronary vasodilation when coronary inflow was at the preocclusion level. Measurements of regional myocardial blood flow demonstrated that endocardial flow slightly exceeded epicardial flow during control conditions. When arterial inflow was limited to the preocclusion rate during vasodilation after a 5-s total coronary artery occlusion, however, flow to the subepicardial myocardium was increased at the expense of underperfusion of the subendocardial myocardium. Thus, in the presence of a flow-limiting proximal coronary artery stenosis, ischemia-induced coronary vasodilation resulted in redistribution of myocardial blood flow with production of subendocardial ischemia in the presence of a net volume of arterial inflow which, if properly distributed, would have been adequate to prevent myocardial ischemia. Images PMID:4279928

Use of blood-pool imaging in evaluation of diffuse activity patterns in technetium-99m pyrophosphate myocardial scintigraphy.

PubMed

Cowley, M J; Mantle, J A; Rogers, W J; Russell, R O; Rackley, C E; Logic, J R

1979-06-01

It has been suggested that diffuse Tc-99m pyrophosphate precordial activity may be due to persistent blood-pool activity in routine delayed views during myocardial imaging. To answer this question, we reviewed myocardial scintigrams recorded 60--90 min following the injection of 12--15 mCi of Tc-99m pyrophosphate for the presence of diffuse precordial activity, and compared these with early images of the blood pool in 265 patients. Diffuse activity in the delayed images was identified in 48 patients: in 20 with acute myocardial infarction and in 28 with no evidence of it. Comparison of these routine delayed images with early views of the blood pool revealed two types of patterns. In patients with acute infarction, 95% had delayed images that were distinguishable from blood pool either because the activity was smaller than the early blood pool, or by the presence of localized activity superimposed on diffuse activity identical to blood pool. In those without infarction, 93% had activity distribution in routine delayed views matching that in the early blood-pool images. The usefulness of the diffuse TcPPi precordial activity in myocardial infarction is improved when early blood-pool imaging is used to exclude persistence of blood-pool activity as its cause. Moreover, it does not require additional amounts of radioactivity nor complex computer processing, a feature that may be of value in the community hospital using the technique to "rule out" infarction 24--72 hr after onset of suggestive symptoms.

Patient-specific coronary artery blood flow simulation using myocardial volume partitioning

NASA Astrophysics Data System (ADS)

Kim, Kyung Hwan; Kang, Dongwoo; Kang, Nahyup; Kim, Ji-Yeon; Lee, Hyong-Euk; Kim, James D. K.

2013-03-01

Using computational simulation, we can analyze cardiovascular disease in non-invasive and quantitative manners. More specifically, computational modeling and simulation technology has enabled us to analyze functional aspect such as blood flow, as well as anatomical aspect such as stenosis, from medical images without invasive measurements. Note that the simplest ways to perform blood flow simulation is to apply patient-specific coronary anatomy with other average-valued properties; in this case, however, such conditions cannot fully reflect accurate physiological properties of patients. To resolve this limitation, we present a new patient-specific coronary blood flow simulation method by myocardial volume partitioning considering artery/myocardium structural correspondence. We focus on that blood supply is closely related to the mass of each myocardial segment corresponding to the artery. Therefore, we applied this concept for setting-up simulation conditions in the way to consider many patient-specific features as possible from medical image: First, we segmented coronary arteries and myocardium separately from cardiac CT; then the myocardium is partitioned into multiple regions based on coronary vasculature. The myocardial mass and required blood mass for each artery are estimated by converting myocardial volume fraction. Finally, the required blood mass is used as boundary conditions for each artery outlet, with given average aortic blood flow rate and pressure. To show effectiveness of the proposed method, fractional flow reserve (FFR) by simulation using CT image has been compared with invasive FFR measurement of real patient data, and as a result, 77% of accuracy has been obtained.

Myocardial Blood Volume Is Associated with Myocardial Oxygen Consumption: An Experimental Study with CMR in a Canine Model

PubMed Central

McCommis, Kyle S.; Zhang, Haosen; Goldstein, Thomas A.; Misselwitz, Bernd; Abendschein, Dana R.; Gropler, Robert J.; Zheng, Jie

2009-01-01

OBJECTIVES To evaluate the feasibility of cardiovascular MR (CMR) to determine regional myocardial perfusion and O2 metabolism, and assess the role of myocardial blood volume (MBV) on oxygen supply. BACKGROUND Coronary artery disease presents as an imbalance of myocardial oxygen supply and demand. We have developed relevant CMR methods to determine the relationship of myocardial blood flow (MBF) and MBV to oxygen consumption (MVO2) during pharmacologic hyperemia. METHODS Twenty-one mongrel dogs were studied with varying stenosis severities imposed on the proximal left anterior descending (LAD) coronary artery. MBF and MBV were determined by CMR first-pass perfusion, while the oxygen extraction fraction (OEF) and MVO2 were determined by the myocardial Blood-Oxygen-Level-Dependent (BOLD) effect and Fick’s law, respectively. MR imaging was performed at rest, and during either dipyridamole-induced vasodilation or dobutamine-induced hyperemia. Regional differences in myocardial perfusion and oxygenation were then evaluated. RESULTS Dipyridamole and dobutamine both led to 145–200% increases in MBF and 50–80% increases in MBV in normal perfused myocardium. As expected, MVO2 increased more significantly with dobutamine (~175%) than dipyridamole (~40%). Coronary stenosis resulted in an attenuation of MBF, MBV, and MVO2 in both the LAD-subtended stenosis region and the left circumflex subtended remote region. Liner regression analysis showed that MBV reserve appears to be more correlated with MVO2 reserve during dobutamine stress than MBF reserve, particularly in the stenotic regions. Conversely, MBF reserve appears to be more correlated with MVO2 reserve during dipyridamole, although neither of these differences was significant. CONCLUSIONS Noninvasive evaluation of both myocardial perfusion and oxygenation by CMR facilitates direct monitoring of regional myocardial ischemia and provides a valuable tool for better understanding microvascular pathophysiology. These techniques could complement delayed enhancement and wall motion analysis protocols, making MRI a valuable “one-stop shop” for imaging of myocardial ischemia. PMID:19909936

Continuous-Flow Left Ventricular Assist Device Support Improves Myocardial Supply:Demand in Chronic Heart Failure.

PubMed

Soucy, Kevin G; Bartoli, Carlo R; Phillips, Dustin; Giridharan, Guruprasad A; Sobieski, Michael A; Wead, William B; Dowling, Robert D; Wu, Zhongjun J; Prabhu, Sumanth D; Slaughter, Mark S; Koenig, Steven C

2017-06-01

Continuous-flow left ventricular assist devices (CF LVADs) are rotary blood pumps that improve mean blood flow, but with potential limitations of non-physiological ventricular volume unloading and diminished vascular pulsatility. In this study, we tested the hypothesis that left ventricular unloading with increasing CF LVAD flow increases myocardial flow normalized to left ventricular work. Healthy (n = 8) and chronic ischemic heart failure (IHF, n = 7) calves were implanted with CF LVADs. Acute hemodynamics and regional myocardial blood flow were measured during baseline (LVAD off, clamped), partial (2-4 L/min) and full (>4 L/min) LVAD support. IHF calves demonstrated greater reduction of cardiac energy demand with increasing LVAD support compared to healthy calves, as calculated by rate-pressure product. Coronary artery flows (p < 0.05) and myocardial blood flow (left ventricle (LV) epicardium and myocardium, p < 0.05) decreased with increasing LVAD support in normal calves. In the IHF model, blood flow to the septum, LV, LV epicardium, and LV myocardium increased significantly with increasing LVAD support when normalized to cardiac energy demand (p < 0.05). In conclusion, myocardial blood flow relative to cardiac demand significantly increased in IHF calves, thereby demonstrating that CF LVAD unloading effectively improves cardiac supply and demand ratio in the setting of ischemic heart failure.

Neuromodulation therapy does not influence blood flow distribution or left-ventricular dynamics during acute myocardial ischemia.

PubMed

Kingma, J G; Linderoth, B; Ardell, J L; Armour, J A; DeJongste, M J; Foreman, R D

2001-08-13

Electrical stimulation of the dorsal aspect of the upper thoracic spinal cord is used increasingly to treat patients with angina pectoris refractory to conventional therapeutic strategies. The purpose of this study was to determine whether spinal cord stimulation (SCS) in dogs affects regional myocardial blood flow and left-ventricular (LV) function before and during transient obstruction of the left anterior descending coronary artery (LAD). In anesthetized dogs, regional myocardial blood flow distribution was determined using radiolabeled microspheres and left-ventricular function was measured by impedance-derived pressure-volume loops. SCS was accomplished by stimulating the dorsal T1-T2 segments of the spinal cord using epidural bipolar electrodes at 90% of motor threshold (MT) (50 Hz, 0.2-ms duration). Effects of 5-min SCS were assessed under basal conditions and during 4-min occlusion of the LAD. SCS alone evoked no change in regional myocardial blood flow or cardiovascular indices. Transient LAD occlusion significantly diminished blood flow within ischemic, but not in non-ischemic myocardial tissue. Left ventricular pressure-volume loops were shifted rightward during LAD occlusion. Cardiac indices were altered similarly during LAD occlusion and concurrent SCS. SCS does not influence the distribution of blood flow within the non-ischemic or ischemic myocardium. Nor does it modify LV pressure-volume dynamics in the anesthetized experimental preparation.

Dynamic CT myocardial perfusion imaging: detection of ischemia in a porcine model with FFR verification

NASA Astrophysics Data System (ADS)

Fahmi, Rachid; Eck, Brendan L.; Vembar, Mani; Bezerra, Hiram G.; Wilson, David L.

2014-03-01

Dynamic cardiac CT perfusion (CTP) is a high resolution, non-invasive technique for assessing myocardial blood ow (MBF), which in concert with coronary CT angiography enable CT to provide a unique, comprehensive, fast analysis of both coronary anatomy and functional ow. We assessed perfusion in a porcine model with and without coronary occlusion. To induce occlusion, each animal underwent left anterior descending (LAD) stent implantation and angioplasty balloon insertion. Normal ow condition was obtained with balloon completely de ated. Partial occlusion was induced by balloon in ation against the stent with FFR used to assess the extent of occlusion. Prospective ECG-triggered partial scan images were acquired at end systole (45% R-R) using a multi-detector CT (MDCT) scanner. Images were reconstructed using FBP and a hybrid iterative reconstruction (iDose4, Philips Healthcare). Processing included: beam hardening (BH) correction, registration of image volumes using 3D cubic B-spline normalized mutual-information, and spatio-temporal bilateral ltering to reduce partial scan artifacts and noise variation. Absolute blood ow was calculated with a deconvolutionbased approach using singular value decomposition (SVD). Arterial input function was estimated from the left ventricle (LV) cavity. Regions of interest (ROIs) were identi ed in healthy and ischemic myocardium and compared in normal and occluded conditions. Under-perfusion was detected in the correct LAD territory and ow reduction agreed well with FFR measurements. Flow was reduced, on average, in LAD territories by 54%.

Dose reduction assessment in dynamic CT myocardial perfusion imaging in a porcine balloon-induced-ischemia model

NASA Astrophysics Data System (ADS)

Fahmi, Rachid; Eck, Brendan L.; Vembar, Mani; Bezerra, Hiram G.; Wilson, David L.

2014-03-01

We investigated the use of an advanced hybrid iterative reconstruction (IR) technique (iDose4, Philips Health- care) for low dose dynamic myocardial CT perfusion (CTP) imaging. A porcine model was created to mimic coronary stenosis through partial occlusion of the left anterior descending (LAD) artery with a balloon catheter. The severity of LAD occlusion was adjusted with FFR measurements. Dynamic CT images were acquired at end-systole (45% R-R) using a multi-detector CT (MDCT) scanner. Various corrections were applied to the acquired scans to reduce motion and imaging artifacts. Absolute myocardial blood flow (MBF) was computed with a deconvolution-based approach using singular value decomposition (SVD). We compared a high and a low dose radiation protocol corresponding to two different tube-voltage/tube-current combinations (80kV p/100mAs and 120kV p/150mAs). The corresponding radiation doses for these protocols are 7.8mSv and 34.3mSV , respectively. The images were reconstructed using conventional FBP and three noise-reduction strengths of the IR method, iDose. Flow contrast-to-noise ratio, CNRf, as obtained from MBF maps, was used to quantitatively evaluate the effect of reconstruction on contrast between normal and ischemic myocardial tissue. Preliminary results showed that the use of iDose to reconstruct low dose images provide better or comparable CNRf to that of high dose images reconstructed with FBP, suggesting significant dose savings. CNRf was improved with the three used levels of iDose compared to FBP for both protocols. When using the entire 4D dynamic sequence for MBF computation, a 77% dose reduction was achieved, while considering only half the scans (i.e., every other heart cycle) allowed even further dose reduction while maintaining relatively higher CNRf.

Sex differences in absolute myocardial perfusion. Non-invasive H2(15)O-PET in young healthy adults.

PubMed

Range, Felix T; Kies, Peter; Schäfers, Klaus P; Breithardt, Günter; Schober, Otmar; Wichter, Thomas; Schäfers, Michael A

2016-09-26

To investigate sex differences in myocardial perfusion especially in healthy individuals since former studies are rare and findings are controversial. Participants, methods: 26 subjects were enrolled: 16 healthy women (age: 34 ±7 years) were compared with 10 healthy men (age: 34 ± 3 years; p = ns). Myocardial blood flow (MBF) and coronary vascular resistance (CVR) were quantified at rest, during adenosine infusion and cold-pressor-testing, using positron emission tomography and radioactive-labelled water (H2(15)O-PET). Women showed higher MBF than men at rest (1.10 ± 0.18 vs. 0.85 ± 0.20 ml/min/ml; p = 0.003) and cold-stress (1.39 ± 0.38 vs. 1.06 ± 0.28 ml/min/ml; p = 0.026). Corrected for rate-pressure-product, baseline findings maintained significance (1.41 ± 0.33 vs. 1.16 ± 0.19 ml/min/ml; p = 0.024). CVR was lower in women at baseline (81 ± 14 vs. 107 ± 22 mmHg*ml(-1)*min*ml; p = 0.006) and during cold-pressor-testing (71 ± 17 vs. 91 ± 20 mmHg*ml(-1)*min*ml; p = 0.013). Under adenosine neither maximal MBF (4.06 ± 1.0 vs. 3.91 ± 0.88 ml/min/ml; p = ns) nor coronary flow reserve (3.07 ± 1.12 vs. 3.44 ± 0.92; p = ns) nor CVR (24 ± 8 vs. 24 ± 6 mmHg*ml(-1)*min*ml; p = ns) showed sex-related differences. Women show higher myocardial perfusion and lower coronary vascular resistance than men in physiologic states. Maximum perfusion and vasodilation under adenosine are not sex-specific.

Effect of cold air inhalation and isometric exercise on coronary blood flow and myocardial function in humans

PubMed Central

Muller, Matthew D.; Gao, Zhaohui; Drew, Rachel C.; Herr, Michael D.; Leuenberger, Urs A.

2011-01-01

The effects of cold air inhalation and isometric exercise on coronary blood flow are currently unknown, despite the fact that both cold air and acute exertion trigger angina in clinical populations. In this study, we used transthoracic Doppler echocardiography to measure coronary blood flow velocity (CBV; left anterior descending coronary artery) and myocardial function during cold air inhalation and handgrip exercise. Ten young healthy subjects underwent the following protocols: 5 min of inhaling cold air (cold air protocol), 5 min of inhaling thermoneutral air (sham protocol), 2 min of isometric handgrip at 30% of maximal voluntary contraction (grip protocol), and 5 min of isometric handgrip at 30% maximal voluntary contraction while breathing cold air (cold + grip protocol). Heart rate, blood pressure, inspired air temperature, CBV, myocardial function (tissue Doppler imaging), O2 saturation, and pulmonary function were measured. The rate-pressure product (RPP) was used as an index of myocardial O2 demand, whereas CBV was used as an index of myocardial O2 supply. Compared with the sham protocol, the cold air protocol caused a significantly higher RPP, but there was a significant reduction in CBV. The cold + grip protocol caused a significantly greater increase in RPP compared with the grip protocol (P = 0.045), but the increase in CBV was significantly less (P = 0.039). However, myocardial function was not impaired during the cold + grip protocol relative to the grip protocol alone. Collectively, these data indicate that there is a supply-demand mismatch in the coronary vascular bed when cold ambient air is breathed during acute exertion but myocardial function is preserved, suggesting an adequate redistribution of blood flow. PMID:21940852

VALSARTAN REGULATES MYOCARDIAL AUTOPHAGY AND MITOCHONDRIAL TURNOVER IN EXPERIMENTAL HYPERTENSION

PubMed Central

Zhang, Xin; Li, Zi-Lun; Crane, John A.; Jordan, Kyra L.; Pawar, Aditya S.; Textor, Stephen C.; Lerman, Amir; Lerman, Lilach O.

2014-01-01

Renovascular hypertension alters cardiac structure and function. Autophagy is activated during left ventricular hypertrophy and linked to adverse cardiac function. The Angiotensin II receptor blocker Valsartan lowers blood pressure and is cardioprotective, but whether it modulates autophagy in the myocardium is unclear. We hypothesized that Valsartan would alleviate autophagy and improve left ventricular myocardial mitochondrial turnover in swine renovascular hypertension. Domestic pigs were randomized to control, unilateral renovascular hypertension, and renovascular hypertension treated with Valsartan (320 mg/day) or conventional triple therapy (Reserpine+hydralazine+hydrochlorothiazide) for 4 weeks post 6-weeks of renovascular hypertension (n=7 each group). Left ventricular remodeling, function and myocardial oxygenation and microcirculation were assessed by multi-detector computer tomography, blood-oxygen-level-dependent magnetic resonance imaging and microcomputer tomography. Myocardial autophagy, markers for mitochondrial degradation and biogenesis, and mitochondrial respiratory-chain proteins were examined ex vivo. Renovascular hypertension induced left ventricular hypertrophy and myocardial hypoxia, enhanced cellular autophagy and mitochondrial degradation, and suppressed mitochondrial biogenesis. Valsartan and triple therapy similarly decreased blood pressure, but Valsartan solely alleviated left ventricular hypertrophy, ameliorated myocardial autophagy and mitophagy, and increased mitochondrial biogenesis. In contrast, triple therapy only slightly attenuated autophagy and preserved mitochondrial proteins, but elicited no improvement in mitophagy. These data suggest a novel potential role of Valsartan in modulating myocardial autophagy and mitochondrial turnover in renovascular hypertension-induced hypertensive heart disease, which may possibly bolster cardiac repair via a blood pressure-independent manner. PMID:24752430

END-DIASTOLIC FLOW REVERSAL LIMITS THE EFFICACY OF PEDIATRIC INTRAAORTIC BALLOON PUMP COUNTERPULSATION

PubMed Central

Bartoli, Carlo R.; Rogers, Benjamin D.; Ionan, Constantine E.; Koenig, Steven C.; Pantalos, George M.

2013-01-01

OBJECTIVE Counterpulsation with an intraaortic balloon pump (IABP) has not achieved the same successes or clinical use in pediatric patients as in adults. In a pediatric animal model, IABP efficacy was investigated to determine whether IABP timing with a high-fidelity blood pressure signal may improve counterpulsation therapy versus a low-fidelity signal. METHODS In Yorkshire piglets (n=19, 13.0±0.5 kg) with coronary ligation-induced acute ischemic left ventricular failure, pediatric IABPs (5 or 7cc) were placed in the descending thoracic aorta. Inflation and deflation were timed with traditional criteria from low-fidelity (fluid-filled) and high-fidelity (micromanometer) blood pressure signals during 1:1 support. Aortic, carotid, and coronary hemodynamics were measured with pressure and flow transducers. Myocardial oxygen consumption was calculated from coronary sinus and arterial blood samples. Left ventricular myocardial blood flow and end-organ blood flow were measured with microspheres. RESULTS Despite significant suprasystolic diastolic augmentation and afterload reduction at heart rates of 105±3bmp, left ventricular myocardial blood flow, myocardial oxygen consumption, the myocardial oxygen supply/demand relationship, cardiac output, and end-organ blood flow did not change. Statistically significant end-diastolic coronary, carotid, and aortic flow reversal occurred with IABP deflation. Inflation and deflation timed with a high-fidelity versus low-fidelity signal did not attenuate systemic flow reversal or improve the myocardial oxygen supply/demand relationship. CONCLUSIONS Systemic end-diastolic flow reversal limited counterpulsation efficacy in a pediatric model of acute left ventricular failure. Adjustment of IABP inflation and deflation timing with traditional criteria and a high-fidelity blood pressure waveform did not improve IABP efficacy or attenuate flow reversal. End-diastolic flow reversal may limit the efficacy of IABP counterpulsation therapy in pediatric patients with traditional timing criteria. Investigation of alternative deflation timing strategies is warranted. PMID:24139614

End-diastolic flow reversal limits the efficacy of pediatric intra-aortic balloon pump counterpulsation.

PubMed

Bartoli, Carlo R; Rogers, Benjamin D; Ionan, Constantine E; Pantalos, George M

2014-05-01

Counterpulsation with an intra-aortic balloon pump (IABP) has not achieved the same success or clinical use in pediatric patients as in adults. In a pediatric animal model, IABP efficacy was investigated to determine whether IABP timing with a high-fidelity blood pressure signal may improve counterpulsation therapy versus a low-fidelity signal. In Yorkshire piglets (n = 19; weight, 13.0 ± 0.5 kg) with coronary ligation-induced acute ischemic left ventricular failure, pediatric IABPs (5 or 7 mL) were placed in the descending thoracic aorta. Inflation and deflation were timed with traditional criteria from low-fidelity (fluid-filled) and high-fidelity (micromanometer) blood pressure signals during 1:1 support. Aortic, carotid, and coronary hemodynamics were measured with pressure and flow transducers. Myocardial oxygen consumption was calculated from coronary sinus and arterial blood samples. Left ventricular myocardial blood flow and end-organ blood flow were measured with microspheres. Despite significant suprasystolic diastolic augmentation and afterload reduction at heart rates of 105 ± 3 beats per minute, left ventricular myocardial blood flow, myocardial oxygen consumption, the myocardial oxygen supply/demand relationship, cardiac output, and end-organ blood flow did not change. Statistically significant end-diastolic coronary, carotid, and aortic flow reversal occurred with IABP deflation. Inflation and deflation timed with a high-fidelity versus low-fidelity signal did not attenuate systemic flow reversal or improve the myocardial oxygen supply/demand relationship. Systemic end-diastolic flow reversal limited counterpulsation efficacy in a pediatric model of acute left ventricular failure. Adjustment of IABP inflation and deflation timing with traditional criteria and a high-fidelity blood pressure waveform did not improve IABP efficacy or attenuate flow reversal. End-diastolic flow reversal may limit the efficacy of IABP counterpulsation therapy in pediatric patients with traditional timing criteria. Investigation of alternative deflation timing strategies is warranted. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Quantification of myocardial infarction: a comparison of single photon-emission computed tomography with pyrophosphate to serial plasma MB-creatine kinase measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jansen, D.E.; Corbett, J.R.; Wolfe, C.L.

1985-08-01

Single photon-emission computed tomography (SPECT) with /sup 99m/Tc-pyrophosphate (PPi) has been shown to estimate size of myocardial infarction accurately in animals. The authors tested the hypothesis that SPECT with /sup /sup 99m//Tc-PPi and blood pool subtraction can provide prompt and accurate estimates of size of myocardial infarction in patients. SPECT estimates are potentially available early after the onset of infarction and should correlate with estimates of infarct size calculated from serial measurements of plasma MB-creatine kinase (CK) activity. Thirty-three patients with acute myocardial infarction and 16 control patients without acute myocardial infarction were studied. Eleven of the patients had transmuralmore » anterior myocardial infarction, 16 had transmural inferior myocardial infarction, and six had nontransmural myocardial infarction. SPECT was performed with a commercially available rotating gamma camera. Identical projection images of the distribution of 99mTc-PPi and the ungated cardiac blood pool were acquired sequentially over 180 degrees. Reconstructed sections were color coded and superimposed for purposes of localization of infarct. Areas of increased PPi uptake within myocardial infarcts were thresholded at 65% of peak activity. The blood pool was thresholded at 50% and subtracted to determine the endocardial border for the left ventricle. Myocardial infarcts ranged in size from 1 to 126 gram equivalents (geq) MB-CK. The correlation of MB-CK estimates of size of infarct with size determined by SPECT (both in geq) was good (r = .89 with a regression line of y = 13.1 + 1.5x).« less

Iodophenylpentadecanoic acid-myocardial blood flow relationship during maximal exercise with coronary occlusion.

PubMed

Caldwell, J H; Martin, G V; Link, J M; Krohn, K A; Bassingthwaighte, J B

1990-01-01

Imaging 123I-labeled iodophenylpentadecanoic acid (IPPA) uptake and clearance from the myocardium following exercise has been advocated as a means of detecting myocardial ischemia because fatty acid deposition is enhanced and clearance prolonged in regions of low flow. However, normal regional myocardial blood flows are markedly heterogeneous, and it is not known how this heterogeneity affects regional metabolism or substrate uptake and thus image interpretation. In five instrumented dogs running at near maximal workload on a treadmill, 131I-labeled IPPA and 15-micron 46Sc microspheres were injected into the left atrium after 30 sec of circumflex coronary artery occlusion. Microsphere and IPPA activity were determined in 250 mapped pieces of myocardium of approximately 400 mg. Myocardial blood flows (from microspheres) ranged from 0.05 to 7.6 ml/min/g. Deposition of IPPA was proportional to regional flows (r = 0.83) with an average retention of 25%. The mean endocardial-epicardial ratio for IPPA (0.90 +/- 0.43) was similar to that for microspheres (0.94 +/- 0.47; p = 0.08). Thus, initial IPPA deposition during treadmill exercise increases in proportion to regional myocardial blood flow over a range of flows from very low to five times normal.

The effects of hypoxemia on myocardial blood flow during exercise.

PubMed

Paridon, S M; Bricker, J T; Dreyer, W J; Reardon, M; Smith, E O; Porter, C B; Michael, L; Fisher, D J

1989-03-01

We evaluated the adequacy of regional and transmural blood flow during exercise and rapid pacing after 1 wk of hypoxemia. Seven mature mongrel dogs were made hypoxemic (mean O2 saturation = 72.4%) by anastomosis of left pulmonary artery to left atrial appendage. Catheters were placed in the left atrium, right atrium, pulmonary artery, and aorta. Atrial and ventricular pacing wires were placed. An aortic flow probe was placed to measure cardiac output. Ten nonshunted dogs, similarly instrumented, served as controls. Recovery time was approximately 1 wk. Cardiac output, mean aortic pressure, and oxygen saturation were measured at rest, with ventricular pacing, atrial pacing, and with treadmill exercise. Ventricular and atrial pace and exercise were at a heart rate of 200. Right ventricular free wall, left ventricular free wall, and septal blood flow were measured with radionuclide-labeled microspheres. Cardiac output, left atrial blood pressure, and aortic blood pressure were similar between the two groups of dogs in all testing states. Myocardial blood flow was significantly higher in the right and left ventricular free wall in the hypoxemic animals during resting and exercise testing states. Myocardial oxygen delivery was similar between the two groups of animals. Pacing resulted in an increase in myocardial blood flow in the control animals but not the hypoxemic animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Myocardial oxygen delivery after experimental hemorrhagic shock.

PubMed Central

Archie, J P; Mertz, W R

1978-01-01

The two components of myocardial oxygen delivery, coronary blood flow to capillaries and diffusion from capillaries to mitochondria, were studied in six dogs, (1) prior to shock, (2) after three hours of hemorrhage shock at a mean systemic arterial pressure of 40 torr, (3) after reinfusion of shed blood, and (4) during the irreversible late posttransfusion stage. There was a maldistribution of left ventricular coronary flow during late shock consistent with subendocardial ischemia. Cardiac performance was significantly impaired after resuscitation and all dogs became irreversible. Total and regional left ventricular coronary blood flow and myocardial oxygen delivery to capillaries were significantly greater than preshock values in (3) but not different from preshock values in (4). However, the myocardial oxygen diffusion area to distance ratio was significantly lower than preshock values in (3), and slightly lower in (4). These data suggest that myocardial oxygen diffusion may be impaired in the early post transfusion period, (3). Accordingly, the probable etiology of left ventricular dysfunction and possibly irreversibility after resuscitation from hemorrhagic shock is subendocardial ischemia during shock with either post-resuscitation impairment of myocardial oxygen diffusion, or in cellular oxygen utilization, or both. PMID:629622

Morphological aspects of myocardial bridges.

PubMed

Lujinović, Almira; Kulenović, Amela; Kapur, Eldan; Gojak, Refet

2013-11-01

Although some myocardial bridges can be asymptomatic, their presence often causes coronary disease either through direct compression of the "tunnel" segment or through stimulation and accelerated development of atherosclerosis in the segment proximally to the myocardial bridge. The studied material contained 30 human hearts received from the Department of Anatomy. The hearts were preserved 3 to 5 days in 10% formalin solution. Thereafter, the fatty tissue was removed and arterial blood vessels prepared by careful dissection with special reference to the presence of the myocardial bridges. Length and thickness of the bridges were measured by the precise electronic caliper. The angle between the myocardial bridge fibre axis and other axis of the crossed blood vessel was measured by a goniometer. The presence of the bridges was confirmed in 53.33% of the researched material, most frequently (43.33%) above the anterior interventricular branch. The mean length of the bridges was 14.64 ± 9.03 mm and the mean thickness was 1.23 ± 1.32 mm. Myocardial bridge fibres pass over the descending blood vessel at the angle of 10-90 degrees. The results obtained on a limited sample suggest that the muscular index of myocardial bridge is the highest for bridges located on RIA, but that the difference is not significant in relation to bridges located on other branches. The results obtained suggest that bridges located on other branches, not only those on RIA, could have a great contractive power and, consequently, a great compressive force, which would be exerted on the wall of a crossed blood vessel.

Parametric techniques for characterizing myocardial tissue by magnetic resonance imaging (part 1): T1 mapping.

PubMed

Perea Palazón, R J; Ortiz Pérez, J T; Prat González, S; de Caralt Robira, T M; Cibeira López, M T; Solé Arqués, M

2016-01-01

The development of myocardial fibrosis is a common process in the appearance of ventricular dysfunction in many heart diseases. Magnetic resonance imaging makes it possible to accurately evaluate the structure and function of the heart, and its role in the macroscopic characterization of myocardial fibrosis by late enhancement techniques has been widely validated clinically. Recent studies have demonstrated that T1-mapping techniques can quantify diffuse myocardial fibrosis and the expansion of the myocardial extracellular space in absolute terms. However, further studies are necessary to validate the usefulness of this technique in the early detection of tissue remodeling at a time when implementing early treatment would improve a patient's prognosis. This article reviews the state of the art for T1 mapping of the myocardium, its clinical applications, and its limitations. Copyright © 2016 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

Effects of oxymatrine on sympathoexcitatory reflex induced by myocardial ischemic signaling mediated by P2X₃ receptors in rat SCG and DRG.

PubMed

Li, Guilin; Liu, Shuangmei; Yang, Yang; Xie, Jinyan; Liu, Jun; Kong, Fanjun; Tu, Guihua; Wu, Raoping; Li, Guodong; Liang, Shangdong

2011-04-05

Sympathoexcitatory reflex is characterized by an increase in blood pressure and sympathetic nerve activity. P2X₃ receptors in SCG neurons are involved in increasing sympathoexcitatory reflex after myocardial ischemic (MI) injury. The present study is aimed to explore the effects of oxymatrine (Oxy) on the transmission of myocardial ischemic signaling mediated by P2X₃ receptors in rat superior cervical ganglia (SCG) and cervical dorsal root ganglia (DRG) in the sympathoexcitatory reflex after myocardial ischemic injury. In this study, the expression levels of P2X₃ immunoreactivity, mRNA and protein were analyzed in SCG and DRG neurons by immunohistochemistry, in situ hybridization and Western blotting. The results show that the myocardial ischemic injury induces the increase of the systolic blood pressure and heart rate and upregulates the expression of P2X₃ receptors in SCG and DRG neurons. Upregulated expression of P2X₃ receptors in SCG and DRG neurons subsequently leads to the aggravated sympathoexcitatory reflex. Oxymatrine reduces the systolic blood pressure and heart rate in myocardial ischemic rats. After myocardial ischemic rats are treated with oxymatrine, the expression levels of P2X₃ immunoreactivity, mRNA and protein are lower than those in myocardial ischemic rats. Oxymatrine may decrease the expression of P2X₃ receptor and depress the aggravated sympathoexcitatory reflex induced by the nociceptive transmission of myocardial ischemic injury via P2X₃ receptors of rat SCG and DRG neurons. Copyright © 2011 Elsevier Inc. All rights reserved.

[Immediate and remote results of endovascular treatment of patients with postinfarction cardiosclerosis].

PubMed

Patrikeev, A V; Rudman, V Ia; Maksimkin, D A; Baranovich, V Iu; Faĭbushevich, A G; Veretnik, G I; Mambetov, A V; Shugushev, Z Kh

2015-01-01

Two approaches in treatment of 131 patients with postinfarction cardiosclerosis are compared in the work. Tactics of "total" myocardial revascularization means restoration of coronary blood flow in all arteries with hemodynamically significant lesion while "selective" revascularization provides restoration of coronary blood flow only in those arteries which have a viable myocardium in their pool. It was concluded that restoration of coronary blood flow in patients after myocardial infarction permits to prevent postinfarction heart remodeling, development of heart failure thereby affecting on the prognosis. Evaluation of myocardial viability in the area of suggested surgery increases efficiency of revascularization, reduces number of implantable stents and decreases frequency of unfounded coronary interventions. Elimination of ischemia in the area of hibernation provides a rapid restoration of myocardial contractility in most of left ventricle segments with initially impaired kinetics. It was revealed that terms of contractility restoration of hibernating myocardium depend on duration of hibernation period up to revascularization.

High dose naloxone does not improve cerebral or myocardial blood flow during cardiopulmonary resuscitation in pigs.

PubMed

Gervais, H W; Eberle, B; Hennes, H J; Grimm, W; Kilian, A; Konietzke, D; Massing, C; Dick, W

1997-06-01

In a prospective, randomized, placebo-controlled, double-blind trial we tested the hypothesis that naloxone given during cardiopulmonary resuscitation (CPR) enhances cerebral and myocardial blood flow. Twenty-one anesthetized, normoventilated pigs were instrumented for measurements of right atrial and aortic pressures, and regional organ blood flow (radiolabeled microspheres). After 5 min of untreated fibrillatory arrest, CPR was commenced using a pneumatic chest compressor/ventilator. With onset of CPR, an i.v. bolus of 40 micrograms/kg b.w. of epinephrine was given, followed by an infusion of 0.4 micrograms/kg per min. After 5 min of CPR, either naloxone, 10 mg/kg b.w. (group N, n = 11) or normal saline (group S, n = 10) was given i.v. Prior to, and after 1, 15, and 30 min of CPR, hemodynamic and blood flow measurements were obtained. After 30 min of CPR, mean arterial pressure was significantly higher in group N (26 +/- 5 vs. 13 +/- 3 mmHg, P < 0.05). Groups did not differ with respect to myocardial perfusion pressure or arterial blood gases at any time during the observation period. Regional brain and heart blood flows were not different between N and S at any point of measurement. We conclude that high-dose naloxone does not augment cerebral or myocardial blood flow during prolonged closed-chest CPR.

VO(2peak), myocardial hypertrophy, and myocardial blood flow in endurance-trained men.

PubMed

Laaksonen, Marko S; Heinonen, Ilkka; Luotolahti, Matti; Knuuti, Juhani; Kalliokoski, Kari K

2014-08-01

Endurance training induces cardiovascular and metabolic adaptations, leading to enhanced endurance capacity and exercise performance. Previous human studies have shown contradictory results in functional myocardial vascular adaptations to exercise training, and we hypothesized that this may be related to different degrees of hypertrophy in the trained heart. We studied the interrelationships between peak aerobic power (V˙O2peak), myocardial blood flow (MBF) at rest and during adenosine-induced vasodilation, and parameters of myocardial hypertrophy in endurance-trained (ET, n = 31) and untrained (n = 17) subjects. MBF and myocardial hypertrophy were studied using positron emission tomography and echocardiography, respectively. Both V˙O2peak (P < 0.001) and left ventricular (LV) mass index (P < 0.001) were higher in the ET group. Basal MBF was similar between the groups. MBF during adenosine was significantly lower in the ET group (2.88 ± 1.01 vs 3.64 ± 1.11 mL·g·min, P < 0.05) but not when the difference in LV mass was taken into account. V˙O2peak correlated negatively with adenosine-stimulated MBF, but when LV mass was taken into account as a partial correlate, this correlation disappeared. The present results show that increased LV mass in ET subjects explains the reduced hyperemic myocardial perfusion in this subject population and suggests that excessive LV hypertrophy has negative effect on cardiac blood flow capacity.

The variable Jung as a predictor of mortality in patients with pulmonary edema.

PubMed

Jung, Robert; Ivanović, Vladimir; Potić, Zoran; Panić, Gordana; Petrović, Milovan; Pavlović, Katica; Cemerlić-Adjić, Nada; Baskot, Branislav

2013-09-01

In our Intensive Coronary Care Unit (CCU) a specific scoring system named the AMIS_NS was developed both for prediction of mortality in patients with acute myocardial infarction and for evaluation of the quality of work. One of the most important variables of the AMIS_NS system is the variable Jung which stands for the interrelationship unified mortality predictors. The variable includes all the values of systolic blood pressure, heart rate and age, without limiting values for any of these. The cutoff value is 2.08. The patients with the lower variable value account for a significantly higher mortality. Data on the actual infarction are not necessitated now for this variable. The aim of this study was to assess the significance of the variable Jung in non-infarction patients with acute pulmonary edema. In a 24-month period out of 2,223 patients there were 1,087 and 1,136 patients with and without acute myocardial infarction, respectively. There was the subgroup without myocardial infarction of 312 (84.1%) patients admitted with the diagnosis of pulmonary edema. The subgroup with myocardial infarction consisted of 59 (15.9%) patients who were admitted for acute myocardial infarction and pulmonary edema which developed immediately after admission or during hospitalization in the CCU. For all the patients a uniform questionnaire was fulfilled on admission. Data were put into the personal computer. The variable "Jung" was used: (systolic bloog pressure/heart rate x age) x 100. RESULTS. Regarding sex, there was no difference in mortality, so that males and females were regarded as a whole. Previous myocardial infarction was equally registered in both groups. The investigated persons had less percent of mortality and a significantly higher systemic pressure as well as higher value of the variable Jung. There was no statistically significant difference in the heart rate between the two groups. In both groups of deceased patients the variable Jung (1.5 vs 1.6) was significantly lower in respect to the survived patients (2.3 vs 2.1). CONCLUSION. The variable Jung is simple, highly reliable and can absolutely be used as a significant indicator of clinical status also in noninfarction patients with the acute pulmonary edema, no matter if it is caused by acute myocardial infarction or not.

Myocardial protection during minimally invasive cardiac surgery through right mini-thoracotomy.

PubMed

De Palo, Micaela; Guida, Pietro; Mastro, Florinda; Nanna, Daniela; Quagliara, Teresa A P; Rociola, Ruggiero; Lionetti, Giosuè; Paparella, Domenico

2017-04-01

Myocardial damage is an independent predictor of adverse outcome following cardiac surgery and myocardial protection is one of the key factors to achieve successful outcomes. Cardioplegia with Custodiol is currently the most used cardioplegia during minimally invasive cardiac surgery (MICS). Different randomized controlled trials compared blood and Custodiol cardioplegia in the context of traditional cardiac surgery. No data are available for MICS. The aim of this study was to compare the efficacy of cold blood versus Custodiol cardioplegia during MICS. We retrospectively evaluated 90 patients undergoing MICS through a right mini-thoracotomy in a three-year period. Myocardial protection was performed using cold blood (44 patients, CBC group) or Custodiol (46 patients, Custodiol group) cardioplegia, based on surgeon preference and complexity of surgery. The primary outcomes were post-operative cardiac troponin I (cTnI) and creatine kinase MB (CKMB) serum release and the incidence of Low Cardiac Output Syndrome (LCOS). Aortic cross-clamp and cardiopulmonary bypass times were higher in the Custodiol group. No difference was observed in myocardial injury enzyme release (peak cTnI value was 18±46 ng/ml in CBC and 21±37 ng/ml in Custodiol; p=0.245). No differences were observed for mortality, LCOS, atrial or ventricular arrhythmias onset, transfusions, mechanical ventilation time duration, intensive care unit and total hospital stay. Custodiol and cold blood cardioplegic solutions seem to assure similar myocardial protection in patients undergoing cardiac surgery through a right mini-thoracotomy approach.

Progressive epicardial coronary blood flow reduction fails to produce ST-segment depression at normal heart rates.

PubMed

de Chantal, Marilyn; Diodati, Jean G; Nasmith, James B; Amyot, Robert; LeBlanc, A Robert; Schampaert, Erick; Pharand, Chantal

2006-12-01

ST-segment depression is commonly seen in patients with acute coronary syndromes. Most authors have attributed it to transient reductions in coronary blood flow due to nonocclusive thrombus formation on a disrupted atherosclerotic plaque and dynamic focal vasospasm at the site of coronary artery stenosis. However, ST-segment depression was never reproduced in classic animal models of coronary stenosis without the presence of tachycardia. We hypothesized that ST-segment depression occurring during acute coronary syndromes is not entirely explained by changes in epicardial coronary artery resistance and thus evaluated the effect of a slow, progressive epicardial coronary artery occlusion on the ECG and regional myocardial blood flow in anesthetized pigs. Slow, progressive occlusion over 72 min (SD 27) of the left anterior descending coronary artery in 20 anesthetized pigs led to a 90% decrease in coronary blood flow and the development of ST-segment elevation associated with homogeneous and transmural myocardial blood flow reductions, confirmed by microspheres and myocardial contrast echocardiography. ST-segment depression was not observed in any ECG lead before the development of ST-segment elevation. At normal heart rates, progressive epicardial stenosis of a coronary artery results in myocardial ischemia associated with homogeneous, transmural reduction in regional myocardial blood flow and ST-segment elevation, without preceding ST-segment depression. Thus, in coronary syndromes with ST-segment depression and predominant subendocardial ischemia, factors other than mere increases in epicardial coronary resistance must be invoked to explain the heterogeneous parietal distribution of flow and associated ECG changes.

Silent myocardial ischemia in patients with stable coronary artery disease receiving conventional antianginal drug therapy.

PubMed

Ferreira, João Fernando Monteiro; César, Luiz Antonio Machado; Gruppi, César J; Giorgi, Dante M A; Hueb, Whady A; Mansur, Antonio P; Ramires, José A F

2007-11-01

Few data are available on the behavior of myocardial ischemia during daily activities in patients with coronary artery disease receiving antianginal drug therapy. To study the mechanism generating myocardial ischemia by evaluating blood pressure and heart rate changes in patients with stable atherosclerotic disease receiving drug therapy and with evidence of myocardial ischemia. Fifty non-hospitalized patients (40 males) underwent 24-hour electrocardiographic monitoring synchronized with blood pressured monitoring. Thirty five episodes of myocardial ischemia were detected in 17 patients, with a total duration of 146.3 minutes; angina was reported in five cases. Twenty nine episodes (100.3 minutes) occurred during wakefulness, with 11 episodes (35.3 + 3.7 min) in the period from 11 a.m. to 3 p.m. Blood pressure and heart rate evaluation in the three ten-minute intervals following the ischemic episodes showed a statistically significant difference (p< 0.05), unlike that shown for the three intervals preceding the episodes. However, during the ischemic episode, a higher than 10-mmHg elevation in blood pressure and 5 beats per minute in heart rate were observed when compared with the time interval between 20 and 10 minutes before the episode. The mean heart rate at the onset of ischemia during the exercise test performed before the study was 118.2 + 14.0, and 81.1 + 20.8 beats per minute on the 24-hour electrocardiogram (p < 0.001). The incidence of silent myocardial ischemia is high in stable coronary artery disease and is related to alterations in blood pressure and heart rate, with different thresholds for ischemia for the same patient.

Myocardial perfusion cardiovascular magnetic resonance: optimized dual sequence and reconstruction for quantification.

PubMed

Kellman, Peter; Hansen, Michael S; Nielles-Vallespin, Sonia; Nickander, Jannike; Themudo, Raquel; Ugander, Martin; Xue, Hui

2017-04-07

Quantification of myocardial blood flow requires knowledge of the amount of contrast agent in the myocardial tissue and the arterial input function (AIF) driving the delivery of this contrast agent. Accurate quantification is challenged by the lack of linearity between the measured signal and contrast agent concentration. This work characterizes sources of non-linearity and presents a systematic approach to accurate measurements of contrast agent concentration in both blood and myocardium. A dual sequence approach with separate pulse sequences for AIF and myocardial tissue allowed separate optimization of parameters for blood and myocardium. A systems approach to the overall design was taken to achieve linearity between signal and contrast agent concentration. Conversion of signal intensity values to contrast agent concentration was achieved through a combination of surface coil sensitivity correction, Bloch simulation based look-up table correction, and in the case of the AIF measurement, correction of T2* losses. Validation of signal correction was performed in phantoms, and values for peak AIF concentration and myocardial flow are provided for 29 normal subjects for rest and adenosine stress. For phantoms, the measured fits were within 5% for both AIF and myocardium. In healthy volunteers the peak [Gd] was 3.5 ± 1.2 for stress and 4.4 ± 1.2 mmol/L for rest. The T2* in the left ventricle blood pool at peak AIF was approximately 10 ms. The peak-to-valley ratio was 5.6 for the raw signal intensities without correction, and was 8.3 for the look-up-table (LUT) corrected AIF which represents approximately 48% correction. Without T2* correction the myocardial blood flow estimates are overestimated by approximately 10%. The signal-to-noise ratio of the myocardial signal at peak enhancement (1.5 T) was 17.7 ± 6.6 at stress and the peak [Gd] was 0.49 ± 0.15 mmol/L. The estimated perfusion flow was 3.9 ± 0.38 and 1.03 ± 0.19 ml/min/g using the BTEX model and 3.4 ± 0.39 and 0.95 ± 0.16 using a Fermi model, for stress and rest, respectively. A dual sequence for myocardial perfusion cardiovascular magnetic resonance and AIF measurement has been optimized for quantification of myocardial blood flow. A validation in phantoms was performed to confirm that the signal conversion to gadolinium concentration was linear. The proposed sequence was integrated with a fully automatic in-line solution for pixel-wise mapping of myocardial blood flow and evaluated in adenosine stress and rest studies on N = 29 normal healthy subjects. Reliable perfusion mapping was demonstrated and produced estimates with low variability.

[Effect of Zishen Huoxue Recipe on Pathomorphology in Coronary Heart Disease Rats with Shen Deficiency Blood Stasis Syndrome].

PubMed

Zhou, Sheng-fang; Liu, Ru-xiu; Luo, He-wei; Li, Hui; Guan, Xuan-ke; Yin, Lin-lin; Li, Li; Hu, Dong-peng

2016-01-01

To observe the effect of Zishen Huoxue Recipe (ZHR) on pathomorphology in coronary heart disease (CHD) rats with Shen deficiency blood stasis syndrome (SDBSS). Totally 60 healthy Wistar rats were divided into the blank control group, the model group, high, middle, and low dose ZHR groups according to random digit table, 12 in each group. Myocardial ischemia SDBSS rat model was prepared by ligating the left anterior descending coronary artery and injecting hydrocortisone. ZHR physic liquor was administered to rats in high, middle, and low dose ZHR groups at the daily dose of 21.6, 10.8, 5.4 g/kg by gastrogavage for 7 successive days, equal volume of pure water was administered to rats in the blank control group and the model group by gastrogavage for 7 successive days. Rat heart was collected for pathomorphological observation under light microscope. In the model group the heart muscle fiber was swollen and deformed with widened space, loose and dropsy tissues. Blood vessels in myocardial mesenchymal were dilated, infiltrated with more inflammatory cells. Myocardial cells were markedly swollen, degenerated, or necrotic, with caryolysis or disappearance of partial nuclear. A large amount of collagen fibrous tissue became hyperplasia. Endocardial blood vessels were swollen and degenerated with infiltration of few inflammatory cells. Epicardium tissue and structure were destroyed and got hyperplasia. Swollen, degenerated, or necrotic vessels could be seen, with infiltration of more inflammatory cells and collagen deposition. Pathomorphological injuries were alleviated in each ZHR group. The higher ZHR concentration, the milder the injury degree of myocardial tissue, the more limited range of damage. ZHR could attenuate pathomorphological injuries of myocardial ischemia rats with SDBSS and regulate myocardial function, thus improving myocardial ischemia in CHD rats with SDBSS.

Acute tamponade alters subendo- and subepicardial pressure-flow relations differently during vasodilation.

PubMed

Kingma, J G; Martin, J; Rouleau, J R

1994-07-01

Instantaneous diastolic left coronary artery pressure-flow relations (PFR) shift during acute tamponade as pressure surrounding the heart increases. Coronary pressure at zero flow (Pf = 0) on the linear portion of the PFR is the weighted mean of the different myocardial waterfall pressures, the distribution of which varies across the left ventricular wall during diastole. However, instantaneous PFR measured in large epicardial coronary arteries cannot be used to estimate Pf = 0 in the different myocardial tissue layers. During coronary vasodilatation in a capacitance-free model, myocardial PFR differs from subendocardium to subepicardium. Therefore, we studied the effects of acute tamponade during maximal pharmacology induced coronary vasodilatation on myocardial PFR in in situ anesthetized dogs. Tamponade reduced cardiac output, aortic pressure, and coronary blood flow. Results demonstrate that different mechanisms influence distribution of myocardial blood flow during tamponade. Subepicardial vascular resistance is unchanged and the extrapolated Pf = 0 is increased, thereby shifting PFR to a higher intercept on the pressure axis. Subendocardial vascular resistance is increased while the extrapolated Pf = 0 remains unchanged. Results indicate that in the setting of acute tamponade with coronary vasodilatation different mechanisms regulate the distribution of myocardial blood flow: in the subepicardium only outflow pressure increases, whereas in the subendocardium only vascular resistance increases.

Puerarin blocks the signaling transmission mediated by P2X3 in SG and DRG to relieve myocardial ischemic damage.

PubMed

Liu, Shuangmei; Zhang, Chunping; Shi, Qingming; Li, Guilin; Song, Miaomiao; Gao, Yun; Xu, Changshui; Xu, Hong; Fan, Bo; Yu, Shicheng; Zheng, Chaoran; Zhu, Qicheng; Wu, Bing; Peng, Lichao; Xiong, Huangui; Wu, Qin; Liang, Shangdong

2014-02-01

P2X₃ receptors in stellate ganglia (SG) and cervical dorsal root ganglia (DRG) neurons are involved in sympathoexcitatory reflex induced by myocardial ischemic damage. Puerarin, a major active ingredient extracted from the traditional Chinese plant medicine Ge-gen, has been widely used in treatment of myocardial and cerebral ischemia. The present study is aimed to observe the effects of puerarin on the signaling transmission mediated by P2X₃ receptor in SG and DRG after myocardial ischemic damage. Our results showed that systolic blood pressure and heart rate increased, and the expression levels of P2X₃ mRNA and protein in SG and DRG were up-regulated after myocardial ischemic damage. Puerarin reduced systolic blood pressure and heart rate, relieved pain and decreased up-regulated expression of P2X₃ mRNA and protein in SG and DRG after myocardial ischemia. Puerarin inhibited the up-regulated ATP-activated currents in DRG neurons after myocardial ischemia. Thus, puerarin can relieve myocardial ischemic damage through blocking the P2X₃ signaling transmission and then depressed the aggravated sympathoexcitatory reflex. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of glutamine treatment on myocardial damage and cardiac function in rats after severe burn injury.

PubMed

Yan, Hong; Zhang, Yong; Lv, Shang-jun; Wang, Lin; Liang, Guang-ping; Wan, Qian-xue; Peng, Xi

2012-01-01

Treatment with glutamine has been shown to reduce myocardial damage associated with ischemia/reperfusion injury. However, the cardioprotective effect of glutamine specifically after burn injury remains unclear. The present study explores the ability of glutamine to protect against myocardial damage in rats that have been severely burned. Seventy-two Wistar rats were randomly divided into three groups: normal controls (C), burned controls (B) and a glutamine-treated group (G). Groups B and G were subjected to full thickness burns comprising 30% of total body surface area. Group G was administered 1.5 g/ (kg•d) glutamine and group B was given the same dose of alanine via intragastric administration for 3 days. Levels of serum creatine kinase (CK), lactate dehydrogenase (LDH), aspartate transaminase (AST) and blood lactic acid were measured, as well as myocardial ATP and glutathione (GSH) contents. Cardiac function indices and histopathological changes were analyzed at 12, 24, 48 and 72 post-burn hours. In both burned groups, levels of serum CK, LDH, AST and blood lactic acid increased significantly, while myocardial ATP and GSH contents decreased. Compared with group B, CK, LDH, and AST levels were lower and blood lactic acid, myocardial ATP and GSH levels were higher in group G. Moreover, cardiac contractile function inhibition and myocardial histopathological damage were significantly reduced in group G compared to B. Taken together, these results show that glutamine supplementation protects myocardial structure and function after burn injury by improving energy metabolism and by promoted the synthesis of ATP and GSH in cardiac myocytes.

Effects of glutamine treatment on myocardial damage and cardiac function in rats after severe burn injury

PubMed Central

Yan, Hong; Zhang, Yong; Lv, Shang-jun; Wang, Lin; Liang, Guang-ping; Wan, Qian-xue; Peng, Xi

2012-01-01

Treatment with glutamine has been shown to reduce myocardial damage associated with ischemia/reperfusion injury. However, the cardioprotective effect of glutamine specifically after burn injury remains unclear. The present study explores the ability of glutamine to protect against myocardial damage in rats that have been severely burned. Seventy-two Wistar rats were randomly divided into three groups: normal controls (C), burned controls (B) and a glutamine-treated group (G). Groups B and G were subjected to full thickness burns comprising 30% of total body surface area. Group G was administered 1.5 g/ (kg•d) glutamine and group B was given the same dose of alanine via intragastric administration for 3 days. Levels of serum creatine kinase (CK), lactate dehydrogenase (LDH), aspartate transaminase (AST) and blood lactic acid were measured, as well as myocardial ATP and glutathione (GSH) contents. Cardiac function indices and histopathological changes were analyzed at 12, 24, 48 and 72 post-burn hours. In both burned groups, levels of serum CK, LDH, AST and blood lactic acid increased significantly, while myocardial ATP and GSH contents decreased. Compared with group B, CK, LDH, and AST levels were lower and blood lactic acid, myocardial ATP and GSH levels were higher in group G. Moreover, cardiac contractile function inhibition and myocardial histopathological damage were significantly reduced in group G compared to B. Taken together, these results show that glutamine supplementation protects myocardial structure and function after burn injury by improving energy metabolism and by promotedthe synthesis of ATP and GSH in cardiac myocytes. PMID:22977661

Increase in mean platelet volume in patients with myocardial bridge.

PubMed

Bilen, Emine; Tanboga, Ibrahim Halil; Kurt, Mustafa; Kocak, Umran; Ayhan, Huseyin; Keles, Telat; Bozkurt, Engin

2013-01-01

Myocardial bridge is associated with atherosclerosis altered in shear stress and endothelial dysfunction. Mean platelet volume (MPV), a determinant of platelet activation, is shown to be related with atherosclerosis and endothelial dysfunction. In this study, we aimed to evaluate platelet function assessed by MPV in patients with myocardial bridge. Forty-two patients with myocardial bridge in the left anterior descending artery (LAD) and 43 age- and gender-matched healthy participants were included in the study. Myocardial bridging was defined as an intramyocardial systolic compression or milking of a segment of an epicardial coronary artery on angiography. For the entire study population, MPV was measured using an automatic blood counter. The study population consisted of 42 patients with myocardial bridge (52.7 ± 10.2, 76.2% male) and 43 age- and sex-matched healthy control participants (52.1 ± 10.4, 74.4% male). Compared to the control group, MPV value was significantly higher in patients with myocardial bridge (8.9 ± 1.24 vs 8.3 ± 0.78; P = .01). Further, there were no significant differences between groups regarding hemoglobin level, platelet count, fasting blood glucose, and creatinine levels. Our study findings indicated that myocardial bridge is associated with elevated MPV values. Our results might partly explain the increased cardiovascular events in patients with myocardial bridge.

Theoretical considerations in measurement of time discrepancies between input and myocardial time-signal intensity curves in estimates of regional myocardial perfusion with first-pass contrast-enhanced MRI.

PubMed

Natsume, Takahiro; Ishida, Masaki; Kitagawa, Kakuya; Nagata, Motonori; Sakuma, Hajime; Ichihara, Takashi

2015-11-01

The purpose of this study was to develop a method to determine time discrepancies between input and myocardial time-signal intensity (TSI) curves for accurate estimation of myocardial perfusion with first-pass contrast-enhanced MRI. Estimation of myocardial perfusion with contrast-enhanced MRI using kinetic models requires faithful recording of contrast content in the blood and myocardium. Typically, the arterial input function (AIF) is obtained by setting a region of interest in the left ventricular cavity. However, there is a small delay between the AIF and the myocardial curves, and such time discrepancies can lead to errors in flow estimation using Patlak plot analysis. In this study, the time discrepancies between the arterial TSI curve and the myocardial tissue TSI curve were estimated based on the compartment model. In the early phase after the arrival of the contrast agent in the myocardium, the relationship between rate constant K1 and the concentrations of Gd-DTPA contrast agent in the myocardium and arterial blood (LV blood) can be described by the equation K1={dCmyo(tpeak)/dt}/Ca(tpeak), where Cmyo(t) and Ca(t) are the relative concentrations of Gd-DTPA contrast agent in the myocardium and in the LV blood, respectively, and tpeak is the time corresponding to the peak of Ca(t). In the ideal case, the time corresponding to the maximum upslope of Cmyo(t), tmax, is equal to tpeak. In practice, however, there is a small difference in the arrival times of the contrast agent into the LV and into the myocardium. This difference was estimated to correspond to the difference between tpeak and tmax. The magnitudes of such time discrepancies and the effectiveness of the correction for these time discrepancies were measured in 18 subjects who underwent myocardial perfusion MRI under rest and stress conditions. The effects of the time discrepancies could be corrected effectively in the myocardial perfusion estimates. Copyright © 2015 Elsevier Inc. All rights reserved.

[Effect of caffeine on myocardial blood flow during pharmacological vasodilation].

PubMed

Wielepp, J P; Fricke, E; Horstkotte, D; Burchert, W

2005-02-01

Pharmacologic stress with adenosine is frequently used for noninvasive detection of coronary artery disease. Dietary intake of caffeinated food, beverages or medications might alter adenosine-induced hyperemic blood flow, thereby compromising the diagnostic sensitivity of adenosine stress testing. In this case we report on a male patient with CAD. Myocardial blood flow at rest and during adenosine-induced hyperemia 2 hours after consumption of decaffeinated coffee and again without caffeine intake were quantified by ammonia PET. After caffeine intake there was a clearly diminished increase of myocardial blood flow during adenosine. The average coronary flow reserve in the myocardium was 1.3 after caffeine. In the baseline study without caffeine the coronary flow reserve has been improved to 2.3. Caffeine intake alters the coronary vasodilatory capacity. These findings emphasize the importance of carefully screening patients for intake of caffeinated food prior to adenosine stress testing.

Regulation of Coronary Blood Flow

PubMed Central

Goodwill, Adam G.; Dick, Gregory M.; Kiel, Alexander M.; Tune, Johnathan D.

2018-01-01

The heart is uniquely responsible for providing its own blood supply through the coronary circulation. Regulation of coronary blood flow is quite complex and, after over 100 years of dedicated research, is understood to be dictated through multiple mechanisms that include extravascular compressive forces (tissue pressure), coronary perfusion pressure, myogenic, local metabolic, endothelial as well as neural and hormonal influences. While each of these determinants can have profound influence over myocardial perfusion, largely through effects on end-effector ion channels, these mechanisms collectively modulate coronary vascular resistance and act to ensure that the myocardial requirements for oxygen and substrates are adequately provided by the coronary circulation. The purpose of this series of Comprehensive Physiology is to highlight current knowledge regarding the physiologic regulation of coronary blood flow, with emphasis on functional anatomy and the interplay between the physical and biological determinants of myocardial oxygen delivery. PMID:28333376

Impact of admission blood glucose levels on prognosis of elderly patients with ST elevation myocardial infarction treated by primary percutaneous coronary intervention

PubMed Central

Ekmekci, Ahmet; Uluganyan, Mahmut; Tufan, Fatif; Uyarel, Huseyin; Karaca, Gurkan; Kul, Seref; Gungor, Barış; Ertas, Gokhan; Erer, Betul; Sayar, Nurten; Gul, Mehmet; Eren, Mehmet

2013-01-01

Objective Admission hyperglycemia in acute myocardial infarction (MI) is related with increased in-hospital and long term mortality and major cardiac adverse events. We aimed to investigate how admission hyperglycemia affects the short and long term outcomes in elderly patients (> 65 years) after primary percutaneous coronary intervention for ST elevation myocardial infarction. Methods We retrospectively analyzed 677 consecutive elderly patients (mean age 72.2 ± 5.4). Patients were divided into two groups according to admission blood glucose levels. Group 1: low glucose group (LLG), glucose < 168 mg/dL; and Group 2: high glucose group (HGG), glucose > 168 mg/dL. Results In-hospital, long term mortality and in-hospital major adverse cardiac events were higher in the high admission blood glucose group (P < 0.001). Multivariate regression analysis showed: Killip > 1, post-thrombolysis in MI < 3 and admission blood glucose levels were independent predictors of in-hospital adverse cardiac events (P < 0.001). Conclusions Admission hyperglycemia in elderly patients presented with ST elevation myocardial infarction is an independent predictor of in-hospital major adverse cardiac events and is associated with in-hospital and long term mortality. PMID:24454322

Relationship between HgbA1c and myocardial blood flow reserve in patients with type 2 diabetes mellitus: noninvasive assessment using real-time myocardial perfusion echocardiography.

PubMed

Huang, Runqing; Abdelmoneim, Sahar S; Nhola, Lara F; Mulvagh, Sharon L

2014-01-01

To study the relationship between glycosylated hemoglobin (HgbA1c) and myocardial perfusion in type 2 diabetes mellitus (T2DM) patients, we prospectively enrolled 24 patients with known or suspected coronary artery disease (CAD) who underwent adenosine stress by real-time myocardial perfusion echocardiography (RTMPE). HgbA1c was measured at time of RTMPE. Microbubble velocity (β min(-1)), myocardial blood flow (MBF, mL/min/g), and myocardial blood flow reserve (MBFR) were quantified. Quantitative MCE analysis was feasible in all patients (272/384 segments, 71%). Those with HgbA1c > 7.1% had significantly lower βreserve and MBFR than those with HgbA1c ≤ 7.1% (P < 0.05). In patients with suspected CAD, there was a significant inverse correlation between MBFR and HgbA1c (r = -0.279, P = 0.01); however, in those with known CAD, this relationship was not significant (r = -0.117, P = 0.129). Using a MBFR cutoff value > 2 as normal, HgbA1c > 7.1% significantly increased the risk for abnormal MBFR, (adjusted odds ratio: 1.92, 95% CI: 1.12-3.35, P = 0.02). Optimal glycemic control is associated with preservation of MBFR as determined by RTMPE, in T2DM patients at risk for CAD.

Intra-renal delivery of mesenchymal stem cells attenuates myocardial injury after reversal of hypertension in porcine renovascular disease.

PubMed

Eirin, Alfonso; Zhu, Xiang-Yang; Ferguson, Christopher M; Riester, Scott M; van Wijnen, Andre J; Lerman, Amir; Lerman, Lilach O

2015-01-19

Percutaneous transluminal renal angioplasty (PTRA) fails to fully improve cardiac injury and dysfunction in patients with renovascular hypertension (RVH). Mesenchymal stem cells (MSCs) restore renal function, but their potential for attenuating cardiac injury after reversal of RVH has not been explored. We hypothesized that replenishment of MSCs during PTRA would improve cardiac function and oxygenation, and decrease myocardial injury in porcine RVH. Pigs were studied after 16 weeks of RVH, RVH treated 4 weeks earlier with PTRA with or without adjunct intra-renal delivery of MSC (10^6 cells), and controls. Cardiac structure, function (fast-computed tomography (CT)), and myocardial oxygenation (Blood-Oxygen-Level-Dependent- magnetic resonance imaging) were assessed in-vivo. Myocardial microvascular density (micro-CT) and myocardial injury were evaluated ex-vivo. Kidney venous and systemic blood levels of inflammatory markers were measured and their renal release calculated. PTRA normalized blood pressure, yet stenotic-kidney glomerular filtration rate, similarly blunted in RVH and RVH + PTRA, normalized only in PTRA + MSC-treated pigs. PTRA attenuated left ventricular remodeling, whereas myocardial oxygenation, subendocardial microvascular density, and diastolic function remained decreased in RVH + PTRA, but normalized in RVH + PTRA-MSC. Circulating isoprostane levels and renal release of inflammatory cytokines increased in RVH and RVH + PTRA, but normalized in RVH + PTRA-MSC, as did myocardial oxidative stress, inflammation, collagen deposition, and fibrosis. Intra-renal MSC delivery during PTRA preserved stenotic-kidney function, reduced systemic oxidative stress and inflammation, and thereby improved cardiac function, oxygenation, and myocardial injury four weeks after revascularization, suggesting a therapeutic potential for adjunctive MSC delivery to preserve cardiac function and structure after reversal of experimental RVH.

Effects of spinal cord stimulation in angina pectoris induced by pacing and possible mechanisms of action.

PubMed Central

Mannheimer, C; Eliasson, T; Andersson, B; Bergh, C H; Augustinsson, L E; Emanuelsson, H; Waagstein, F

1993-01-01

OBJECTIVE--To investigate the effects of spinal cord stimulation on myocardial ischaemia, coronary blood flow, and myocardial oxygen consumption in angina pectoris induced by atrial pacing. DESIGN--The heart was paced to angina during a control phase and treatment with spinal cord stimulation. Blood samples were drawn from a peripheral artery and the coronary sinus. SETTING--Multidisciplinary pain centre, department of medicine, Ostra Hospital, and Wallenberg Research Laboratory, Sahlgrenska Hospital, Gothenburg, Sweden. SUBJECTS--Twenty patients with intractable angina pectoris, all with a spinal cord stimulator implanted before the study. RESULTS--Spinal cord stimulation increased patients' tolerance to pacing (p < 0.001). At the pacing rate comparable to that producing angina during the control recording, myocardial lactate production during control session turned into extraction (p = 0.003) and, on the electrocardiogram, ST segment depression decreased, time to ST depression increased, and time to recovery from ST depression decreased (p = 0.01; p < 0.05, and p < 0.05, respectively). Spinal cord stimulation also reduced coronary sinus blood flow (p = 0.01) and myocardial oxygen consumption (p = 0.02). At the maximum pacing rate during treatment, all patients experienced anginal pain. Myocardial lactate extraction reverted to production (p < 0.01) and the magnitude and duration of ST segment depression increased to the same values as during control pacing, indicating that myocardial ischaemia during treatment with spinal cord stimulation gives rise to anginal pain. CONCLUSIONS--Spinal cord stimulation has an anti-anginal and anti-ischaemic effect in severe coronary artery disease. These effects seem to be secondary to a decrease in myocardial oxygen consumption. Furthermore, myocardial ischemia during treatment gives rise to anginal pain. Thus, spinal cord stimulation does not deprive the patient of a warning signal. PMID:8400930

[Oxygen-transporting function of the blood circulation system in sevoflurane anesthesia during myocardial revascularization under extracorporeal circulation].

PubMed

Skopets, A A; Lomivorotov, V V; Karakhalis, N B; Makarov, A A; Duman'ian, E S; Lomivorotova, L V

2009-01-01

The purpose of the study was to evaluate the efficiency of oxygen-transporting function of the circulatory system under sevoflurane anesthesia during myocardial revascularization operations under extracorporeal circulation. Twenty-five patients with coronary heart disease were examined. Mean blood pressure, heart rate, cardiac index, total peripheral vascular resistance index, pulmonary pressure, pulmonary wedge pressure, and central venous pressure were measured. Arterial and mixed venous blood oxygen levels, oxygen delivery and consumption index, arteriovenous oxygen difference, and glucose and lactate concentrations were calculated. The study has demonstrated that sevoflurane is an effective and safe anesthetic for myocardial revascularization operations in patients with coronary heart disease. The use of sevoflurane contributes to steady-state oxygen-transporting function of the circulatory system at all surgical stages.

Assessment of vital exhaustion and identification of subjects at increased risk of myocardial infarction in general practice.

PubMed

Schuitemaker, G E; Dinant, G J; van der Pol, G A; Appels, A

2004-01-01

Vital exhaustion, a state characterized by unusual fatigue, loss of energy, increased irritability, and feelings of demoralization, is one of the cardiovascular risk factors. The authors investigated whether vital exhaustion contributes to the identification of subjects at increased risk of myocardial infarction in general practice. In this prospective cohort study, vital exhaustion was assessed with the Maastricht Interview on Vital Exhaustion. Other cardiovascular risk factors established were age, gender, systolic and diastolic blood pressure, total cholesterol, body mass index, smoking habits, cardiovascular disease, and diabetes mellitus. A Cox regression analysis was used. The subjects were adults (41-66 years) in an average Dutch village population. Outcome measures were fatal and nonfatal myocardial infarction. At the univariate level, vital exhaustion doubled the risk of myocardial infarction. The effect of exhaustion was confounded by gender; women had higher exhaustion scores and a lower incidence of myocardial infarction. With control for gender, age, systolic blood pressure, total cholesterol, smoking habits, self-reported cardiovascular disease, and diabetes mellitus, vital exhaustion almost tripled the risk of myocardial infarction. Assessment of vital exhaustion contributes to the identification of subjects at increased risk of myocardial infarction in general practice.

[Comparison of initial and delayed myocardial imaging with beta-methyl-p-[123I]-iodophenylpentadecanoic acid in acute myocardial infarction].

PubMed

Naruse, H; Yoshimura, N; Yamamoto, J; Morita, M; Fukutake, N; Ohyanagi, M; Iwasaki, T; Fukuchi, M

1994-01-01

Myocardial imaging using beta-methyl-p-[123I]-iodophenylpentadecanoic acid (BMIPP) of 15 patients with acute myocardial infarction was performed to assess "fill-in" and "washout" defects in the delayed myocardial image. The initial and delayed images were evaluated by a visual and quantitative washout rate method. Visual judgement found 8/180 (4%) segments showed "fill-in" defects, and 24/180 segments (13%) showed "washout" defects. There was no relationship between days from onset to the study and the frequency of fill-in and washout defects. The mean washout rate in the segments with "fill-in" defects was 9.0 +/- 16.6%, and that of "washout" defects was 24.9 +/- 18.1% which was significantly higher than in controls (8.7 +/- 15.4%, p < 0.05). There was no correlation between mean washout rate and total blood lipids, total cholesterol, triglyceride and HDL-cholesterol. Therefore, neither time from onset nor blood lipids level was related to changes from the initial image to the delayed image. These changes may be due to relative (false) findings due to changes in circumference, and may be based on myocardial characteristics after myocardial infarction and/or reperfusion.

KLF2 and KLF4 control endothelial identity and vascular integrity

PubMed Central

Sangwung, Panjamaporn; Zhou, Guangjin; Nayak, Lalitha; Chan, E. Ricky; Kang, Dong-Won; Zhang, Rongli; Lu, Yuan; Sugi, Keiki; Fujioka, Hisashi; Shi, Hong; Lapping, Stephanie D.; Ghosh, Chandra C.; Higgins, Sarah J.; Parikh, Samir M.; Jain, Mukesh K.

2017-01-01

Maintenance of vascular integrity in the adult animal is needed for survival, and it is critically dependent on the endothelial lining, which controls barrier function, blood fluidity, and flow dynamics. However, nodal regulators that coordinate endothelial identity and function in the adult animal remain poorly characterized. Here, we show that endothelial KLF2 and KLF4 control a large segment of the endothelial transcriptome, thereby affecting virtually all key endothelial functions. Inducible endothelial-specific deletion of Klf2 and/or Klf4 reveals that a single allele of either gene is sufficient for survival, but absence of both (EC-DKO) results in acute death from myocardial infarction, heart failure, and stroke. EC-DKO animals exhibit profound compromise in vascular integrity and profound dysregulation of the coagulation system. Collectively, these studies establish an absolute requirement for KLF2/4 for maintenance of endothelial and vascular integrity in the adult animal. PMID:28239661

Myocardial blood flow and its transit time, oxygen utilization, and efficiency of highly endurance-trained human heart.

PubMed

Heinonen, Ilkka; Kudomi, Nobuyuki; Kemppainen, Jukka; Kiviniemi, Antti; Noponen, Tommi; Luotolahti, Matti; Luoto, Pauliina; Oikonen, Vesa; Sipilä, Hannu T; Kopra, Jaakko; Mononen, Ilkka; Duncker, Dirk J; Knuuti, Juhani; Kalliokoski, Kari K

2014-07-01

Highly endurance-trained athlete's heart represents the most extreme form of cardiac adaptation to physical stress, but its circulatory alterations remain obscure. In the present study, myocardial blood flow (MBF), blood mean transit time (MTT), oxygen extraction fraction (OEF) and consumption (MVO2), and efficiency of cardiac work were quantified in highly trained male endurance athletes and control subjects at rest and during supine cycling exercise using [(15)O]-labeled radiotracers and positron emission tomography. Heart rate and MBF were lower in athletes both at rest and during exercise. OEF increased in response to exercise in both groups, but was higher in athletes (70 ± 21 vs. 63 ± 11 % at rest and 86 ± 13 vs. 73 ± 10 % during exercise). MTT was longer and vascular resistance higher in athletes both at rest and during exercise, but arterial content of 2,3-diphosphoglycerate (oxygen affinity) was unchanged. MVO2 per gram of myocardium trended (p = 0.08) lower in athletes both at rest and during exercise, while myocardial efficiency of work and MVO2 per beat were not different between groups. Arterial levels of free fatty acids were ~twofold higher in athletes likely leading to higher myocardial fatty acid oxidation and hence oxygen cost, which may have blunted the bradycardia-induced decrease in MVO2. Finally, the observed group differences in MBF, OEF, MTT and vascular resistance remained significant also after they were controlled for differences in MVO2. In conclusion, in highly endurance-trained human heart, increased myocardial blood transition time enables higher oxygen extraction levels with a lower myocardial blood flow and higher vascular resistance. These physiological adaptations to exercise training occur independently of the level of oxygen consumption and together with training-induced bradycardia may serve as mechanisms to increase functional reserve of the human heart.

Regional Myocardial Blood Flow and Ultrastructure Following Acute Temporary Ischemia.

DTIC Science & Technology

1982-01-01

relationship of vascular injury and myocardial hemorrhage to necrosis after reperfusion. Circulation 62:1274-1279 39. Flores J, DiBona DR, Beck CH, Leaf A...the reptilian and amphibian circulations. Anat Rec 3:75-109 87. Powell WF, Flores J, DiBona DR, Leaf A (1973) The role of cell swelling in myocardial

Myocardial revascularization with miniaturized extracorporeal circulation versus off pump: Evaluation of systemic and myocardial inflammatory response in a prospective randomized study.

PubMed

Formica, Francesco; Broccolo, Francesco; Martino, Antonello; Sciucchetti, Jennifer; Giordano, Vincenzo; Avalli, Leonello; Radaelli, Gianluigi; Ferro, Orazio; Corti, Fabrizio; Cocuzza, Clementina; Paolini, Giovanni

2009-05-01

This prospective randomized study sought to verify the systemic inflammatory response, inflammatory myocardial damage, and early clinical outcome in coronary surgery with the miniaturized extracorporeal circulation system or on the beating heart. Sixty consecutive patients were randomized to miniaturized extracorporeal circulation (n = 30) or off-pump coronary revascularization (off-pump coronary artery bypass grafting, n = 30). Intraoperative and postoperative data were recorded. Plasma levels of interleukin-6 and tumor necrosis factor-alpha were measured from systemic blood intraoperatively, at the end of operation, and 24 and 48 hours thereafter. Levels of the same markers and blood lactate were measured from coronary sinus blood intraoperatively to evaluate myocardial inflammation. Markers of myocardial damage were also analyzed. One patient died in the off-pump coronary artery bypass grafting group. There was no statistical difference in early clinical outcome in both groups. Release of interleukin-6 was higher in the off-pump coronary artery bypass grafting group 24 hours after the operation (P = .03), whereas levels of tumor necrosis factor-alpha were not different in both groups. Cardiac release of interleukin-6, tumor necrosis factor-alpha, and blood lactate were not different in both groups. Release of troponin T was not significantly different in both groups. Levels of creatine kinase mass were statistically higher in the miniaturized extracorporeal circulation group than in the off-pump coronary artery bypass grafting group, but only at the end of the operation (P < .0001). Hemoglobin levels were significantly higher in the miniaturized extracorporeal circulation group than in the off-pump coronary artery bypass grafting group after 24 hours (P = .01). Miniaturized extracorporeal circulation can be considered similar to off-pump surgery in terms of systemic inflammatory response, myocardial inflammation and damage, and early outcome.

Improvement of Hyperemic Myocardial Oxygen Extraction Fraction Estimation By A Diffusion Prepared Sequence

PubMed Central

McCommis, Kyle S.; Koktzoglou, Ioannis; Zhang, Haosen; Goldstein, Thomas A.; Northrup, Benjamin E.; Li, Debiao; Gropler, Robert J.; Zheng, Jie

2010-01-01

Myocardial oxygen extraction fraction (OEF) during hyperemia can be estimated using a double-inversion-recovery (DIR) prepared T2-weighted black-blood sequence. Severe irregular ECG-triggering due to elevated heart rate and/or arrhythmias may render it difficult to adequately suppress the flowing left ventricle blood signal and thus potentially cause errors in the estimates of myocardial OEF. Thus, the goal of this study was to evaluate another black-blood technique, a diffusion-weighted (DW)-prepared TSE sequence for its ability to determine regional myocardial OEF during hyperemia. Control dogs and dogs with acute coronary artery stenosis were imaged with both the DIR- and DW-prepared TSE sequences at rest and during either dipyridamole or dobutamine hyperemia. Validation of MRI OEF estimates was performed using blood sampling from the artery and coronary sinus in control dogs. The two methods showed comparable correlations with blood sampling results (R2 = 0.9). Similar OEF estimations for all dogs were observed except for the group of dogs with severe coronary stenosis during dobutamine stress. In these dogs, the DW method provided more physiologically reasonable OEF (hyperemic OEF = 0.75 ± 0.08 vs resting OEF of 0.6) than the DIR method (hyperemic OEF = 0.56 ± 0.10). DW-preparation may be a valuable alternative for more accurate oxygenation measurements during irregular ECG-triggering. PMID:20512871

[Myocardial bridge as the only cause of acute coronary syndrome among the young patients].

PubMed

Miakinkova, Liudmila O; Teslenko, Yurii V; Tsyhanenko, Irina V

2018-01-01

Introduction: Myocardial bridge is an inborn anomaly of coronary artery development, when a part of it is submerged in a myocard, which is pressing the coronary artery to a systola and restrains coronary blood circulation. Generally this feature of coronary blood circulation does not cause any clinical symptoms because the 85% of coronary blood stream of the left ventricle is provided by diastolic filling. Hemodynamic changes in atherosclerosis, tahicardie, hypertrophie of myocard are leading to the manifestation of clinical symptoms of ischemia. The aim: The purpose of the investigation was to discover the features of clinical development of acute coronary syndrome caused by myocardial bridge of young patients without the features of atherosclerotical harm of coronary arteries. Materials and methods: Eight causes of acute coronary syndrome among patients of 28±8,5 years with myocardial bridge which was revealed during coronary angiography, were investigated. Standardized examination and conservative treatment of patients was held, except for three who have got interventional therapy. Results: According to our investigation, myocardial bridge of all investigated patients was located in the middle of the third front interventricular branch of the left coronary artery. Causes of acute coronary syndrome manifestation were tahicardia, spasms of coronary artery, inducted by iatrogenic factors hypertrophie of myocard, hypertrophic cardiomyopatie. Connection between the manifestation of clinical symptoms and length of tunneled segment which did not depend on the level of systolic compres was discovered. The results of conservative and interventional treatment were analyzed. Conclusions: Myocardial bridge can be the cause of myocardial ischemia among patients without signs of coronary atherosclerosis with additional hemodynamic risk facts such as tahicardia, spasms of coronary artery, hypertrophie of myocard. Clinical symptomatology of the acute coronary syndrome is more often observed among patients who's myocsrdial bridge is located in the middle of the third front interventricular branch of the left coronary artery. This is caused by perpendicular location of muscle fibers to coronary artery that increases systolic compression. Diastolic function and blood filling of coronary artery can be improved due to the medication beta-blockers therapy of patients with symptomatic myocardial bridge. A higher risk of appearance of restenosis of the stent is possible due to interventional treatment of young patients with myocardial bridge without atherosclerosis of coronary arteries.

Absolute quantification of myocardial blood flow with 13N-ammonia and 3-dimensional PET.

PubMed

Schepis, Tiziano; Gaemperli, Oliver; Treyer, Valerie; Valenta, Ines; Burger, Cyrill; Koepfli, Pascal; Namdar, Mehdi; Adachi, Itaru; Alkadhi, Hatem; Kaufmann, Philipp A

2007-11-01

The aim of this study was to compare 2-dimensional (2D) and 3-dimensional (3D) dynamic PET for the absolute quantification of myocardial blood flow (MBF) with (13)N-ammonia ((13)N-NH(3)). 2D and 3D MBF measurements were collected from 21 patients undergoing cardiac evaluation at rest (n = 14) and during standard adenosine stress (n = 7). A lutetium yttrium oxyorthosilicate-based PET/CT system with retractable septa, enabling the sequential acquisition of 2D and 3D images within the same patient and study, was used. All 2D studies were performed by injecting 700-900 MBq of (13)N-NH(3). For 14 patients, 3D studies were performed with the same injected (13)N-NH(3) dose as that used in 2D studies. For the remaining 7 patients, 3D images were acquired with a lower dose of (13)N-NH(3), that is, 500 MBq. 2D images reconstructed by use of filtered backprojection (FBP) provided the reference standard for MBF measurements. 3D images were reconstructed by use of Fourier rebinning (FORE) with FBP (FORE-FBP), FORE with ordered-subsets expectation maximization (FORE-OSEM), and a reprojection algorithm (RP). Global MBF measurements derived from 3D PET with FORE-FBP (r = 0.97), FORE-OSEM (r = 0.97), and RP (r = 0.97) were well correlated with those derived from 2D FBP (all Ps < 0.0001). The mean +/- SD differences in global MBF measurements between 3D FORE-FBP and 2D FBP and between 3D FORE-OSEM and 2D FBP were 0.01 +/- 0.14 and 0.01 +/- 0.15 mL/min/g, respectively. The mean +/- SD difference in global MBF measurements between 3D RP and 2D FBP was 0.00 +/- 0.16 mL/min/g. The best correlation between 2D PET and 3D PET performed with the lower injected activity was found for the 3D FORE-FBP reconstruction algorithm (r = 0.95, P < 0.001). For this scanner type, quantitative measurements of MBF with 3D PET and (13)N-NH(3) were in excellent agreement with those obtained with the 2D technique, even when a lower activity was injected.

[The specific features of the blood gas transport system in patients with postinfarction cardiosclerosis].

PubMed

Mikashinovich, Z I; Suroedova, R A; Olempieva, E V

2009-10-01

The specific features of blood gas transport system functioning were analyzed in patients with cardiovascular diseases. In patients with postinfarction cardiosclerosis (PICS), the quantitative mechanism for hypoxia adaptation tended to decrease, which may be considered to be a compensatory-adaptive reaction aimed at eliminating the sludge phenomenon and improving the rheological characteristics of blood. Acute myocardial reinfarction developed in patents with PICS is characterized by the lower functional activity of red blood cells, and developing hypoxia is an important link of activation of apoptotic cell death. The degree of hypoxia may be believed to correlate with the sizes of a myocardial necrosis focus.

Correlation of ABO blood groups with spontaneous recanalization in acute myocardial infarction.

PubMed

Lin, Xian-Liang; Zhou, Bing-Yang; Li, Sha; Li, Xiao-Lin; Luo, Zhu-Rong; Li, Jian-Jun

2017-08-01

Although previous studies have demonstrated the relationship between ABO blood groups and cardiovascular disease, the association of ABO blood type with spontaneous recanalization (SR) in patients with acute myocardial infarction (AMI) has not been previously investigated. We performed an initial exploratory study on the association of ABO blood groups with the presence of SR in 1209 patients with AMI. They were divided into two groups according to the thrombolysis in myocardial infarction (TIMI) grades: no-SR group (TIMI 0-1, n = 442) and SR group (TIMI 2-3, n = 767). To confirm our primary findings, data from a second AMI population (n = 200) was analyzed. In the initial data, SR group had a significantly higher percentage of blood type O and a lower percentage of blood type A compared to the no-SR group. Multivariate logistic regression analysis showed that blood type O was positively associated with SR (odds ratio: 1.40, 95% confidence interval: 1.05-1.87, p = .02), and this finding was confirmed in our second population. The present study demonstrates that blood type O was independently and positively associated with an open culprit artery in patients with AMI, suggesting that the ABO blood type is not only associated with the susceptibility to coronary artery disease but also to spontaneous reperfusion in AMI patients.

[Evaluation of left ventricular perfusion and regional wall motion in myocardial infarction: using 201Tl myocardial SPECT and 99mTc-HSAD multigated cardiac blood pool emission computed tomography].

PubMed

Nanjyo, S

1994-09-01

In order to evaluate left ventricular regional wall motion and regional myocardial perfusion, 99mTc-HSAD multigated cardiac blood pool emission computed tomography (cardiac pool SPECT) and 201Tl myocardial SPECT (Tl) were performed on 12 patients with acute myocardial infarction (AMI), 6 patients had treated with only thrombolysis in group I and 6 patients had treated with thrombolysis and selective PTCA in group II, 17 patients with old myocardial infarction (OMI) in group III and 5 normal volunteers (controls). The relationship between left ventricular regional wall motion and regional myocardial perfusion was estimated. The relationship between % length shortening (%LS) by cardiac pool SPECT and %Tl uptake (%TU) was good (r = 0.820) in group III. The value for %TU in the segments of akinesia was low (35%) and in the those of severe hypokinesia was higher (48%). In all phases, two groups showed significant relationships between %LS and %TU in group I and II. The %TU was unchanged in the akinetic segment, the %LS changed 30% in group I and the %LS changed to 49% in group II. If the %TU is more than 50% (AMI) or 40% (OMI), we would observe viable muscle. The combination of Tl and cardiac pool SPECT are useful for evaluating myocardial viability in the patients with AMI.

Cobalt Chloride Upregulates Impaired HIF-1α Expression to Restore Sevoflurane Post-conditioning-Dependent Myocardial Protection in Diabetic Rats.

PubMed

Wu, Jianjiang; Yang, Long; Xie, Peng; Yu, Jin; Yu, Tian; Wang, Haiying; Maimaitili, Yiliyaer; Wang, Jiang; Ma, Haiping; Yang, Yining; Zheng, Hong

2017-01-01

Previous studies from our group have demonstrated that sevoflurane post-conditioning (SPC) protects against myocardial ischemia reperfusion injury via elevating the intranuclear expression of hypoxia inducible factor-1 alpha (HIF-1α). However, diabetic SPC is associated with decreased myocardial protection and disruption of the HIF-1 signaling pathway. Previous studies have demonstrated that cobalt chloride (CoCl 2 ) can upregulate HIF-1α expression under diabetic conditions, but whether myocardial protection by SPC can be restored afterward remains unclear. We established a rat model of type 2 diabetes and a Langendorff isolated heart model of ischemia-reperfusion injury. Prior to reperfusion, 2.4% sevoflurane was used as a post-conditioning treatment. The diabetic rats were treated with CoCl 2 24 h before the experiment. At the end of reperfusion, tests were performed to assess myocardial function, infarct size, mitochondrial morphology, nitric oxide (NO), Mitochondrial reactive oxygen species (ROS), mitochondrial respiratory function and enzyme activity, HIF-1α, vascular endothelial growth factor (VEGF) and endothelial NO synthase (eNOS) protein levels. In addition, myocardial protection by SPC was monitored after the blood glucose levels were lowered by insulin. The diabetic state was associated with deficient SPC protection and decreased HIF-1α expression. After treating the diabetic rats with CoCl 2 , SPC significantly upregulated the expression of HIF-1α, VEGF and eNOS, which markedly improved cardiac function, NO, mitochondrial respiratory function, and enzyme activity and decreased the infarction areas and ROS. In addition, these effects were not influenced by blood glucose levels. This study proved that CoCl 2 activates the HIF-1α signaling pathway, which restores SPC-dependent myocardial protection under diabetic conditions, and the protective effects of SPC were independent of blood glucose levels.

Relationship between blood viscosity and infarct size in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

PubMed

Cecchi, Emanuele; Liotta, Agatina Alessandriello; Gori, Anna Maria; Valente, Serafina; Giglioli, Cristina; Lazzeri, Chiara; Sofi, Francesco; Gensini, Gian Franco; Abbate, Rosanna; Mannini, Lucia

2009-05-15

Previous studies explored the association between hemorheological alterations and acute myocardial infarction, pointing out the role of hematological components on microvascular flow. The aim of this study was to evaluate the association between blood viscosity and infarct size, estimated by creatine kinase (CK) peak activity and cardiac Troponin I (cTnI) peak concentration in ST-segment elevation myocardial infarction (STEMI) patients after primary percutaneous coronary intervention (PCI). The study population included 197 patients with diagnosis of STEMI undergoing PCI. Hemorheological studies were performed by assessing whole blood viscosity (measured at shear rates of 0.512 s(-1) and 94.5 s(-1)) and plasma viscosity using the Rotational Viscosimeter LS 30 and erythrocyte deformability index by Myrenne filtrometer. Significant correlations between CK peak activity, cTnI peak concentration, left ventricular ejection fraction and hemorheological variables were observed. At linear regression analysis (adjusted for age, gender, traditional cardiovascular risk factors, renal dysfunction, timeliness of reperfusion, pre-PCI TIMI flow, infarct location, multivessel disease and previous coronary artery disease) leukocytes and whole blood viscosity at 0.512 s(-1) and 94.5 s(-1) were independently and positively associated with infarct size. These results demonstrate a significant and independent association between hemorheology and infarct size in STEMI patients after PCI suggesting that blood viscosity, in a condition of low flow, might worsen myocardial perfusion leading to an increased infarct size. The measurement of whole blood viscosity in STEMI patients could help to identify those who may benefit from new therapeutic strategies.

3D motion and strain estimation of the heart: initial clinical findings

NASA Astrophysics Data System (ADS)

Barbosa, Daniel; Hristova, Krassimira; Loeckx, Dirk; Rademakers, Frank; Claus, Piet; D'hooge, Jan

2010-03-01

The quantitative assessment of regional myocardial function remains an important goal in clinical cardiology. As such, tissue Doppler imaging and speckle tracking based methods have been introduced to estimate local myocardial strain. Recently, volumetric ultrasound has become more readily available, allowing therefore the 3D estimation of motion and myocardial deformation. Our lab has previously presented a method based on spatio-temporal elastic registration of ultrasound volumes to estimate myocardial motion and deformation in 3D, overcoming the spatial limitations of the existing methods. This method was optimized on simulated data sets in previous work and is currently tested in a clinical setting. In this manuscript, 10 healthy volunteers, 10 patient with myocardial infarction and 10 patients with arterial hypertension were included. The cardiac strain values extracted with the proposed method were compared with the ones estimated with 1D tissue Doppler imaging and 2D speckle tracking in all patient groups. Although the absolute values of the 3D strain components assessed by this new methodology were not identical to the reference methods, the relationship between the different patient groups was similar.

Integrating atlas and graph cut methods for right ventricle blood-pool segmentation from cardiac cine MRI

NASA Astrophysics Data System (ADS)

Dangi, Shusil; Linte, Cristian A.

2017-03-01

Segmentation of right ventricle from cardiac MRI images can be used to build pre-operative anatomical heart models to precisely identify regions of interest during minimally invasive therapy. Furthermore, many functional parameters of right heart such as right ventricular volume, ejection fraction, myocardial mass and thickness can also be assessed from the segmented images. To obtain an accurate and computationally efficient segmentation of right ventricle from cardiac cine MRI, we propose a segmentation algorithm formulated as an energy minimization problem in a graph. Shape prior obtained by propagating label from an average atlas using affine registration is incorporated into the graph framework to overcome problems in ill-defined image regions. The optimal segmentation corresponding to the labeling with minimum energy configuration of the graph is obtained via graph-cuts and is iteratively refined to produce the final right ventricle blood pool segmentation. We quantitatively compare the segmentation results obtained from our algorithm to the provided gold-standard expert manual segmentation for 16 cine-MRI datasets available through the MICCAI 2012 Cardiac MR Right Ventricle Segmentation Challenge according to several similarity metrics, including Dice coefficient, Jaccard coefficient, Hausdorff distance, and Mean absolute distance error.

Factoring socioeconomic status into cardiac performance profiling for hospitals: does it matter?

PubMed

Alter, David A; Austin, Peter C; Naylor, C David; Tu, Jack V

2002-01-01

Critics of "scorecard medicine" often highlight the incompleteness of risk-adjustment methods used when accounting for baseline patient differences. Although socioeconomic status is a highly important determinant of adverse outcome for patients admitted to the hospital with acute myocardial infarction, it has not been used in most risk-adjustment models for cardiovascular report cards. To determine the incremental impact of socioeconomic status adjustments on age, sex, and illness severity for hospital-specific 30-day mortality rates after acute myocardial infarction. The authors compared the absolute and relative hospital-specific 30-day acute myocardial infarction mortality rates in 169 hospitals throughout Ontario between April 1, 1994 and March 31, 1997. Patient socioeconomic status was characterized by median neighborhood income using postal codes and 1996 Canadian census data. They examined two risk-adjustment models: the first adjusted for age, sex, and illness severity (standard), whereas the second adjusted for age, sex, illness severity, and median neighborhood income level (socioeconomic status). There was an extremely strong correlation between 'standard' and 'socioeconomic status' risk-adjusted mortality rates (r = 0.99). Absolute differences in 30-day risk-adjusted mortality rates between the socioeconomic status and standard risk-adjustment models were small (median, 0.1%; 25th-75th percentile, 0.1-0.2). The agreement in the quintile rankings of hospitals between the socioeconomic status and standard risk-adjustment models was high (weighted kappa = 0.93). Despite its importance as a determinant of patient outcomes, the effect of socioeconomic status on hospital-specific mortality rates over and above standard risk-adjustment methods for acute myocardial infarction hospital profiling in Ontario was negligible.

Measurements Of Coronary Mean Transit Time And Myocardial Tissue Blood Flow By Deconvolution Of Intravasal Tracer Dilution Curves

NASA Astrophysics Data System (ADS)

Korb, H.; Hoeft, A.; Hellige, G.

1984-10-01

Previous studies have shown that intramyocardial blood volume does not vary to a major extent even during extreme variation of hemodynamics and coronary vascular tone. Based on a constant intramyocardial blood volume it is therefore possible to calculate tissue blood flow from the mean transit time of an intravascular tracer. The purpose of this study was to develop a clinically applicable method for measurement of coronary blood flow. The new method was based on indocyanine green, a dye which is bound to albumin and intravasally detectable by means of a fiberoptic catheter device. One fiberoptic catheter was placed in the aortic root and another in the coronary sinus. After central venous dye injection the resulting arterial and coronary venous dye dilution curves were processed on-line by a micro-computer. The mean transit time as well as myocardial blood flow were calculated from the step response function of the deconvoluted arterial and coronary venous signals. Reference flow was determined with an extracorporeal electromagnetic flowprobe within a coronary sinus bypass system. 38 steady states with coronary blood flow ranging from 49 - 333 ml/min*100g were analysed in 5 dogs. Mean transit times varied from 2.9 to 16.6 sec. An average intracoronary blood volume of 13.9 -7 1.8 m1/100g was calculated. The correlation between flow determined by the dye dilution technique and flow measured with the reference method was 0.98. According to these results determination of coronary blood flow with a double fiberoptic system and indocyanine green should be possible even under clinical conditions. Furthermore, the arterial and coronary venous oxygen saturation can be monitored continuously by the fiberoptic catheters. Therefore, additional information about the performance of the heart such as myocardial oxygen consumption and myocardial efficiency is available with the same equipment.

A mathematical model of coronary blood flow control: simulation of patient-specific three-dimensional hemodynamics during exercise

PubMed Central

Lau, Kevin D.; Asrress, Kaleab N.; Redwood, Simon R.; Figueroa, C. Alberto

2016-01-01

This work presents a mathematical model of the metabolic feedback and adrenergic feedforward control of coronary blood flow that occur during variations in the cardiac workload. It is based on the physiological observations that coronary blood flow closely follows myocardial oxygen demand, that myocardial oxygen debts are repaid, and that control oscillations occur when the system is perturbed and so are phenomenological in nature. Using clinical data, we demonstrate that the model can provide patient-specific estimates of coronary blood flow changes between rest and exercise, requiring only the patient's heart rate and peak aortic pressure as input. The model can be used in zero-dimensional lumped parameter network studies or as a boundary condition for three-dimensional multidomain Navier-Stokes blood flow simulations. For the first time, this model provides feedback control of the coronary vascular resistance, which can be used to enhance the physiological accuracy of any hemodynamic simulation, which includes both a heart model and coronary arteries. This has particular relevance to patient-specific simulation for which heart rate and aortic pressure recordings are available. In addition to providing a simulation tool, under our assumptions, the derivation of our model shows that β-feedforward control of the coronary microvascular resistance is a mathematical necessity and that the metabolic feedback control must be dependent on two error signals: the historical myocardial oxygen debt, and the instantaneous myocardial oxygen deficit. PMID:26945076

A mathematical model of coronary blood flow control: simulation of patient-specific three-dimensional hemodynamics during exercise.

PubMed

Arthurs, Christopher J; Lau, Kevin D; Asrress, Kaleab N; Redwood, Simon R; Figueroa, C Alberto

2016-05-01

This work presents a mathematical model of the metabolic feedback and adrenergic feedforward control of coronary blood flow that occur during variations in the cardiac workload. It is based on the physiological observations that coronary blood flow closely follows myocardial oxygen demand, that myocardial oxygen debts are repaid, and that control oscillations occur when the system is perturbed and so are phenomenological in nature. Using clinical data, we demonstrate that the model can provide patient-specific estimates of coronary blood flow changes between rest and exercise, requiring only the patient's heart rate and peak aortic pressure as input. The model can be used in zero-dimensional lumped parameter network studies or as a boundary condition for three-dimensional multidomain Navier-Stokes blood flow simulations. For the first time, this model provides feedback control of the coronary vascular resistance, which can be used to enhance the physiological accuracy of any hemodynamic simulation, which includes both a heart model and coronary arteries. This has particular relevance to patient-specific simulation for which heart rate and aortic pressure recordings are available. In addition to providing a simulation tool, under our assumptions, the derivation of our model shows that β-feedforward control of the coronary microvascular resistance is a mathematical necessity and that the metabolic feedback control must be dependent on two error signals: the historical myocardial oxygen debt, and the instantaneous myocardial oxygen deficit. Copyright © 2016 the American Physiological Society.

Myocardial injury in dogs with snake envenomation and its relation to systemic inflammation.

PubMed

Langhorn, Rebecca; Persson, Frida; Ablad, Björn; Goddard, Amelia; Schoeman, Johan P; Willesen, Jakob L; Tarnow, Inge; Kjelgaard-Hansen, Mads

2014-01-01

To investigate the presence of myocardial injury in dogs hospitalized for snake envenomation and to examine its relationship with systemic inflammation. Prospective case-control study. University teaching hospital and small animal referral hospital. Dogs naturally envenomed by the European viper (Vipera berus; n = 24), African puff adder (Bitis arietans; n = 5), or snouted cobra (Naja annulifera; n = 9). Blood was collected from dogs envenomed by V. berus at admission, 12-24 hours postadmission, and 5-10 days postadmission. Blood was collected from dogs envenomed by B. arietans or N. annulifera at admission, and 12, 24, and 36 hours postadmission. Concentrations of cardiac troponin I (cTnI), a marker of myocardial injury, and C-reactive protein (CRP), a marker of systemic inflammation, were measured in each blood sample. Evidence of myocardial injury was found in 58% of dogs envenomed by V. berus at one or more time points. A significant correlation between cTnI and CRP concentrations was found at all time points. Evidence of myocardial injury was found in 80% of dogs envenomed by B. arietans at one or more time points; however, no correlation was found between cTnI and CRP concentrations. Evidence of myocardial injury was found in 67% of dogs envenomed by N. annulifera at one or more time points. A significant correlation between cTnI and CRP concentrations was found at admission, but not at other time points. Myocardial injury frequently occurred in dogs with snake envenomation. While the degree of systemic inflammation was significantly correlated with degree of myocardial injury in V. berus envenomation at all time points, this was not the case in dogs envenomed by N. annulifera or B. arietans. This could be due to differences in the toxic substances of the snake venoms or to differences in the cytokines induced by the venom toxins. © Veterinary Emergency and Critical Care Society 2013.

A tourniquet assisted cardiopulmonary resuscitation augments myocardial perfusion in a porcine model of cardiac arrest.

PubMed

Yang, Zhengfei; Tang, David; Wu, Xiaobo; Hu, Xianwen; Xu, Jiefeng; Qian, Jie; Yang, Min; Tang, Wanchun

2015-01-01

During cardiopulmonary resuscitation (CPR), myocardial blood flow generated by chest compression rarely exceeds 35% of its normal level. Cardiac output generated by chest compression decreases gradually with the prolongation of cardiac arrest and resuscitation. Early studies have demonstrated that myocardial blood flow during CPR is largely dependent on peripheral vascular resistance. In this study, we investigated the effects of chest compression in combination with physical control of peripheral vascular resistance assisted by tourniquets on myocardial blood flow during CPR. Ventricular fibrillation was induced and untreated for 7 min in ten male domestic pigs weighing between 33 and 37 kg. The animals were then randomized to receive CPR alone or a tourniquet assisted CPR (T-CPR). In the CPR alone group, chest compression was performed by a miniaturized mechanical chest compressor. In the T-CPR group, coincident with the start of resuscitation, the thin elastic tourniquets were wrapped around the four limbs from the distal end to the proximal part. After 2 min of CPR, epinephrine (20 μg/kg) was administered via the femoral vein. After 5 min of CPR, defibrillation was attempted by a single 150 J shock. If resuscitation was not successful, CPR was resumed for 2 min before the next defibrillation. The protocol was continued until successful resuscitation or for a total of 15 min. Five minutes after resuscitation, the elastic tourniquets were removed. The resuscitated animals were observed for 2h. T-CPR generated significantly greater coronary perfusion pressure, end-tidal carbon dioxide and carotid blood flow. There was no difference in both intrathoracic positive and negative pressures between the two groups. All animals were successfully resuscitated with a single shock in both groups. There were no significant changes in hemodynamics observed in the animals treated in the T-CPR group before-and-after the release of tourniquets at post-resuscitation 5 min. T-CPR improves myocardial and cerebral perfusion during CPR. It may provide a new and convenient method for augmenting myocardial and cerebral blood flow during CPR. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Myocardial potency of Bio-tea against Isoproterenol induced myocardial damage in rats.

PubMed

Lobo, Reema Orison; Shenoy, Chandrakala K

2015-07-01

Kombucha (Bio-tea) is a beverage produced by the fermentation of sugared black tea using a symbiotic association of bacteria and yeasts. Traditional claims about Kombucha report beneficial effects such as antibiotic properties, gastric regulation, relief from joint rheumatism and positive influence on the cholesterol level, arteriosclerosis, diabetes, and aging problems. The present investigation was carried out to understand the preventive effect of Kombucha on heart weight, blood glucose, total protein, lipid profile and cardiac markers in rats with myocardial damage induced using Isoproterenol. As Bio-tea is produced by fermenting tea, the parameters were compared in rats pre-treated with normal black tea and Bio-tea for 30 days followed by subcutaneous injection of Isoproterenol (85 mg/kg body weight). Normal rats as well as Isoproterenol induced myocardial infarcted rats were also used, which served as controls. Isoproterenol induced myocardial infarcted control rats showed a significant increase in heart weight, blood glucose and cardiac markers and a decrease in plasma protein. Increased levels of cholesterol, triglycerides, low density lipids (LDL) and very low density lipids (VLDL) were also observed, while the high density lipid (HDL) content decreased. Bio-tea showed a higher preventive effect against myocardial infarction when compared to tea, as was observed by the significant reduction in heart weight, and blood glucose and increase in plasma albumin levels. Bio-tea significantly decreased cholesterol, triglycerides, LDL and VLDL while simultaneously increasing the levels of HDL. Similarly a decrease in leakage of cardiac markers from the myocardium was also observed.

Effects of glycyl-glutamine dipeptide supplementation on myocardial damage and cardiac function in rats after severe burn injury

PubMed Central

Zhang, Yong; Yan, Hong; Lv, Shang-Gun; Wang, Lin; Liang, Guang-Ping; Wan, Qian-Xue; Peng, Xi

2013-01-01

Glutamine decreases myocardial damage in ischemia/reperfusion injury. However, the cardioprotective effect of glutamine after burn injury remains unclear. Present study was to explore the protective effect of glycyl-glutamine dipeptide on myocardial damage in severe burn rats. Seventy-two Wistar rats were randomly divided into three groups: normal control (C), burned control (B) and glycyl-glutamine dipeptide-treated (GG) groups. B and GG groups were inflicted with 30% total body surface area of full thickness burn. The GG group was given 1.5 g/kg glycyl-glutamine dipeptide per day and the B group was given the same dose of alanine via intraperitoneal injection for 3 days. The serum CK, LDH, AST, and, blood lactic acid levels, as well as the myocardium ATP and GSH contents, were measured. The indices of cardiac contractile function and histopathological change were analyzed at 12, 24, 48, and 72 post-burn hours (PBH). The serum CK, LDH, AST and blood lactic acid levels increased, and the myocardium ATP and GSH content decreased in both burned groups. Compared with B group, the CK, LDH, AST and blood lactic acid levels reduced, myocardium ATP and GSH content increased in GG group. Moreover, the inhibition of cardiac contractile function and myocardial histopathological damage were reduced significantly in GG group. We conclude that myocardial histological structure and function were damaged significantly after burn injury, glycyl-glutamine dipeptide supplementation is beneficial to myocardial preservation by improving cardiocyte energy metabolism, increasing ATP and glutathione synthesis. PMID:23638213

Usefulness of myocardial parametric imaging to evaluate myocardial viability in experimental and in clinical studies.

PubMed

Korosoglou, G; Hansen, A; Bekeredjian, R; Filusch, A; Hardt, S; Wolf, D; Schellberg, D; Katus, H A; Kuecherer, H

2006-03-01

To evaluate whether myocardial parametric imaging (MPI) is superior to visual assessment for the evaluation of myocardial viability. Myocardial contrast echocardiography (MCE) was assessed in 11 pigs before, during, and after left anterior descending coronary artery occlusion and in 32 patients with ischaemic heart disease by using intravenous SonoVue administration. In experimental studies perfusion defect area assessment by MPI was compared with visually guided perfusion defect planimetry. Histological assessment of necrotic tissue was the standard reference. In clinical studies viability was assessed on a segmental level by (1) visual analysis of myocardial opacification; (2) quantitative estimation of myocardial blood flow in regions of interest; and (3) MPI. Functional recovery between three and six months after revascularisation was the standard reference. In experimental studies, compared with visually guided perfusion defect planimetry, planimetric assessment of infarct size by MPI correlated more significantly with histology (r2 = 0.92 versus r2 = 0.56) and had a lower intraobserver variability (4% v 15%, p < 0.05). In clinical studies, MPI had higher specificity (66% v 43%, p < 0.05) than visual MCE and good accuracy (81%) for viability detection. It was less time consuming (3.4 (1.6) v 9.2 (2.4) minutes per image, p < 0.05) than quantitative blood flow estimation by regions of interest and increased the agreement between observers interpreting myocardial perfusion (kappa = 0.87 v kappa = 0.75, p < 0.05). MPI is useful for the evaluation of myocardial viability both in animals and in patients. It is less time consuming than quantification analysis by regions of interest and less observer dependent than visual analysis. Thus, strategies incorporating this technique may be valuable for the evaluation of myocardial viability in clinical routine.

Endothelial function is associated with myocardial diastolic function in women with systemic lupus erythematosus.

PubMed

Chin, Calvin W L; Chin, Chee-Yang; Ng, Marie X R; Le, Thu-Thao; Huang, Fei-Qiong; Fong, Kok-Yong; Thumboo, Julian; Tan, Ru-San

2014-09-01

Endothelial dysfunction is associated with traditional and systemic lupus erythematosus (SLE)-specific risk factors, and early data suggest reversibility of endothelial dysfunction with therapy. The clinical relevance of endothelial function assessment has been limited by the lack of studies, demonstrating its prognostic significance and impact on early myocardial function. Therefore, we aimed to determine the association between endothelial and myocardial diastolic function in SLE women. Women with SLE and no coronary artery disease were prospectively recruited and underwent radionuclide myocardial perfusion imaging (MPI) (Jetstream, Philips, the Netherlands) to exclude subclinical myocardial ischemia. Cardiac and vascular functions were assessed in all patients (Alpha 10, Aloka, Tokyo). Diastolic function was assessed using pulse wave early (E) and late mitral blood inflow and myocardial tissue Doppler (mean of medial and lateral annulus e') velocities. Endothelial function was measured using brachial artery flow-mediated vasodilatation (FMD%). Univariate and multivariate linear regressions were used to assess the association between FMD% and myocardial diastolic function, adjusting for potential confounders. Thirty-eight patients without detectable myocardial ischemia on MPI were studied (mean age 44 ± 10 years; mean disease duration 14 ± 6 years). About 61 % of patients had normal diastolic function (E/e' ≤ 8), and 5 % of patients had definite diastolic dysfunction with E/e' > 13 (mean 7.1 ± 2.9). FMD% was associated with E/e' (regression coefficient β = -0.35; 95 % CI -0.62 to -0.08; p = 0.01) independent of systolic blood pressure, age, and SLICC/ACR Damage Index.

Cardiorespiratory fitness modifies the relationship between myocardial function and cerebral blood flow in older adults.

PubMed

Johnson, Nathan F; Gold, Brian T; Bailey, Alison L; Clasey, Jody L; Hakun, Jonathan G; White, Matthew; Long, Doug E; Powell, David K

2016-05-01

A growing body of evidence indicates that cardiorespiratory fitness attenuates some age-related cerebral declines. However, little is known about the role that myocardial function plays in this relationship. Brain regions with high resting metabolic rates, such as the default mode network (DMN), may be especially vulnerable to age-related declines in myocardial functions affecting cerebral blood flow (CBF). This study explored the relationship between a measure of myocardial mechanics, global longitudinal strain (GLS), and CBF to the DMN. In addition, we explored how cardiorespiratory affects this relationship. Participants were 30 older adults between the ages of 59 and 69 (mean age=63.73years, SD=2.8). Results indicated that superior cardiorespiratory fitness and myocardial mechanics were positively associated with DMN CBF. Moreover, results of a mediation analysis revealed that the relationship between GLS and DMN CBF was accounted for by individual differences in fitness. Findings suggest that benefits of healthy heart function to brain function are modified by fitness. Copyright © 2015 Elsevier Inc. All rights reserved.

Activation of complement factor B contributes to murine and human myocardial ischemia/reperfusion injury

PubMed Central

Hou, Yunfang; Wong, Karen A.; Lee, Daniel; Rushbrook, Julie I.; Gulaya, Karan; Hines, Roberta; Hollis, Tamika; Nistal Nuno, Beatriz; Mangi, Abeel A.; Hashim, Sabet; Pekna, Marcela; Catalfamo, Amy; Chin, Hsiao-ying; Patel, Foramben; Rayala, Sravani; Shevde, Ketan; Heeger, Peter S.

2017-01-01

The pathophysiology of myocardial injury that results from cardiac ischemia and reperfusion (I/R) is incompletely understood. Experimental evidence from murine models indicates that innate immune mechanisms including complement activation via the classical and lectin pathways are crucial. Whether factor B (fB), a component of the alternative complement pathway required for amplification of complement cascade activation, participates in the pathophysiology of myocardial I/R injury has not been addressed. We induced regional myocardial I/R injury by transient coronary ligation in WT C57BL/6 mice, a manipulation that resulted in marked myocardial necrosis associated with activation of fB protein and myocardial deposition of C3 activation products. In contrast, in fB-/- mice, the same procedure resulted in significantly reduced myocardial necrosis (% ventricular tissue necrotic; fB-/- mice, 20 ± 4%; WT mice, 45 ± 3%; P < 0.05) and diminished deposition of C3 activation products in the myocardial tissue (fB-/- mice, 0 ± 0%; WT mice, 31 ± 6%; P<0.05). Reconstitution of fB-/- mice with WT serum followed by cardiac I/R restored the myocardial necrosis and activated C3 deposition in the myocardium. In translational human studies we measured levels of activated fB (Bb) in intracoronary blood samples obtained during cardio-pulmonary bypass surgery before and after aortic cross clamping (AXCL), during which global heart ischemia was induced. Intracoronary Bb increased immediately after AXCL, and the levels were directly correlated with peripheral blood levels of cardiac troponin I, an established biomarker of myocardial necrosis (Spearman coefficient = 0.465, P < 0.01). Taken together, our results support the conclusion that circulating fB is a crucial pathophysiological amplifier of I/R-induced, complement-dependent myocardial necrosis and identify fB as a potential therapeutic target for prevention of human myocardial I/R injury. PMID:28662037

Activation of complement factor B contributes to murine and human myocardial ischemia/reperfusion injury.

PubMed

Chun, Nicholas; Haddadin, Ala S; Liu, Junying; Hou, Yunfang; Wong, Karen A; Lee, Daniel; Rushbrook, Julie I; Gulaya, Karan; Hines, Roberta; Hollis, Tamika; Nistal Nuno, Beatriz; Mangi, Abeel A; Hashim, Sabet; Pekna, Marcela; Catalfamo, Amy; Chin, Hsiao-Ying; Patel, Foramben; Rayala, Sravani; Shevde, Ketan; Heeger, Peter S; Zhang, Ming

2017-01-01

The pathophysiology of myocardial injury that results from cardiac ischemia and reperfusion (I/R) is incompletely understood. Experimental evidence from murine models indicates that innate immune mechanisms including complement activation via the classical and lectin pathways are crucial. Whether factor B (fB), a component of the alternative complement pathway required for amplification of complement cascade activation, participates in the pathophysiology of myocardial I/R injury has not been addressed. We induced regional myocardial I/R injury by transient coronary ligation in WT C57BL/6 mice, a manipulation that resulted in marked myocardial necrosis associated with activation of fB protein and myocardial deposition of C3 activation products. In contrast, in fB-/- mice, the same procedure resulted in significantly reduced myocardial necrosis (% ventricular tissue necrotic; fB-/- mice, 20 ± 4%; WT mice, 45 ± 3%; P < 0.05) and diminished deposition of C3 activation products in the myocardial tissue (fB-/- mice, 0 ± 0%; WT mice, 31 ± 6%; P<0.05). Reconstitution of fB-/- mice with WT serum followed by cardiac I/R restored the myocardial necrosis and activated C3 deposition in the myocardium. In translational human studies we measured levels of activated fB (Bb) in intracoronary blood samples obtained during cardio-pulmonary bypass surgery before and after aortic cross clamping (AXCL), during which global heart ischemia was induced. Intracoronary Bb increased immediately after AXCL, and the levels were directly correlated with peripheral blood levels of cardiac troponin I, an established biomarker of myocardial necrosis (Spearman coefficient = 0.465, P < 0.01). Taken together, our results support the conclusion that circulating fB is a crucial pathophysiological amplifier of I/R-induced, complement-dependent myocardial necrosis and identify fB as a potential therapeutic target for prevention of human myocardial I/R injury.

Regulation of coronary blood flow

PubMed Central

Gorlin, Richard

1971-01-01

Coronary blood flow is dependent upon arterial pressure, diastolic time, and small vessel resistance. The system is regulated to achieve a low flow high oxygen extraction and low myocardial Po2. This setting is sensitive to change in oxygen needs. Regulation of blood flow occurs primarily through local intrinsic regulation, most likely through production of vasodilating metabolites in response to minimal degrees of ischaemia. Local regulation appears to dominate over remote regulation in most circumstances. Blood flow distribution to the myocardium is depth dependent as well as regional in variation. Both types of distribution of blood flow are profoundly disturbed in the presence of obstructive coronary atherosclerosis. This results in either concentric myocardial shells or patchy transmural zones of selective ischaemia with clear-cut but local abnormalities in metabolism and performance. Images PMID:4929442

Pericardial application as a new route for implanting stem-cell cardiospheres to treat myocardial infarction.

PubMed

Zhang, Jianhua; Wu, Zheng; Fan, Zepei; Qin, Zixi; Wang, Yingwei; Chen, Jiayuan; Wu, Maoxiong; Chen, Yangxin; Wu, Changhao; Wang, Jingfeng

2018-06-01

Cardiospheres (CSps) are a promising new form of cardiac stem cells with advantage over other stem cells for myocardial regeneration, but direct implantation of CSps by conventional routes has been limited due to potential embolism. We have implanted CSps into the pericardial cavity and systematically demonstrated its efficacy regarding myocardial infarction. Stem cell potency and cell viability can be optimized in vitro prior to implantation by pre-conditioning CSps with pericardial fluid and hydrogel packing. Transplantation of optimized CSps into the pericardial cavity improved cardiac function and alleviated myocardial fibrosis, increased myocardial cell survival and promoted angiogenesis. Mechanistically, CSps are able to directly differentiate into cardiomyocytes in vivo and promote regeneration of myocardial cells and blood vessels through a paracrine effect with released growth factors as potential paracrine mediators. These findings establish a new strategy for therapeutic myocardial regeneration to treat myocardial infarction. Cardiospheres (CSps) are a new form of cardiac stem cells with an advantage over other stem cells for myocardial regeneration. However, direct implantation of CSps by conventional routes to treat myocardial infarction has been limited due to potential embolism. We have implanted CSps into the pericardial cavity and systematically assessed its efficacy on myocardial infarction. Preconditioning with pericardial fluid enhanced the activity of CSps and matrix hydrogel prolonged their viability. This shows that pretransplant optimization of stem cell potency and maintenance of cell viability can be achieved with CSps. Transplantation of optimized CSps into the pericardial cavity improved cardiac function and alleviated myocardial fibrosis in the non-infarcted area, and increased myocardial cell survival and promoted angiogenesis in the infarcted area. Mechanistically, CSps were able to directly differentiate into cardiomyocytes in vivo and promoted regeneration of myocardial cells and blood vessels in the infarcted area through a paracrine effect with released growth factors in pericardial cavity serving as possible paracrine mediators. This is the first demonstration of direct pericardial administration of pre-optimized CSps, and its effectiveness on myocardial infarction by functional and morphological outcomes with distinct mechanisms. These findings establish a new strategy for therapeutic myocardial regeneration to treat myocardial infarction. © 2018 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

Ventricular Fibrillation Waveform Changes during Controlled Coronary Perfusion Using Extracorporeal Circulation in a Swine Model.

PubMed

Gazmuri, Raúl J; Kaufman, Christopher L; Baetiong, Alvin; Radhakrishnan, Jeejabai

2016-01-01

Several characteristics of the ventricular fibrillation (VF) waveform have been found predictive of successful defibrillation and hypothesized to reflect the myocardial energy state. In an open-chest swine model of VF, we modeled "average CPR" using extracorporeal circulation (ECC) and assessed the time course of coronary blood flow, myocardial metabolism, and myocardial structure in relation to the amplitude spectral area (AMSA) of the VF waveform without artifacts related to chest compression. VF was induced and left untreated for 8 minutes in 16 swine. ECC was then started adjusting its flow to maintain a coronary perfusion pressure of 10 mmHg for 10 minutes. AMSA was calculated in the frequency domain and analyzed continuously with a 2.1 s timeframe and a Tukey window that moved ahead every 0.5 s. AMSA progressively declined during untreated VF. With ECC, AMSA increased from 7.0 ± 1.9 mV·Hz (at minute 8) to 12.8 ± 3.3 mV·Hz (at minute 14) (p < 0.05) without subsequent increase and showing a modest correlation with coronary blood flow of borderline statistical significance (r = 0.489, p = 0.0547). Myocardial energy measurements showed marked reduction in phosphocreatine and moderate reduction in ATP with increases in ADP, AMP, and adenosine along with myocardial lactate, all indicative of ischemia. Yet, ischemia did not resolve during ECC despite a coronary blood flow of ~ 30% of baseline. AMSA increased upon return of coronary blood flow during ECC. However, the maximal level was reached after ~ 6 minutes without further change. The significance of the findings for determining the optimal timing for delivering an electrical shock during resuscitation from VF remains to be further explored.

Mechanical tissue resuscitation (MTR): a nonpharmacological approach to treatment of acute myocardial infarction.

PubMed

Jordan, James E; Pereira, Beatriz D; Lane, Magan R; Morykwas, Michael J; McGee, Maria; Argenta, Louis C

2015-08-01

Myocardial ischemia-reperfusion injury is known to trigger an inflammatory response involving edema, apoptosis, and neutrophil activation/accumulation. Recently, mechanical tissue resuscitation (MTR) was described as a potent cardioprotective strategy for reduction of myocardial ischemia-reperfusion injury. Here, we further describe the protective actions of MTR and begin to define its therapeutic window. A left ventricular, free-wall ischemic area was created in anesthetized swine for 85 minutes and then reperfused for three hours. Animals were randomized to two groups: (1) untreated controls (Control) and (2) application of MTR that was delayed 90 minutes after the initiation of reperfusion (D90). Hemodynamics and regional myocardial blood flow were assessed at multiple time points. Infarct size and neutrophil accumulation were assessed following the reperfusion period. In separate cohorts, the effect of MTR on myocardial interstitial water (MRI imaging) and blood flow was examined. Both groups had similar areas at risk (AAR), hemodynamics, and arterial blood gas values. MTR, even when delayed 90 minutes into reperfusion (D90, 29.2 ± 5.0% of AAR), reduced infarct size significantly compared to Controls (51.9 ± 2.7%, p = 0.006). This protection was associated with a 33% decrease in neutrophil accumulation (p = 0.047). Improvements in blood flow and interstitial water were also observed. Moreover, we demonstrated that the therapeutic window for MTR lasts for at least 90 minutes following reperfusion. This study confirms our previous observations that MTR is an effective therapeutic approach to reducing reperfusion injury with a clinically useful treatment window. © 2015 Wiley Periodicals, Inc.

Quantitative Myocardial Perfusion Imaging Versus Visual Analysis in Diagnosing Myocardial Ischemia: A CE-MARC Substudy.

PubMed

Biglands, John D; Ibraheem, Montasir; Magee, Derek R; Radjenovic, Aleksandra; Plein, Sven; Greenwood, John P

2018-05-01

This study sought to compare the diagnostic accuracy of visual and quantitative analyses of myocardial perfusion cardiovascular magnetic resonance against a reference standard of quantitative coronary angiography. Visual analysis of perfusion cardiovascular magnetic resonance studies for assessing myocardial perfusion has been shown to have high diagnostic accuracy for coronary artery disease. However, only a few small studies have assessed the diagnostic accuracy of quantitative myocardial perfusion. This retrospective study included 128 patients randomly selected from the CE-MARC (Clinical Evaluation of Magnetic Resonance Imaging in Coronary Heart Disease) study population such that the distribution of risk factors and disease status was proportionate to the full population. Visual analysis results of cardiovascular magnetic resonance perfusion images, by consensus of 2 expert readers, were taken from the original study reports. Quantitative myocardial blood flow estimates were obtained using Fermi-constrained deconvolution. The reference standard for myocardial ischemia was a quantitative coronary x-ray angiogram stenosis severity of ≥70% diameter in any coronary artery of >2 mm diameter, or ≥50% in the left main stem. Diagnostic performance was calculated using receiver-operating characteristic curve analysis. The area under the curve for visual analysis was 0.88 (95% confidence interval: 0.81 to 0.95) with a sensitivity of 81.0% (95% confidence interval: 69.1% to 92.8%) and specificity of 86.0% (95% confidence interval: 78.7% to 93.4%). For quantitative stress myocardial blood flow the area under the curve was 0.89 (95% confidence interval: 0.83 to 0.96) with a sensitivity of 87.5% (95% confidence interval: 77.3% to 97.7%) and specificity of 84.5% (95% confidence interval: 76.8% to 92.3%). There was no statistically significant difference between the diagnostic performance of quantitative and visual analyses (p = 0.72). Incorporating rest myocardial blood flow values to generate a myocardial perfusion reserve did not significantly increase the quantitative analysis area under the curve (p = 0.79). Quantitative perfusion has a high diagnostic accuracy for detecting coronary artery disease but is not superior to visual analysis. The incorporation of rest perfusion imaging does not improve diagnostic accuracy in quantitative perfusion analysis. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Myocardial Tissue Characterization by Magnetic Resonance Imaging

PubMed Central

Ferreira, Vanessa M.; Piechnik, Stefan K.; Robson, Matthew D.; Neubauer, Stefan

2014-01-01

Cardiac magnetic resonance (CMR) imaging is a well-established noninvasive imaging modality in clinical cardiology. Its unsurpassed accuracy in defining cardiac morphology and function and its ability to provide tissue characterization make it well suited for the study of patients with cardiac diseases. Late gadolinium enhancement was a major advancement in the development of tissue characterization techniques, allowing the unique ability of CMR to differentiate ischemic heart disease from nonischemic cardiomyopathies. Using T2-weighted techniques, areas of edema and inflammation can be identified in the myocardium. A new generation of myocardial mapping techniques are emerging, enabling direct quantitative assessment of myocardial tissue properties in absolute terms. This review will summarize recent developments involving T1-mapping and T2-mapping techniques and focus on the clinical applications and future potential of these evolving CMR methodologies. PMID:24576837

Impact of impaired coronary flow reserve and insulin resistance on myocardial energy metabolism in patients with syndrome X.

PubMed

Bøtker, H E; Sonne, H S; Bagger, J P; Nielsen, T T

1997-06-15

To evaluate the role of a decreased coronary flow reserve in the genesis of angina pectoris in patients with syndrome X, we studied myocardial hemodynamics and metabolism at rest, during pace stress, and in the recovery period after pacing in 18 consecutive patients with syndrome X and in 10 control subjects. By means of positron emission tomography or the intracoronary flow-wire method, patients were subclassified as having microvascular angina (MA, n = 8) when coronary flow reserve was reduced (<2.5) or no microvascular angina (non-MA, n = 10) when coronary flow reserve was preserved (> or =2.5). At rest, coronary sinus blood flow was increased in MA patients. During pace stress, coronary sinus blood flow increased by 39 +/- 6% in MA patients versus 67 +/- 12% in non-MA patients and 69 +/- 7% in controls (p <0.05). Patients with non-MA revealed fasting hyperinsulinemia, increased arterial concentration of free fatty acids, and a similar tendency for beta-hydroxybutyrate. Oxygen extraction and carbon dioxide release did not differ between groups. Net myocardial lactate release was not observed in any patient during pace stress and myocardial energy metabolism was preserved in all patients with syndrome X. During pacing, myocardial uptake of free fatty acids and beta-hydroxybutyrate was increased in non-MA patients. Myocardial uptake of free fatty acids correlated positively and myocardial glucose and lactate uptake correlated inversely with arterial concentrations of free fatty acids in all subjects. Metabolic evidence of myocardial ischemia is uncommon in patients with syndrome X, irrespective of a globally reduced coronary flow reserve. Although patients with syndrome X can be subclassified according to presence of a microvascular or a metabolic disorder, angina pectoris and ST-segment depressions coexist with a preserved global myocardial energy efficiency in all patients.

Blood pressure targets for the treatment of people with hypertension and cardiovascular disease.

PubMed

Saiz, Luis Carlos; Gorricho, Javier; Garjón, Javier; Celaya, Mª Concepción; Muruzábal, Lourdes; Malón, Mª Del Mar; Montoya, Rodolfo; López, Antonio

2017-10-11

Hypertension is a prominent preventable cause of premature morbidity and mortality. People with hypertension and established cardiovascular disease are at particularly high risk, so reducing blood pressure below standard targets may be beneficial. This strategy could reduce cardiovascular mortality and morbidity but could also increase adverse events. The optimal blood pressure target in people with hypertension and established cardiovascular disease remains unknown. To determine if 'lower' blood pressure targets (≤ 135/85 mmHg) are associated with reduction in mortality and morbidity as compared with 'standard' blood pressure targets (≤ 140 to 160/ 90 to 100 mmHg) in the treatment of people with hypertension and a history of cardiovascular disease (myocardial infarction, angina, stroke, peripheral vascular occlusive disease). The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials up to February 2017: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We also searched the Latin American and Caribbean Health Science Literature Database (from 1982) and contacted authors of relevant papers regarding further published and unpublished work. There were no language restrictions. We included randomized controlled trials (RCTs) with more than 50 participants per group and at least six months follow-up. Trial reports needed to present data for at least one primary outcome (total mortality, serious adverse events, total cardiovascular events, cardiovascular mortality). Eligible interventions were lower target for systolic/diastolic blood pressure (≤ 135/85 mmHg) compared with standard target for blood pressure (≤ 140 to 160/90 to 100 mmHg).Participants were adults with documented hypertension or who were receiving treatment for hypertension and cardiovascular history for myocardial infarction, stroke, chronic peripheral vascular occlusive disease or angina pectoris. Two review authors independently assessed search results and extracted data using standard methodological procedures expected by The Cochrane Collaboration. We included six RCTs that involved a total of 9795 participants. Mean follow-up was 3.7 years (range 1.0 to 4.7 years). Five RCTs provided individual patient data for 6775 participants.We found no change in total mortality (RR 1.05, 95% CI 0.90 to 1.22) or cardiovascular mortality (RR 0.96, 95% CI 0.77 to 1.21; moderate-quality evidence). Similarly, no differences were found in serious adverse events (RR 1.02, 95% CI 0.95 to 1.11; low-quality evidence). There was a reduction in fatal and non fatal cardiovascular events (including myocardial infarction, stroke, sudden death, hospitalization or death from congestive heart failure) with the lower target (RR 0.87, 95% CI 0.78 to 0.98; ARR 1.6% over 3.7 years; low-quality evidence). There were more participant withdrawals due to adverse effects in the lower target arm (RR 8.16, 95% CI 2.06 to 32.28; very low-quality evidence). Blood pressures were lower in the lower' target group by 9.5/4.9 mmHg. More drugs were needed in the lower target group but blood pressure targets were achieved more frequently in the standard target group. No evidence of a difference in total mortality and serious adverse events was found between treating to a lower or to a standard blood pressure target in people with hypertension and cardiovascular disease. This suggests no net health benefit from a lower systolic blood pressure target despite the small absolute reduction in total cardiovascular serious adverse events. There was very limited evidence on adverse events, which lead to high uncertainty. At present there is insufficient evidence to justify lower blood pressure targets (≤ 135/85 mmHg) in people with hypertension and established cardiovascular disease. More trials are needed to answer this question.

Impact of rosiglitazone and glyburide on nitrosative stress and myocardial blood flow regulation in type 2 diabetes mellitus.

PubMed

Pop-Busui, Rodica; Oral, Elif; Raffel, David; Byun, Jaeman; Bajirovic, Valida; Vivekanandan-Giri, Anuradha; Kellogg, Aaron; Pennathur, Subramaniam; Stevens, Martin J

2009-07-01

Cardiovascular disease, the leading cause of death in patients with type 2 diabetes mellitus (T2DM), is usually preceded by endothelial dysfunction and altered myocardial blood flow (MBF) regulation. Hyperglycemia, oxidative-nitrosative stress, systemic inflammation, and insulin resistance are implicated in the pathogenesis of abnormal MBF regulation, myocardial ischemia, and apoptosis. However, the impact of oral antihyperglycemic therapy on myocardial perfusion is controversial. Our objective was to explore the effect of rosiglitazone and glyburide on nitrosative stress and MBF regulation in subjects with T2DM. [(13)N]ammonia positron emission tomography and cold pressor testing were used in 27 diabetic subjects (mean age, 49 +/- 11 years; glycohemoglobin, 7% +/- 1.5%) randomized to either rosiglitazone 8 mg/d or glyburide 10 mg/d for 6 months. Isotope dilution gas chromatography-mass spectrometry was used to quantify plasma 3-nitrotyrosine, a stable marker of reactive nitrogen species. At 6 months, there were no significant differences between groups in the mean glycohemoglobin, blood pressure, or plasma lipids. Rosiglitazone significantly reduced plasma nitrotyrosine, high-sensitivity C-reactive protein, and von Willebrand antigen (P < .03 for all) and significantly increased plasma adiponectin (P < .05). No significant changes in these parameters were observed with glyburide. Treatment with glyburide, but not rosiglitazone, resulted in a significant deterioration in both resting and stress MBF. Rosiglitazone, but not glyburide, ameliorated markers of nitrosative stress and inflammation in subjects with T2DM without impairing myocardial perfusion.

Cobalt Chloride Upregulates Impaired HIF-1α Expression to Restore Sevoflurane Post-conditioning-Dependent Myocardial Protection in Diabetic Rats

PubMed Central

Wu, Jianjiang; Yang, Long; Xie, Peng; Yu, Jin; Yu, Tian; Wang, Haiying; Maimaitili, Yiliyaer; Wang, Jiang; Ma, Haiping; Yang, Yining; Zheng, Hong

2017-01-01

Previous studies from our group have demonstrated that sevoflurane post-conditioning (SPC) protects against myocardial ischemia reperfusion injury via elevating the intranuclear expression of hypoxia inducible factor-1 alpha (HIF-1α). However, diabetic SPC is associated with decreased myocardial protection and disruption of the HIF-1 signaling pathway. Previous studies have demonstrated that cobalt chloride (CoCl2) can upregulate HIF-1α expression under diabetic conditions, but whether myocardial protection by SPC can be restored afterward remains unclear. We established a rat model of type 2 diabetes and a Langendorff isolated heart model of ischemia-reperfusion injury. Prior to reperfusion, 2.4% sevoflurane was used as a post-conditioning treatment. The diabetic rats were treated with CoCl2 24 h before the experiment. At the end of reperfusion, tests were performed to assess myocardial function, infarct size, mitochondrial morphology, nitric oxide (NO), Mitochondrial reactive oxygen species (ROS), mitochondrial respiratory function and enzyme activity, HIF-1α, vascular endothelial growth factor (VEGF) and endothelial NO synthase (eNOS) protein levels. In addition, myocardial protection by SPC was monitored after the blood glucose levels were lowered by insulin. The diabetic state was associated with deficient SPC protection and decreased HIF-1α expression. After treating the diabetic rats with CoCl2, SPC significantly upregulated the expression of HIF-1α, VEGF and eNOS, which markedly improved cardiac function, NO, mitochondrial respiratory function, and enzyme activity and decreased the infarction areas and ROS. In addition, these effects were not influenced by blood glucose levels. This study proved that CoCl2activates the HIF-1α signaling pathway, which restores SPC-dependent myocardial protection under diabetic conditions, and the protective effects of SPC were independent of blood glucose levels. PMID:28659817

Prevalence and hemodynamic effects of leaning during CPR

PubMed Central

Niles, Dana E.; Sutton, Robert M.; Nadkarni, Vinay M.; Glatz, Andrew; Zuercher, Mathias; Maltese, Matthew R.; Eilevstjønn, Joar; Abella, Benjamin S.; Becker, Lance B.; Berg, Robert A.

2013-01-01

Background Cardiopulmonary resuscitation (CPR) guidelines recommend complete release between chest compressions (CC). Objective Evaluate the hemodynamic effects of leaning (incomplete chest wall release) during CPR and the prevalence of leaning during CPR. Results In piglet ventricular fibrillation cardiac arrests, 10% and 20% (1.8 kg and 3.6 kg, respectively), leaning during CPR increased right atrial pressures, decreased coronary perfusion pressures, and decreased cardiac index and left ventricular myocardial blood flow by nearly 50%. In contrast, residual leaning of a 260 g accelerometer/ force feedback device did not adversely affect cardiac index or myocardial blood flow. Among 108 adult in-hospital CPR events, leaning ≥2.5 kg was demonstrable in 91% of the events and 12% of the evaluated CC. For 12 children with in-hospital CPR, 28% of CC had residual leaning ≥2.5 kg and 89% had residual leaning ≥0.5 kg. Conclusions Leaning during CPR increases intrathoracic pressure, decreases coronary perfusion pressure, and decreases cardiac output and myocardial blood flow. Leaning is common during CPR. PMID:22208173

Wide-field absolute transverse blood flow velocity mapping in vessel centerline

NASA Astrophysics Data System (ADS)

Wu, Nanshou; Wang, Lei; Zhu, Bifeng; Guan, Caizhong; Wang, Mingyi; Han, Dingan; Tan, Haishu; Zeng, Yaguang

2018-02-01

We propose a wide-field absolute transverse blood flow velocity measurement method in vessel centerline based on absorption intensity fluctuation modulation effect. The difference between the light absorption capacities of red blood cells and background tissue under low-coherence illumination is utilized to realize the instantaneous and average wide-field optical angiography images. The absolute fuzzy connection algorithm is used for vessel centerline extraction from the average wide-field optical angiography. The absolute transverse velocity in the vessel centerline is then measured by a cross-correlation analysis according to instantaneous modulation depth signal. The proposed method promises to contribute to the treatment of diseases, such as those related to anemia or thrombosis.

[Effects of Chinese herbal compound for supplementing qi and activating blood circulation on actin, Cx43 expressions and gap junctional intercellular communication functions of myocardial cells in patients with Coxsackie virus B 3 viral myocarditis].

PubMed

Zhang, Ming-xue; He, Wei; Gu, Ping

2010-08-01

To observe the effect of Chinese herbal compound for supplementing qi and activating blood circulation (CHC) on the gap junctional intercellular communication (GJIC) function of myocardial cells in patients with Coxsackie virus B 3 (CVB3) viral myocarditis. Expressions of actin and connexin43 (Cx43) in myocardial cells of patients arranged in three groups (the normal control group, the viral infected group and the CHC treated group) were detected by immunohistochemical method; the fluorescence photobleaching recovery rate of cells was detected by laser scanning confocal microscope. As compared with the viral infected group, the expressions of actin and Cx43 were increased and the GJIC function was improved in the CHC treated group. CHC could antagonize viral injury on skeleton protein, and repair the structure of gap junction channel to improve the GJIC function of myocardial cells after being attacked by CVB3.

PET measurements of myocardial blood flow post myocardial infarction: Relationship to invasive and cardiac magnetic resonance studies and potential clinical applications.

PubMed

Gewirtz, Henry

2017-12-01

This review focuses on clinical studies concerning assessment of coronary microvascular and conduit vessel function primarily in the context of acute and sub acute myocardial infarction (MI). The ability of quantitative PET measurements of myocardial blood flow (MBF) to delineate underlying pathophysiology and assist in clinical decision making in this setting is discussed. Likewise, considered are physiological metrics fractional flow reserve, coronary flow reserve, index of microvascular resistance (FFR, CFR, IMR) obtained from invasive studies performed in the cardiac catheterization laboratory, typically at the time of PCI for MI. The role both of invasive studies and cardiac magnetic resonance (CMR) imaging in assessing microvascular function, a key determinant of prognosis, is reviewed. The interface between quantitative PET MBF measurements and underlying pathophysiology, as demonstrated both by invasive and CMR methodology, is discussed in the context of optimal interpretation of the quantitative PET MBF exam and its potential clinical applications.

Imaging of myocardial infarction in dogs and humans using monoclonal antibodies specific for human myosin heavy chains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leger, J.; Chevalier, J.; Larue, C.

1991-08-01

The use of three different monoclonal antibodies specific for human ventricular myosin heavy chains in the visualization of the location and extent of necrosis in dogs with experimental acute myocardial infarction and in humans is described. Using a classic immunohistochemical method or ex vivo analysis of heart slices in dogs with acute myocardial infarction subjected to intravenous injection of unlabeled antimyosin antibodies or antimyosin antibodies labeled with indium-111, it was observed that all antibody fragments specifically reached the targeted necrotic zone less than 2 h after antibody injection and remained bound for up to 24 h. In a limited butmore » significant number of cases (5 of the 12 humans and 11 of 43 dogs), it was possible to image the necrotic zone in vivo as early as 2 to 4 h after antibody injection. In other cases, individual blood clearance variations retarded or even prevented in vivo necrosis detection. Higher antimyosin fixation values were obtained in the necrotic zones in dogs with a rapid blood clearance relative to that of the other dogs. It is concluded that antimyosin antibodies always reached necrotic areas within 2 h. If blood clearance was rapid, in vivo imaging of the necrotic area was possible 2 to 6 h after necrosis, even in humans. In some cases, however, uncontrolled individual variations in the timing required for sufficient blood clearance hampered this rapid in vivo detection of myocardial necrosis.« less

Social Support Versus Social Evaluation: Unique Effects on Vascular and Myocardial Response Patterns

PubMed Central

Christian, Lisa M.; Stoney, Catherine M.

2010-01-01

Objectives This study examined the effects of companion presence and evaluation on cardiovascular reactivity to an acute stressor. Methods Eighty-two women completed a speech task in one of four conditions: with an evaluative companion present, with a nonevaluative companion present, alone while being evaluated by a companion with a video camera, or alone while the companion waited outside. Results A significant interaction between companion condition and evaluative condition on systolic blood pressure was found; women who were evaluated while alone demonstrated significantly greater reactivity than did women who were in the nonevaluative alone condition. Furthermore, both potential for evaluation and the presence of a companion had important influences on hemodynamic parameters underlying the blood pressure response. Specifically, those in evaluative conditions showed greater myocardial responding than those in nonevaluative conditions and those in alone conditions showed greater vascular responding than did those with companions present. Taken together, those in the evaluative alone condition demonstrated systolic blood pressure responses reflecting both myocardial and vascular contributions. Conclusions Social support and social evaluation have unique effects on vascular and myocardial responding. The implications for future research include focus on the stress-buffering model of social support and the value of including impedance cardiography measures in investigations of cardiovascular functioning. PMID:17079702

Volumetric vessel reconstruction method for absolute blood flow velocity measurement in Doppler OCT images

NASA Astrophysics Data System (ADS)

Qi, Li; Zhu, Jiang; Hancock, Aneeka M.; Dai, Cuixia; Zhang, Xuping; Frostig, Ron D.; Chen, Zhongping

2017-02-01

Doppler optical coherence tomography (DOCT) is considered one of the most promising functional imaging modalities for neuro biology research and has demonstrated the ability to quantify cerebral blood flow velocity at a high accuracy. However, the measurement of total absolute blood flow velocity (BFV) of major cerebral arteries is still a difficult problem since it not only relates to the properties of the laser and the scattering particles, but also relates to the geometry of both directions of the laser beam and the flow. In this paper, focusing on the analysis of cerebral hemodynamics, we presents a method to quantify the total absolute blood flow velocity in middle cerebral artery (MCA) based on volumetric vessel reconstruction from pure DOCT images. A modified region growing segmentation method is first used to localize the MCA on successive DOCT B-scan images. Vessel skeletonization, followed by an averaging gradient angle calculation method, is then carried out to obtain Doppler angles along the entire MCA. Once the Doppler angles are determined, the absolute blood flow velocity of each position on the MCA is easily found. Given a seed point position on the MCA, our approach could achieve automatic quantification of the fully distributed absolute BFV. Based on experiments conducted using a swept-source optical coherence tomography system, our approach could achieve automatic quantification of the fully distributed absolute BFV across different vessel branches in the rodent brain.

Intermediate coronary revascularization using the Deltastream blood pump: results from an experimental study.

PubMed

Litmathe, J; Hansen, E; Feindt, P; Kurt, M; Boeken, U; Gams, E

2009-01-01

Myocardial revascularization using a complete heart-lung machine may involve many problems, as do complete off-pump attempts. Thus, it was the aim of this study to evaluate the effects of intermediate on-pump/off-pump myocardial revascularization using the miniaturized Deltastream blood pump, on ischemia and hemolysis, in comparison with standard myocardial revascularization. In a group of 8 mini-pigs, combined on-pump/off-pump myocardial revascularization was performed using the Deltastream blood pump as beating-heart support for the on-pump part of the operation (group A). Seven other animals served as controls and underwent standard myocardial revascularization with the same device as integrated pump of a complete heart-lung machine (group B). Blood samples for blood gas metabolism, creatine kinase (CK), troponin I, lactate dehydrogenase (LDH), and hydroxybutyrate dehydrogenase (HBDH) were taken before and after the entire operation. Comparing the baseline values, the increase of CK was more pronounced in group B than in group A (176.4-/+41.2 to 279.7-/+29 U/L vs. 274-/+142.7 to 288.1-/+118.6 U/L, respectively; p=0.0006). Increase of troponin I was significantly higher in group B than in group A (1-/+0.3 to 2.9-/+1 ng/mL vs. 1.1-/+0.9 to 3-/+3.8 ng/mL, respectively; p=0.002). LDH increase was also more pronounced in group B (231.7-/+54.3 to 299.9-/+39.8 U/L vs. 274.9-/+59.7 to 263.8-/+57.9 U/L, respectively; p=0.01). HBDH values increased significantly in group B after the operation (group A: 215.9-/+34.7 to 200-/+39.2 U/L vs. group B: 195.4-/+41.7 to 274.9-/+51.6 U/L; p=0.02). Hemodynamic measures and LDH values under luxation (group A: 1.9-/+0.6 U/L; B: 3.5-/+1 U/L,p=0.001) were also superior in the study group. The current set-up might be superior to conventional extracorporeal circulation and thus be an alternative for high-risk candidates to avoid the adverse events of a complete heart-lung machine, when they are scheduled for complete myocardial revascularization.

A Prospective International Multicentre Cohort Study of Intraoperative Heart Rate and Systolic Blood Pressure and Myocardial Injury After Noncardiac Surgery: Results of the VISION Study

PubMed Central

Abbott, Tom E. F.; Pearse, Rupert M.; Archbold, R. Andrew; Ahmad, Tahania; Niebrzegowska, Edyta; Wragg, Andrew; Rodseth, Reitze N.; Devereaux, Philip J.

2018-01-01

BACKGROUND: The association between intraoperative cardiovascular changes and perioperative myocardial injury has chiefly focused on hypotension during noncardiac surgery. However, the relative influence of blood pressure and heart rate (HR) remains unclear. We investigated both individual and codependent relationships among intraoperative HR, systolic blood pressure (SBP), and myocardial injury after noncardiac surgery (MINS). METHODS: Secondary analysis of the Vascular Events in Noncardiac Surgery Cohort Evaluation (VISION) study, a prospective international cohort study of noncardiac surgical patients. Multivariable logistic regression analysis tested for associations between intraoperative HR and/or SBP and MINS, defined by an elevated serum troponin T adjudicated as due to an ischemic etiology, within 30 days after surgery. Predefined thresholds for intraoperative HR and SBP were: maximum HR >100 beats or minimum HR <55 beats per minute (bpm); maximum SBP >160 mm Hg or minimum SBP <100 mm Hg. Secondary outcomes were myocardial infarction and mortality within 30 days after surgery. RESULTS: After excluding missing data, 1197 of 15,109 patients (7.9%) sustained MINS, 454 of 16,031 (2.8%) sustained myocardial infarction, and 315 of 16,061 patients (2.0%) died within 30 days after surgery. Maximum intraoperative HR >100 bpm was associated with MINS (odds ratio [OR], 1.27 [1.07–1.50]; P < .01), myocardial infarction (OR, 1.34 [1.05–1.70]; P = .02), and mortality (OR, 2.65 [2.06–3.41]; P < .01). Minimum SBP <100 mm Hg was associated with MINS (OR, 1.21 [1.05–1.39]; P = .01) and mortality (OR, 1.81 [1.39–2.37]; P < .01), but not myocardial infarction (OR, 1.21 [0.98–1.49]; P = .07). Maximum SBP >160 mm Hg was associated with MINS (OR, 1.16 [1.01–1.34]; P = .04) and myocardial infarction (OR, 1.34 [1.09–1.64]; P = .01) but, paradoxically, reduced mortality (OR, 0.76 [0.58–0.99]; P = .04). Minimum HR <55 bpm was associated with reduced MINS (OR, 0.70 [0.59–0.82]; P < .01), myocardial infarction (OR, 0.75 [0.58–0.97]; P = .03), and mortality (OR, 0.58 [0.41–0.81]; P < .01). Minimum SBP <100 mm Hg with maximum HR >100 bpm was more strongly associated with MINS (OR, 1.42 [1.15–1.76]; P < .01) compared with minimum SBP <100 mm Hg alone (OR, 1.20 [1.03–1.40]; P = .02). CONCLUSIONS: Intraoperative tachycardia and hypotension are associated with MINS. Further interventional research targeting HR/blood pressure is needed to define the optimum strategy to reduce MINS. PMID:29077608

Usefulness of myocardial parametric imaging to evaluate myocardial viability in experimental and in clinical studies

PubMed Central

Korosoglou, G; Hansen, A; Bekeredjian, R; Filusch, A; Hardt, S; Wolf, D; Schellberg, D; Katus, H A; Kuecherer, H

2006-01-01

Objective To evaluate whether myocardial parametric imaging (MPI) is superior to visual assessment for the evaluation of myocardial viability. Methods and results Myocardial contrast echocardiography (MCE) was assessed in 11 pigs before, during, and after left anterior descending coronary artery occlusion and in 32 patients with ischaemic heart disease by using intravenous SonoVue administration. In experimental studies perfusion defect area assessment by MPI was compared with visually guided perfusion defect planimetry. Histological assessment of necrotic tissue was the standard reference. In clinical studies viability was assessed on a segmental level by (1) visual analysis of myocardial opacification; (2) quantitative estimation of myocardial blood flow in regions of interest; and (3) MPI. Functional recovery between three and six months after revascularisation was the standard reference. In experimental studies, compared with visually guided perfusion defect planimetry, planimetric assessment of infarct size by MPI correlated more significantly with histology (r2  =  0.92 versus r2  =  0.56) and had a lower intraobserver variability (4% v 15%, p < 0.05). In clinical studies, MPI had higher specificity (66% v 43%, p < 0.05) than visual MCE and good accuracy (81%) for viability detection. It was less time consuming (3.4 (1.6) v 9.2 (2.4) minutes per image, p < 0.05) than quantitative blood flow estimation by regions of interest and increased the agreement between observers interpreting myocardial perfusion (κ  =  0.87 v κ  =  0.75, p < 0.05). Conclusion MPI is useful for the evaluation of myocardial viability both in animals and in patients. It is less time consuming than quantification analysis by regions of interest and less observer dependent than visual analysis. Thus, strategies incorporating this technique may be valuable for the evaluation of myocardial viability in clinical routine. PMID:15939722

The influence of short-term endurance training on the insulin blood level, binding, and degradation of 125I-insulin by erythrocyte receptors in patients after myocardial infarction.

PubMed

Dylewicz, P; Przywarska, I; Szcześniak, L; Rychlewski, T; Bieńkowska, S; Długiewicz, I; Wilk, M

1999-01-01

This study was directed toward establishing whether and to what extent, short-term endurance training influences the insulin blood level, and the binding and degradation of 125I-insulin by erythrocyte receptors in patients undergoing rehabilitation after myocardial infarction. The study was conducted in a group of 60 patients who had had myocardial infarction within the past 1.5 to 3 months and who did not have arterial hypertension and diabetes mellitus. All the patients took a symptom-limited cardiopulmonary exercise test. Before and after the test, venous blood was collected to determine lactic acid and insulin blood levels as well as the binding and degradation of 125I-insulin. The study group was randomized into two subgroups. One subgroup entered into a 3-week in-patient rehabilitation course. The control group was discharged from the hospital and was given no recommendations for physical exercise. The same investigation was repeated 3 weeks later. In the patients (50%) with hyperinsulinemia (insulin resistance index, > 10 microIU/mL), which was detected during the first investigation, insulin blood level decreased from 23.9 +/- 4.4 to 15.0 +/- 1.9 microIU/mL (P < 0.05) after rehabilitation, whereas insulin binding increased from 0.67 +/- 0.05 to 0.85 +/- 0.08 pg 125I/10(11) erythrocytes (P < 0.05). In the control group, which included normal subjects and those with hyperinsulinemia, the results obtained during the first and second investigations showed no statistically significant changes when compared. The results suggest that a 3-week endurance training period during rehabilitation after myocardial infarction reduces insulin resistance in patients with hyperinsulinemia.

Acute myocardial infarction associated with blood transfusion: case report and literature review.

PubMed

Velibey, Yalcin; Erbay, Aliriza; Ozkurt, Enver; Usta, Emrah; Akin, Filiz

2014-04-01

A 62-year old patient with a history of chronic anemia associated with malabsorption secondary to short gut syndrome, experienced acute chest pain the second hour after the transfusion of a crossmatch-compatible erythrocyte suspension. His electrocardiogram (ECG) revealed widespread ST-segment depressions and he had an elevated troponin level. Laboratory findings and physical examination did not indicate the presence of immunological or non-immunological blood transfusion reactions. Cardiac catheterization was performed and showed angiographically non-obstructive, atherosclerotic plaques and the absence of vasospasm or thrombus formation. Following antiischemic therapy his symptoms resolved completely. The ECG obtained 24 hours after the emergence of chest pain demonstrated normal sinus rhythm with no ST-T wave changes. We present a rare case of acute myocardial infarction induced following a blood transfusion. To the best of our knowledge, a few cases of acute myocardial infarction associated with blood transfusion have been formally recorded in the medical literature and the clinical experience regarding such cases is indeed quite limited. The present case is reviewed in the context of the relevant literature as a practical resource for clinical practice. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

[Changes of monocyte and monocyte-platelet aggregates in different subgroups of thrombotic events in patients with acute myocardial infarction during PCI].

PubMed

Wang, Sheng; Sun, Cuifang; Liao, Wang; Wu, Zhongwei; Wang, Yudai; Huang, Xiuxian; Lu, Sijia; Dong, Xiaoli; Shuai, Fujie; Li, Bin

2017-07-01

Objective To investigate the impact of thrombotic events on the alterations of monocyte and monocyte-platelet aggregates (MPAs) in patients with acute myocardial infarction (AMI) during percutaneous coronary intervention (PCI). Methods Blood was collected before PCI for flow cytometry. Monocyte subsets and MPAs were detected by four-color platform (CDl4-APC, CDl6-PE-Cy7, CD86-PE and CD41-Alexa Fluor R 488). According to the expression of the platelet surface marker CD41, the number of monocyte subsets and MPAs was analyzed using the fluorescent microspheres of absolute counting tube. The Wilcoxon rank sum test and receiver operating characteristic (ROC) curve analysis were performed. Results CD14 + CD16 ++ monocytes in intraprocedural thrombotic events (IPTE) group were significantly fewer than those in non-IPTE group, and the percentage in total mononuclear cells decreased. Compared with non-IPTE group, MPA binding ratio and monocyte subset MPA binding ratio were significantly higher in IPTE group. ROC analysis showed that MPA binding ratio and subgroup MPA binding ratio had a better predictive value for IPTE in patients with AMI. Conclusion The CD14 + CD16 ++ monocytes in IPTE group were significantly fewer than those in the non-IPTE group. MPA binding ratio and MPA binding ratio of monocyte subsets were significantly higher in the IPTE group than in the non-IPTE group, so they have a good predictive value for IPTE in patients with AMI.

Optimally Repeatable Kinetic Model Variant for Myocardial Blood Flow Measurements with 82Rb PET.

PubMed

Ocneanu, Adrian F; deKemp, Robert A; Renaud, Jennifer M; Adler, Andy; Beanlands, Rob S B; Klein, Ran

2017-01-01

Purpose. Myocardial blood flow (MBF) quantification with 82 Rb positron emission tomography (PET) is gaining clinical adoption, but improvements in precision are desired. This study aims to identify analysis variants producing the most repeatable MBF measures. Methods. 12 volunteers underwent same-day test-retest rest and dipyridamole stress imaging with dynamic 82 Rb PET, from which MBF was quantified using 1-tissue-compartment kinetic model variants: (1) blood-pool versus uptake region sampled input function (Blood/Uptake-ROI), (2) dual spillover correction (SOC-On/Off), (3) right blood correction (RBC-On/Off), (4) arterial blood transit delay (Delay-On/Off), and (5) distribution volume (DV) constraint (Global/Regional-DV). Repeatability of MBF, stress/rest myocardial flow reserve (MFR), and stress/rest MBF difference (ΔMBF) was assessed using nonparametric reproducibility coefficients (RPC np = 1.45 × interquartile range). Results. MBF using SOC-On, RVBC-Off, Blood-ROI, Global-DV, and Delay-Off was most repeatable for combined rest and stress: RPC np = 0.21 mL/min/g (15.8%). Corresponding MFR and ΔMBF RPC np were 0.42 (20.2%) and 0.24 mL/min/g (23.5%). MBF repeatability improved with SOC-On at stress ( p < 0.001) and tended to improve with RBC-Off at both rest and stress ( p < 0.08). DV and ROI did not significantly influence repeatability. The Delay-On model was overdetermined and did not reliably converge. Conclusion. MBF and MFR test-retest repeatability were the best with dual spillover correction, left atrium blood input function, and global DV.

Losartan treatment attenuates tumor-induced myocardial dysfunction

PubMed Central

Stevens, Sarah CW; Velten, Markus; Youtz, Dane J.; Clark, Yvonne; Jing, Runfeng; Reiser, Peter J.; Bicer, Sabahattin; Devine, Raymond; McCarthy, Donna O.; Wold, Loren E.

2015-01-01

Fatigue and muscle wasting are common symptoms experienced by cancer patients. Data from animal models demonstrate that angiotensin is involved in tumor-induced muscle wasting, and that tumor growth can independently affect myocardial function, which could contribute to fatigue in cancer patients. In clinical studies, inhibitors of angiotensin converting enzyme (ACE) can prevent the development of chemotherapy-induced cardiovascular dysfunction, suggesting a mechanistic role for the renin-angiotensin-aldosterone system (RAAS). In the present study, we investigated whether an angiotensin (AT)1-receptor antagonist could prevent the development of tumor-associated myocardial dysfunction. Methods and Results: Colon26 adenocarcinoma (c26) cells were implanted into female CD2F1 mice at 8 weeks of age. Simultaneously, mice were administered Losartan (10 mg/kg) daily via their drinking water. In vivo echocardiography, blood pressure, in vitro cardiomyocyte function, cell proliferation assays, and measures of systemic inflammation and myocardial protein degradation were performed 19 days following tumor cell injection. Losartan treatment prevented tumor-induced loss of muscle mass and in vitro c26 cell proliferation, decreased tumor weight, and attenuated myocardial expression of interleukin-6. Furthermore, Losartan treatment mitigated tumor-associated alterations in calcium signaling in cardiomyocytes, which was associated with improved myocyte contraction velocity, systolic function, and blood pressures in the hearts of tumor-bearing mice. Conclusions: These data suggest that Losartan may mitigate tumor-induced myocardial dysfunction and inflammation. PMID:25988231

Losartan treatment attenuates tumor-induced myocardial dysfunction.

PubMed

Stevens, Sarah C W; Velten, Markus; Youtz, Dane J; Clark, Yvonne; Jing, Runfeng; Reiser, Peter J; Bicer, Sabahattin; Devine, Raymond D; McCarthy, Donna O; Wold, Loren E

2015-08-01

Fatigue and muscle wasting are common symptoms experienced by cancer patients. Data from animal models demonstrate that angiotensin is involved in tumor-induced muscle wasting, and that tumor growth can independently affect myocardial function, which could contribute to fatigue in cancer patients. In clinical studies, inhibitors of angiotensin converting enzyme (ACE) can prevent the development of chemotherapy-induced cardiovascular dysfunction, suggesting a mechanistic role for the renin-angiotensin-aldosterone system (RAAS). In the present study, we investigated whether an angiotensin (AT) 1-receptor antagonist could prevent the development of tumor-associated myocardial dysfunction. Colon26 adenocarcinoma (c26) cells were implanted into female CD2F1 mice at 8weeks of age. Simultaneously, mice were administered Losartan (10mg/kg) daily via their drinking water. In vivo echocardiography, blood pressure, in vitro cardiomyocyte function, cell proliferation assays, and measures of systemic inflammation and myocardial protein degradation were performed 19days following tumor cell injection. Losartan treatment prevented tumor-induced loss of muscle mass and in vitro c26 cell proliferation, decreased tumor weight, and attenuated myocardial expression of interleukin-6. Furthermore, Losartan treatment mitigated tumor-associated alterations in calcium signaling in cardiomyocytes, which was associated with improved myocyte contraction velocity, systolic function, and blood pressures in the hearts of tumor-bearing mice. These data suggest that Losartan may mitigate tumor-induced myocardial dysfunction and inflammation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Myocardial Blood Flow and Inflammatory Cardiac Sarcoidosis.

PubMed

Kruse, Matthew J; Kovell, Lara; Kasper, Edward K; Pomper, Martin G; Moller, David R; Solnes, Lilja; Chen, Edward S; Schindler, Thomas H

2017-02-01

This study sought to evaluate the effects of inflammatory sarcoid disease on coronary circulatory function and the response to immune-suppressive treatment. Although positron emission tomography assessment of myocardial inflammation is increasingly applied to identify active cardiac sarcoidosis, its effect on coronary flow and immune-suppressive treatment remains to be characterized. Thirty-two individuals, who were referred for positron emission tomography/computed tomography, were evaluated for known or suspected cardiac sarcoidosis applying 18 F-fluorodeoxyglucose to determine inflammation and 13 N-ammonia to assess for perfusion deficits following a high-fat/low-carbohydrate diet and fasting state >12 h to suppress myocardial glucose uptake. Inflammation was quantified with standardized uptake value and regional myocardial blood flow at rest and during regadenoson-stimulated hyperemia was determined in ml/g/min. Positron emission tomography studies were repeated in 18 cases with a median follow-up of 2.5 years (interquartile range [IQR]:1.3 to 3.4 years). Twenty-five exams had normal perfusion but evidence of regional inflammation (group 1), and 21 exams presented a regional perfusion deficit associated with inflammation (group 2). Median myocardial blood flow did not differ between inflamed and noninflamed myocardium in both groups (0.86 ml/g/min [IQR: 0.66 to 1.11 ml/g/min] vs. 0.83 ml/g/min [IQR: 0.64 to 1.12 ml/g/min] and 0.74 ml/g/min [IQR: 0.60 to 0.93 ml/g/min] vs. 0.77 ml/g/min [IQR: 0.59 to 0.95 ml/g/min], respectively). As regards median hyperemic myocardial blood flows, they were significantly lower in the inflamed than in the remote regions in group 1 and 2 (2.31 ml/g/min [IQR: 1.81 to 2.95 ml/g/min] vs. 2.70 ml/g/min [IQR: 2.07 to 3.30 ml/g/min] and 1.61 ml/g/min [IQR: 1.17 to 2.18 ml/g/min] vs. 1.94 ml/g/min [IQR: 1.49 to 2.39 ml/g/min]; p < 0.001, respectively). Immune-suppression-mediated decrease in inflammation was associated with preserved myocardial flow reserve (MFR) at follow-up, whereas MFR significantly worsened in regions without changes or even increases in inflammation (median ΔMFR: 0.07 [IQR: -0.29 to 0.45] vs. -0.24 [IQR: -0.84 to 0.21]; p < 0.001). There was an inverse correlation between pronounced alterations in myocardial inflammation (Δ regional myocardial volume with standardized uptake value >4.1) and ΔMFR (r = -0.47; p = 0.048). Sarcoid-mediated myocardial inflammation is associated with a regional impairment of coronary circulatory function. The association between immune-suppressive treatment-related alterations in myocardial inflammation and changes in coronary vasodilator capacity suggests direct adverse effect of inflammation on coronary circulatory function in cardiac sarcoidosis. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Peripheral inflammatory biomarkers for myocardial infarction risk: a prospective community-based study

USDA-ARS?s Scientific Manuscript database

BACKGROUND: Most previous studies regarding chronic inflammation and risk of myocardial infarction (MI) have lacked repeated measures of high-sensitivity C-reactive protein (hs-CRP) and/or white blood cell (WBC) count over time. We examined whether cumulative average and longitudinal changes in thes...

Dynamic CT myocardial perfusion imaging: performance of 3D semi-automated evaluation software.

PubMed

Ebersberger, Ullrich; Marcus, Roy P; Schoepf, U Joseph; Lo, Gladys G; Wang, Yining; Blanke, Philipp; Geyer, Lucas L; Gray, J Cranston; McQuiston, Andrew D; Cho, Young Jun; Scheuering, Michael; Canstein, Christian; Nikolaou, Konstantin; Hoffmann, Ellen; Bamberg, Fabian

2014-01-01

To evaluate the performance of three-dimensional semi-automated evaluation software for the assessment of myocardial blood flow (MBF) and blood volume (MBV) at dynamic myocardial perfusion computed tomography (CT). Volume-based software relying on marginal space learning and probabilistic boosting tree-based contour fitting was applied to CT myocardial perfusion imaging data of 37 subjects. In addition, all image data were analysed manually and both approaches were compared with SPECT findings. Study endpoints included time of analysis and conventional measures of diagnostic accuracy. Of 592 analysable segments, 42 showed perfusion defects on SPECT. Average analysis times for the manual and software-based approaches were 49.1 ± 11.2 and 16.5 ± 3.7 min respectively (P < 0.01). There was strong agreement between the two measures of interest (MBF, ICC = 0.91, and MBV, ICC = 0.88, both P < 0.01) and no significant difference in MBF/MBV with respect to diagnostic accuracy between the two approaches for both MBF and MBV for manual versus software-based approach; respectively; all comparisons P > 0.05. Three-dimensional semi-automated evaluation of dynamic myocardial perfusion CT data provides similar measures and diagnostic accuracy to manual evaluation, albeit with substantially reduced analysis times. This capability may aid the integration of this test into clinical workflows. • Myocardial perfusion CT is attractive for comprehensive coronary heart disease assessment. • Traditional image analysis methods are cumbersome and time-consuming. • Automated 3D perfusion software shortens analysis times. • Automated 3D perfusion software increases standardisation of myocardial perfusion CT. • Automated, standardised analysis fosters myocardial perfusion CT integration into clinical practice.

Quantification of Regional Myocardial Oxygenation by Magnetic Resonance Imaging: Validation with Positron Emission Tomography

PubMed Central

McCommis, Kyle S.; Goldstein, Thomas A.; Abendschein, Dana R.; Herrero, Pilar; Misselwitz, Bernd; Gropler, Robert J.; Zheng, Jie

2011-01-01

Background A comprehensive evaluation of myocardial ischemia requires measures of both oxygen supply and demand. Positron emission tomography (PET) is currently the gold standard for such evaluations, but its use is limited due to its ionizing radiation, limited availability, and high cost. A cardiac magnetic resonance imaging (MRI) method was developed for assessing myocardial oxygenation. The purpose of this study was to evaluate and validate this technique compared to PET during pharmacologic stress in a canine model of coronary artery stenosis. Methods and Results Twenty-one beagles and small mongrel dogs without coronary artery stenosis (controls), or with moderate to severe acute coronary artery stenosis underwent MRI and PET imaging at rest and during dipyridamole vasodilation or dobutamine stress to induce a wide range of changes in cardiac perfusion and oxygenation. MRI first-pass perfusion imaging was performed to quantify myocardial blood flow (MBF) and volume (MBV). The MRI blood-oxygen-level-dependent (BOLD) technique was used to determine the myocardial oxygen extraction fraction (OEF) during pharmacologic hyperemia. Myocardial oxygen consumption (MVO2) was determined by Fick’s law. In the same dogs, 15O-water and 11C-acetate were used to measure MBF and MVO2, respectively, by PET. Regional assessments were performed for both MR and PET. MRI data correlated nicely with PET values for MBF (R2 = 0.79, P < 0.001), MVO2 (R2 = 0.74, P < 0.001), and OEF (R2 = 0.66, P < 0.01). Conclusions Cardiac MRI methods may provide an alternative to radionuclide imaging in settings of myocardial ischemia. Our newly developed quantitative MRI oxygenation imaging technique may be a valuable non-invasive tool to directly evaluate myocardial energetics and efficiency. PMID:19933371

Glucose targets for preventing diabetic kidney disease and its progression.

PubMed

Ruospo, Marinella; Saglimbene, Valeria M; Palmer, Suetonia C; De Cosmo, Salvatore; Pacilli, Antonio; Lamacchia, Olga; Cignarelli, Mauro; Fioretto, Paola; Vecchio, Mariacristina; Craig, Jonathan C; Strippoli, Giovanni Fm

2017-06-08

Diabetes is the leading cause of end-stage kidney disease (ESKD) around the world. Blood pressure lowering and glucose control are used to reduce diabetes-associated disability including kidney failure. However there is a lack of an overall evidence summary of the optimal target range for blood glucose control to prevent kidney failure. To evaluate the benefits and harms of intensive (HbA1c < 7% or fasting glucose levels < 120 mg/dL versus standard glycaemic control (HbA1c ≥ 7% or fasting glucose levels ≥ 120 mg/dL for preventing the onset and progression of kidney disease among adults with diabetes. We searched the Cochrane Kidney and Transplant Specialised Register up to 31 March 2017 through contact with the Information Specialist using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE, and EMBASE; handsearching conference proceedings; and searching the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. Randomised controlled trials evaluating glucose-lowering interventions in which people (aged 14 year or older) with type 1 or 2 diabetes with and without kidney disease were randomly allocated to tight glucose control or less stringent blood glucose targets. Two authors independently assessed studies for eligibility and risks of bias, extracted data and checked the processes for accuracy. Outcomes were mortality, cardiovascular complications, doubling of serum creatinine (SCr), ESKD and proteinuria. Confidence in the evidence was assessing using GRADE. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes. Fourteen studies involving 29,319 people with diabetes were included and 11 studies involving 29,141 people were included in our meta-analyses. Treatment duration was 56.7 months on average (range 6 months to 10 years). Studies included people with a range of kidney function. Incomplete reporting of key methodological details resulted in uncertain risks of bias in many studies. Using GRADE assessment, we had moderate confidence in the effects of glucose lowering strategies on ESKD, all-cause mortality, myocardial infarction, and progressive protein leakage by kidney disease and low or very low confidence in effects of treatment on death related to cardiovascular complications and doubling of serum creatinine (SCr).For the primary outcomes, tight glycaemic control may make little or no difference to doubling of SCr compared with standard control (4 studies, 26,874 participants: RR 0.84, 95% CI 0.64 to 1.11; I 2 = 73%, low certainty evidence), development of ESKD (4 studies, 23,332 participants: RR 0.62, 95% CI 0.34 to 1.12; I 2 = 52%; low certainty evidence), all-cause mortality (9 studies, 29,094 participants: RR 0.99, 95% CI 0.86 to 1.13; I 2 = 50%; moderate certainty evidence), cardiovascular mortality (6 studies, 23,673 participants: RR 1.19, 95% CI 0.73 to 1.92; I 2 = 85%; low certainty evidence), or sudden death (4 studies, 5913 participants: RR 0.82, 95% CI 0.26 to 2.57; I 2 = 85%; very low certainty evidence). People who received treatment to achieve tighter glycaemic control probably experienced lower risks of non-fatal myocardial infarction (5 studies, 25,596 participants: RR 0.82, 95% CI 0.67 to 0.99; I 2 = 46%, moderate certainty evidence), onset of microalbuminuria (4 studies, 19,846 participants: RR 0.82, 95% CI 0.71 to 0.93; I 2 = 61%, moderate certainty evidence), and progression of microalbuminuria (5 studies, 13,266 participants: RR 0.59, 95% CI 0.38 to 0.93; I 2 = 75%, moderate certainty evidence). In absolute terms, tight versus standard glucose control treatment in 1,000 adults would lead to between zero and two people avoiding non-fatal myocardial infarction, while seven adults would avoid experiencing new-onset albuminuria and two would avoid worsening albuminuria. This review suggests that people who receive intensive glycaemic control for treatment of diabetes had comparable risks of kidney failure, death and major cardiovascular events as people who received less stringent blood glucose control, while experiencing small clinical benefits on the onset and progression of microalbuminuria and myocardial infarction. The adverse effects of glycaemic management are uncertain. Based on absolute treatment effects, the clinical impact of targeting an HbA1c < 7% or blood glucose < 6.6 mmol/L is unclear and the potential harms of this treatment approach are largely unmeasured.

[Primary prevention of coronary thrombosis by antithrombotic agents].

PubMed

Milon, H; Lantelme, P; Khettab, F; Mestre-Fernandes, C; Lasserre-Remy, S

2001-11-01

At the start of the eighties, in the wake of the good results obtained with aspirin in secondary prevention, two studies were launched aimed at testing the effect of aspirin on the primary prevention of myocardial infarction. The results published in 1988 and 1989 were divergent: the study conducted by British doctors showed no benefit with aspirin, that conducted by American doctors showed a very distinct benefit concerning myocardial infarction but no advantage for cerebral vascular accidents. Besides, in both studies an additional risk of haemorrhagic cerebral vascular accident was described. Methodological reasons were the origin of these facts, but it resulted in a certain confusion as to the practical conduct to adopt. Ten years later it is much more clear after the publication of three supplementary trials. The benefits of aspirin in terms of prevention of myocardial infarction are certain and considerable, at the price of a haemorrhagic risk equally certain but moderate. On the other hand, questions remain concerning the preventive effect of aspirin on cerebral vascular accidents and also on the expected benefits in the female sex. In practice, the prescription of aspirin with the objective of primary prevention must take into account the absolute benefit which can be expected. This is a function of the individual absolute risk before treatment which therefore signifies an evaluation based on the risk factors. Only subjects exposed to a substantial risk before treatment are likely to benefit from aspirin. For the others, the risks linked with aspirin could counterbalance its preventive advantages.

Noninvasive image derived heart input function for CMRglc measurements in small animal slow infusion FDG PET studies

NASA Astrophysics Data System (ADS)

Xiong, Guoming; Cumming, Paul; Todica, Andrei; Hacker, Marcus; Bartenstein, Peter; Böning, Guido

2012-12-01

Absolute quantitation of the cerebral metabolic rate for glucose (CMRglc) can be obtained in positron emission tomography (PET) studies when serial measurements of the arterial [18F]-fluoro-deoxyglucose (FDG) input are available. Since this is not always practical in PET studies of rodents, there has been considerable interest in defining an image-derived input function (IDIF) by placing a volume of interest (VOI) within the left ventricle of the heart. However, spill-in arising from trapping of FDG in the myocardium often leads to progressive contamination of the IDIF, which propagates to underestimation of the magnitude of CMRglc. We therefore developed a novel, non-invasive method for correcting the IDIF without scaling to a blood sample. To this end, we first obtained serial arterial samples and dynamic FDG-PET data of the head and heart in a group of eight anaesthetized rats. We fitted a bi-exponential function to the serial measurements of the IDIF, and then used the linear graphical Gjedde-Patlak method to describe the accumulation in myocardium. We next estimated the magnitude of myocardial spill-in reaching the left ventricle VOI by assuming a Gaussian point-spread function, and corrected the measured IDIF for this estimated spill-in. Finally, we calculated parametric maps of CMRglc using the corrected IDIF, and for the sake of comparison, relative to serial blood sampling from the femoral artery. The uncorrected IDIF resulted in 20% underestimation of the magnitude of CMRglc relative to the gold standard arterial input method. However, there was no bias with the corrected IDIF, which was robust to the variable extent of myocardial tracer uptake, such that there was a very high correlation between individual CMRglc measurements using the corrected IDIF with gold-standard arterial input results. Based on simulation, we furthermore find that electrocardiogram-gating, i.e. ECG-gating is not necessary for IDIF quantitation using our approach.

Effects of respiratory alkalosis and acidosis on myocardial blood flow and metabolism in patients with coronary artery disease.

PubMed

Kazmaier, S; Weyland, A; Buhre, W; Stephan, H; Rieke, H; Filoda, K; Sonntag, H

1998-10-01

Variation of the arterial carbon dioxide partial pressure (PaCO2) is not uncommon in anesthetic practice. However, little is known about the myocardial consequences of respiratory alkalosis and acidosis, particularly in patients with coronary artery disease. The aim of the current study was to investigate the effects of variation in PaCO2 on myocardial blood flow (MBF), metabolism, and systemic hemodynamics in patients before elective coronary artery bypass graft surgery. In 10 male anesthetized patients, measurements of MBF, myocardial contractility, metabolism, and systemic hemodynamics were made in a randomized sequence at PaCO2 levels of 30, 40, and 50 mmHg, respectively. The MBF was measured using the Kety-Schmidt technique with argon as a tracer. End-diastolic left ventricular pressure and the maximal increase of left ventricular pressure were assessed using a manometer-tipped catheter. The cardiac index significantly changed with varying PaCO2 levels (hypocapnia, - 9%; hypercapnia, 13%). This reaction was associated with inverse changes in systemic vascular resistance index levels. The MBF significantly increased by 15% during hypercapnia, whereas no change was found during hypocapnia. Myocardial oxygen and glucose uptake and the maximal increase of left ventricular pressure were not affected by varying PaCO2 levels. In anesthetized patients with coronary artery disease, short-term variations in PaCO2 have significant effects on MBF but do not influence global myocardial oxygen and glucose uptake. Changes in systemic hemodynamics associated with respiratory alkalosis and acidosis are caused by changes in systemic vascular resistance rather than by alterations in myocardial contractility.

Impact of Hypertension on Ventricular-Arterial Coupling and Regional Myocardial Work at Rest and during Isometric Exercise

PubMed Central

Kuznetsova, Tatiana; D’hooge, Jan; Kloch-Badelek, Malgorzata; Sakiewicz, Wojciech; Thijs, Lutgarde; Staessen, Jan A.

2013-01-01

Background To understand better the mechanism of left ventricular (LV) remodeling related to hypertension, it is important to evaluate LV function in relation to the changes in loading conditions. The aim of this study was to investigate changes in conventional ventricular-arterial coupling indexes, LV strain, and a new index reflecting regional myocardial work assessed noninvasively at rest and during isometric exercise in a random sample including participants with normal blood pressure and those with hypertension. Methods A total of 148 participants (53.4% women; mean age, 52.0 years; 39.2% with hypertension) underwent simultaneous echocardiographic and arterial data acquisition at rest and during increased afterload (handgrip exercise). End-systolic pressure was determined from the carotid pulse wave. Arterial elastance (Ea) and LV elastance (Ees) were calculated as end-systolic pressure/stroke volume and end-systolic pressure/end-systolic volume. Doppler tissue imaging and two-dimensional speckle tracking were used to derive LV longitudinal strain. Regional myocardial work (ejection work density [EWD]) was the area of the pressure-strain loop during ejection. Results At rest, with adjustments applied, Ees (3.06 vs 3.71 mmHg/mL,P = .0003), Ea/Ees (0.54 vs 0.47,P=.002) and EWD (670 vs 802 Pa/m2, P = .0001) differed significantly between participants with normal blood pressure and those with hypertension. During handgrip exercise, Ea and Ea/Ees significantly increased (P < .0001) in both groups. Doppler tissue imaging and two-dimensional LV strain decreased in participants with hypertension (P ≤ .008). Only in subjects with normal blood pressure EWD significantly increased (+14.7%, P = .0009). Conclusions Although patients with hypertension compared with those with normal blood pressure have increased LV systolic stiffness and regional myocardial work to match arterial load at rest, they might have diminished cardiac reserve to increase myocardial performance, as estimated by EWD during isometric exercise. PMID:22622108

Characterization of 3-Dimensional PET Systems for Accurate Quantification of Myocardial Blood Flow.

PubMed

Renaud, Jennifer M; Yip, Kathy; Guimond, Jean; Trottier, Mikaël; Pibarot, Philippe; Turcotte, Eric; Maguire, Conor; Lalonde, Lucille; Gulenchyn, Karen; Farncombe, Troy; Wisenberg, Gerald; Moody, Jonathan; Lee, Benjamin; Port, Steven C; Turkington, Timothy G; Beanlands, Rob S; deKemp, Robert A

2017-01-01

Three-dimensional (3D) mode imaging is the current standard for PET/CT systems. Dynamic imaging for quantification of myocardial blood flow with short-lived tracers, such as 82 Rb-chloride, requires accuracy to be maintained over a wide range of isotope activities and scanner counting rates. We proposed new performance standard measurements to characterize the dynamic range of PET systems for accurate quantitative imaging. 82 Rb or 13 N-ammonia (1,100-3,000 MBq) was injected into the heart wall insert of an anthropomorphic torso phantom. A decaying isotope scan was obtained over 5 half-lives on 9 different 3D PET/CT systems and 1 3D/2-dimensional PET-only system. Dynamic images (28 × 15 s) were reconstructed using iterative algorithms with all corrections enabled. Dynamic range was defined as the maximum activity in the myocardial wall with less than 10% bias, from which corresponding dead-time, counting rates, and/or injected activity limits were established for each scanner. Scatter correction residual bias was estimated as the maximum cavity blood-to-myocardium activity ratio. Image quality was assessed via the coefficient of variation measuring nonuniformity of the left ventricular myocardium activity distribution. Maximum recommended injected activity/body weight, peak dead-time correction factor, counting rates, and residual scatter bias for accurate cardiac myocardial blood flow imaging were 3-14 MBq/kg, 1.5-4.0, 22-64 Mcps singles and 4-14 Mcps prompt coincidence counting rates, and 2%-10% on the investigated scanners. Nonuniformity of the myocardial activity distribution varied from 3% to 16%. Accurate dynamic imaging is possible on the 10 3D PET systems if the maximum injected MBq/kg values are respected to limit peak dead-time losses during the bolus first-pass transit. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Burst stimulation improves hemodynamics during resuscitation after prolonged ventricular fibrillation.

PubMed

Walcott, Gregory; Melnick, Sharon; Killingsworth, Cheryl; Ideker, Raymond

2009-02-01

Although return of spontaneous circulation (ROSC) is frequently achieved during resuscitation for sudden cardiac arrest, systolic blood pressure can then decrease, requiring additional myocardial support. Previous studies have shown that a series of 1-ms electrical pulses delivered through the defibrillation patches during ventricular fibrillation (VF) can stimulate the autonomic nervous system to increase myocardial function following defibrillation. We hypothesized that a similar series of electrical pulses could increase myocardial function and blood pressure during the early post-resuscitation period. Six swine were studied that underwent 6-7 min. Each animal received 5, 10, 15, or 20 pulse packets consisting of 6 10 A, 1-ms pulses every 3-4 s in random order whenever systolic blood pressure became less than 50 mmHg. All four sets of pulse packets were delivered to each animal. Systolic blood pressure and cardiac function (left ventricular +dP/dt) were increased to pre-stimulation levels or above by all four sets of pulse packets. The increases were significantly greater for the longer than the shorter number of pulse packets. The mean+/-SD duration of the time that the systolic pressure remained above 50 mmHg following pulse delivery was 4.2+/-2.5 min. Electrical stimulation during regular rhythm following prolonged VF and resuscitation can increase blood pressure and cardiac function to above prestimulation levels.

Burst Stimulation Improves Hemodynamics During Resuscitation after Prolonged Ventricular Fibrillation

PubMed Central

Walcott, Gregory; Melnick, Sharon; Killingsworth, Cheryl; Ideker, Raymond

2009-01-01

Background Although return of spontaneous circulation (ROSC) is frequently achieved during resuscitation for sudden cardiac arrest, systolic blood pressure can then decrease, requiring additional myocardial support. Previous studies have shown that a series of 1-ms electrical pulses delivered through the defibrillation patches during ventricular fibrillation (VF) can stimulate the autonomic nervous system to increase myocardial function following defibrillation. We hypothesized that a similar series of electrical pulses could increase myocardial function and blood pressure during the early post-resuscitation period. Methods and Results Six swine were studied that underwent 6–7 min. Each animal received 5, 10, 15, or 20 pulse packets consisting of 6 10 A, 1-ms pulses every 3–4 s in random order whenever systolic blood pressure became less than 50 mmHg. All four sets of pulse packets were delivered to each animal. Systolic blood pressure and cardiac function (left ventricular +dP/dt) were increased to pre-stimulation levels or above by all four sets of pulse packets. The increases were significantly greater for the longer than the shorter number of pulse packets. The mean±SD duration of the time that the systolic pressure remained above 50 mmHg following pulse delivery was 4.2±2.5 min. Conclusions Electrical stimulation during regular rhythm following prolonged VF and resuscitation can increase blood pressure and cardiac function to above pre-arrest levels. PMID:19655042

Diurnal variation in myocardial ischemia/reperfusion tolerance; mediation by the circadian clock within the cardiomyocyte

USDA-ARS?s Scientific Manuscript database

Circadian rhythms in cardiovascular physiology (e.g. blood pressure and heart rate) and pathophysiology (e.g. myocardial infarction (MI)) exist. Humans exhibit a marked increase in MI frequency during the early hours of the morning. However, MIs occurring during the evening are more likely to result...

Development of an Ex Vivo, Beating Heart Model for CT Myocardial Perfusion

PubMed Central

Das, Marco; Haberland, Ulrike; Slump, Cees; Handayani, Astri; van Tuijl, Sjoerd; Stijnen, Marco; Oudkerk, Matthijs; Wildberger, Joachim E.; Vliegenthart, Rozemarijn

2015-01-01

Objective. To test the feasibility of a CT-compatible, ex vivo, perfused porcine heart model for myocardial perfusion CT imaging. Methods. One porcine heart was perfused according to Langendorff. Dynamic perfusion scanning was performed with a second-generation dual source CT scanner. Circulatory parameters like blood flow, aortic pressure, and heart rate were monitored throughout the experiment. Stenosis was induced in the circumflex artery, controlled by a fractional flow reserve (FFR) pressure wire. CT-derived myocardial perfusion parameters were analysed at FFR of 1 to 0.10/0.0. Results. CT images did not show major artefacts due to interference of the model setup. The pacemaker-induced heart rhythm was generally stable at 70 beats per minute. During most of the experiment, blood flow was 0.9–1.0 L/min, and arterial pressure varied between 80 and 95 mm/Hg. Blood flow decreased and arterial pressure increased by approximately 10% after inducing a stenosis with FFR ≤ 0.50. Dynamic perfusion scanning was possible across the range of stenosis grades. Perfusion parameters of circumflex-perfused myocardial segments were affected at increasing stenosis grades. Conclusion. An adapted Langendorff porcine heart model is feasible in a CT environment. This model provides control over physiological parameters and may allow in-depth validation of quantitative CT perfusion techniques. PMID:26185756

National Assessment of Early Beta-Blocker Therapy in Patients with Acute Myocardial Infarction in China, 2001–2011: The China PEACE-Retrospective AMI Study

PubMed Central

Zhang, Haibo; Masoudi, Frederick A; Li, Jing; Wang, Qing; Li, Xi; Spertus, John A; Ross, Joseph S; Desai, Nihar R; Krumholz, Harlan M; Jiang, Lixin

2017-01-01

Background Since 2007, clinical practice guidelines have recommended beta-blocker therapy early in the course of acute myocardial infarction (AMI) for patients who are not at high risk for complications. Our objective was to perform a national quality assessment of early beta-blocker use during hospitalization for AMI over the past decade in China. Methods We conducted medical record review of a nationally representative sample of patients admitted to Chinese hospitals with AMI and studied those without absolute contraindications to beta-blocker therapy during 2001, 2006, and 2011. We evaluated the use, type, and dose of beta-blockers within the first 24 hours of admission over time and identified predictors of not using this treatment both in ideal candidates and in those with risk factors for cardiogenic shock. Results Among 14,241 patients with AMI (representing 43,165 patients in 2001, 106,167 patients in 2006, and 221,874 patients in 2011 in China, respectively), 45.1% had no contraindications to early beta-blocker therapy; 21.1% had risk factors for cardiogenic shock but no absolute contraindication. Beta-blocker use in ideal patients was 54.3% in 2001, 67.8% in 2006, and 61.8% in 2011 (P=0.28 for trend). Predictors of non-treatment were older age, lower systolic blood pressure, lower heart rate, absence of chest discomfort and admission to a non-teaching hospital. Use in patients with risk factors for cardiogenic shock was 42.6% in 2001, 59.5% in 2006, and 52.9% in 2011 (P=0.31 for trend). Metoprolol was used most frequently (91.5%), but dosages were often below those recommended in guidelines. Conclusions The use of early beta-blocker therapy for patients with AMI in China is suboptimal, with underuse in patients who could benefit and substantial use among those who might be harmed. Patterns of use have not changed over time, thus creating an important target of efforts to improve quality of care for AMI. PMID:26385034

Continuous monitoring of myocardial acid-base status during intermittent warm blood cardioplegia.

PubMed

Graffigna, A C L; Nollo, G; Pederzolli, C; Ferrari, P; Widesott, L; Antolini, R

2002-06-01

Intermittent warm blood cardioplegia (IWBC) is a well-established technique for myocardial protection during cardiac operations. According to standardized protocols, IWBC administration is currently performed every 15-20 min regardless of any individual variable and in the absence of any instrumental monitoring. We devised a new system for continuous measurement of the acid-base status of coronary sinus blood for on-line evaluation of myocardial oxygenation during IWBC. In 19 patients undergoing cardiac surgery for coronary artery bypass graft and/or valve surgery and receiving IWBC (34-37 degrees C) by antegrade induction (3 min) and retrograde or antegrade maintenance (2 min) every 15 min, continuous monitoring of myocardial oxygenation and acid/base status was performed by means of a multiparameter PO(2), PCO(2), pH, and temperature sensor (Paratrend7 (R), Philips Medical System) inserted into the coronary sinus. Mean cross-clamping time was 76+/-26 min; ischemic time was 13+/-0.2 min. pH decline was not linear, showing an initial fast decline, a point of flexus, and a progressive slow decline. After every ischemic period, the pH adaptation curve showed a complex pattern reaching step-by-step lower minimum levels (7.28+/-0.14 during the first ischemic period, to 7.16+/-0.19 during the third ischemic period - P=0.003). PO(2) decreased rapidly at 90% in 5.0+/-1.2 min after every reperfusion. During ischemia, PCO(2) increased steadily at 1.6+/-0.1 mmHg per minute, with progressively incomplete removal after successive reperfusion, and progressive increase of maximal level (42+/-12 mmHg during the first ischemic period, to 53+/-23 mmHg during the third ischemic period - P=0.05). Myocardial oxygen, carbon dioxide, and pH show marked changes after repeated IWBC. Myocardial ischemia is not completely reversed by standardized reperfusions, as reflected by steady deterioration of PCO(2) and pH after each reperfusion. Progressive increase of reperfusion durations or direct monitoring of myocardial oxygenation could be advisable in cases of prolonged cross-clamping time.

Physiologic ischaemic training induces endothelial progenitor cell mobilization and myocardial angiogenesis via endothelial nitric oxide synthase related pathway in rabbits.

PubMed

Xiao, Mingyue; Lu, Xiao; Li, Jianan; Li, Ling; Li, Yongxue

2014-04-01

Ischaemia-induced angiogenesis promises to improve neovascularization by delivery of angiogenic factors or endothelial progenitor cells (EPCs) to cardiac ischaemic areas. In order to avoid the risk of excessive myocardial ischaemia, therefore, we hypothesized that physiological ischaemic training (PIT) of normal skeletal muscle might contribute to myocardial angiogenesis via nitric oxide mediated mobilization of EPCs from the bone marrow in the established rabbit model of controllable myocardial ischaemia. The rabbits were grouped by sham-operation, myocardial ischaemia without PIT, PIT and PIT with pretreatment with the endothelial nitric oxide synthase (eNOS) inhibitor L-nitroarginine methyl ester (L-NAME). Controlled myocardial ischaemia was modelled by a water balloon constrictor implanted on the left ventricular branch in a rabbit. The PIT procedure included three cycles of 3 min of cuff inflation followed by 5 min of deflation on hind limbs of the rabbits for 4 weeks. At the endpoints, circulating EPCs (CD34/Flk-1) were measured by fluorescence-activated cell sorter; capillary density, by immunohistochemistry; blood flow, by a microsphere technique; endothelial nitric oxide synthase (eNOS) mRNA and protein, by real-time reverse transcriptase (RT)-PCR and Western blotting. The mRNA levels of eNOS were significantly higher in the PIT and L-NAME groups than in the sham-operation group (P < 0.05). Phospho-eNOS protein expression was higher in the PIT group than in the sham-operation and myocardial ischaemia without PIT groups (P < 0.05), and the effect was inhibited by L-NAME pretreatment (P < 0.05). Compared with sham-operation and myocardial ischaemia without PIT groups, the PIT group had the highest EPC count (P < 0.001), and the increase of capillary density (P < 0.01) and collateral blood flow (P < 0.05) in the ischaemic myocardium was consistent with the finding of EPC count. These effects were also inhibited by pretreatment with the eNOS inhibitor L-NAME. Capillary density and collateral blood flow were highly correlated with the increase of EPC count (r = 0.913 and r = 0.929, respectively, P = 0.000). PIT improved EPC mobilization and contributed to compensatory neovascularization via eNOS-related pathway. These results might support the future development of strategies for therapeutic neovascularization.

Significant suppression of myocardial (18)F-fluorodeoxyglucose uptake using 24-h carbohydrate restriction and a low-carbohydrate, high-fat diet.

PubMed

Kobayashi, Yasuhiro; Kumita, Shin-ichiro; Fukushima, Yoshimitsu; Ishihara, Keiichi; Suda, Masaya; Sakurai, Minoru

2013-11-01

(18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is a useful tool for evaluating inflammation. Because, myocardial-FDG uptake occurs with diverse physiology, it should be suppressed during evaluation of myocardial inflammation by FDG-PET/CT. Diets inducing fat-based metabolism, such as a low-carbohydrate, high-fat diet (LCHF), are used in uptake-suppression protocols. However, a complete suppression of myocardial-FDG uptake has not been established. Hence, we assessed the efficacy of 24-h carbohydrate restriction along with an LCHF diet compared to that of the conventional protocol in suppressing myocardial-FDG uptake and also compared fat and glucose metabolism between these protocols. Fourteen healthy volunteers agreed to undergo >24-h carbohydrate restriction (glucose, <10g) and drank an LCHF beverage an hour before FDG administration. A scan performed under conventional fasting protocol served as the control. The maximal standardized uptake values (SUVmax) of the left ventricular (LV) myocardium, and left atrium lumen (blood pool), liver, and lung fields as background, were measured. Blood sugar, free fatty acids (FFAs), insulin, and triglyceride concentrations were measured just before FDG injection and compared between the 2 protocols. Global LV myocardial uptake was significantly lower with the diet-preparation protocol (SUVmax 1.31 [1.15-1.49] vs. 2.98 [1.76-6.43], p=0.001). Target-to-background ratios [myocardium-to-blood ratio (MBR), myocardium-to-lung ratio (MLR), and myocardium-to-liver ratio (MLvR)] were also significantly lower with the diet-preparation protocol [MBR: 0.75 (0.68-0.84) vs. 1.63 (0.98-4.09), p<0.001; MLR: 1.87 (1.53-2.47) vs. 4.54 (2.53-12.78), p=0.004; MLvR: 0.48 (0.44-0.56) vs. 1.11 (0.63-2.32), p=0.002]. Only insulin levels were significantly different between the subjects in each protocol group (11.3 [6.2-15.1] vs. 3.9 [2.9-6.2]). Carbohydrate restriction together with an LCHF supplement administered 1h before FDG significantly suppressed myocardial-FDG uptake. FFAs and insulin might not directly affect myocardial-FDG uptake. Copyright © 2013 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Evaluation of the novel myocardial perfusion positron-emission tomography tracer 18F-BMS-747158-02: comparison to 13N-ammonia and validation with microspheres in a pig model.

PubMed

Nekolla, S G; Reder, S; Saraste, A; Higuchi, T; Dzewas, G; Preissel, A; Huisman, M; Poethko, T; Schuster, T; Yu, M; Robinson, S; Casebier, D; Henke, J; Wester, H J; Schwaiger, M

2009-05-05

Positron-emission tomography (PET) tracers for myocardial perfusion are commonly labeled with short-lived isotopes that limit their widespread clinical use. 18F-BMS-747158-02 (18F-BMS) is a novel pyridaben derivative that was evaluated for assessment of myocardial perfusion by comparison with 13N-ammonia (13NH3) and with radioactive microspheres in a pig model. Fourteen pigs injected with 500 MBq of 13NH3 or 100 to 200 MBq of 18F-BMS underwent dynamic PET at rest and during pharmacological stress. In 8 of these pigs, 18F-BMS was injected during stress combined with transient, 2.5-minute constriction of the left anterior descending coronary artery. Radioactive microspheres were coinjected with 18F-BMS. Ratios of myocardial tracer uptake to surrounding tissues were determined, and myocardial blood flow was quantified by compartmental modeling. Both tracers showed high and homogeneous myocardial uptake. Compared with 13NH3, 18F-BMS showed higher activity ratios between myocardium and blood (rest 2.5 versus 4.1; stress 2.1 versus 5.8), liver (rest 1.2 versus 1.8; stress 0.7 versus 2.0), and lungs (rest 2.5 versus 4.2; stress 2.9 versus 6.4). Regional myocardial blood flow assessed with 18F-BMS PET showed good correlation (r=0.88, slope=0.84) and agreement (mean difference -0.10 [25th percentile -0.3, 75th percentile 0.1 mL x min(-1) x g(-1)]) with that measured with radioactive microspheres over a flow range from 0.1 to 3.0 mL x min(-1) x g(-1). The extent of defects induced by left anterior descending coronary artery constriction measured by 18F-BMS and microspheres also correlated closely (r=0.63, slope=1.1). 18F-BMS-747158-02 is a very attractive new PET perfusion tracer that allows quantitative assessment of regional myocardial perfusion over a wide flow range. The long half-life of 18F renders this tracer useful for clinical PET/CT applications in the workup of patients with suspected or proven coronary artery disease.

Early diagnosis of severe combined immunodeficiency (SCID) in Turkey: a pilot study.

PubMed

Can, Ceren; Hamilçıkan, Şahin; Can, Emrah

2017-08-29

Severe combined immunodeficiency (SCID) is a neonatal emergency. As the T-cell receptor excision circles (TREC) test is not cost effective for neonatal screening of SCID in developing countries, this pilot study's objective aimed at identifying preliminary data to enable SCID identification in the general population. This observational study was performed in Bagcılar Training and Research Hospital, Istanbul, Turkey. Cord-blood complete blood count (CBC) was recorded in all neonates included in the study. Absolute lymphopenia was considered in cord-blood samples if the absolute lymphocyte count was less than 2500/mm 3 . A control blood count was performed 1-month later for cases with detected lymphopenia. A total of 2945 term neonates were included in the study. Absolute lymphopenia was found in nine (0.3%) neonates, while 2936 (99.7%) had an absolute lymphocytic count above 2.5 × 10 3 /mm 3 . The mean counts of red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), platelets (PLT), and monocytes in the lymphopenia group were not found to significantly differ from the non-lymphopenia group. However, there were significantly lower mean white blood cell (WBC), lymphocyte, and neutrophil counts between the groups (p < .05). Absolute lymphopenia detected using CBC analysis is a simple, easier, more non-invasive, and cheaper method than the TREC method for detection of SCID neonates, and this method may prove to be a useful alternative, especially in developing countries.

Diagnostic Application of Absolute Neutron Activation Analysis in Hematology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zamboni, C.B.; Oliveira, L.C.; Dalaqua, L. Jr.

2004-10-03

The Absolute Neutron Activation Analysis (ANAA) technique was used to determine element concentrations of Cl and Na in blood of healthy group (male and female blood donators), select from Blood Banks at Sao Paulo city, to provide information which can help in diagnosis of patients. This study permitted to perform a discussion about the advantages and limitations of using this nuclear methodology in hematological examinations.

Fully distributed absolute blood flow velocity measurement for middle cerebral arteries using Doppler optical coherence tomography

PubMed Central

Qi, Li; Zhu, Jiang; Hancock, Aneeka M.; Dai, Cuixia; Zhang, Xuping; Frostig, Ron D.; Chen, Zhongping

2016-01-01

Doppler optical coherence tomography (DOCT) is considered one of the most promising functional imaging modalities for neuro biology research and has demonstrated the ability to quantify cerebral blood flow velocity at a high accuracy. However, the measurement of total absolute blood flow velocity (BFV) of major cerebral arteries is still a difficult problem since it is related to vessel geometry. In this paper, we present a volumetric vessel reconstruction approach that is capable of measuring the absolute BFV distributed along the entire middle cerebral artery (MCA) within a large field-of-view. The Doppler angle at each point of the MCA, representing the vessel geometry, is derived analytically by localizing the artery from pure DOCT images through vessel segmentation and skeletonization. Our approach could achieve automatic quantification of the fully distributed absolute BFV across different vessel branches. Experiments on rodents using swept-source optical coherence tomography showed that our approach was able to reveal the consequences of permanent MCA occlusion with absolute BFV measurement. PMID:26977365

Fully distributed absolute blood flow velocity measurement for middle cerebral arteries using Doppler optical coherence tomography.

PubMed

Qi, Li; Zhu, Jiang; Hancock, Aneeka M; Dai, Cuixia; Zhang, Xuping; Frostig, Ron D; Chen, Zhongping

2016-02-01

Doppler optical coherence tomography (DOCT) is considered one of the most promising functional imaging modalities for neuro biology research and has demonstrated the ability to quantify cerebral blood flow velocity at a high accuracy. However, the measurement of total absolute blood flow velocity (BFV) of major cerebral arteries is still a difficult problem since it is related to vessel geometry. In this paper, we present a volumetric vessel reconstruction approach that is capable of measuring the absolute BFV distributed along the entire middle cerebral artery (MCA) within a large field-of-view. The Doppler angle at each point of the MCA, representing the vessel geometry, is derived analytically by localizing the artery from pure DOCT images through vessel segmentation and skeletonization. Our approach could achieve automatic quantification of the fully distributed absolute BFV across different vessel branches. Experiments on rodents using swept-source optical coherence tomography showed that our approach was able to reveal the consequences of permanent MCA occlusion with absolute BFV measurement.

Cardiovascular magnetic resonance of myocardial edema using a short inversion time inversion recovery (STIR) black-blood technique: Diagnostic accuracy of visual and semi-quantitative assessment

PubMed Central

2012-01-01

Background The short inversion time inversion recovery (STIR) black-blood technique has been used to visualize myocardial edema, and thus to differentiate acute from chronic myocardial lesions. However, some cardiovascular magnetic resonance (CMR) groups have reported variable image quality, and hence the diagnostic value of STIR in routine clinical practice has been put into question. The aim of our study was to analyze image quality and diagnostic performance of STIR using a set of pulse sequence parameters dedicated to edema detection, and to discuss possible factors that influence image quality. We hypothesized that STIR imaging is an accurate and robust way of detecting myocardial edema in non-selected patients with acute myocardial infarction. Methods Forty-six consecutive patients with acute myocardial infarction underwent CMR (day 4.5, +/- 1.6) including STIR for the assessment of myocardial edema and late gadolinium enhancement (LGE) for quantification of myocardial necrosis. Thirty of these patients underwent a follow-up CMR at approximately six months (195 +/- 39 days). Both STIR and LGE images were evaluated separately on a segmental basis for image quality as well as for presence and extent of myocardial hyper-intensity, with both visual and semi-quantitative (threshold-based) analysis. LGE was used as a reference standard for localization and extent of myocardial necrosis (acute) or scar (chronic). Results Image quality of STIR images was rated as diagnostic in 99.5% of cases. At the acute stage, the sensitivity and specificity of STIR to detect infarcted segments on visual assessment was 95% and 78% respectively, and on semi-quantitative assessment was 99% and 83%, respectively. STIR differentiated acutely from chronically infarcted segments with a sensitivity of 95% by both methods and with a specificity of 99% by visual assessment and 97% by semi-quantitative assessment. The extent of hyper-intense areas on acute STIR images was 85% larger than those on LGE images, with a larger myocardial salvage index in reperfused than in non-reperfused infarcts (p = 0.035). Conclusions STIR with appropriate pulse sequence settings is accurate in detecting acute myocardial infarction (MI) and distinguishing acute from chronic MI with both visual and semi-quantitative analysis. Due to its unique technical characteristics, STIR should be regarded as an edema-weighted rather than a purely T2-weighted technique. PMID:22455461

Distribution and Determinants of Myocardial Perfusion Grade Following Late Mechanical Recanalization of Occluded Infarct-Related Arteries Postmyocardial Infarction: A Report From the Occluded Artery Trial

PubMed Central

Jorapur, Vinod; Steigen, Terje K.; Buller, Christopher E.; Dẑavík, Vladimír; Webb, John G.; Strauss, Bradley H.; Yeoh, Eunice E.S.; Kurray, Peter; Sokalski, Leszek; Machado, Mauricio C.; Kronsberg, Shari S.; Lamas, Gervasio A.; Hochman, Judith S.; John Mancini, G.B.

2010-01-01

Objective To evaluate the distribution and determinants of myocardial perfusion grade (MPG) following late recanalization of persistently occluded infarct-related arteries (IRA). Background MPG reflects microvascular integrity. It is an independent prognostic factor following myocardial infarction, but has been studied mainly in the setting of early reperfusion. The occluded artery trial (OAT) enrolled stable patients with persistently occluded IRAs beyond 24 hr and up to 28 days post-MI. Methods Myocardial blush was assessed using TIMI MPG grading in 261 patients with TIMI 3 epicardial flow following IRA PCI. Patients demonstrating impaired (0–1) versus preserved (2–3) MPG were compared with regard to baseline clinical and pre-PCI angiographic characteristics. Results Impaired MPG was observed in 60 of 261 patients (23%). By univariate analysis, impaired MPG was associated with failed fibrinolytic therapy, higher heart rate, lower systolic blood pressure, lower ejection fraction, LAD occlusion, absence of collaterals (P < 0.01) and ST elevation MI, lower diastolic blood pressure, and higher systolic sphericity index (P < 0.05). By multivariable analysis, higher heart rate, LAD occlusion, absence of collaterals and higher systolic sphericity index (P < 0.01), and lower systolic blood pressure (P < 0.05) were independently associated with impaired MPG. Conclusion Preserved microvascular integrity was present in a high proportion of patients following late recanalization of occluded IRAs post-MI. Presence of collaterals was independently associated with preserved MPG and likely accounted for the high frequency of preserved myocardial perfusion in this clinical setting. Impaired MPG was associated with baseline clinical and angiographic features consistent with larger infarct size. PMID:18798327

Effects of Baicalin on Blood Pressure and Left Ventricular Remodeling in Rats with Renovascular Hypertension

PubMed Central

Dai, Hualei; Zhang, Xinjin; Yang, Zhigang; Li, Jianmei; Zheng, Jialin

2017-01-01

Background This study aimed to explore the effect of baicalin, which is a kind of bioactive flavonoid, on blood pressure and left ventricular remodeling in rats with renovascular hypertension. Material/Methods A total of 40 male Wistar rats were randomly assigned into sham-operation (n=10) and renal hypertension model groups (2-kidney-1 clip; 2K-1C, n=30). The rats in the renal hypertension model group were randomly subdivided into 2K-1C (n=13) and 2K-1C/Baicalin groups (n=14). The cardiac function indexes were determined after 4 weeks. The morphological changes in the myocardial tissue were observed using hematoxylin and eosin and Masson staining. The myocardial apoptosis was detected using the terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling method, and the expression of C/EBP homologous protein and caspase-3 was monitored by Western blot. The expression of GRP78 and GRP94 in myocardial cells of rats was detected by qPCR and Western blot technology. Results No significant change in blood pressure was observed in the 2K-1C/Baicalin group compared with the 2K-1C group, but the indexes of left ventricular remodeling significantly improved. Pathological myocardial fibrosis and expression of fibrosis-related factors significantly decreased in the 2K-1C/Baicalin group compared with the 2K-1C group. The expression of glucose-regulated protein (GRP)78, GRP94, CHOP, and caspase-3, and apoptosis of cardiomyocytes also decreased in the 2K-1C/Baicalin group. Conclusions Baicalin has no significant antihypertensive effect, but reduced pathological changes in the myocardium, alleviated endoplasmic reticulum stress, and reduced myocardial apoptosis, reverting left ventricular remodeling in rats with renovascular hypertension. PMID:28622281

Phaeochromocytoma in a 86-year-old patient presenting with reversible myocardial dysfunction.

PubMed

Szwench, Elżbieta; P Czkowska, Mariola; Marczewski, Krzysztof; Klisiewicz, Anna; Micha Owska, Ilona; Ciuba, Iwona; Januszewicz, Magdalena; Prejbisz, Aleksander; Hoffman, Piotr; Januszewicz, Andrzej

2011-12-01

BACKGROUND. Phaeochromocytomas and paragangliomas are rare, mostly benign catecholamine-producing tumours of chromaffin cells of the adrenal medulla or of extra-adrenal paraganglia. Phaeochromocytoma may occur at any age, the greatest frequency being in the fourth and fifth decades. Only on extremely rare occasions does the tumour develop in the very old patients. METHODS. We are describing an 86-year-old patient with phaeochromocytoma, presenting with reversible myocardial dysfunction. RESULTS. This very old patient with phaeochromocytoma had hypertension characterized by labile blood pressure values and increased daytime blood pressure variability. This patient exhibited reversible myocardial dysfunction suggestive for "catecholaminergic cardiomyopathy", as the complication of phaeochromocytoma. After surgical removal of the tumour, recovery of left ventricular function was documented by echocardiography showing normalization of systolic function and improvement of diastolic function. CONCLUSION. Phaeochromocytomas are rare forms of secondary hypertension, but should be considered in the differential diagnosis, regardless of age, even in very old patients.

Nuclear cardiograph and scintigraphy

NASA Technical Reports Server (NTRS)

Mclaughlin, P.

1975-01-01

Extensive advances in the technology of detectors, data analysis systems, and tracers used have resulted in greatly expanded applications of radioisotopes to the assessment of cardiac function and disease. The development of nuclear cardiology has proceeded along four lines: (1) radionuclide angiography, (2) myocardial perfusion imaging, (3) intracoronary microsphere imaging, and (4) regional myocardial blood flow determination using inert gases.

Relation of coronary flow pattern to myocardial blush grade in patients with first acute myocardial infarction

PubMed Central

Hoffmann, R; Haager, P; Lepper, W; Franke, A; Hanrath, P

2003-01-01

Background: Analysis of myocardial blush grade (MBG) and coronary flow velocity pattern has been used to obtain direct or indirect information about microvascular damage and reperfusion injury after percutaneous transluminal coronary angiography for acute myocardial infarction. Objective: To evaluate the relation between coronary blood flow velocity pattern and MBG immediately after angioplasty plus stenting for acute myocardial infarction. Design: The coronary blood flow velocity pattern in the infarct related artery was determined immediately after angioplasty in 35 patients with their first acute myocardial infarct using a Doppler guide wire. Measurements were related to MBG as a direct index of microvascular function in the infarct zone. Results: Coronary flow velocity patterns were different between patients with absent myocardial blush (n = 14), reduced blush (n = 7), or normal blush (n = 14). The following variables (mean (SD)) differed significantly between the three groups: systolic peak flow velocity (cm/s): absent blush 10.9 (4.2), reduced blush 14.2 (6.4), normal blush 19.2 (11.2); p = 0.036; diastolic deceleration rate (ms): absent blush 103 (58), reduced blush 80 (65), normal blush 50 (19); p = 0.025; and diastolic–systolic velocity ratio: absent blush 4.06 (2.18), reduced blush 2.02 (0.55), normal blush 1.88 (1.03); p = 0.002. In a multivariate analysis MBG was the only variable with a significant impact on the diastolic deceleration rate (p = 0.034,) while age, infarct location, time to revascularisation, infarct vessel diameter, and maximum creatine kinase had no significant impact. Conclusions: The coronary flow velocity pattern in the infarct related epicardial artery is primarily determined by the microvascular function of the dependent myocardium, as reflected by MBG. PMID:12975402

Pericardial fluid level of heart-type cytoplasmic fatty acid-binding protein (H-FABP) is an indicator of severe myocardial ischemia.

PubMed

Tambara, Keiichi; Fujita, Masatoshi; Miyamoto, Shoichi; Doi, Kazuhiko; Nishimura, Kazunobu; Komeda, Masashi

2004-02-01

Heart-type cytoplasmic fatty acid-binding protein (H-FABP) has been reported as a sensitive and specific marker for the early diagnosis of acute myocardial infarction. Our hypothesis was that serum or pericardial fluid levels of H-FABP can reflect not only myocardial infarction but also myocardial ischemia. A total of 34 patients with unstable angina, who had anginal symptoms and/or ST-changes in ECG monitoring within 24 h before operation, were classified into group A (n=17), and those without these symptoms and changes into group B (n=17). Blood and pericardial fluid samples were obtained immediately after median sternotomy, and serum and pericardial fluid levels of creatine kinase-MB, cardiac troponin-T, and H-FABP were measured. Serum H-FABP levels were slightly elevated compared with their normal values in both groups. While they showed no difference between groups A and B (group A vs. B: 8.5+/-1.0 vs. 7.1+/-0.7 ng/ml, P=0.25), pericardial fluid levels of H-FABP were significantly higher in group A than in group B (16.3+/-2.0 vs. 9.6+/-1.0 ng/ml, P=0.0046). H-FABP showed a weak correlation between its serum levels and pericardial fluid levels (r=0.40). Pericardial fluid levels of H-FABP reflect myocardial ischemia occurring within 24 h of their measurements. H-FABP may be secreted into the interstitial space by increased permeability of the myocardial cell membrane associated with severe myocardial ischemia. Thus, pericardial fluid reflects pathophysiological conditions of cardiomyocytes more sensitively than circulating blood.

Non-O blood groups can be a prognostic marker of in-hospital and long-term major adverse cardiovascular events in patients with ST elevation myocardial infarction undergoing primary percutaneous coronary intervention.

PubMed

Cetin, Mehmet Serkan; Ozcan Cetin, Elif Hande; Aras, Dursun; Topaloglu, Serkan; Temizhan, Ahmet; Kisacik, Halil Lutfi; Aydogdu, Sinan

2015-09-01

Recent studies have suggested ABO blood type locus as an inherited predictor of thrombosis, cardiovascular risk factors, myocardial infarction. However, data is scarce about the impact of non-O blood groups on prognosis in patients with ST-elevation myocardial infarction (STEMI). Therefore, we aimed to evaluate the prognostic importance of non-O blood groups in patients with STEMI undergoing primary percutaneous coronary intervention (pPCI) METHODS: 1835 consecutive patients who were admitted with acute STEMI between 2010 and 2015 were included and followed-up for a median of 35.6months. The prevalence of hyperlipidemia, total cholesterol, LDL, peak CKMB and no-reflow as well as hospitalization duration were higher in patients with non-O blood groups. Gensini score did not differ between groups. During the in-hospital and long-term follow-up period, MACE, the prevalence of stent thrombosis, non-fatal MI, and mortality were higher in non-O blood groups. In multivariate logistic regression analysis, non-0 blood groups were demonstrated to be independent predictors of in-hospital (OR:2.085 %CI: 1.328-3.274 p=0.001) and long term MACE (OR:2.257 %CI: 1.325-3.759 p<0.001). Kaplan-Meier analysis according to the long-term MACE free survival revealed a higher occurrence of MACE in non-O blood group compared with O blood group (p<0.001, Chi-square: 22.810). Non-O blood groups were determined to be significant prognostic indicators of short- and long-term cardiovascular adverse events and mortality in patients with STEMI undergoing pPCI. In conjunction with other prognostic factors, evaluation of this parameter may improve the risk categorization and tailoring the individual therapy and follow-up in STEMI patient population. Copyright © 2015 Elsevier Ltd. All rights reserved.

Myocardial Perfusion and Function Are Distinctly Altered by Sevoflurane Anesthesia in Diet-Induced Prediabetic Rats.

PubMed

van den Brom, Charissa E; Boly, Chantal A; Bulte, Carolien S E; van den Akker, Rob F P; Kwekkeboom, Rick F J; Loer, Stephan A; Boer, Christa; Bouwman, R Arthur

2016-01-01

Preservation of myocardial perfusion during surgery is particularly important in patients with increased risk for perioperative complications, such as diabetes. Volatile anesthetics, like sevoflurane, have cardiodepressive effects and may aggravate cardiovascular complications. We investigated the effect of sevoflurane on myocardial perfusion and function in prediabetic rats. Rats were fed a western diet (WD; n = 18) or control diet (CD; n = 18) for 8 weeks and underwent (contrast) echocardiography to determine perfusion and function during baseline and sevoflurane exposure. Myocardial perfusion was estimated based on the product of microvascular filling velocity and blood volume. WD-feeding resulted in a prediabetic phenotype characterized by obesity, hyperinsulinemia, hyperlipidemia, glucose intolerance, and hyperglycemia. At baseline, WD-feeding impaired myocardial perfusion and systolic function compared to CD-feeding. Exposure of healthy rats to sevoflurane increased the microvascular filling velocity without altering myocardial perfusion but impaired systolic function. In prediabetic rats, sevoflurane did also not affect myocardial perfusion; however, it further impaired systolic function. Diet-induced prediabetes is associated with impaired myocardial perfusion and function in rats. While sevoflurane further impaired systolic function, it did not affect myocardial perfusion in prediabetic rats. Our findings suggest that sevoflurane anesthesia leads to uncoupling of myocardial perfusion and function, irrespective of the metabolic state.

Non-contrast T1-mapping detects acute myocardial edema with high diagnostic accuracy: a comparison to T2-weighted cardiovascular magnetic resonance

PubMed Central

2012-01-01

Background T2w-CMR is used widely to assess myocardial edema. Quantitative T1-mapping is also sensitive to changes in free water content. We hypothesized that T1-mapping would have a higher diagnostic performance in detecting acute edema than dark-blood and bright-blood T2w-CMR. Methods We investigated 21 controls (55 ± 13 years) and 21 patients (61 ± 10 years) with Takotsubo cardiomyopathy or acute regional myocardial edema without infarction. CMR performed within 7 days included cine, T1-mapping using ShMOLLI, dark-blood T2-STIR, bright-blood ACUT2E and LGE imaging. We analyzed wall motion, myocardial T1 values and T2 signal intensity (SI) ratio relative to both skeletal muscle and remote myocardium. Results All patients had acute cardiac symptoms, increased Troponin I (0.15-36.80 ug/L) and acute wall motion abnormalities but no LGE. T1 was increased in patient segments with abnormal and normal wall motion compared to controls (1113 ± 94 ms, 1029 ± 59 ms and 944 ± 17 ms, respectively; p < 0.001). T2 SI ratio using STIR and ACUT2E was also increased in patient segments with abnormal and normal wall motion compared to controls (all p < 0.02). Receiver operator characteristics analysis showed that T1-mapping had a significantly larger area-under-the-curve (AUC = 0.94) compared to T2-weighted methods, whether the reference ROI was skeletal muscle or remote myocardium (AUC = 0.58-0.89; p < 0.03). A T1 value of greater than 990 ms most optimally differentiated segments affected by edema from normal segments at 1.5 T, with a sensitivity and specificity of 92 %. Conclusions Non-contrast T1-mapping using ShMOLLI is a novel method for objectively detecting myocardial edema with a high diagnostic performance. T1-mapping may serve as a complementary technique to T2-weighted imaging for assessing myocardial edema in ischemic and non-ischemic heart disease, such as quantifying area-at-risk and diagnosing myocarditis. PMID:22720998

The effects of graded changes in oxygen and carbon dioxide tension on coronary blood velocity independent of myocardial energy demand.

PubMed

Boulet, Lindsey M; Stembridge, Mike; Tymko, Michael M; Tremblay, Joshua C; Foster, Glen E

2016-08-01

In humans, coronary blood flow is tightly regulated by microvessels within the myocardium to match myocardial energy demand. However, evidence regarding inherent sensitivity of the microvessels to changes in arterial partial pressure of carbon dioxide and oxygen is conflicting because of the accompanied changes in myocardial energy requirements. This study aimed to investigate the changes in coronary blood velocity while manipulating partial pressures of end-tidal CO2 (Petco2) and O2 (Peto2). It was hypothesized that an increase in Petco2 (hypercapnia) or decrease in Peto2 (hypoxia) would result in a significant increase in mean blood velocity in the left anterior descending artery (LADVmean) due to an increase in both blood gases and energy demand associated with the concomitant cardiovascular response. Cardiac energy demand was assessed through noninvasive measurement of the total left ventricular mechanical energy. Healthy subjects (n = 13) underwent a euoxic CO2 test (Petco2 = -8, -4, 0, +4, and +8 mmHg from baseline) and an isocapnic hypoxia test (Peto2 = 64, 52, and 45 mmHg). LADVmean was assessed using transthoracic Doppler echocardiography. Hypercapnia evoked a 34.6 ± 8.5% (mean ± SE; P < 0.01) increase in mean LADVmean, whereas hypoxia increased LADVmean by 51.4 ± 8.8% (P < 0.05). Multiple stepwise regressions revealed that both mechanical energy and changes in arterial blood gases are important contributors to the observed changes in LADVmean (P < 0.01). In summary, regulation of the coronary vasculature in humans is mediated by metabolic changes within the heart and an inherent sensitivity to arterial blood gases. Copyright © 2016 the American Physiological Society.

[Analysis of mortality and convergence tendencies in inpatient care of stroke and myocardial infarction].

PubMed

Rath, T; Büscher, G; Schwartze, D; Drabik, A; Bokern, E; Lüngen, M

2010-09-01

An increase in the convergence of medical services toward specialized hospitals with high case numbers as well as the effects on quality of care are often assumed to be the result of diagnosis-related groups (DRGs; case-based lump-sum reimbursement). Estimates of the extent to which these effects occur in emergency diagnoses are not available. Claims data relating to approximately 23.6 million insured within the period 2004-2007 (inclusive) were analyzed. All cases with the main diagnosis of stroke (ICD-10: I63 and I64) and myocardial infarction (ICD-10: I21) were included in the study. Increasing case numbers could be observed for all entities within the period studied (myocardial infarction: +12.71%; stroke: +1.73%). The absolute increase in case numbers seems to affect those hospitals with case numbers >100 per year, whereas case numbers of hospital groups including hospitals with low case numbers per year remain unchanged or grow slower. No absolute trend in mortality could be seen. However, a disproportionate rate of mortality in hospitals with low case numbers per year for both diagnoses was observed. The convergence of emergency treatment in a few specialized centers has not yet been accelerated by the implementation of DRGs. Essentially, relative changes can be seen due to case number increases in large centers rather than because of service cutbacks and shifts from smaller hospitals. The reason for this could be the need to maintain emergency care in rural regions, while specialized centers are increasingly built in urban areas.

"Spice" (Synthetic Marijuana) Induced Acute Myocardial Infarction: A Case Series.

PubMed

Ul Haq, E; Shafiq, A; Khan, A A; Awan, A A; Ezad, S; Minteer, W J; Omar, B

2017-01-01

Marijuana is the most widely abused "recreational" substance in the United States, with highest prevalence in young adults. It is reported to cause ischemic strokes, hepatitis, anxiety, and psychosis. Although it is associated with dose dependent tachycardia and can lead to coronary vasospasm, it has not been directly related to acute myocardial infarction (AMI). Marijuana induced coronary vasospasm can result in endothelial denudation at the site of a vulnerable atherosclerotic plaque in response to hemodynamic stressors, potentially causing an AMI. Spice refers to herbal mixture with composition and effects similar to that of marijuana and therefore is referred to as "synthetic marijuana." Herein, we report 3 cases of spice induced ST-segment elevation myocardial infarction. All patients were relatively young and had few or absolutely no risk factors for cardiovascular disease. All patients underwent emergent coronary angiography, with two needing stent placement and the third requiring only aspiration thrombectomy. Our case series emphasizes the importance of suspecting and investigating synthetic marijuana use in low risk young adults presenting with AMI.

Superior short-term cholesterol control and achievement of the adult treatment panel III low-density lipoprotein goals with initiation of statin therapy by the time of hospital discharge following acute myocardial infarction.

PubMed

Bybee, Kevin A; Powell, Brian D; Williams, Brent A; Murphy, Joseph G; Kopecky, Stephen L; Wright, R Scott

2004-03-15

In a community-based population, we compared serum cholesterol concentrations following hospital discharge after acute myocardial infarction based on statin therapy at the time of hospital discharge. At the time of follow-up cholesterol measurement, patients discharged from the hospital on a statin had lower mean low-density lipoprotein (LDL) (106.4 vs 116.7 mg/dl, p <0.01) and total cholesterol (182.2 vs 193.6 mg/dl, p <0.01) concentrations, larger absolute reductions in LDL (-24.7 vs -4.7 mg/dl, p <0.01) and total cholesterol (-24.2 vs -0.1 mg/dl, p <0.01) from pre-myocardial infarction levels, and superior attainment of the Adult Treatment Panel III LDL goal of <100 mg/dl at the time of follow-up compared with patients who were discharged without a statin (49% vs 33%; adjusted odds ratio 2.56; p <0.01).

Cardiac PET/CT for the Evaluation of Known or Suspected Coronary Artery Disease

PubMed Central

Murthy, Venkatesh L.

2011-01-01

Positron emission tomography (PET) is increasingly being applied in the evaluation of myocardial perfusion. Cardiac PET can be performed with an increasing variety of cyclotron- and generator-produced radiotracers. Compared with single photon emission computed tomography, PET offers lower radiation exposure, fewer artifacts, improved spatial resolution, and, most important, improved diagnostic performance. With its capacity to quantify rest–peak stress left ventricular systolic function as well as coronary flow reserve, PET is superior to other methods for the detection of multivessel coronary artery disease and, potentially, for risk stratification. Coronary artery calcium scoring may be included for further risk stratification in patients with normal perfusion imaging findings. Furthermore, PET allows quantification of absolute myocardial perfusion, which also carries substantial prognostic value. Hybrid PET–computed tomography scanners allow functional evaluation of myocardial perfusion combined with anatomic characterization of the epicardial coronary arteries, thereby offering great potential for both diagnosis and management. Additional studies to further validate the prognostic value and cost effectiveness of PET are warranted. © RSNA, 2011 PMID:21918042

[Effects of circulating microvesicles derived from myocardial ischemic preconditioning on myocardial ischemia/reperfusion injury in rats].

PubMed

Wang, Yi-Lu; Liu, Miao; Shang, Man; Wang, Yao; Zhang, Qi; Wang, Shao-Xun; Wei, Su; Zhang, Kun-Wei; Liu, Chao; Wu, Yan-Na; Song, Jun-Qiu; Liu, Yan-Xia

2016-02-08

To investigate the effects of circulating microvesicles (MVs) derived from ischemic preconditioning (IPC) on myocardial ischemia/reperfusion (I/R) injury in rats and explore the underlying mechanism. To establish the IPC model, the rats were subjected to brief cycles of left anterior descending (LAD) coronary occlusion and reperfusion. The blood was drawn from abdominal aorta once the operation was finished. IPC-MVs were isolated by ultracentrifugation from the peripheral blood and characterized by flow cytometry. The myocardial I/R model of rats was established in vivo. Rats were injected via the femoral vein with IPC-MVs at 7 mg/kg. Morphological changes of myocardium were observed microscopically after HE staining. Apoptosis of myocardial cells was detected with TUNEL assay. Myocardial infarct size was detected by TTC staining. Moreover, activity of plasma lactate dehydrogenase (LDH) was tested by colorimetry. The activity of caspase 3 in myocardium was assayed with spectrophotometry. Expression levels of Bcl-2 and Bax protein were examined with Western blot. The concentration of IPC-MVs, which was detected by flow cytometry, was 4380±745 cells/ μ l. Compared with I/R group, IPC-MVs alleviated the damage of tissues in I/R injured rats significantly. The myocardial infarct size and the cardiomyocyte apoptotic index were obviously decreased after IPC-MVs treatment ( P <0.01, respectively). The activity of plasma LDH was significantly decreased in IPC-MVs treated rats ( P <0.01). Moreover, the activity of caspase 3 was markedly decreased after IPC-MVs treatment ( P <0.01). In addition, the expression of Bcl-2 was increased ( P <0.01), the expression of Bax was decreased ( P <0.01), the ratio of Bcl-2/Bax was significantly increased after IPC-MVs treatment ( P <0.01). IPC-MVs protected myocardial against I/R injury by up-regulating the expression of Bcl-2 protein, down-regulating the expression of Bax protein, increasing the ratio of Bcl-2/Bax and decreasing cleavage of caspase 3.

Sepiapterin reduces postischemic injury in the rat heart.

PubMed

Tiefenbacher, Christiane P; Lee, Ching-Hua; Kapitza, Jolanthe; Dietz, Volker; Niroomand, Feraydoon

2003-10-01

A reduced availability of tetrahydrobiopterin (BH4), an essential cofactor for NO-synthesis, is causally involved in the development of endothelial dysfunction associated with ischemia/reperfusion. We, therefore, investigated the effect of sepiapterin, a substrate for BH4 synthesis, on postischemic injury in myocardial infarction and myocardial stunning. In rats, myocardial stunning was induced by repetitive ischemia (5 x 10-min ligature of the left coronary artery, 5 x 20-min reperfusion) and myocardial infarction by 50-min ligature and 60-min reperfusion. Myocardial blood flow was determined by H2-clearance, regional myocardial function by pulsed Doppler and infarct size by tetrazolium staining. Myeloperoxidase (MPO) activity was measured as a marker of neutrophil extravasation. cGMP was determined in rat serum as an indicator of increased NO synthesis. In animals treated with sepiapterin, regional myocardial function was significantly improved in both myocardial stunning and infarction and infarct size was significantly reduced. MPO activity decreased with sepiapterin treatment in both models. The systemic level of cGMP was reduced both following myocardial stunning and myocardial infarction in the control group. Pretreatment with sepiapterin induced a significant increase of cGMP level at the end of the protocol in both models. Substitution of sepiapterin reduces postischemic injury both in myocardial stunning and infarction apparently by ameliorating the availability of NO, thereby attenuating the activation of neutrophils in ischemia/reperfusion.

Custodiol for myocardial protection and preservation: a systematic review

PubMed Central

Seco, Michael; Dunne, Ben; Matzelle, Shannon J.; Murphy, Michelle; Joshi, Pragnesh; Yan, Tristan D.; Wilson, Michael K.; Bannon, Paul G.; Vallely, Michael P.; Passage, Jurgen

2013-01-01

Introduction Custodiol cardioplegia is attractive for minimally invasive cardiac surgery, as a single dose provides a long period of myocardial protection. Despite widespread use in Europe, there is little data confirming its efficacy compared with conventional (blood or crystalloid) cardioplegia. There is similar enthusiasm for its use in organ preservation for transplant, but also a lack of data. This systematic review aimed to assess the evidence for the efficacy of Custodiol in myocardial protection and as a preservation solution in heart transplant. Methods Electronic searches were performed of six databases from inception to October 2013. Reviewers independently identified studies that compared Custodiol with conventional cardioplegia (blood or extracellular crystalloid) in adult patients for meta-analysis; large case series that reported results using Custodiol were analyzed. Next, we identified studies that compared Custodiol with other organ preservation solutions for organ preservation in heart transplant. Results Fourteen studies compared Custodiol with conventional cardioplegia for myocardial protection in adult cardiac surgery. No difference was identified in mortality; there was a trend for increased incidence of ventricular fibrillation in the Custodiol group that did not reach statistical significance. No difference was identified in studies that compared Custodiol with other solutions for heart transplant. Conclusions Despite widespread clinical use, the evidence supporting the superiority of Custodiol over other solutions for myocardial protection or organ preservation is limited. Large randomised trials are required. PMID:24349972

[EFFICACY OF STANDARD TWO-YEAR COMPREHENSIVE THERAPY TO ACHIEVE TARGET BLOOD PRESSURE AND REGRESSION DEGREES OF REMODELING OF THE LEFT VENTRICULAR HYPERTROPHY IN PATIENTS AFTER ACUTE MYOCARDIAL INFARCTION WITH COMORBID HYPERTENSION].

PubMed

Denesiuk, E V

2015-01-01

The study involved 23 men after acute myocardial infarction (AMI) with comorbid arterial hypertension (AH). Mean age of patients was 56.7 years. Recurrent myocardial infarction was determined in 38.4%, cardiac failure I-III functional classes--100% of the cases. All patients underwent clinical examination, electrocardiography and echocardiography, blood lipid profile. Standard comprehensive treatment for two years included an perindopril 5-10 mg/day, beta-blocker bisoprolol--5-10 mg/day, antisclerotic drug atorvastatin--20 mg/day and aspirin--75 mg/day. The patients after treatment was determined by a gradual increase towards the target of AT at 3, 6 and 12 to 24 months. Concentric left ventricular hypertrophy (LVH) before treatment was determined in 47.8%, eccentric--in 52.2% of patients. In the study of degrees of LVH I (initial) the extent to treatment was determined by 4.3%, II (moderate)--26.1%, III (large)--at 69.6%, indicating the development of cardiac remodeling. After the treatment was determined by marked reduction III (large) degree and transfer it in the II (moderate) and I (small) degree of left ventricular hypertrophy due to more or less pronounced changes remodeling left ventricular. The obtained data allow a more detailed and adequately assess the structural and functional outcome variables and determine the regression of myocardial hypertrophy in the background to achieve target blood pressure, which is important in practical cardiology.

Fractal regional myocardial blood flows pattern according to metabolism, not vascular anatomy

PubMed Central

Yipintsoi, Tada; Kroll, Keith

2015-01-01

Regional myocardial blood flows are markedly heterogeneous. Fractal analysis shows strong near-neighbor correlation. In experiments to distinguish control by vascular anatomy vs. local vasomotion, coronary flows were increased in open-chest dogs by stimulating myocardial metabolism (catecholamines + atropine) with and without adenosine. During control states mean left ventricular (LV) myocardial blood flows (microspheres) were 0.5–1 ml·g−1·min−1 and increased to 2–3 ml·g−1·min−1 with catecholamine infusion and to ∼4 ml·g−1·min−1 with adenosine (Ado). Flow heterogeneity was similar in all states: relative dispersion (RD = SD/mean) was ∼25%, using LV pieces 0.1–0.2% of total. During catecholamine infusion local flows increased in proportion to the mean flows in 45% of the LV, “tracking” closely (increased proportionately to mean flow), while ∼40% trended toward the mean. Near-neighbor regional flows remained strongly spatially correlated, with fractal dimension D near 1.2 (Hurst coefficient 0.8). The spatial patterns remain similar at varied levels of metabolic stimulation inferring metabolic dominance. In contrast, adenosine vasodilation increased flows eightfold times control while destroying correlation with the control state. The Ado-induced spatial patterns differed from control but were self-consistent, inferring that with full vasodilation the relaxed arterial anatomy dominates the distribution. We conclude that vascular anatomy governs flow distributions during adenosine vasodilation but that metabolic vasoregulation dominates in normal physiological states. PMID:26589329

Fractal regional myocardial blood flows pattern according to metabolism, not vascular anatomy.

PubMed

Yipintsoi, Tada; Kroll, Keith; Bassingthwaighte, James B

2016-02-01

Regional myocardial blood flows are markedly heterogeneous. Fractal analysis shows strong near-neighbor correlation. In experiments to distinguish control by vascular anatomy vs. local vasomotion, coronary flows were increased in open-chest dogs by stimulating myocardial metabolism (catecholamines + atropine) with and without adenosine. During control states mean left ventricular (LV) myocardial blood flows (microspheres) were 0.5-1 ml·g(-1)·min(-1) and increased to 2-3 ml·g(-1)·min(-1) with catecholamine infusion and to ∼4 ml·g(-1)·min(-1) with adenosine (Ado). Flow heterogeneity was similar in all states: relative dispersion (RD = SD/mean) was ∼25%, using LV pieces 0.1-0.2% of total. During catecholamine infusion local flows increased in proportion to the mean flows in 45% of the LV, "tracking" closely (increased proportionately to mean flow), while ∼40% trended toward the mean. Near-neighbor regional flows remained strongly spatially correlated, with fractal dimension D near 1.2 (Hurst coefficient 0.8). The spatial patterns remain similar at varied levels of metabolic stimulation inferring metabolic dominance. In contrast, adenosine vasodilation increased flows eightfold times control while destroying correlation with the control state. The Ado-induced spatial patterns differed from control but were self-consistent, inferring that with full vasodilation the relaxed arterial anatomy dominates the distribution. We conclude that vascular anatomy governs flow distributions during adenosine vasodilation but that metabolic vasoregulation dominates in normal physiological states. Copyright © 2016 the American Physiological Society.

Defibrotide reduces infarct size in a rabbit model of experimental myocardial ischaemia and reperfusion.

PubMed Central

Thiemermann, C.; Thomas, G. R.; Vane, J. R.

1989-01-01

1. Defibrotide, a single-stranded polydeoxyribonucleotide obtained from bovine lungs, has significant anti-thrombotic, pro-fibrinolytic and prostacyclin-stimulating properties. 2. The present study was designed to evaluate the effects of defibrotide on infarct size and regional myocardial blood flow in a rabbit model of myocardial ischaemia and reperfusion. 3. Defibrotide (32 mg kg-1 bolus + 32 mg kg-1 h-1, i.v.) either with or without co-administration of indomethacin (5 mg kg-1 x 2, i.v.) was administered 5 min after occlusion of the left anterior-lateral coronary artery and continued during the 60 min occlusion and subsequent 3 h reperfusion periods. 4. Defibrotide significantly attenuated the ischaemia-induced ST-segment elevation and abolished the reperfusion-related changes (R-wave reduction and Q-wave development) in the electrocardiogram. In addition, defibrotide significantly improved myocardial blood flow in normal and in ischaemic, but not in infarcted sections of the heart. The improvement in blood flow in normal perfused myocardium, but not in the ischaemic area was prevented by indomethacin. 5. Although the area at risk was similar in all animal groups studied, defibrotide treatment resulted in a 51% reduction of infarct size. Indomethacin treatment abolished the reduction of infarct size seen with defibrotide alone. 6. The data demonstrate a considerable cardioprotective effect of defibrotide in the reperfused ischaemic rabbit myocardium. This effect may be related, at least in part, to a stimulation of endogenous prostaglandin formation. Other possible mechanisms are discussed. PMID:2758223

Highly automatic quantification of myocardial oedema in patients with acute myocardial infarction using bright blood T2-weighted CMR

PubMed Central

2013-01-01

Background T2-weighted cardiovascular magnetic resonance (CMR) is clinically-useful for imaging the ischemic area-at-risk and amount of salvageable myocardium in patients with acute myocardial infarction (MI). However, to date, quantification of oedema is user-defined and potentially subjective. Methods We describe a highly automatic framework for quantifying myocardial oedema from bright blood T2-weighted CMR in patients with acute MI. Our approach retains user input (i.e. clinical judgment) to confirm the presence of oedema on an image which is then subjected to an automatic analysis. The new method was tested on 25 consecutive acute MI patients who had a CMR within 48 hours of hospital admission. Left ventricular wall boundaries were delineated automatically by variational level set methods followed by automatic detection of myocardial oedema by fitting a Rayleigh-Gaussian mixture statistical model. These data were compared with results from manual segmentation of the left ventricular wall and oedema, the current standard approach. Results The mean perpendicular distances between automatically detected left ventricular boundaries and corresponding manual delineated boundaries were in the range of 1-2 mm. Dice similarity coefficients for agreement (0=no agreement, 1=perfect agreement) between manual delineation and automatic segmentation of the left ventricular wall boundaries and oedema regions were 0.86 and 0.74, respectively. Conclusion Compared to standard manual approaches, the new highly automatic method for estimating myocardial oedema is accurate and straightforward. It has potential as a generic software tool for physicians to use in clinical practice. PMID:23548176

Blood pool and tissue phase patient motion effects on 82rubidium PET myocardial blood flow quantification.

PubMed

Lee, Benjamin C; Moody, Jonathan B; Poitrasson-Rivière, Alexis; Melvin, Amanda C; Weinberg, Richard L; Corbett, James R; Ficaro, Edward P; Murthy, Venkatesh L

2018-03-23

Patient motion can lead to misalignment of left ventricular volumes of interest and subsequently inaccurate quantification of myocardial blood flow (MBF) and flow reserve (MFR) from dynamic PET myocardial perfusion images. We aimed to identify the prevalence of patient motion in both blood and tissue phases and analyze the effects of this motion on MBF and MFR estimates. We selected 225 consecutive patients that underwent dynamic stress/rest rubidium-82 chloride ( 82 Rb) PET imaging. Dynamic image series were iteratively reconstructed with 5- to 10-second frame durations over the first 2 minutes for the blood phase and 10 to 80 seconds for the tissue phase. Motion shifts were assessed by 3 physician readers from the dynamic series and analyzed for frequency, magnitude, time, and direction of motion. The effects of this motion isolated in time, direction, and magnitude on global and regional MBF and MFR estimates were evaluated. Flow estimates derived from the motion corrected images were used as the error references. Mild to moderate motion (5-15 mm) was most prominent in the blood phase in 63% and 44% of the stress and rest studies, respectively. This motion was observed with frequencies of 75% in the septal and inferior directions for stress and 44% in the septal direction for rest. Images with blood phase isolated motion had mean global MBF and MFR errors of 2%-5%. Isolating blood phase motion in the inferior direction resulted in mean MBF and MFR errors of 29%-44% in the RCA territory. Flow errors due to tissue phase isolated motion were within 1%. Patient motion was most prevalent in the blood phase and MBF and MFR errors increased most substantially with motion in the inferior direction. Motion correction focused on these motions is needed to reduce MBF and MFR errors.

Evaluation of cerebral-cardiac syndrome using echocardiography in a canine model of acute traumatic brain injury.

PubMed

Qian, Rong; Yang, Weizhong; Wang, Xiumei; Xu, Zhen; Liu, Xiaodong; Sun, Bing

2015-01-01

Previous studies have confirmed that traumatic brain injury (TBI) can induce general adaptation syndrome (GAS), which subsequently results in myocardial dysfunction and damage in some patients with acute TBI; this condition is also termed as cerebral-cardiac syndrome. However, most clinicians ignore the detection and treatment of myocardial dysfunction, and instead concentrate only on the serious neural damage that is observed in acute TBI, which is one of the most important fatal factors. Therefore, clarification is urgently needed regarding the relationship between TBI and myocardial dysfunction. In the present study, we evaluated 18 canine models of acute TBI, by using real-time myocardial contrast echocardiography and strain rate imaging to accurately evaluate myocardial function and regional microcirculation, including the strain rate of the different myocardial segments, time-amplitude curves, mean ascending slope of the curve, and local myocardial blood flow. Our results suggest that acute TBI often results in cerebral-cardiac syndrome, which rapidly progresses to the serious stage within 3 days. This study is the first to provide comprehensive ultrasonic characteristics of cerebral-cardiac syndrome in an animal model of TBI.

Novel cardiovascular magnetic resonance oxygenation approaches in understanding pathophysiology of cardiac diseases.

PubMed

Sree Raman, Karthigesh; Nucifora, Gaetano; Selvanayagam, Joseph B

2018-05-01

Cardiovascular magnetic resonance imaging (CMR) permits accurate phenotyping of many cardiac diseases. CMR's inherent advantages are its non-invasive nature, lack of ionizing radiation and high accuracy and reproducibility. Furthermore, it is able to assess many aspects of cardiac anatomy, structure and function. Specifically, it can characterize myocardial tissue, myocardial function, myocardial mass, myocardial blood flow/perfusion, irreversible and reversible injury, all with a high degree of accuracy and reproducibility. Hence, CMR is a powerful tool in clinical and pre-clinical research. In recent years there have been novel advances in CMR myocardial tissue characterization. Oxygenation-sensitive CMR (OS-CMR) is a novel non-invasive, contrast independent technique that permits direct quantification of myocardial tissue oxygenation, both at rest and during stress. In this review, we will address the principles of the OS-CMR technique, its recent advances and summarize the studies in the effects of oxygenation on cardiac diseases. © 2018 John Wiley & Sons Australia, Ltd.

The continual innovation of commercial PET/CT solutions in nuclear cardiology: Siemens Healthineers.

PubMed

Bendriem, Bernard; Reed, Jessie; McCullough, Kathryn; Khan, Mohammad Raza; Smith, Anne M; Thomas, Damita; Long, Misty

2018-04-10

Cardiac PET/CT is an evolving, non-invasive imaging modality that impacts patient management in many clinical scenarios. Beyond offering the capability to assess myocardial perfusion, inflammatory cardiac pathologies, and myocardial viability, cardiac PET/CT also allows for the non-invasive quantitative assessment of myocardial blood flow (MBF) and myocardial flow reserve (MFR). Recognizing the need for an enhanced comprehension of coronary physiology, Siemens Healthineers implemented a sophisticated solution for the calculation of MBF and MFR in 2009. As a result, each aspect of their innovative scanner and image-processing technology seamlessly integrates into an efficient, easy-to-use workflow for everyday clinical use that maximizes the number of patients who potentially benefit from this imaging modality.

Off-pump supra-arterial myotomy for myocardial bridging.

PubMed

Crespo, Alejandro; Aramendi, José I; Hamzeh, Gadah; Voces, Roberto

2008-09-01

We report the results of surgery and midterm outcome in two patients with symptomatic myocardial bridging who underwent off-pump supra-arterial myotomy. Both patients were operated upon through a median sternotomy. The anterior wall of the heart was exposed in the same manner as in off-pump CABG. The left anterior descending coronary artery is unroofed from its myocardial bridge with the aid of a heart stabilizer and a blower. Neither heparin nor blood transfusion was required. Both patients survived the operation and are asymptomatic. Postoperative coronary angiogram showed good resolution of the muscle bridge in one patient. We conclude that in symptomatic patients with myocardial bridging despite medical therapy, surgical myotomy can be considered an adequate therapy. It can be safely done off-pump.

A New Biomarkers Feature Pattern Consisting of TNF-α, IL-10, and IL-8 for Blood Stasis Syndrome with Myocardial Ischemia

PubMed Central

Chen, Jianxin; Chuo, Wenjing; Liu, Lei; Lian, Hongjian; Zheng, Lei; Wang, Yong; Xie, Hua; Luo, Liangtao; Zheng, Chenglong; Fu, Bangze; Wang, Wei

2013-01-01

Objective. To explore new diagnostic patterns for syndromes to overcome the insufficiency of obtainable macrocharacteristics and specific biomarkers. Methods. Chinese miniswines were subjected to Ameroid constrictor, placed around the proximal left anterior descending branch. On the 4th week, macrocharacteristics, coronary angiography, echocardiography, and hemorheology indices were detected for diagnosis. IL-1, IL-6, IL-8, IL-10, TNF-α, and hsCRP in serum were detected, and Decision Tree was built. Results. According to current official-issued standard, model animals matched the diagnosis of blood stasis syndrome with myocardial ischemia based on findings, including >90% occlusion, attenuated left ventricular segmental motion, dark red or purple tongues, and higher blood viscosity. Significant decrease of IL-10 and increase of TNF-α were found in model animals. However, in the Decision Tree, besides IL-10 and TNF-α, IL-8 helped to increase the accuracy of classification to 86%. Conclusions. The Decision Tree building with TNF-α, IL-10, and IL-8 is helpful for the diagnosis of blood stasis syndrome in myocardial ischemia animals. What is more is that our data set up a new path to the differentiation of syndrome by feature patterns consisting of multiple biomarkers not only for animals but also for patients. We believe that it will contribute to the standardization and international application of syndromes. PMID:24371451

Umbilical cord vitamin D, ionized calcium and myocardial oxygen demand.

PubMed

Reeves, Inez; Liang, Willie; Asadi, M Sadegh; Millis, Richard M

2014-07-01

Systemic blood vitamin D and total calcium are correlates of birthweight and cardiovascular disease but whether umbilical cord blood vitamin D and ionized calcium are correlates of birthweight and cardiovascular function is not known. This cross-sectional study correlates umbilical cord vitamin D, ionized calcium and birthweight with the heart rate-systolic pressure product (RPP), an indicator of myocardial oxygen demand. Cord blood vitamin D and ionized calcium concentrations were compared for vitamin D normal (≥50 nM, 20 ng/mL) and vitamin D deficiency (<50 nM, 20 ng/mL) in normal weight (≥2500 g) and low birthweight (LBW, <2500 g) newborns. Heart rate and blood pressure were measured during postnatal transition and RPP was computed. RPP was positively correlated with birthweight (r = +0.52, p < 0.001) and with cord ionized calcium level (r = +0.42, p < 0.01) in the normal and LBW newborns. RPP was positively correlated with cord vitamin D level in the LBW newborns (raw r = +0.50, p < 0.05, normalized for birthweight r = +0.73, p < 0.01). Small RPP, an indicator of low myocardial oxygen demand, in LBW newborns appears to correlate with low umbilical cord vitamin D and ionized calcium levels, suggestive of pathological heart development.

Blood B-type natriuretic peptide level increases in patients who complain shortness of breath and chest pain in the course of panic attack.

PubMed

Vural, Mutlu; Akbas, Befru; Acer, Mehmet; Karabay, Ocal

2007-04-25

Blood pro-B-type natriuretic peptide (pro-BNP) level increases in case of myocardial ischemia and myocardial volume or pressure overload. The aim of this study is to measure changes in blood pro-BNP level during the course of panic attack with symptoms of chest pain and/or dyspnea. Patients who were admitted to the emergency room with panic attack have been regarded as the study group. Blood pro-BNP level has been measured during follow-up of the patients upon admission and 2h later. Systolic and diastolic blood pressure and pulse rate were significantly decreased (p<0.0001) during follow-up of the patients (ages between 18 and 43 years; mean 26+/-6.13 years). Paradoxically, blood pro-BNP level of patients was significantly increased during the same period (52.86+/-59.73 versus 50.97+/-57.42 U/L; p<0.0001). Blood pro-BNP level has increased among patients who have complained chest pain and/or dyspnea as symptoms of panic attack. It is thought that chest pain and dyspnea in the course of panic attack may not be purely psychological.

Warm blood cardioplegia versus cold crystalloid cardioplegia for myocardial protection during coronary artery bypass grafting surgery.

PubMed

Nardi, Paolo; Pisano, Calogera; Bertoldo, Fabio; Vacirca, Sara R; Saitto, Guglielmo; Costantino, Antonino; Bovio, Emanuele; Pellegrino, Antonio; Ruvolo, Giovanni

2018-12-01

We retrospectively analyzed early results of coronary artery bypass grafting (CABG) surgery using two different types of cardioplegia for myocardial protection: antegrade intermittent warm blood or cold crystalloid cardioplegia. From January 2015 to October 2016, 330 consecutive patients underwent isolated on-pump CABG. Cardiac arrest was obtained with use of warm blood cardioplegia (WBC group, n  = 297) or cold crystalloid cardioplegia (CCC group, n  = 33), according to the choice of the surgeon. Euroscore II and preoperative characteristics were similar in both groups, except for the creatinine clearance, slightly lower in WBC group (77.33 ± 27.86 mL/min versus 88.77 ± 51.02 mL/min) ( P  < 0.05). Complete revascularization was achieved in both groups. In-hospital mortality was 2.0% ( n  = 6) in WBC group, absent in CCC group. The required mean number of cardioplegia's doses per patient was higher in WBC group (2.3 ± 0.8) versus CCC group (2.0 ± 0.7) ( P  = 0.045), despite a lower number of distal coronary artery anastomoses (2.7 ± 0.8 versus 3.2 ± 0.9) ( P  = 0.0001). Cardiopulmonary and aortic cross-clamp times were similar in both groups. The incidence of perioperative myocardial infarction (WBC group 3.4% versus CCC group 3.0%) and low cardiac output syndrome (4.4% versus 3.0%) were similar in both groups. As compared with WBC group, in CCC group CK-MB/CK ratio >10% was lower during each time points of evaluation, with a statistical significant difference at time 0 (4% ± 1.6% versus 5% ± 2.5%) ( P  = 0.021). In presence of complete revascularization, despite the value of CK-MB/CK ratio >10% was less in the CCC group, clinical results were not affected by both types of cardioplegia adopted to myocardial protection. As compared with cold crystalloid, warm blood cardioplegia requires a shorter interval of administration to achieve better myocardial protection.

Early Use of N-acetylcysteine With Nitrate Therapy in Patients Undergoing Primary Percutaneous Coronary Intervention for ST-Segment-Elevation Myocardial Infarction Reduces Myocardial Infarct Size (the NACIAM Trial [N-acetylcysteine in Acute Myocardial Infarction]).

PubMed

Pasupathy, Sivabaskari; Tavella, Rosanna; Grover, Suchi; Raman, Betty; Procter, Nathan E K; Du, Yang Timothy; Mahadavan, Gnanadevan; Stafford, Irene; Heresztyn, Tamila; Holmes, Andrew; Zeitz, Christopher; Arstall, Margaret; Selvanayagam, Joseph; Horowitz, John D; Beltrame, John F

2017-09-05

Contemporary ST-segment-elevation myocardial infarction management involves primary percutaneous coronary intervention, with ongoing studies focusing on infarct size reduction using ancillary therapies. N-acetylcysteine (NAC) is an antioxidant with reactive oxygen species scavenging properties that also potentiates the effects of nitroglycerin and thus represents a potentially beneficial ancillary therapy in primary percutaneous coronary intervention. The NACIAM trial (N-acetylcysteine in Acute Myocardial Infarction) examined the effects of NAC on infarct size in patients with ST-segment-elevation myocardial infarction undergoing percutaneous coronary intervention. This randomized, double-blind, placebo-controlled, multicenter study evaluated the effects of intravenous high-dose NAC (29 g over 2 days) with background low-dose nitroglycerin (7.2 mg over 2 days) on early cardiac magnetic resonance imaging-assessed infarct size. Secondary end points included cardiac magnetic resonance-determined myocardial salvage and creatine kinase kinetics. Of 112 randomized patients with ST-segment-elevation myocardial infarction, 75 (37 in NAC group, 38 in placebo group) underwent early cardiac magnetic resonance imaging. Median duration of ischemia pretreatment was 2.4 hours. With background nitroglycerin infusion administered to all patients, those randomized to NAC exhibited an absolute 5.5% reduction in cardiac magnetic resonance-assessed infarct size relative to placebo (median, 11.0%; [interquartile range 4.1, 16.3] versus 16.5%; [interquartile range 10.7, 24.2]; P =0.02). Myocardial salvage was approximately doubled in the NAC group (60%; interquartile range, 37-79) compared with placebo (27%; interquartile range, 14-42; P <0.01) and median creatine kinase areas under the curve were 22 000 and 38 000 IU·h in the NAC and placebo groups, respectively ( P =0.08). High-dose intravenous NAC administered with low-dose intravenous nitroglycerin is associated with reduced infarct size in patients with ST-segment-elevation myocardial infarction undergoing percutaneous coronary intervention. A larger study is required to assess the impact of this therapy on clinical cardiac outcomes. Australian New Zealand Clinical Trials Registry. URL: http://www.anzctr.org.au/. Unique identifier: 12610000280000. © 2017 American Heart Association, Inc.

Recurrent ventricular arrhythmias complicating myocardial infarction in the presence of phaeochromocytoma.

PubMed Central

McNeill, A J; Adgey, A A; Wilson, C

1992-01-01

After an acute myocardial infarction a 49 year old man developed late recurrent severe ventricular arrhythmias coincident with transient hypertensive episodes. A phaeochromocytoma was diagnosed on the basis of the urinary concentration of catecholamines and computerised tomography of the adrenal glands. After stabilisation of his cardiac rhythm and blood pressure with alpha and beta adrenergic blockade and anti-arrhythmic treatment the right adrenal gland, which contained the tumour, was successfully resected. The diagnosis of a phaeochromocytoma should be considered when recurrent ventricular arrhythmias are associated with intermittent hypertension after myocardial infarction. PMID:1739535

Rapid computation of single PET scan rest-stress myocardial blood flow parametric images by table look up.

PubMed

Guehl, Nicolas J; Normandin, Marc D; Wooten, Dustin W; Rozen, Guy; Ruskin, Jeremy N; Shoup, Timothy M; Woo, Jonghye; Ptaszek, Leon M; Fakhri, Georges El; Alpert, Nathaniel M

2017-09-01

We have recently reported a method for measuring rest-stress myocardial blood flow (MBF) using a single, relatively short, PET scan session. The method requires two IV tracer injections, one to initiate rest imaging and one at peak stress. We previously validated absolute flow quantitation in ml/min/cc for standard bull's eye, segmental analysis. In this work, we extend the method for fast computation of rest-stress MBF parametric images. We provide an analytic solution to the single-scan rest-stress flow model which is then solved using a two-dimensional table lookup method (LM). Simulations were performed to compare the accuracy and precision of the lookup method with the original nonlinear method (NLM). Then the method was applied to 16 single scan rest/stress measurements made in 12 pigs: seven studied after infarction of the left anterior descending artery (LAD) territory, and nine imaged in the native state. Parametric maps of rest and stress MBF as well as maps of left (f LV ) and right (f RV ) ventricular spill-over fractions were generated. Regions of interest (ROIs) for 17 myocardial segments were defined in bull's eye fashion on the parametric maps. The mean of each ROI was then compared to the rest (K 1r ) and stress (K 1s ) MBF estimates obtained from fitting the 17 regional TACs with the NLM. In simulation, the LM performed as well as the NLM in terms of precision and accuracy. The simulation did not show that bias was introduced by the use of a predefined two-dimensional lookup table. In experimental data, parametric maps demonstrated good statistical quality and the LM was computationally much more efficient than the original NLM. Very good agreement was obtained between the mean MBF calculated on the parametric maps for each of the 17 ROIs and the regional MBF values estimated by the NLM (K 1map LM  = 1.019 × K 1 ROI NLM  + 0.019, R 2  = 0.986; mean difference = 0.034 ± 0.036 mL/min/cc). We developed a table lookup method for fast computation of parametric imaging of rest and stress MBF. Our results show the feasibility of obtaining good quality MBF maps using modest computational resources, thus demonstrating that the method can be applied in a clinical environment to obtain full quantitative MBF information. © 2017 American Association of Physicists in Medicine.

Non-Invasive Method of Determining Absolute Intracranial Pressure

NASA Technical Reports Server (NTRS)

Yost, William T. (Inventor); Cantrell, John H., Jr. (Inventor); Hargens, Alan E. (Inventor)

2004-01-01

A method is presented for determining absolute intracranial pressure (ICP) in a patient. Skull expansion is monitored while changes in ICP are induced. The patient's blood pressure is measured when skull expansion is approximately zero. The measured blood pressure is indicative of a reference ICP value. Subsequently, the method causes a known change in ICP and measured the change in skull expansion associated therewith. The absolute ICP is a function of the reference ICP value, the known change in ICP and its associated change in skull expansion; and a measured change in skull expansion.

Neighbourhood socioeconomic inequalities in incidence of acute myocardial infarction: a cohort study quantifying age- and gender-specific differences in relative and absolute terms.

PubMed

Koopman, Carla; van Oeffelen, Aloysia A M; Bots, Michiel L; Engelfriet, Peter M; Verschuren, W M Monique; van Rossem, Lenie; van Dis, Ineke; Capewell, Simon; Vaartjes, Ilonca

2012-08-07

Socioeconomic status has a profound effect on the risk of having a first acute myocardial infarction (AMI). Information on socioeconomic inequalities in AMI incidence across age-gender-groups is lacking. Our objective was to examine socioeconomic inequalities in the incidence of AMI considering both relative and absolute measures of risk differences, with a particular focus on age and gender. We identified all patients with a first AMI from 1997 to 2007 through linked hospital discharge and death records covering the Dutch population. Relative risks (RR) of AMI incidence were estimated by mean equivalent household income at neighbourhood-level for strata of age and gender using Poisson regression models. Socioeconomic inequalities were also shown within the stratified age-gender groups by calculating the total number of events attributable to socioeconomic disadvantage. Between 1997 and 2007, 317,564 people had a first AMI. When comparing the most deprived socioeconomic quintile with the most affluent quintile, the overall RR for AMI was 1.34 (95 % confidence interval (CI): 1.32-1.36) in men and 1.44 (95 % CI: 1.42-1.47) in women. The socioeconomic gradient decreased with age. Relative socioeconomic inequalities were most apparent in men under 35 years and in women under 65 years. The largest number of events attributable to socioeconomic inequalities was found in men aged 45-74 years and in women aged 65-84 years. The total proportion of AMIs that was attributable to socioeconomic inequalities in the Dutch population of 1997 to 2007 was 14 % in men and 18 % in women. Neighbourhood socioeconomic inequalities were observed in AMI incidence in the Netherlands, but the magnitude across age-gender groups depended on whether inequality was expressed in relative or absolute terms. Relative socioeconomic inequalities were high in young persons and women, where the absolute burden of AMI was low. Absolute socioeconomic inequalities in AMI were highest in the age-gender groups of middle-aged men and elderly women, where the number of cases was largest.

Neighbourhood socioeconomic inequalities in incidence of acute myocardial infarction: a cohort study quantifying age- and gender-specific differences in relative and absolute terms

PubMed Central

2012-01-01

Background Socioeconomic status has a profound effect on the risk of having a first acute myocardial infarction (AMI). Information on socioeconomic inequalities in AMI incidence across age- gender-groups is lacking. Our objective was to examine socioeconomic inequalities in the incidence of AMI considering both relative and absolute measures of risk differences, with a particular focus on age and gender. Methods We identified all patients with a first AMI from 1997 to 2007 through linked hospital discharge and death records covering the Dutch population. Relative risks (RR) of AMI incidence were estimated by mean equivalent household income at neighbourhood-level for strata of age and gender using Poisson regression models. Socioeconomic inequalities were also shown within the stratified age-gender groups by calculating the total number of events attributable to socioeconomic disadvantage. Results Between 1997 and 2007, 317,564 people had a first AMI. When comparing the most deprived socioeconomic quintile with the most affluent quintile, the overall RR for AMI was 1.34 (95 % confidence interval (CI): 1.32 – 1.36) in men and 1.44 (95 % CI: 1.42 – 1.47) in women. The socioeconomic gradient decreased with age. Relative socioeconomic inequalities were most apparent in men under 35 years and in women under 65 years. The largest number of events attributable to socioeconomic inequalities was found in men aged 45–74 years and in women aged 65–84 years. The total proportion of AMIs that was attributable to socioeconomic inequalities in the Dutch population of 1997 to 2007 was 14 % in men and 18 % in women. Conclusions Neighbourhood socioeconomic inequalities were observed in AMI incidence in the Netherlands, but the magnitude across age-gender groups depended on whether inequality was expressed in relative or absolute terms. Relative socioeconomic inequalities were high in young persons and women, where the absolute burden of AMI was low. Absolute socioeconomic inequalities in AMI were highest in the age-gender groups of middle-aged men and elderly women, where the number of cases was largest. PMID:22870916

Vitexin exerts cardioprotective effect on chronic myocardial ischemia/reperfusion injury in rats via inhibiting myocardial apoptosis and lipid peroxidation.

PubMed

Che, Xia; Wang, Xin; Zhang, Junyan; Peng, Chengfeng; Zhen, Yilan; Shao, Xu; Zhang, Gongliang; Dong, Liuyi

2016-01-01

The aim of this study was to explore the cardioprotective effect of vitexin on chronic myocardial ischemia/reperfusion injury in rats and potential mechanisms. A chronic myocardial ischemia/reperfusion injury model was established by ligating left anterior descending coronary for 60 minutes, and followed by reperfusion for 14 days. After 2 weeks ischemia/reperfusion, cardiac function was measured to assess myocardial injury. The level of ST segment was recorded in different periods by electrocardiograph. The change of left ventricular function and myocardial reaction degree of fibrosis of heart was investigated by hematoxylin and eosin (HE) staining and Sirius red staining. Endothelium-dependent relaxations due to acetylcholine were observed in isolated rat thoracic aortic ring preparation. The blood samples were collected to measure the levels of MDA, the activities of SOD and NADPH in serum. Epac1, Rap1, Bax and Bcl-2 were examined by using Western Blotting. Vitexin exerted significant protective effect on chronic myocardial ischemia/reperfusion injury, improved obviously left ventricular diastolic function and reduced myocardial reactive fibrosis degree in rats of myocardial ischemia. Medium and high-dose vitexin groups presented a significant decrease in Bax, Epac1 and Rap1 production and increase in Bcl-2 compared to the I/R group. It may be related to preventing myocardial cells from apoptosis, improving myocardial diastolic function and inhibiting lipid peroxidation. Vitexin is a cardioprotective herb, which may be a promising useful complementary and alternative medicine for patients with coronary heart disease.

Emerging MRI Methods in Translational Cardiovascular Research

PubMed Central

Vandsburger, Moriel H; Epstein, Frederick H

2011-01-01

Cardiac magnetic resonance imaging (CMR) has become a reference standard modality for imaging of left ventricular (LV) structure and function, and, using late gadolinium enhancement, for imaging myocardial infarction. Emerging CMR techniques enable a more comprehensive examination of the heart, making CMR an excellent tool for use in translational cardiovascular research. Specifically, emerging CMR methods have been developed to measure the extent of myocardial edema, changes in ventricular mechanics, changes in tissue composition as a result of fibrosis, and changes in myocardial perfusion as a function of both disease and infarct healing. New CMR techniques also enable the tracking of labeled cells, molecular imaging of biomarkers of disease, and changes in calcium flux in cardiomyocytes. In addition, MRI can quantify blood flow velocity and wall shear stress in large blood vessels. Almost all of these techniques can be applied in both pre-clinical and clinical settings, enabling both the techniques themselves and the knowledge gained using such techniques in pre-clinical research to be translated from the lab bench to the patient bedside. PMID:21452060

Experimental basis of myocardial imaging with 123I-labeled hexadecenoic acid.

PubMed

Poe, N D; Robinson, G D; Graham, L S; MacDonald, N S

1976-12-01

Progress in myocardial perfusion imaging has been slowed by the lack or radiopharmaceuticals with suitable physical and biologic characteristics. Hexadecenoic acid, terminally labeled with 123I, partially overcomes these limitations by providing a compound that concentrates in the myocardium in proportion to relative regional blood flow and carries a gamma-emitter with desirable detection and imaging qualities. After intravenous injection in experimental animals, the clearance half-times of hexadecenoic acid for blood and myocardium are 1.7 and 20 min, respectively. These values compare favorably with 18-carbon fatty-acid analogs labeled with 11C. In acute and chronic infarction, similar distribution patterns are found for hexadecenoic acid and 43K, which indicates that hexadecenoic acid is a suitable substitute for the potassium analogs now in use for myocardial imaging. Because of the high count rates obtainable with 123I-hexadecenoic acid, good-guality images can be acquired in as little as 2-3 min per view. Iodine-123-hexadecenoic acid is potentially a useful radiopharmaceutical for clinical application.

Diagnostic performance of dark-blood T2-weighted CMR for evaluation of acute myocardial injury.

PubMed

Srichai, Monvadi B; Lim, Ruth P; Lath, Narayan; Babb, James; Axel, Leon; Kim, Daniel

2013-01-01

We compared the image quality and diagnostic performance of 2 fat-suppression methods for black-blood T2-weighted fast spin-echo (FSE), which are as follows: (a) short T1 inversion recovery (STIR; FSE-STIR) and (b) spectral adiabatic inversion recovery (SPAIR; FSE-SPAIR), for detection of acute myocardial injury. Edema-sensitive T2-weighted FSE cardiac magnetic resonance (CMR) imaging is useful in detecting acute myocardial injury but may experience reduced myocardial signal and signal dropout. The SPAIR pulse aims to eliminate artifacts associated with the STIR pulse. A total of 65 consecutive patients referred for CMR evaluation of myocardial structure and function underwent FSE-STIR and FSE-SPAIR, in addition to cine and late gadolinium enhancement (LGE) CMR. T2-weighted FSE images were independently evaluated by 2 readers for image quality and artifacts (Likert scale of 1-5; best-worst) and presence of increased myocardial signal suggestive of edema. In addition, clinical CMR interpretation, incorporating all CMR sequences available, was recorded for comparison. Diagnostic performance of each T2-weighted sequence was measured using recent (<30 days) troponin elevation greater than 2 times the upper limit of normal as the reference standard for acute myocardial injury. Of the 65 patients, there were 21 (32%) with acute myocardial injury. Image quality and artifact scores were significantly better with FSE-SPAIR compared with FSE-STIR (2.15 vs 2.68, P < 0.01; 2.62 vs 3.05, P < 0.01, respectively). The sensitivity, specificity, positive predictive value, and negative predictive value for acute myocardial injury were as follows: 29%, 93%, 67%, and 73% for FSE-SPAIR; 38%, 91%, 67%, and 75% for FSE-STIR; 71%, 98%, 94%, and 88% for clinical interpretation including LGE, T2, and wall motion. There was a statistically significant difference in sensitivity between the clinical interpretation and each of the T2-weighted sequences but not between each T2-weighted sequence. Although FSE-SPAIR demonstrated significantly improved image quality and decreased artifacts, isolated interpretations of each T2-weighted technique demonstrated high specificity but overall low sensitivity for the detection of myocardial injury, with no difference in accuracy between the techniques. However, real-world interpretation in combination with cine and LGE CMR methods significantly improves the overall sensitivity and diagnostic performance.

Contribution of voltage-dependent K+ channels to metabolic control of coronary blood flow

PubMed Central

Berwick, Zachary C.; Dick, Gregory M.; Moberly, Steven P.; Kohr, Meredith C.; Sturek, Michael; Tune, Johnathan D.

2011-01-01

The purpose of this investigation was to test the hypothesis that KV channels contribute to metabolic control of coronary blood flow and that decreases in KV channel function and/or expression significantly attenuate myocardial oxygen supply-demand balance in the metabolic syndrome (MetS). Experiments were conducted in conscious, chronically instrumented Ossabaw swine fed either a normal maintenance diet or an excess calorie atherogenic diet that produces the clinical phenotype of early MetS. Data were obtained under resting conditions and during graded treadmill exercise before and after inhibition of KV channels with 4-aminopyridine (4-AP, 0.3 mg/kg, i.v.). In lean-control swine, 4-AP reduced coronary blood flow ~15% at rest and ~20% during exercise. Inhibition of KV channels also increased aortic pressure (P < 0.01) while reducing coronary venous Po2 (P < 0.01) at a given level of myocardial oxygen consumption (MVo2). Administration of 4-AP had no effect on coronary blood flow, aortic pressure, or coronary venous Po2 in swine with MetS. The lack of response to 4-AP in MetS swine was associated with a ~20% reduction in coronary KV current (P < 0.01) and decreased expression of KV1.5 channels in coronary arteries (P < 0.01). Together, these data demonstrate that KV channels play an important role in balancing myocardial oxygen delivery with metabolism at rest and during exercise-induced increases in MVo2. Our findings also indicate that decreases in KV channel current and expression contribute to impaired control of coronary blood flow in the MetS. PMID:21771599

Biokinetics of radiolabeled Iodophenylpentadecanoic acid (I-123-IPPA) and thallium-201 in a rabbit model of chronic myocardial infarction measured using a series of thermoluminescent dosimeters

NASA Astrophysics Data System (ADS)

Medich, David Christopher

1997-09-01

The biokinetics of Iodophenylpentadecanoic acid (123I-IPPA) during a chronic period of myocardial infarction were determined and compared to 201Tl. IPPA was assessed as a perfusion and metabolic tracer in the scintigraphic diagnosis of coronary artery disease. The myocardial clearance kinetics were measured by placing a series of thermoluminescent dosimeters (TLDs) on normal and infarcted tissue to measure the local myocardial activity content over time. The arterial blood pool activity was fit to a bi-exponential function for 201Tl and a tri-exponential function for 123I-IPPA to estimate the left ventricle contribution to TLD response. At equilibrium, the blood pool contribution was estimated experimentally to be less than 5% of the total TLD response. The method was unable to resolve the initial uptake of the imaging agent due in part to the 2 minute TLD response integration time and in part to the 30 second lag time for the first TLD placement. A noticeable disparity was observed between the tracer concentrations of IPPA in normal and ischemic tissue of approximately 2:1. The fitting parameters (representing the biokinetic eigenvalue rate constants) were related to the fundamental rate constants of a recycling biokinetic model. The myocardial IPPA content within normal tissue was elevated after approximately 130 minutes post injection. This phenomenon was observed in all but one (950215) of the IPPA TLD kinetics curves.

THE AMPK ACTIVATOR AICAR AMELIORATES AGE-DEPENDENT MYOCARDIAL INJURY IN MURINE HEMORRHAGIC SHOCK

PubMed Central

Matsiukevich, Dzmitry; Piraino, Giovanna; Klingbeil, Lindsey R.; Hake, Paul W.; Wolfe, Vivian; O’Connor, Michael; Zingarelli, Basilia

2016-01-01

The development of myocardial dysfunction in patients with hemorrhagic shock is significantly impacted by the patient age. AMP-activated protein kinase (AMPK) is a pivotal orchestrator of energy homeostasis, which coordinates metabolic recovery after cellular stress. We investigated whether AMPK-regulated pathways are age-dependent in hemorrhage-induced myocardial injury and whether AMPK activation by 5-amino-4-imidazole carboxamide riboside (AICAR) affords cardioprotective effects. Anesthetized C57/BL6 young (3–5 months old) and mature male mice (9–12 months old) were subjected to hemorrhagic shock by blood withdrawing followed by resuscitation with shed blood and Lactated Ringer’s solution. Mice were sacrificed at 3 hours after resuscitation, and plasma and hearts were harvested for biochemical assays. Vehicle-treated mature mice exhibited higher myocardial injury and higher levels of plasma biomarkers of cardiovascular injury (endocan and follistatin) when compared with young mice. Cardiac cell mitochondrial structure was also markedly impaired in vehicle-treated mature mice when compared to young mice. At molecular analysis, an increase of the phosphorylated catalytic subunit pAMPKα was associated with nuclear translocation of the peroxisome proliferator-activated receptor γ co-activator-α in young, but not mature mice. No changes in autophagy were observed as evaluated by the conversion of the light-chain (LC)3B-I protein to LC3B-II form. Treatment with AICAR ameliorated myocardial damage in both age groups. However, AICAR therapeutic effects were less effective in mature mice compared to young mice and involved distinct mechanisms of action. Thus, our data demonstrate that during hemorrhagic shock AMPK-dependent metabolic mechanisms are important for mitigating myocardial injury. However, these mechanisms are less competent with age. PMID:27513082

Positron-emitting myocardial blood flow tracers and clinical potential.

PubMed

Schindler, Thomas H

2015-01-01

Positron-emitting myocardial flow radiotracers such as (15)O-water, (13)N-ammonia and (82)Rubidium in conjunction with positron-emission-tomography (PET) are increasingly applied in clinical routine for coronary artery disease (CAD) detection, yielding high diagnostic accuracy, while providing valuable information on cardiovascular (CV) outcome. Owing to a cyclotron dependency of (15)O-water and (13)N-ammonia, their clinical use for PET myocardial perfusion imaging is limited to a few centers. This limitation could be overcome by the increasing use of (82)Rubidium as it can be eluted from a commercially available (82)Strontium generator and, thus, is independent of a nearby cyclotron. Another novel F-18-labeled myocardial flow radiotracer is flurpiridaz which has attracted increasing interest due to its excellent radiotracer characteristics for perfusion and flow imaging with PET. In particular, the relatively long half-life of 109 minutes of flurpiridaz may afford a general application of this radiotracer for PET perfusion imaging comparable to technetium-99m-labeled single-photon emission computed tomography (SPECT). The ability of PET in conjunction with several radiotracers to assess myocardial blood flow (MBF) in ml/g/min at rest and during vasomotor stress has contributed to unravel pathophysiological mechanisms underlying coronary artery disease (CAD), to improve the detection and characterization of CAD burden in multivessel disease, and to provide incremental prognostic information in individuals with subclinical and clinically-manifest CAD. The concurrent evaluation of myocardial perfusion and MBF may lead to a new era of a personalized, image-guided therapy approach that may offer potential to further improve clinical outcome in CV disease patients but needing validation in large-scale clinical trials. Copyright © 2015 Elsevier Inc. All rights reserved.

CXCR4 expression is associated with time-course permanent and temporary myocardial infarction in rats.

PubMed

Kiani, Ali Asghar; Babaei, Fereshteh; Sedighi, Mehrnoosh; Soleimani, Azam; Ahmadi, Kolsum; Shahrokhi, Somayeh; Anbari, Khatereh; Nazari, Afshin

2017-06-01

Experimental myocardial infarction triggers secretion of Stromal cell-derived factor1 and lead to increase in the expression of its receptor "CXCR4" on the surface of various cells. The aim of this study was to evaluate the expression pattern of CXCR4 in peripheral blood cells following time-course permanent and temporary ischemia in rats. Fourteen male Wistar rats were divided into two groups of seven and were placed under permanent and transient ischemia. Peripheral blood mononuclear cells were isolated at different time points, RNAs extracted and applied to qRT-PCR analysis of the CXCR4 gene. Based on repeated measures analysis of variance, the differences in the expression levels of the gene in each of the groups were statistically significant over time (the effect of time) ( P <0.001). Additionally, the difference in gene expression between the two groups was statistically significant (the effect of group), such that at all times, the expression levels of the gene were significantly higher in the permanent ischemia than in the transient ischemia group ( P <0.001). Moreover, the interactive effect of time-group on gene expression was statistically significant ( P <0.001). CXCR4 is modulated in an induced ischemia context implying a possible association with myocardial infarction. Checking of CXCR4 expression in the ischemic changes shows that damage to the heart tissue trigger the secretion of inflammatory chemokine SDF, Followed by it CXCR4 expression in blood cells. These observations suggest that changes in the expression of CXCR4 may be considered a valuable marker for monitoring myocardial infarction.

Irisin: a potentially candidate marker for myocardial infarction.

PubMed

Kuloglu, Tuncay; Aydin, Suna; Eren, Mehmet Nesimi; Yilmaz, Musa; Sahin, Ibrahim; Kalayci, Mehmet; Sarman, Emine; Kaya, Nalan; Yilmaz, Osman Fatih; Turk, Ahmet; Aydin, Yalcin; Yalcin, Mehmet Hanifi; Uras, Nimet; Gurel, Ali; Ilhan, Selcuk; Gul, Evrim; Aydin, Suleyman

2014-05-01

Myocardial infarction (MI) causes energy depletion through imbalance between coronary blood supply and myocardial demand. Irisin produced by the heart reduces ATP production by increasing heat generation. Energy depletion affects irisin concentration in circulation and cardiac tissues, suggesting an association with MI. We examined: (1) irisin expression immunohistochemically in rat heart, skeletal muscle, kidney and liver in isoproterenol (ISO)-induced MI, and (2) serum irisin concentration by ELISA. Rats were randomly allocated into 6 groups (n=6), (i) control, (ii) ISO (1h), (iii) ISO (2h), (iv) ISO (4h), (v) ISO (6h), and (vi) ISO (24h), 200mg ISO in each case. Rats were decapitated and the blood and tissues collected for irisin analysis. Blood was centrifuged at 1792 g for 5 min. Tissues were washed with saline and fixed in 10% formalin for histology. Serum irisin levels gradually decreased from 1h to 24h in MI rats compared with controls, the minimum being at 2h, increasing again after 6h. Cardiac muscle cells, glomerular, peritubular renal cortical interstitial cells, hepatocytes and liver sinusoidal cells and perimysium, endomysium and nucleoi of skeletal muscle were irisin positive, but its synthesis decreased 1-4h after MI. At all time-points, irisin increased near myocardial connective tissue, with production in skeletal muscle, liver and kidney recovering after 6h, although slower than controls. Unique insight into the pathogenesis of MI is shown, and the gradually decrease of serum irisin might be a diagnostic marker for MI. Copyright © 2014 Elsevier Inc. All rights reserved.

Diabetes Mellitus and Ischemic Heart Disease: The Role of Ion Channels

PubMed Central

D’Amato, Andrea; Netti, Lucrezia; Pucci, Mariateresa; De Marchis, Marialaura; Volterrani, Maurizio; Mancone, Massimo; Fedele, Francesco

2018-01-01

Diabetes mellitus is one the strongest risk factors for cardiovascular disease and, in particular, for ischemic heart disease (IHD). The pathophysiology of myocardial ischemia in diabetic patients is complex and not fully understood: some diabetic patients have mainly coronary stenosis obstructing blood flow to the myocardium; others present with coronary microvascular disease with an absence of plaques in the epicardial vessels. Ion channels acting in the cross-talk between the myocardial energy state and coronary blood flow may play a role in the pathophysiology of IHD in diabetic patients. In particular, some genetic variants for ATP-dependent potassium channels seem to be involved in the determinism of IHD. PMID:29534462

Educational inequality in cardiovascular disease depends on diagnosis: A nationwide register based study from Denmark.

PubMed

Christensen, Anne V; Koch, Mette B; Davidsen, Michael; Jensen, Gorm B; Andersen, Lisbeth V; Juel, Knud

2016-05-01

Social inequality is present in the morbidity as well as the mortality of cardiovascular diseases. This paper aims to quantify and compare the level of educational inequality across different cardiovascular diagnoses. Register based study. Comparison of the extent of inequality across different cardiovascular diagnoses requires a measure of inequality which is comparable across subgroups with different educational distributions. The slope index of inequality and the relative index of inequality were applied for measuring inequalities in incidence of six cardiovascular diagnoses: ischaemic heart disease, acute myocardial infarction, valvular heart disease, congestive heart failure, atrial fibrillation and stroke in the period 2005-2009. All individuals in the general Danish population aged 35-84 years were followed in national registers regarding hospitalisation, death and education from 1985 to 2009 (annual average of 2.9 million people) to define incident cases. Marked educational inequality was found in the incidence of ischaemic heart disease, acute myocardial infarction, heart failure and stroke (relative index of inequality: 0.37 (95% confidence interval 0.34; 0.40) to 0.60 (0.57; 0.63), absolute index of inequality: -241 (-254.4; -227.4) to -37 (-42.7; -31.1)) while inequality in atrial fibrillation and, in particular, in valvular heart disease was small and insignificant (relative index of inequality: 0.57 (0.49; 0.65) to 0.97 (0.88; 1.08), absolute index of inequality: -29 (-35.1; -21.9) to -1 (-4.8; -3.8)). The degree of educational inequality in cardiovascular diseases depends on the diagnosis, with the highest inequality in ischaemic heart disease, acute myocardial infarction, heart failure and stroke. Small differences were found between men and women. © The European Society of Cardiology 2015.

Feasibility of high-resolution quantitative perfusion analysis in patients with heart failure.

PubMed

Sammut, Eva; Zarinabad, Niloufar; Wesolowski, Roman; Morton, Geraint; Chen, Zhong; Sohal, Manav; Carr-White, Gerry; Razavi, Reza; Chiribiri, Amedeo

2015-02-12

Cardiac magnetic resonance (CMR) is playing an expanding role in the assessment of patients with heart failure (HF). The assessment of myocardial perfusion status in HF can be challenging due to left ventricular (LV) remodelling and wall thinning, coexistent scar and respiratory artefacts. The aim of this study was to assess the feasibility of quantitative CMR myocardial perfusion analysis in patients with HF. A group of 58 patients with heart failure (HF; left ventricular ejection fraction, LVEF ≤ 50%) and 33 patients with normal LVEF (LVEF >50%), referred for suspected coronary artery disease, were studied. All subjects underwent quantitative first-pass stress perfusion imaging using adenosine according to standard acquisition protocols. The feasibility of quantitative perfusion analysis was then assessed using high-resolution, 3 T kt perfusion and voxel-wise Fermi deconvolution. 30/58 (52%) subjects in the HF group had underlying ischaemic aetiology. Perfusion abnormalities were seen amongst patients with ischaemic HF and patients with normal LV function. No regional perfusion defect was observed in the non-ischaemic HF group. Good agreement was found between visual and quantitative analysis across all groups. Absolute stress perfusion rate, myocardial perfusion reserve (MPR) and endocardial-epicardial MPR ratio identified areas with abnormal perfusion in the ischaemic HF group (p = 0.02; p = 0.04; p = 0.02, respectively). In the Normal LV group, MPR and endocardial-epicardial MPR ratio were able to distinguish between normal and abnormal segments (p = 0.04; p = 0.02 respectively). No significant differences of absolute stress perfusion rate or MPR were observed comparing visually normal segments amongst groups. Our results demonstrate the feasibility of high-resolution voxel-wise perfusion assessment in patients with HF.

The benefits of ribose in cardiovascular disease.

PubMed

Pauly, D F; Johnson, C; St Cyr, J A

2003-02-01

Cardiovascular disease still ranks as the leading cause of death in men and women. Adults have tried to lower their risk of cardiovascular disease by improving their diet, quitting smoking, controlling blood pressure and exercising regularly. Additionally, many adults have turned to nutriceutical or natural products. Myocardial ischemia, produces a depression in myocardial tissue levels of high energy compounds, along with a compromise in myocardial function. Ribose, a naturally occurring sugar, has been extensively investigated, both in animal and clinical studies, as an agent to enhance the recovery of these depressed energy compounds. Results of these studies have been promising in enhancing the recovery of these energy molecules along with an improvement in myocardial function. Therefore, ribose should be considered as a potential agent in the treatment of ischemic cardiovascular disease.

Research report: the effects of hyperbaric oxygen preconditioning on myocardial biomarkers of cardioprotection in patients having coronary artery bypass graft surgery.

PubMed

Jeysen, Zivan Yogaratnam; Gerard, Laden; Levant, Guvendik; Cowen, Mike; Cale, Alex; Griffin, Steve

2011-01-01

We have previously conducted and reported on the primary endpoint of a clinical study which demonstrated that hyperbaric oxygen (HBO2) preconditioning consisting of two 30-minute intervals of 100% oxygen at 2.4 atmospheres absolute (ATA) prior to coronary artery bypass graft (CABG) surgery leads to an improvement in left ventricular stroke work (LVSW) 24 hours following CABG. In that study, 81 patients were randomized to treatment with HBO2 (HBO2; n = 41) or routine treatment (Control Group; n = 40) prior to surgery. The objective of this manuscript is to further report on the result of the exploratory secondary endpoints from that study, specifically the effects of HBO2 preconditioning on biomarkers of myocardial protection. Intraoperative right atrial biopsies were assessed, via an Enzyme Linked ImmunoSorbent Assay (ELISA), for the expression of eNOS and HSP72. In this study, no significant differences were observed between the groups with respect to the quantity of myocardial eNOS and HSP72. However, in the HBO2 Group, following ischemia and reperfusion, the quantities of myocardial eNOS and HSP72 were increased. This suggests that HBO2 preconditioning in this group of patients may be capable of inducing endogenous cardioprotection following ischemic reperfusion injury (IRI).

A time dependent anatomically detailed model of cardiac conduction

NASA Technical Reports Server (NTRS)

Saxberg, B. E.; Grumbach, M. P.; Cohen, R. J.

1985-01-01

In order to understand the determinants of transitions in cardiac electrical activity from normal patterns to dysrhythmias such as ventricular fibrillation, we are constructing an anatomically and physiologically detailed finite element simulation of myocardial electrical propagation. A healthy human heart embedded in paraffin was sectioned to provide a detailed anatomical substrate for model calculations. The simulation of propagation includes anisotropy in conduction velocity due to fiber orientation as well as gradients in conduction velocities, absolute and relative refractory periods, action potential duration and electrotonic influence of nearest neighbors. The model also includes changes in the behaviour of myocardial tissue as a function of the past local activity. With this model, we can examine the significance of fiber orientation and time dependence of local propagation parameters on dysrhythmogenesis.

Estrogen modulation of the ethanol-evoked myocardial oxidative stress and dysfunction via DAPK3/Akt/ERK activation in male rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

El-Mas, Mahmoud M., E-mail: mahelm@hotmail.com; Abdel-Rahman, Abdel A., E-mail: abdelrahmana@ecu.edu

Evidence suggests that male rats are protected against the hypotensive and myocardial depressant effects of ethanol compared with females. We investigated whether E{sub 2} modifies the myocardial and oxidative effects of ethanol in male rats. Conscious male rats received ethanol (0.5, 1 or 1.5 g/kg i.v.) 30-min after E{sub 2} (1 μg/kg i.v.) or its vehicle (saline), and hearts were collected at the conclusion of hemodynamic measurements for ex vivo molecular studies. Ethanol had no effect in vehicle-treated rats, but it caused dose-related reductions in LV developed pressure (LVDP), end-diastolic pressure (LVEDP), rate of rise in LV pressure (dP/dt{sub max})more » and systolic (SBP) and diastolic (DBP) blood pressures in E{sub 2}-pretreated rats. These effects were associated with elevated (i) indices of reactive oxygen species (ROS), (ii) malondialdehyde (MDA) protein adducts, and (iii) phosphorylated death-associated protein kinase-3 (DAPK3), Akt, and extracellular signal-regulated kinases (ERK1/2). Enhanced myocardial anti-oxidant enzymes (heme oxygenase-1, catalase and aldehyde dehydrogenase 2) activities were also demonstrated. In conclusion, E{sub 2} promotes ethanol-evoked myocardial oxidative stress and dysfunction in male rats. The present findings highlight the risk of developing myocardial dysfunction in men who consume alcohol while receiving E{sub 2} for specific medical conditions. - Highlights: • Ethanol lowers blood pressure and causes LV dysfunction in E{sub 2}-treated rats. • E{sub 2}/ethanol aggravates cardiac oxidative state via of DAPK3/Akt/ERK activation. • E{sub 2}/ethanol causes a feedback increase in cardiac HO-1, catalase and ALDH2. • Alcohol might increase risk of myocardial dysfunction in men treated with E{sub 2}.« less

Normal results of post-race thallium-201 myocardial perfusion imaging in marathon runners with elevated serum MB creatine kinase levels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siegel, A.J.; Silverman, L.M.; Holman, B.L.

1985-10-01

Elevated cardiac enzyme values in asymptomatic marathon runners after competition can arise from skeletal muscle through exertional rhabdomyolysis, silent injury to the myocardium, or a combined tissue source. Peak post-race levels of the MB isoenzyme of creatine kinase are similar to values in patients with acute myocardial infarction. Previously reported normal results of infarct-avid myocardial scintigraphy with technetium 99m pyrophosphate in runners after competition suggest a non-cardiac source but cannot exclude silent injury to the myocardium. Therefore, thallium 201 myocardial perfusion imaging was performed in runners immediately after competition together with determination of sequential cardiac enzyme levels. Among 15 runnersmore » tested, the average peak in serum MB creatine kinase 24 hours after the race was 128 IU/liter with a cumulative MB creatine kinase release of 117 IU/liter; these values are comparable to those in patients with acute transmural myocardial infarction. Thallium 201 myocardial scintigraphic results were normal in five runners randomly selected from those who volunteered for determination of sequential blood levels. It is concluded that elevations of serum MB creatine kinase in marathon runners arise from a skeletal muscle source and that thallium 201 myocardial scintigraphy is useful to assess runners for myocardial injury when clinical questions arise.« less

Myocardial contrast echocardiography in mice: technical and physiological aspects.

PubMed

Verkaik, Melissa; van Poelgeest, Erik M; Kwekkeboom, Rick F J; Ter Wee, Piet M; van den Brom, Charissa E; Vervloet, Marc G; Eringa, Etto C

2018-03-01

Myocardial contrast echocardiography (MCE) offers the opportunity to study myocardial perfusion defects in mice in detail. The value of MCE compared with single-photon emission computed tomography, positron emission tomography, and computed tomography consists of high spatial resolution, the possibility of quantification of blood volume, and relatively low costs. Nevertheless, a number of technical and physiological aspects should be considered to ensure reproducibility among research groups. The aim of this overview is to describe technical aspects of MCE and the physiological parameters that influence myocardial perfusion data obtained with this technique. First, technical aspects of MCE discussed in this technical review are logarithmic compression of ultrasound data by ultrasound systems, saturation of the contrast signal, and acquisition of images during different phases of the cardiac cycle. Second, physiological aspects of myocardial perfusion that are affected by the experimental design are discussed, including the anesthesia regimen, systemic cardiovascular effects of vasoactive agents used, and fluctuations in body temperature that alter myocardial perfusion. When these technical and physiological aspects of MCE are taken into account and adequately standardized, MCE is an easily accessible technique for mice that can be used to study the control of myocardial perfusion by a wide range of factors.

Release kinetics of N-terminal pro-B-type natriuretic peptide in a clinical model of acute myocardial infarction.

PubMed

Liebetrau, Christoph; Gaede, Luise; Dörr, Oliver; Troidl, Christian; Voss, Sandra; Hoffmann, Jedrzej; Paszko, Agata; Weber, Michael; Rolf, Andreas; Hamm, Christian; Nef, Holger; Möllmann, Helge

2014-02-15

N-terminal segment of B-type natriuretic peptide prohormone (NT-proBNP) is elevated in patients with acute myocardial infarction (AMI) thus providing both diagnostic information and prognostic information. The aim of the present study was to determine the time course of NT-proBNP release in patients undergoing transcoronary ablation of septal hypertrophy (TASH) a procedure mimicking AMI. We analyzed the release kinetics of NT-proBNP in 18 consecutive patients with hypertrophic obstructive cardiomyopathy undergoing TASH. Serum samples were collected prior to and at 15, 30, 45, 60, 75, 90, and 105 min, and 2, 4, 8, and 24h after TASH. NT-proBNP concentrations showed a continuous increase during the first 75 min with a significant percent change compared to baseline value already 15 min after TASH (105.6% [IQR 102.2-112.7]; P<0.001). All patients had a significant increase of NT-proBNP at 45 min (range of percent increase [min-max]: 103.5-137.2%; range of absolute increase [min-max]: 23.5-304.0 ng/L). NT-proBNP concentrations decreased below the baseline value until the 8th h after initiation of myocardial infarction. NT-proBNP concentration increases immediately after induction of myocardial infarction proving early evidence of myocardial injury despite the decrease of the left ventricular wall stress due to the TASH related reduction of the left ventricular outflow gradient. Copyright © 2013 Elsevier B.V. All rights reserved.

Range of control of cardiovascular variables by the hypothalamus

NASA Technical Reports Server (NTRS)

Smith, O. A.; Stephenson, R. B.; Randall, D. C.

1974-01-01

New methodologies were utilized to study the influence of the hypothalamus on the cardiovascular system. The regulation of myocardial activity was investigated in monkeys with hypothalamic lesions that eliminate cardiovascular responses. Observations showed that a specific part of the hypothalamus regulates changes in myocardial contractility that accompanies emotion. Studies of the hypothalamus control of renal blood flow showed the powerful potential control of this organ over renal circulation.

Postinfarction Functional Recovery Driven by a Three-Dimensional Engineered Fibrin Patch Composed of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells.

PubMed

Roura, Santiago; Soler-Botija, Carolina; Bagó, Juli R; Llucià-Valldeperas, Aida; Férnandez, Marco A; Gálvez-Montón, Carolina; Prat-Vidal, Cristina; Perea-Gil, Isaac; Blanco, Jerónimo; Bayes-Genis, Antoni

2015-08-01

Considerable research has been dedicated to restoring myocardial cell slippage and limiting ventricular remodeling after myocardial infarction (MI). We examined the ability of a three-dimensional (3D) engineered fibrin patch filled with human umbilical cord blood-derived mesenchymal stem cells (UCBMSCs) to induce recovery of cardiac function after MI. The UCBMSCs were modified to coexpress luciferase and fluorescent protein reporters, mixed with fibrin, and applied as an adhesive, viable construct (fibrin-cell patch) over the infarcted myocardium in mice (MI-UCBMSC group). The patch adhered well to the heart. Noninvasive bioluminescence imaging demonstrated early proliferation and differentiation of UCBMSCs within the construct in the postinfarct mice in the MI-UCBMSC group. The implanted cells also participated in the formation of new, functional microvasculature that connected the fibrin-cell patch to both the subjacent myocardial tissue and the host circulatory system. As revealed by echocardiography, the left ventricular ejection fraction and fractional shortening at sacrifice were improved in MI-UCBMSC mice and were markedly reduced in mice treated with fibrin alone and untreated postinfarction controls. In conclusion, a 3D engineered fibrin patch composed of UCBMSCs attenuated infarct-derived cardiac dysfunction when transplanted locally over a myocardial wound. ©AlphaMed Press.

The evaluation of pulmonary hypertension using right ventricular myocardial isovolumic relaxation time.

PubMed

Dambrauskaite, Virginija; Delcroix, Marion; Claus, Piet; Herbots, Lieven; Palecek, Tomas; D'hooge, Jan; Bijnens, Bart; Rademakers, Frank; Sutherland, George R

2005-11-01

Right ventricular (RV) blood pool-derived isovolumic relaxation time (IVRT) correlates well with systolic pulmonary arterial pressure (PAP). However, because of complex parameter derivation, the method is rarely used. The aim of this study was to validate the measurement of myocardial velocity imaging-derived RV IVRT (IVRT') against invasively measured PAP. Transthoracic echocardiography with myocardial velocity imaging and right heart catheterization were performed in 33 patients with pulmonary hypertension. Blood pool IVRT and myocardial IVRTs for the tricuspid valve annulus ring, basal and apical RV free wall segments were measured and compared with data from 33 age- and sex-matched control subjects. Measured IVRTs were significantly longer in patients with pulmonary hypertension than in control subjects. The strongest correlation (R = 0.74, P < .0001) was found between systolic PAP and the heart rate-corrected IVRT' derived from the basal RV free wall segment. The basal segment IVRT' corrected for heart rate correlates well with the invasive PAP measurement and, therefore, can be used to predict systolic PAP. It can even be considered as an alternative to tricuspid regurgitation-derived PAP systolic when tricuspid regurgitation is nonrecordable. A proposed method to derive systolic PAP should be used while screening the patients at risk for pulmonary hypertension, monitoring the disease progression and the effect of treatment.

Three-dimensional imaging of absolute blood flow velocity and blood vessel position under low blood flow velocity based on Doppler signal information included in scattered light from red blood cells

NASA Astrophysics Data System (ADS)

Kyoden, Tomoaki; Akiguchi, Shunsuke; Tajiri, Tomoki; Andoh, Tsugunobu; Hachiga, Tadashi

2017-11-01

The development of a system for in vivo visualization of occluded distal blood vessels for diabetic patients is the main target of our research. We herein describe two-beam multipoint laser Doppler velocimetry (MLDV), which measures the instantaneous multipoint flow velocity and can be used to observe the blood flow velocity in peripheral blood vessels. By including a motorized stage to shift the measurement points horizontally and in the depth direction while measuring the velocity, the path of the blood vessel in the skin could be observed using blood flow velocity in three-dimensional space. The relationship of the signal power density between the blood vessel and the surrounding tissues was shown and helped us identify the position of the blood vessel. Two-beam MLDV can be used to simultaneously determine the absolute blood flow velocity distribution and identify the blood vessel position in skin.

Understanding the physiology of mindfulness: aortic hemodynamics and heart rate variability.

PubMed

May, Ross W; Bamber, Mandy; Seibert, Gregory S; Sanchez-Gonzalez, Marcos A; Leonard, Joseph T; Salsbury, Rebecca A; Fincham, Frank D

2016-01-01

Data were collected to examine autonomic and hemodynamic cardiovascular modulation underlying mindfulness from two independent samples. An initial sample (N = 185) underwent laboratory assessments of central aortic blood pressure and myocardial functioning to investigated the association between mindfulness and cardiac functioning. Controlling for religiosity, mindfulness demonstrated a strong negative relationship with myocardial oxygen consumption and left ventricular work but not heart rate or blood pressure. A second sample (N = 124) underwent a brief (15 min) mindfulness inducing intervention to examine the influence of mindfulness on cardiovascular autonomic modulation via blood pressure variability and heart rate variability. The intervention had a strong positive effect on cardiovascular modulation by decreasing cardiac sympathovagal tone, vasomotor tone, vascular resistance and ventricular workload. This research establishes a link between mindfulness and cardiovascular functioning via correlational and experimental methodologies in samples of mostly female undergraduates. Future directions for research are outlined.

Intravenous human umbilical cord blood improves electrophysiological and metabolic properties in ISO induced myocardial necrosis in rats.

PubMed

Mohan, Mahalaxmi; Rokade, Rahul; Kasturet, Sanjay

2013-03-01

Rats treated with isoproterenol (ISO, 85 mg/kg, sc, twice at an interval of 24 h) showed a significant increase in heart rate, mean arterial blood pressure, pressure rate index, ST elevation on ECG, and a significant increase in the levels of cardiac marker enzymes- lactate dehydrogenase, and creatine kinase in serum and a significant reduction in superoxide dismutase, and catalase and increase in thiobarbituric acid reactive substance activity in heart tissue. Treatment with Human umbilical cord blood (hUCBC; 500 and 1000 microL, iv, via the tail vein; 2 h after the second dose of ISO) significantly restored back to normal levels and showed a lesser degree of cellular infiltration and infarct size in histopathological and planimetry studies respectively. Thus, hUCBC ameliorates cardiotoxic effects of isoproterenol and may be of value in the treatment of myocardial infarction.

Nitroglycerin Use in Myocardial Infarction Patients: Risks and Benefits

PubMed Central

Ferreira, Julio C.B.; Mochly-Rosen, Daria

2012-01-01

Acute myocardial infarction and its sequelae are leading causes of morbidity and mortality worldwide. Nitroglycerin remains a first-line treatment for angina pectoris and acute myocardial infarction. Nitroglycerin achieves its benefit by giving rise to nitric oxide, which causes vasodilation and increases blood flow to the myocardium. However, continuous delivery of nitroglycerin results in tolerance, limiting the use of this drug. Nitroglycerin tolerance is due, at least in part, to inactivation of aldehyde dehydrogenase 2 (ALDH2), an enzyme that converts nitroglycerin to the vasodilator, nitric oxide. We have recently found that, in addition to nitroglycerin’s effect on the vasculature, sustained treatment with nitroglycerin negatively affects cardiomyocyte viability following ischemia, thus resulting in increased infarct size in a myocardial infarction model in animals. Co-administration of Alda-1, an activator of ALDH2, with nitroglycerin improves metabolism of reactive aldehyde adducts and prevents the nitroglycerin-induced increase in cardiac dysfunction following myocardial infarction. In this review, we describe the molecular mechanisms associated with the benefits and risks of nitroglycerin administration in myocardial infarction. (167 of 200). PMID:22040938

Effects of diaspirin cross-linked hemoglobin (DCLHb) during and post-CPR in swine.

PubMed

Chow, M S; Fan, C; Tran, H; Zhao, H; Zhou, L

2001-04-01

The purpose of the study was to test the hypothesis that diaspirin cross-linked hemoglobin (DCLHb) can produce improved resuscitation during cardiac arrest. DCLHb, a derivative of human hemoglobin, has previously been demonstrated to produce a vasopressor response that is associated with increased blood flow to vital organs. In addition, it is an oxygen carrier. These effects may be beneficial to extreme low flow states, such as that during cardiac arrest and cardiopulmonary resuscitation (CPR). Experimental cardiac arrest and CPR were carried out in 32 anesthetized immature pigs. In each animal, ventricular fibrillation was induced for 5 min, followed by 10 min of standard CPR with a pneumatic device and room air ventilation. High (15 ml/kg) and low (5 ml/kg) doses of DCLHb or equivalent volume of normal saline were infused at the beginning of CPR in a random and blind manner. Cardiac output, organ blood flow, aortic pressure, coronary perfusion pressure, blood gases, and lactate concentrations were obtained before and during CPR. Following the 10-min CPR, the animals were defibrillated and the return of spontaneous circulation (ROSC) determined. DCLHb treatment achieved 75% ROSC compared with 25% in the saline group (p < 0.05). In addition, a better (p < 0.05) myocardial O(2) delivery, venous blood O(2) content, and myocardial and cerebral perfusion pressure were observed in the DCLHb group. DCLHb treatment during cardiac arrest and CPR significantly improves ROSC. This is most likely related to its improvement in coronary perfusion and myocardial oxygen delivery.

Folic acid prevents cardiac dysfunction and reduces myocardial fibrosis in a mouse model of high-fat diet-induced obesity.

PubMed

Li, Wei; Tang, Renqiao; Ouyang, Shengrong; Ma, Feifei; Liu, Zhuo; Wu, Jianxin

2017-01-01

Folic acid (FA) is an antioxidant that can reduce reactive oxygen species generation and can blunt cardiac dysfunction during ischemia. We hypothesized that FA supplementation prevents cardiac fibrosis and cardiac dysfunction induced by obesity. Six-week-old C57BL6/J mice were fed a high-fat diet (HFD), normal diet (ND), or an HFD supplemented with folic acid (FAD) for 14 weeks. Cardiac function was measured using a transthoracic echocardiographic exam. Phenotypic analysis included measurements of body and heart weight, blood glucose and tissue homocysteine (Hcy) content, and heart oxidative stress status. HFD consumption elevated fasting blood glucose levels and caused obesity and heart enlargement. FA supplementation in HFD-fed mice resulted in reduced fasting blood glucose, heart weight, and heart tissue Hcy content. We also observed a significant cardiac systolic dysfunction when mice were subjected to HFD feeding as indicated by a reduction in the left ventricular ejection fraction and fractional shortening. However, FAD treatment improved cardiac function. FA supplementation protected against cardiac fibrosis induced by HFD. In addition, HFD increased malondialdehyde concentration of the heart tissue and reduced the levels of antioxidant enzyme, glutathione, and catalase. HFD consumption induced myocardial oxidant stress with amelioration by FA treatment. FA supplementation significantly lowers blood glucose levels and heart tissue Hcy content and reverses cardiac dysfunction induced by HFD in mice. These functional improvements of the heart may be mediated by the alleviation of oxidative stress and myocardial fibrosis.

Biodistribution and radiation dosimetry of LMI1195: first-in-human study of a novel 18F-labeled tracer for imaging myocardial innervation.

PubMed

Sinusas, Albert J; Lazewatsky, Joel; Brunetti, Jacqueline; Heller, Gary; Srivastava, Ajay; Liu, Yi-Hwa; Sparks, Richard; Puretskiy, Andrey; Lin, Shu-fei; Crane, Paul; Carson, Richard E; Lee, L Veronica

2014-09-01

A novel (18)F-labeled ligand for the norepinephrine transporter (N-[3-bromo-4-(3-(18)F-fluoro-propoxy)-benzyl]-guanidine [LMI1195]) is in clinical development for mapping cardiac nerve terminals in vivo using PET. Human safety, whole-organ biodistribution, and radiation dosimetry of LMI1195 were evaluated in a phase 1 clinical trial. Twelve healthy subjects at 3 clinical sites were injected intravenously with 150-250 MBq of LMI1195. Dynamic PET images were obtained over the heart for 10 min, followed by sequential whole-body images for approximately 5 h. Blood samples were obtained, and heart rate, electrocardiogram, and blood pressure were monitored before and during imaging. Residence times were determined from multiexponential regression of organ region-of-interest data normalized by administered activity (AA). Radiation dose estimates were calculated using OLINDA/EXM. Myocardial, lung, liver, and blood-pool standardized uptake values were determined at different time intervals. No adverse events due to LMI1195 were seen. Blood radioactivity cleared quickly, whereas myocardial uptake remained stable and uniform throughout the heart over 4 h. Liver and lung activity cleared relatively rapidly, providing favorable target-to-background ratios for cardiac imaging. The urinary bladder demonstrated the largest peak uptake (18.3% AA), followed by the liver (15.5% AA). The mean effective dose was 0.026 ± 0.0012 mSv/MBq. Approximately 1.6% AA was seen in the myocardium initially, remaining above 1.5% AA (decay-corrected) through 4 h after injection. The myocardium-to-liver ratio was approximately unity initially, increasing to more than 2 at 4 h. These preliminary data suggest that LMI1195 is well tolerated and yields a radiation dose comparable to that of other commonly used PET radiopharmaceuticals. The kinetics of myocardial and adjacent organ activity suggest that cardiac imaging should be possible with acceptable patient radiation dose. © 2014 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Cardiac rehabilitation improves coronary endothelial function in patients with heart failure due to dilated cardiomyopathy: A positron emission tomography study.

PubMed

Legallois, Damien; Belin, Annette; Nesterov, Sergey V; Milliez, Paul; Parienti, J-J; Knuuti, Juhani; Abbas, Ahmed; Tirel, Olivier; Agostini, Denis; Manrique, Alain

2016-01-01

Endothelial dysfunction is common in patients with heart failure and is associated with poor clinical outcome. Cardiac rehabilitation is able to enhance peripheral endothelial function but its impact on coronary vasomotion remains unknown. We aimed to evaluate the effect of cardiac rehabilitation on coronary vasomotion in patients with heart failure. We prospectively enrolled 29 clinically stable heart failure patients from non-ischaemic dilated cardiomyopathy and without coronary risk factors. Myocardial blood flow was quantified using (15)-O water positron emission tomography at rest and during a cold pressor test, before and after 12 weeks of cardiac rehabilitation and optimization of medical therapy. Rest myocardial blood flow was significantly improved after the completion of rehabilitation compared to baseline (1.31 ± 0.38 mL/min/g vs. 1.16 ± 0.41 mL/min/g, p = 0.04). The endothelium-related change in myocardial blood flow from rest to cold pressor test and the percentage of myocardial blood flow increase during the cold pressor test were both significantly improved after cardiac rehabilitation (respectively from -0.03 ± 0.22 mL/min/g to 0.19 ± 0.22 mL/min/g, p < 0.001 and from 101.5 ± 16.5% to 118.3 ± 24.4%, p < 0.001). Left ventricular ejection fraction, plasma levels of brain natriuretic peptide, maximal oxygen consumption and the Minnesota Living with Heart Failure Questionnaire score were also significantly improved. The improvement was not related to uptitration of medical therapy. Coronary endothelial function is altered in patients with heart failure due to non-ischaemic dilated cardiomyopathy. In these patients, cardiac rehabilitation significantly improves coronary vasomotion. © The European Society of Cardiology 2014.

Coronary vasomotor abnormalities in insulin-resistant individuals.

PubMed

Quiñones, Manuel J; Hernandez-Pampaloni, Miguel; Schelbert, Heinrich; Bulnes-Enriquez, Isabel; Jimenez, Xochitl; Hernandez, Gustavo; De La Rosa, Roxana; Chon, Yun; Yang, Huiying; Nicholas, Susanne B; Modilevsky, Tamara; Yu, Katherine; Van Herle, Katja; Castellani, Lawrence W; Elashoff, Robert; Hsueh, Willa A

2004-05-04

Insulin resistance is a metabolic spectrum that progresses from hyperinsulinemia to the metabolic syndrome, impaired glucose tolerance, and finally type 2 diabetes mellitus. It is unclear when vascular abnormalities begin in this spectrum of metabolic effects. To evaluate the association of insulin resistance with the presence and reversibility of coronary vasomotor abnormalities in young adults at low cardiovascular risk. Cross-sectional study followed by prospective, open-label treatment study. University hospital. 50 insulin-resistant and 22 insulin-sensitive, age-matched Mexican-American participants without glucose intolerance or traditional risk factors for or evidence of coronary artery disease. 3 months of thiazolidinedione therapy for 25 insulin-resistant patients. Glucose infusion rate in response to insulin infusion was used to define insulin resistance (glucose infusion rate < or = 4.00 mg/kg of body weight per minute [range, 0.90 to 3.96 mg/kg per minute]) and insulin sensitivity (glucose infusion rate > or = 7.50 mg/kg per minute [range, 7.52 to 13.92 mg/kg per minute]). Myocardial blood flow was measured by using positron emission tomography at rest, during cold pressor test (largely endothelium-dependent), and after dipyridamole administration (largely vascular smooth muscle-dependent). Myocardial blood flow responses to dipyridamole were similar in the insulin-sensitive and insulin-resistant groups. However, myocardial blood flow response to cold pressor test increased by 47.6% from resting values in insulin-sensitive patients and by 14.4% in insulin-resistant patients. During thiazolidinedione therapy in a subgroup of insulin-resistant patients, insulin sensitivity improved, fasting plasma insulin levels decreased, and myocardial blood flow responses to cold pressor test normalized. The study was not randomized, and it included only 1 ethnic group. Insulin-resistant patients who do not have hypercholesterolemia or hypertension and do not smoke manifest coronary vasomotor abnormalities. Insulin-sensitizing thiazolidinedione therapy normalized these abnormalities. These results suggest an association between insulin resistance and abnormal coronary vasomotor function, a relationship that requires confirmation in larger studies.

Further insights into blood pressure induced premature beats: Transient depolarizations are associated with fast myocardial deformation upon pressure decline.

PubMed

Haemers, Peter; Sutherland, George; Cikes, Maja; Jakus, Nina; Holemans, Patricia; Sipido, Karin R; Willems, Rik; Claus, Piet

2015-11-01

An acute increase in blood pressure is associated with the occurrence of premature ventricular complexes (PVCs). We aimed to study the timing of these PVCs with respect to afterload-induced changes in myocardial deformation in a controlled, preclinically relevant, novel closed-chest pig model. An acute left ventricular (LV) afterload challenge was induced by partial balloon inflation in the descending aorta, lasting 5-10 heartbeats (8 pigs; 396 inflations). Balloon inflation enhanced the reflected wave (augmentation index 30% ± 8% vs 59% ± 6%; P < .001), increasing systolic central blood pressure by 35% ± 4%. This challenge resulted in a more abrupt LV pressure decline, which was delayed beyond ventricular repolarization (rate of pressure decline 0.16 ± 0.01 mm Hg/s vs 0.27 ± 0.04 mm Hg/ms; P < .001 and interval T-wave to peak pressure 1 ± 12 ms vs 36 ± 9 ms; P = .008), during which the velocity of myocardial shortening at the basal septum increased abruptly (ie, postsystolic shortening) (peak strain rate -0.6 ± 0.5 s(-1) vs -2.5 ± 0.8 s(-1); P < .001). It is exactly at this time of LV pressure decline, with increased postsystolic shortening, and not at peak pressure, that PVCs occur (22% of inflations). These PVCs preferentially occurred at the basal and apical segments. In the same regions, monophasic action potentials demonstrated the appearance of delayed afterdepolarization-like transient depolarizations as origin of PVCs. An acute blood pressure increase results in a more abrupt LV pressure decline, which is delayed after ventricular repolarization. This has a profound effect on myocardial mechanics with enhanced postsystolic shortening. Coincidence with induced transient depolarizations and PVCs provides support for the mechanoelectrical origin of pressure-induced premature beats. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Measurement of absolute myocardial blood flow in humans using dynamic cardiac SPECT and 99mTc-tetrofosmin: Method and validation

DOE PAGES

Shrestha, Uttam; Sciammarella, Maria; Alhassen, Fares; ...

2015-12-29

The objective of this study was to measure myocardial blood flow (MBF) in humans using 99mTc-tetrofosmin and dynamic single-photon emission computed tomography (SPECT). Dynamic SPECT using 99mTc-tetrofosmin and dynamic positron emission tomography (PET) was performed on a group of 16 patients. The SPECT data were reconstructed using a 4D-spatiotemporal iterative reconstruction method. The data corresponding to 9 patients were used to determine the flow-extraction curve for 99mTc-tefrofosmin while data from the remaining 7 patients were used for method validation. The nonlinear tracer correction parameters A and B for 99mTc-tefrofosmin were estimated for the 9 patients by fitting the flow-extraction curvemore » K 1 = F(1–Aexp(–B/F)) for K 1 values estimated with 99mTc-tefrofosmin using SPECT and MBF values estimated with 13N-NH 3 using PET. These parameters were then used to calculate MBF and coronary flow reserve (CFR) in three coronary territories (LAD, RCA, and LCX) using SPECT for an independent cohort of 7 patients. The results were then compared with that estimated with 13N-NH 3 PET. The flow-dependent permeability surface-area product (PS) for 99mTc-tefrofosmin was also estimated. The estimated flow-extraction parameters for 99mTc-tefrofosmin were found to be A = 0.91 ± 0.11, B = 0.34 ± 0.20 (R 2 = 0.49). The range of MBF in LAD, RCA, and LCX was 0.44-3.81 mL/min/g. The MBF between PET and SPECT in the group of independent cohort of 7 patients showed statistically significant correlation, r = 0.71 (P < .001). However, the corresponding CFR correlation was moderate r = 0.39 yet statistically significant (P = .037). The PS for 99mTc-tefrofosmin was (0.019 ± 0.10)*MBF + (0.32 ± 0.16). Dynamic cardiac SPECT using 99mTc-tetrofosmin and a clinical two-headed SPECT/CT scanner can be a useful tool for estimation of MBF.« less

Measurement of absolute myocardial blood flow in humans using dynamic cardiac SPECT and 99mTc-tetrofosmin: Method and validation.

PubMed

Shrestha, Uttam; Sciammarella, Maria; Alhassen, Fares; Yeghiazarians, Yerem; Ellin, Justin; Verdin, Emily; Boyle, Andrew; Seo, Youngho; Botvinick, Elias H; Gullberg, Grant T

2017-02-01

The objective of this study was to measure myocardial blood flow (MBF) in humans using 99m Tc-tetrofosmin and dynamic single-photon emission computed tomography (SPECT). Dynamic SPECT using 99m Tc-tetrofosmin and dynamic positron emission tomography (PET) was performed on a group of 16 patients. The SPECT data were reconstructed using a 4D-spatiotemporal iterative reconstruction method. The data corresponding to 9 patients were used to determine the flow-extraction curve for 99m Tc-tefrofosmin while data from the remaining 7 patients were used for method validation. The nonlinear tracer correction parameters A and B for 99m Tc-tefrofosmin were estimated for the 9 patients by fitting the flow-extraction curve [Formula: see text] for K 1 values estimated with 99m Tc-tefrofosmin using SPECT and MBF values estimated with 13 N-NH 3 using PET. These parameters were then used to calculate MBF and coronary flow reserve (CFR) in three coronary territories (LAD, RCA, and LCX) using SPECT for an independent cohort of 7 patients. The results were then compared with that estimated with 13 N-NH 3 PET. The flow-dependent permeability surface-area product (PS) for 99m Tc-tefrofosmin was also estimated. The estimated flow-extraction parameters for 99m Tc-tefrofosmin were found to be A = 0.91 ± 0.11, B = 0.34 ± 0.20 (R 2  = 0.49). The range of MBF in LAD, RCA, and LCX was 0.44-3.81 mL/min/g. The MBF between PET and SPECT in the group of independent cohort of 7 patients showed statistically significant correlation, r = 0.71 (P < .001). However, the corresponding CFR correlation was moderate r = 0.39 yet statistically significant (P = .037). The PS for 99m Tc-tefrofosmin was (0.019 ± 0.10)*MBF + (0.32 ± 0.16). Dynamic cardiac SPECT using 99m Tc-tetrofosmin and a clinical two-headed SPECT/CT scanner can be a useful tool for estimation of MBF.

Measurement of Absolute Myocardial Blood Flow in Humans Using Dynamic Cardiac SPECT and 99mTc-tetrofosmin: Method and Validation

PubMed Central

Shrestha, Uttam; Sciammarella, Maria; Alhassen, Fares; Yeghiazarians, Yerem; Ellin, Justin; Verdin, Emily; Boyle, Andrew; Seo, Youngho; Botvinick, Elias H.; Gullberg, Grant T.

2015-01-01

Background The objective of this study was to measure myocardial blood flow (MBF) in humans using 99mTc-tetrofosmin and dynamic single photon emission computed tomography (SPECT). Methods Dynamic SPECT using 99mTc-tetrofosmin and dynamic positron emission tomography (PET) was performed on a group of 16 patients. The SPECT data were reconstructed using a 4D-spatiotemporal iterative reconstruction method. The data corresponding to 9 patients were used to determine the flow-extraction curve for 99mTc-tefrofosmin while data from the remaining 7 patients were used for method validation. The nonlinear tracer correction parameters A and B for 99mTc-tefrofosmin were estimated for the 9 patients by fitting the flow-extraction curve K1=F(1−Aexp(−BF)) for K1 values estimated with 99mTc-tefrofosmin using SPECT and MBF values estimated with 13N-NH3 using PET. These parameters were then used to calculate MBF and coronary flow reserve (CFR) in three coronary territories (LAD, RCA, and LCX) using SPECT for an independent cohort of 7 patients. The results were then compared with that estimated with 13N-NH3 PET. The flow dependent permeability surface-area product (PS) for 99mTc-tefrofosmin was also estimated. Results The estimated flow extraction parameters for 99mTc-tefrofosmin was found to be A=0.91±0.11, B=0.34±0.20 (R2 = 0.49). The range of MBF in LAD, RCA, and LCX was 0.44 ml/min/g to 3.81 ml/min/g. The MBF between PET and SPECT in the group of independent cohort of 7 patients showed statistically significant correlation, r = 0.71 (p < 0.001). However, the corresponding CFR correlation was moderate r = 0.39 yet statistically significant (p = 0.037). The PS for 99mTc-tefrofosmin was (0.091 ± 0.10) * MBF = (0.32 ± 0.16). Conclusions Dynamic cardiac SPECT using 99mTc-tetrofosmin and a clinical two-headed SPECT/CT scanner can be a useful tool for estimation of MBF. PMID:26715603

Measurement of absolute myocardial blood flow in humans using dynamic cardiac SPECT and 99mTc-tetrofosmin: Method and validation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shrestha, Uttam; Sciammarella, Maria; Alhassen, Fares

The objective of this study was to measure myocardial blood flow (MBF) in humans using 99mTc-tetrofosmin and dynamic single-photon emission computed tomography (SPECT). Dynamic SPECT using 99mTc-tetrofosmin and dynamic positron emission tomography (PET) was performed on a group of 16 patients. The SPECT data were reconstructed using a 4D-spatiotemporal iterative reconstruction method. The data corresponding to 9 patients were used to determine the flow-extraction curve for 99mTc-tefrofosmin while data from the remaining 7 patients were used for method validation. The nonlinear tracer correction parameters A and B for 99mTc-tefrofosmin were estimated for the 9 patients by fitting the flow-extraction curvemore » K 1 = F(1–Aexp(–B/F)) for K 1 values estimated with 99mTc-tefrofosmin using SPECT and MBF values estimated with 13N-NH 3 using PET. These parameters were then used to calculate MBF and coronary flow reserve (CFR) in three coronary territories (LAD, RCA, and LCX) using SPECT for an independent cohort of 7 patients. The results were then compared with that estimated with 13N-NH 3 PET. The flow-dependent permeability surface-area product (PS) for 99mTc-tefrofosmin was also estimated. The estimated flow-extraction parameters for 99mTc-tefrofosmin were found to be A = 0.91 ± 0.11, B = 0.34 ± 0.20 (R 2 = 0.49). The range of MBF in LAD, RCA, and LCX was 0.44-3.81 mL/min/g. The MBF between PET and SPECT in the group of independent cohort of 7 patients showed statistically significant correlation, r = 0.71 (P < .001). However, the corresponding CFR correlation was moderate r = 0.39 yet statistically significant (P = .037). The PS for 99mTc-tefrofosmin was (0.019 ± 0.10)*MBF + (0.32 ± 0.16). Dynamic cardiac SPECT using 99mTc-tetrofosmin and a clinical two-headed SPECT/CT scanner can be a useful tool for estimation of MBF.« less

Vitexin exerts cardioprotective effect on chronic myocardial ischemia/reperfusion injury in rats via inhibiting myocardial apoptosis and lipid peroxidation

PubMed Central

Che, Xia; Wang, Xin; Zhang, Junyan; Peng, Chengfeng; Zhen, Yilan; Shao, Xu; Zhang, Gongliang; Dong, Liuyi

2016-01-01

Purpose: The aim of this study was to explore the cardioprotective effect of vitexin on chronic myocardial ischemia/reperfusion injury in rats and potential mechanisms. Methods: A chronic myocardial ischemia/reperfusion injury model was established by ligating left anterior descending coronary for 60 minutes, and followed by reperfusion for 14 days. After 2 weeks ischemia/reperfusion, cardiac function was measured to assess myocardial injury. The level of ST segment was recorded in different periods by electrocardiograph. The change of left ventricular function and myocardial reaction degree of fibrosis of heart was investigated by hematoxylin and eosin (HE) staining and Sirius red staining. Endothelium-dependent relaxations due to acetylcholine were observed in isolated rat thoracic aortic ring preparation. The blood samples were collected to measure the levels of MDA, the activities of SOD and NADPH in serum. Epac1, Rap1, Bax and Bcl-2 were examined by using Western Blotting. Results: Vitexin exerted significant protective effect on chronic myocardial ischemia/reperfusion injury, improved obviously left ventricular diastolic function and reduced myocardial reactive fibrosis degree in rats of myocardial ischemia. Medium and high-dose vitexin groups presented a significant decrease in Bax, Epac1 and Rap1 production and increase in Bcl-2 compared to the I/R group. It may be related to preventing myocardial cells from apoptosis, improving myocardial diastolic function and inhibiting lipid peroxidation. Conclusions: Vitexin is a cardioprotective herb, which may be a promising useful complementary and alternative medicine for patients with coronary heart disease. PMID:27648122

21 CFR 866.5560 - Lactic dehydrogenase immunological test system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... immunological test system is a device that consists of the reagents used to measure by immunochemical techniques... found in a variety of conditions, including megaloblastic anemia (decrease in the number of mature red blood cells), myocardial infarction (heart disease), and some forms of leukemia (cancer of the blood...

21 CFR 866.5560 - Lactic dehydrogenase immunological test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... immunological test system is a device that consists of the reagents used to measure by immunochemical techniques... found in a variety of conditions, including megaloblastic anemia (decrease in the number of mature red blood cells), myocardial infarction (heart disease), and some forms of leukemia (cancer of the blood...

21 CFR 866.5560 - Lactic dehydrogenase immunological test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... immunological test system is a device that consists of the reagents used to measure by immunochemical techniques... found in a variety of conditions, including megaloblastic anemia (decrease in the number of mature red blood cells), myocardial infarction (heart disease), and some forms of leukemia (cancer of the blood...

21 CFR 866.5560 - Lactic dehydrogenase immunological test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... immunological test system is a device that consists of the reagents used to measure by immunochemical techniques... found in a variety of conditions, including megaloblastic anemia (decrease in the number of mature red blood cells), myocardial infarction (heart disease), and some forms of leukemia (cancer of the blood...

Weekend versus weekday admission and mortality from myocardial infarction.

PubMed

Kostis, William J; Demissie, Kitaw; Marcella, Stephen W; Shao, Yu-Hsuan; Wilson, Alan C; Moreyra, Abel E

2007-03-15

Management of acute myocardial infarction requires urgent diagnostic and therapeutic procedures, which may not be uniformly available throughout the week. We examined differences in mortality between patients admitted on weekends and those admitted on weekdays for a first acute myocardial infarction, using the Myocardial Infarction Data Acquisition System. All such admissions in New Jersey from 1987 to 2002 (231,164) were included and grouped in 4-year intervals. There were no significant differences in demographic characteristics, coexisting conditions, or infarction site between patients admitted on weekends and those admitted on weekdays. However, patients admitted on weekends were less likely to undergo invasive cardiac procedures, especially on the first and second days of hospitalization (P<0.001). In the interval from 1999 to 2002 (59,786 admissions), mortality at 30 days was significantly higher for patients admitted on weekends (12.9% vs. 12.0%, P=0.006). The difference became significant the day after admission (3.3% vs. 2.7%, P<0.001) and persisted at 1 year (1% absolute difference in mortality). The difference in mortality at 30 days remained significant after adjustment for demographic characteristics, coexisting conditions, and site of infarction (hazard ratio, 1.048; 95% confidence interval [CI], 1.022 to 1.076; P<0.001), but it became nonsignificant after additional adjustment for invasive cardiac procedures (hazard ratio, 1.023; 95% CI, 0.997 to 1.049; P=0.09). For patients with myocardial infarction, admission on weekends is associated with higher mortality and lower use of invasive cardiac procedures. Our findings suggest that the higher mortality on weekends is mediated in part by the lower rate of invasive procedures, and we speculate that better access to care on weekends could improve the outcome for patients with acute myocardial infarction. Copyright 2007 Massachusetts Medical Society.

Differences in immune responses between CMV-seronegative and -seropositive patients with myocardial ischemia and reperfusion

PubMed Central

Shmeleva, Evgeniya V; Boag, Stephen E; Murali, Santosh; Bennaceur, Karim; Das, Rajiv; Egred, Mohaned; Purcell, Ian; Edwards, Richard; Todryk, Stephen; Spyridopoulos, Ioakim

2015-01-01

CMV infection is responsible for acceleration of immune senescence and linked to systemic pathologies, including cardiovascular diseases. In this study, we investigated differences in the immune response between CMV-seropositive and seronegative patients undergoing primary percutaneous coronary intervention (PPCI) for acute myocardial infarction (MI). Peripheral blood samples were taken at six different time points: pre-, 15, 30, 90 min, 24 h after PPCI and at 3 months after MI. Absolute counts of lymphocyte subpopulations, immune response to specific and nonspecific stimulation, serum cytokines and levels of CMV-IgG, cardiolipin-IgG, and anti-endothelial cell antibodies were assessed. CMV-seropositive patients with MI showed a twofold higher IFN-γ production to PHA-stimulation, up to 2.5-fold higher levels of IP-10 in serum and up to 30% lower serum levels of IL-16 compared to CMV-seronegative individuals. CMV-seropositive patients could be divided into two subgroups with high (IL-10Hi) and low (IL-10Lo) IL-10 serum levels during the acute stage of MI. The IL-10Hi CMV-seropositive subgroup showed an increased exit of late-differentiated T lymphocytes, NK and NKT-like cells from the circulation, which may potentially enhance cytotoxic damage in the ischemic myocardium. Finally, we did not observe an acceleration of autoimmunity by MI in CMV-seropositive individuals. The immune response during acute MI showed characteristic differences between CMV seronegative and seropositive patients, with a stronger pro-inflammatory response in seropositive patients. The effects of IP-10, IL-16, and IL-10 on characteristics of acute immune responses and formation of different immune profiles in CMV-seropositive individuals require further investigation. PMID:26029366

Impaired global myocardial flow dynamics despite normal left ventricular function and regional perfusion in chronic kidney disease: a quantitative analysis of clinical 82Rb PET/CT studies.

PubMed

Fukushima, Kenji; Javadi, Mehrbod S; Higuchi, Takahiro; Bravo, Paco E; Chien, David; Lautamäki, Riikka; Merrill, Jennifer; Nekolla, Stephan G; Bengel, Frank M

2012-06-01

Impaired global myocardial flow reserve (MFR) may be associated with increased risk for cardiac events and coronary artery disease progression. Chronic kidney disease (CKD) is also considered a risk factor for cardiovascular disease. We sought to investigate the effect of CKD on the myocardial microcirculation in patients referred for clinical (82)Rb PET/CT, who had normal left ventricular (LV) function and no flow-limiting coronary artery disease. Estimated glomerular filtration rate (eGFR) was available for 230 patients who had undergone rest and pharmacologic stress (82)Rb PET/CT for suspected coronary artery disease. CKD was defined as an eGFR less than 60 mL/min/1.73 m(2). After patients with hemodialysis, a renal transplant, abnormal regional perfusion (summed stress score > 4), or reduced LV function (LV ejection fraction < 45%) were excluded, 40 CKD patients remained. Those were compared with a control group without CKD, which was matched for age, sex, coronary risk factors, and systemic hemodynamics (n = 42). List-mode acquisition of PET enabled quantification of myocardial blood flow (MBF) and MFR using a previously validated retention model with correction for (82)Rb extraction. Rest MBF was normalized to rate-pressure product. Mean eGFR in the CKD group was reduced (44 ± 14 vs. 99 ± 28 mL/min/1.73 m(2); P < 0.0001), and creatinine was significantly elevated, compared with controls (1.9 ± 1.1 vs. 0.8 ± 0.2 mg/dL; P < 0.0001). MFR was significantly reduced in CKD (2.2 ± 1.0 vs. 3.0 ± 1.2 for controls; P = 0.027). This reduction was mainly due to increased rest MBF (1.1 ± 0.4 in CKD vs. 0.8 ± 0.2 mL/min/g in controls; P = 0.007). Stress myocardial flow was comparable between both groups (2.3 ± 0.9 vs. 2.3 ± 0.8 mL/min/g; P = 0.08). Overall, MFR was significantly correlated with eGFR (r = 0.41; P = 0.0005). Stress MBF did not correlate with eGFR (r = 0.002; P = 0.45), but rest MBF showed an inverse correlation (r = -0.49; P < 0.0001). Rest MBF was also inversely correlated with hemoglobin (r = -0.28; P = 0.014), but only eGFR was an independent correlate at multivariate analysis. MFR is impaired in patients with renal insufficiency with normal regional perfusion and LV function, mostly because of elevated rest flow. Absolute quantification of flow may be useful to identify microvascular dysfunction as a precursor of clinically overt coronary disease in this specific risk group.

Wavelength-modulated differential photoacoustic radar imager (WM-DPARI): accurate monitoring of absolute hemoglobin oxygen saturation

PubMed Central

Choi, Sung Soo Sean; Lashkari, Bahman; Dovlo, Edem; Mandelis, Andreas

2016-01-01

Accurate monitoring of blood oxy-saturation level (SO2) in human breast tissues is clinically important for predicting and evaluating possible tumor growth at the site. In this work, four different non-invasive frequency-domain photoacoustic (PA) imaging modalities were compared for their absolute SO2 characterization capability using an in-vitro sheep blood circulation system. Among different PA modes, a new WM-DPAR imaging modality could estimate the SO2 with great accuracy when compared to a commercial blood gas analyzer. The developed WM-DPARI theory was further validated by constructing SO2 tomographic images of a blood-containing plastisol phantom. PMID:27446691

Tissue Sodium Concentration in Myocardial Infarction in Humans: A Quantitative 23Na MR Imaging Study1

PubMed Central

Ouwerkerk, Ronald; Bottomley, Paul A.; Solaiyappan, Meiyappan; Spooner, Amy E.; Tomaselli, Gordon F.; Wu, Katherine C.; Weiss, Robert G.

2008-01-01

Purpose: To prospectively determine whether the absolute tissue sodium concentration (TSC) increases in myocardial infarctions (MIs) in humans and whether TSC is related to infarct size, infarct age, ventricular dysfunction, and/or electrophysiologic inducibility of ventricular arrhythmias. Materials and Methods: Delayed contrast material–enhanced 1.5-T hydrogen 1 (1H) magnetic resonance (MR) imaging was used to measure the size and location of nonacute MIs in 20 patients (18 men, two women; mean age, 63 years ± 9 [standard deviation]; age range, 48–82 years) examined at least 90 days after MI. End-systolic and end-diastolic volumes, ejection fraction, and left ventricle (LV) mass were measured with cine MR imaging. The TSC in normal, infarcted, and adjacent myocardial tissue was measured on sodium 23 (23Na) MR images coregistered with delayed contrast-enhanced 1H MR images. Programmed electric stimulation to induce monomorphic ventricular tachycardia (MVT) was used to assess arrhythmic potential, and myocardial TSC was compared between the inducible MVT and noninducible MVT patient groups. Results: The mean TSC for MIs (59 μmol/g wet weight ± 10) was 30% higher than that for noninfarcted (remote) LV regions (45 μmol/g wet weight ± 5, P < .001) and that for healthy control subjects, and TSC did not correlate with infarct age or functional and morphologic indices. The mean TSC for tissue adjacent to the MI (50 μmol/g wet weight ± 6) was intermediate between that for the MI and that for remote regions. The elevated TSC measured in the MI at 23Na MR imaging lacked sufficient contrast and spatial resolution for routine visualization of MI. Cardiac TSC did not enable differentiation between patients in whom MVT was inducible and those in whom it was not. Conclusion: Absolute TSC is measurable with 23Na MR imaging and is significantly elevated in human MI; however, TSC increase is not related to infarct age, infarct size, or global ventricular function. In regions adjacent to the MI, TSC is slightly increased but not to levels in the MI. © RSNA, 2008 PMID:18566171

Correlation of platelet count and acute ST-elevation in myocardial infarction.

PubMed

Paul, G K; Sen, B; Bari, M A; Rahman, Z; Jamal, F; Bari, M S; Sazidur, S R

2010-07-01

The role of platelets in the pathogenesis of ST-elevation myocardial infarction (STEMI) has been substantiated by studies that demonstrated significant clinical benefits associated with antiplatelet therapy. Initial platelet counts in Acute Myocardial Infarction (AMI) may be a useful adjunct for identifying those patients who may or may not respond to fibrinolytic agents. Patient with acute STEMI has variable level of platelet count and with higher platelet count have poor in hospital outcome. There are many predictors of poor outcome in Acute Myocardial Infarction (AMI) like cardiac biomarkers (Troponin I, Troponin T and CK-MB), C-Reactive Protien (CRP) and WBC (White Blood Cell) counts. Platelet count on presentation of STEMI is one of them. Higher platelet count is associated with higher rate of adverse clinical outcome in ST-Elevation Myocardial Infarction (STEMI), like heart failure, arrhythmia, re-infarction & death. So, categorization of patient with STEMI on the basis of platelet counts may be helpful for risk stratification and management of these patients.

Early detection of myocardial dysfunction using two-dimensional speckle tracking echocardiography in a young cat with hypertrophic cardiomyopathy

PubMed Central

Mochizuki, Yohei; Yoshimatsu, Hiroki; Niina, Ayaka; Teshima, Takahiro; Matsumoto, Hirotaka; Koyama, Hidekazu

2018-01-01

Case summary A 5-month-old intact female Scottish Fold cat was presented for cardiac evaluation. Careful auscultation detected a slight systolic murmur (Levine I/VI). The findings of electrocardiography, thoracic radiography, non-invasive blood pressure measurements and conventional echocardiographic studies were unremarkable. However, two-dimensional speckle tracking echocardiography revealed abnormalities in myocardial deformations, including decreased early-to-late diastolic strain rate ratios in longitudinal, radial and circumferential directions, and deteriorated segmental systolic longitudinal strain. At the follow-up examinations, the cat exhibited echocardiographic left ventricular hypertrophy and was diagnosed with hypertrophic cardiomyopathy using conventional echocardiography. Relevance and novel information This is the first report on the use of two-dimensional speckle tracking echocardiography for the early detection of myocardial dysfunction in a cat with hypertrophic cardiomyopathy; the myocardial dysfunction was detected before the development of hypertrophy. The findings from this case suggest that two-dimensional speckle tracking echocardiography can be useful for myocardial assessment when conventional echocardiographic and Doppler findings are ambiguous. PMID:29449957

Experimental and clinical experience with iodine 123-labeled iodophenylpentadecanoic acid in cardiology.

PubMed

Reske, S N

1994-01-01

Iodine 123-labeled iodophenylpentadecanoic acid (IPPA) has been synthesized for investigating myocardial free fatty acid (FFA) metabolism. The diagnostic application of labeled FFA in heart disease may be important, because FFA is the preferred substrate of cardiac energy metabolism at rest in the fasting state. In addition, regional myocardial FFA uptake and regional myocardial blood flow are tightly coupled in normal myocardium with beta-oxidation, which is extremely sensitive to oxygen deprivation. This article outlines basic physiologic pathways of cardiac IPPA metabolism in normal, acutely ischemic, and reperfused viable myocardium and summarizes the results of experimental studies in animals, validating the application of IPPA as an 123I-labeled fatty acid analog. In addition, the most important clinical studies indicating the clinical use of IPPA for diagnosis of coronary heart disease and myocardial viability are presented.

Cytogenetic, cytotoxic and GC-MS studies on concrete and absolute oils from Taif rose, Saudi Arabia.

PubMed

Hagag, Heba A; Bazaid, Salih A; Abdel-Hameed, El-Sayed S; Salman, Mahmood

2014-12-01

Taif rose (Rosa damascena trigintipetala Dieck) is a sort of damask rose, which is considered as one of the most important economic products of Taif. In this study, the authors investigated the possible cytotoxic, genotoxic, antimutagenic and anticancer effect of concrete and absolute rose oils. The results showed that both concrete and absolute rose oils were cytotoxically and genotoxically safe at a dose of 10 μg/ml when tested on cultures of normal human blood lymphocytes. Also, the results showed significant antimutagenic activity at p < 0.001 for absolute rose oil at the same dose level when tested on cultures of normal human blood lymphocytes supplemented with 300 ng/ml mitomycin C (MMC). On the other hand, concrete and absolute oils exerted a cytotoxic activity against two kinds of human cancer cell lines: HepG2 and MCF7. Concrete oil showed cytotoxic activity against HepG2 and MCF7 with a half maximal inhibitory concentration (IC50) of 16.28 and 18.09 μg/ml, respectively, whereas absolute rose oil showed its cytotoxic activity against HepG2 and MCF7 with an IC50 of 24.94 and 19.69, respectively. From this study, it is concluded that concrete and absolute rose oils are cytotoxically and genotoxically safe at a dose of 10 μg/ml when tested on cultures of normal human blood lymphocytes. In addition, absolute oil has an antimutagenic activity at the same dose. Further investigations are needed to study the activity of higher doses of both oils in vitro and in vivo in experimental animals in order to evaluate the capability of using these oils as therapeutic for treatment of some kinds of cancers.

Regional Myocardial Blood Flow*

PubMed Central

Sullivan, Jay M.; Taylor, Warren J.; Elliott, William C.; Gorlin, Richard

1967-01-01

A method is described which measures the local effectiveness of the myocardial circulation, expressed as a clearance constant. Uniform clearance constants have been demonstrated in the normal canine and human myocardium. A distinct difference in clearance constants has been demonstrated between the normal canine myocardium and areas of naturally occurring disease. Heterogeneous clearance constants have been found in a majority of human subjects with coronary artery disease—the lowest rates being noted in areas of fibrous aneurysm. PMID:6036537

Synchronization of low-frequency oscillations in the cardiovascular system: Application to medical diagnostics and treatment

NASA Astrophysics Data System (ADS)

Ponomarenko, V. I.; Prokhorov, M. D.; Karavaev, A. S.; Kiselev, A. R.; Gridnev, V. I.; Bezruchko, B. P.

2013-10-01

We investigate synchronization between the low-frequency oscillations of heart rate and blood pressure having in humans a basic frequency close to 0.1 Hz. A quantitative estimation of this synchronization based on calculation of relative time of phase synchronization of oscillations is proposed. We show that assessment of synchronization between the considered oscillations can be useful for selecting an optimal dose of beta-blocker treatment in patients after acute myocardial infarction. It is found out that low value of synchronization between the low-frequency rhythms in heart rate and blood pressure at the first week after acute myocardial infarction is a sensitive marker of high risk of mortality during the subsequent 5 years.

Synthetic Generation of Myocardial Blood-Oxygen-Level-Dependent MRI Time Series via Structural Sparse Decomposition Modeling

PubMed Central

Rusu, Cristian; Morisi, Rita; Boschetto, Davide; Dharmakumar, Rohan; Tsaftaris, Sotirios A.

2014-01-01

This paper aims to identify approaches that generate appropriate synthetic data (computer generated) for Cardiac Phase-resolved Blood-Oxygen-Level-Dependent (CP–BOLD) MRI. CP–BOLD MRI is a new contrast agent- and stress-free approach for examining changes in myocardial oxygenation in response to coronary artery disease. However, since signal intensity changes are subtle, rapid visualization is not possible with the naked eye. Quantifying and visualizing the extent of disease relies on myocardial segmentation and registration to isolate the myocardium and establish temporal correspondences and ischemia detection algorithms to identify temporal differences in BOLD signal intensity patterns. If transmurality of the defect is of interest pixel-level analysis is necessary and thus a higher precision in registration is required. Such precision is currently not available affecting the design and performance of the ischemia detection algorithms. In this work, to enable algorithmic developments of ischemia detection irrespective to registration accuracy, we propose an approach that generates synthetic pixel-level myocardial time series. We do this by (a) modeling the temporal changes in BOLD signal intensity based on sparse multi-component dictionary learning, whereby segmentally derived myocardial time series are extracted from canine experimental data to learn the model; and (b) demonstrating the resemblance between real and synthetic time series for validation purposes. We envision that the proposed approach has the capacity to accelerate development of tools for ischemia detection while markedly reducing experimental costs so that cardiac BOLD MRI can be rapidly translated into the clinical arena for the noninvasive assessment of ischemic heart disease. PMID:24691119

Interleukin-6 Mediates Myocardial Fibrosis, Concentric Hypertrophy and Diastolic Dysfunction in Rats

PubMed Central

Meléndez, Giselle C.; McLarty, Jennifer L.; Levick, Scott P.; Du, Yan; Janicki, Joseph S.; Brower, Gregory L.

2010-01-01

While there is a correlation between hypertension and levels of IL-6, the exact role of this cytokine in myocardial remodeling is unknown. This is complicated by the variable tissue and circulating levels of IL-6 reported in numerous experimental models of hypertension. Accordingly, we explored the hypothesis that elevated levels of IL-6 mediate adverse myocardial remodeling. To this end, adult male Sprague Dawley rats were infused with IL-6 (2.5 μg·kg-1·hr-1, IP) for 7 days via osmotic minipump and compared to vehicle infused aged-matched controls. Left ventricular function was evaluated using a blood-perfused isolated heart preparation. In addition, myocardial interstitial collagen volume fraction and isolated cardiomyocyte size were also assessed. Isolated adult cardiac fibroblast experiments were performed to determine the importance of the soluble IL-6 receptor in mediating cardiac fibrosis. IL-6 infusions in vivo resulted in concentric left ventricular hypertrophy, increased ventricular stiffness, a marked increase in collagen volume fraction (6.2 vs. 1.7%; p < 0.001), and proportional increases in cardiomyocyte width and length; all independent of blood pressure. The soluble IL-6 receptor in combination with IL-6 was found to be essential in increasing collagen content regulated by isolated cardiac fibroblasts, and also played a role in mediating a phenotypic conversion to myofibroblasts. These novel observations demonstrate that IL-6 induces a myocardial phenotype almost identical to that of the hypertensive heart, identifying IL-6 as potentially important in this remodeling process. PMID:20606113

Synthetic generation of myocardial blood-oxygen-level-dependent MRI time series via structural sparse decomposition modeling.

PubMed

Rusu, Cristian; Morisi, Rita; Boschetto, Davide; Dharmakumar, Rohan; Tsaftaris, Sotirios A

2014-07-01

This paper aims to identify approaches that generate appropriate synthetic data (computer generated) for cardiac phase-resolved blood-oxygen-level-dependent (CP-BOLD) MRI. CP-BOLD MRI is a new contrast agent- and stress-free approach for examining changes in myocardial oxygenation in response to coronary artery disease. However, since signal intensity changes are subtle, rapid visualization is not possible with the naked eye. Quantifying and visualizing the extent of disease relies on myocardial segmentation and registration to isolate the myocardium and establish temporal correspondences and ischemia detection algorithms to identify temporal differences in BOLD signal intensity patterns. If transmurality of the defect is of interest pixel-level analysis is necessary and thus a higher precision in registration is required. Such precision is currently not available affecting the design and performance of the ischemia detection algorithms. In this work, to enable algorithmic developments of ischemia detection irrespective to registration accuracy, we propose an approach that generates synthetic pixel-level myocardial time series. We do this by 1) modeling the temporal changes in BOLD signal intensity based on sparse multi-component dictionary learning, whereby segmentally derived myocardial time series are extracted from canine experimental data to learn the model; and 2) demonstrating the resemblance between real and synthetic time series for validation purposes. We envision that the proposed approach has the capacity to accelerate development of tools for ischemia detection while markedly reducing experimental costs so that cardiac BOLD MRI can be rapidly translated into the clinical arena for the noninvasive assessment of ischemic heart disease.

The impact of prompt gamma compensation on myocardial blood flow measurements with rubidium-82 dynamic PET.

PubMed

Armstrong, Ian S; Memmott, Matthew J; Tonge, Christine M; Arumugam, Parthiban

2018-04-01

Rubidium-82 myocardial perfusion imaging is a well-established technique for assessing myocardial ischemia. With continuing interest on myocardial blood flow (MBF) and myocardial flow reserve (MFR) measurements, there is a requirement to fully appreciate the impact of technical aspects of the process. One such factor for rubidium-82 is prompt gamma compensation (PGC). This study aims to assess the impact of PGC on MBF and MFR calculated from dynamic Rb-82 data. Dynamic rest and stress images were acquired on a Siemens Biograph mCT and reconstructed with and without PGC in 50 patients (29 male). MBF and MFR were measured in the three main coronary territories as well as globally. With PGC, statistically significant reductions in MBF were observed in LAD (-6.9%), LCx (-4.8%), and globally (-6.5%) but only in obese patients. Significant increases in MBF were observed in RCA (+6.4%) in only nonobese patients. In very obese patients, differences of up to 40% in MBF were observed between PGC and non-PGC images. In nearly all cases, similar PGC differences were observed at stress and rest so there were no significant differences in MFR; however, in a small number of very obese patients, differences in excess of 20% were observed. PGC results in statistically significant changes in MBF, with the greatest reductions observed in the LAD and LCx territories of obese patients. In most cases, the impact on stress and rest data is of similar relative magnitudes and changes to MFR are small.

Quantitative Analysis of First-Pass Contrast-Enhanced Myocardial Perfusion Multidetector CT Using a Patlak Plot Method and Extraction Fraction Correction During Adenosine Stress

NASA Astrophysics Data System (ADS)

Ichihara, Takashi; George, Richard T.; Silva, Caterina; Lima, Joao A. C.; Lardo, Albert C.

2011-02-01

The purpose of this study was to develop a quantitative method for myocardial blood flow (MBF) measurement that can be used to derive accurate myocardial perfusion measurements from dynamic multidetector computed tomography (MDCT) images by using a compartment model for calculating the first-order transfer constant (K1) with correction for the capillary transit extraction fraction (E). Six canine models of left anterior descending (LAD) artery stenosis were prepared and underwent first-pass contrast-enhanced MDCT perfusion imaging during adenosine infusion (0.14-0.21 mg/kg/min). K1 , which is the first-order transfer constant from left ventricular (LV) blood to myocardium, was measured using the Patlak plot method applied to time-attenuation curve data of the LV blood pool and myocardium. The results were compared against microsphere MBF measurements, and the extraction fraction of contrast agent was calculated. K1 is related to the regional MBF as K1=EF, E=(1-exp(-PS/F)), where PS is the permeability-surface area product and F is myocardial flow. Based on the above relationship, a look-up table from K1 to MBF can be generated and Patlak plot-derived K1 values can be converted to the calculated MBF. The calculated MBF and microsphere MBF showed a strong linear association. The extraction fraction in dogs as a function of flow (F) was E=(1-exp(-(0.2532F+0.7871)/F)) . Regional MBF can be measured accurately using the Patlak plot method based on a compartment model and look-up table with extraction fraction correction from K1 to MBF.

Clinical performance of a new point-of-care cardiac troponin I test.

PubMed

Christ, Michael; Geier, Felicitas; Blaschke, Sabine; Giannitsis, Evangelos; Khellaf, Mehdi; Mair, Johannes; Pariente, David; Scharnhorst, Volkher; Semjonow, Veronique; Hausfater, Pierre

2018-04-09

We evaluated the clinical performance of the Minicare cardiac troponin-I (cTnI), a new point-of-care (POC) cTnI test for the diagnosis of acute myocardial infarction (AMI) in a prospective, multicentre study (ISRCTN77371338). Of 474 patients (≥18 years) admitted to an emergency department (ED) or chest pain unit (CPU) with symptoms suggestive of acute coronary syndrome (ACS; ≤12 h from symptom onset), 465 were eligible. Minicare cTnI was tested immediately, 3 h and 6 h after presentation. AMI diagnoses were adjudicated independently based on current guidelines. The diagnostic performance of the Minicare cTnI test at 3 h was similar for whole blood and in plasma: sensitivity 0.92 vs. 0.90; specificity 0.91 vs. 0.90; positive predictive value (PPV) 0.68 vs. 0.66; negative predictive value (NPV) 0.98 vs. 0.98; positive likelihood ratio (LR+) 10.18 vs. 9.41; negative likelihood ratio (LR-) 0.09 vs. 0.11. The optimal diagnostic performance was obtained at 3 h using cut-offs cTnI >43 ng/L plus cTnI change from admission ≥18.5 ng/L: sensitivity 0.90, specificity 0.96, PPV 0.81, NPV 0.98, and LR+ 21.54. The area under the receiver operating characteristics (ROC) curve for cTnI whole blood baseline value and absolute change after 3 h curve was 0.93. These data support the clinical usefulness of Minicare cTnI within a 0 h/3 h-blood sampling protocol supported by current guidelines for the evaluation of suspected ACS.

Baicalin ameliorates isoproterenol-induced acute myocardial infarction through iNOS, inflammation and oxidative stress in rat

PubMed Central

Chen, Huaguo; Xu, Yongfu; Wang, Jianzhong; Zhao, Wei; Ruan, Huihui

2015-01-01

Baicalin belongs to glucuronic acid glycosides and after hydrolysisbaicalein and glucuronic acid come into being. It has such effects as clearing heat and removing toxicity, anti-inflammation, choleresis, bringing high blood pressure down, diuresis, anti-allergic reaction and so on. In this study, we investigated whether baicalin ameliorates isoproterenol-induced acute myocardial infarction and its mechanism. Rat model of acute myocardial infarction was induced by isoproterenol. Casein kinase (CK), the MB isoenzyme of creatine kinase (CK-MB), lactate dehydrogenase (LDH), cardiac troponin T (cTnT) and infarct size measurement were used to measure the protective effect of baicalin on isoproterenol-induced acute myocardial infarction. iNOS protein expression in rat was analyzed using western blot analysis. Tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), malondialdehyde (MDA) and superoxide dismutase (SOD) and caspase-3 activation levels were explored using commercial ELISA kits. In the acute myocardial infarction experiment, baicalin effectively ameliorates the level of CK, CK-MB, LDH and cTnT, reduced infarct size in acute myocardial infarction rat model. Meanwhile, treatment with baicalin effectively decreased the iNOS protein expression, inflammatory factors and oxidative stresses in a rat model of acute myocardial infarction. However, baicalin emerged that anti-apoptosis activity and suppressed the activation of caspase-3 in a rat model of acute myocardial infarction. The data suggest that the protective effect of baicalin ameliorates isoproterenol-induced acute myocardial infarction through iNOS, inflammation and oxidative stress in rat. PMID:26617721

Cardiac CT for myocardial ischaemia detection and characterization--comparative analysis.

PubMed

Bucher, A M; De Cecco, C N; Schoepf, U J; Wang, R; Meinel, F G; Binukrishnan, S R; Spearman, J V; Vogl, T J; Ruzsics, B

2014-11-01

The assessment of patients presenting with symptoms of myocardial ischaemia remains one of the most common and challenging clinical scenarios faced by physicians. Current imaging modalities are capable of three-dimensional, functional and anatomical views of the heart and as such offer a unique contribution to understanding and managing the pathology involved. Evidence has accumulated that visual anatomical coronary evaluation does not adequately predict haemodynamic relevance and should be complemented by physiological evaluation, highlighting the importance of functional assessment. Technical advances in CT technology over the past decade have progressively moved cardiac CT imaging into the clinical workflow. In addition to anatomical evaluation, cardiac CT is capable of providing myocardial perfusion parameters. A variety of CT techniques can be used to assess the myocardial perfusion. The single energy first-pass CT and dual energy first-pass CT allow static assessment of myocardial blood pool. Dynamic cardiac CT imaging allows quantification of myocardial perfusion through time-resolved attenuation data. CT-based myocardial perfusion imaging (MPI) is showing promising diagnostic accuracy compared with the current reference modalities. The aim of this review is to present currently available myocardial perfusion techniques with a focus on CT imaging in light of recent clinical investigations. This article provides a comprehensive overview of currently available CT approaches of static and dynamic MPI and presents the results of corresponding clinical trials.

Catheter-Based Measurements of Absolute Coronary Blood Flow and Microvascular Resistance: Feasibility, Safety, and Reproducibility in Humans.

PubMed

Xaplanteris, Panagiotis; Fournier, Stephane; Keulards, Daniëlle C J; Adjedj, Julien; Ciccarelli, Giovanni; Milkas, Anastasios; Pellicano, Mariano; Van't Veer, Marcel; Barbato, Emanuele; Pijls, Nico H J; De Bruyne, Bernard

2018-03-01

The principle of continuous thermodilution can be used to calculate absolute coronary blood flow and microvascular resistance (R). The aim of the study is to explore the safety, feasibility, and reproducibility of coronary blood flow and R measurements as measured by continuous thermodilution in humans. Absolute coronary flow and R can be calculated by thermodilution by infusing saline at room temperature through a dedicated monorail catheter. The temperature of saline as it enters the vessel, the temperature of blood and saline mixed in the distal part of the vessel, and the distal coronary pressure were measured by a pressure/temperature sensor-tipped guidewire. The feasibility and safety of the method were tested in 135 patients who were referred for coronary angiography. No significant adverse events were observed; in 11 (8.1%) patients, bradycardia and concomitant atrioventricular block appeared transiently and were reversed immediately on interruption of the infusion. The reproducibility of measurements was tested in a subgroup of 80 patients (129 arteries). Duplicate measurements had a strong correlation both for coronary blood flow (ρ=0.841, P <0.001; intraclass correlation coefficient=0.89, P <0.001) and R (ρ=0.780, P <0.001; intraclass correlation coefficient=0.89, P <0.001). In Bland-Altman plots, there was no significant bias or asymmetry. Absolute coronary blood flow (in L/min) and R (in mm Hg/L/min or Wood units) can be safely and reproducibly measured with continuous thermodilution. This approach constitutes a new opportunity for the study of the coronary microcirculation. © 2018 American Heart Association, Inc.

Impact of the Absolute Difference in Diastolic Blood Pressure Between Arms in Patients With Coronary Artery Disease

PubMed Central

Hitaka, Yuka; Miura, Shin-ichiro; Koyoshi, Rie; Shiga, Yuhei; Miyase, Yuiko; Norimatsu, Kenji; Nakamura, Ayumi; Adachi, Sen; Kuwano, Takashi; Sugihara, Makoto; Ike, Amane; Nishikawa, Hiroaki; Saku, Keijiro

2015-01-01

Background We investigated the relationship between the severity and presence of coronary artery disease (CAD) and a difference in systolic and diastolic blood pressure (SBP and DBP) between arms or between lower limbs. Methods We enrolled 277 patients who underwent coronary angiography. We calculated the absolute (|right BP (rt. BP) - left BP (lt. BP)|) and relative (rt. BP - lt. BP) differences in SBP or DBP between arms or between lower limbs, and assessed the severity of CAD in terms of the Gensini score. Results The absolute difference in DBP between arms in the CAD group was significantly lower than that in the non-CAD group, whereas the absolute difference in DBP between lower limbs in the CAD group was significantly higher. There were no differences in the absolute or relative difference in SBP between arms or lower limbs between the groups. The absolute difference in DBP between arms decreased as the Gensini score increased. In a logistic regression analysis, the presence of CAD was independently associated with the absolute difference in DBP between arms, in addition to male, family history, dyslipidemia, diabetes mellitus and hypertension. Conclusion The absolute difference in DBP between arms in addition to traditional factors may be a critical risk factor for the presence of CAD. PMID:26491500

Impact of the Absolute Difference in Diastolic Blood Pressure Between Arms in Patients With Coronary Artery Disease.

PubMed

Hitaka, Yuka; Miura, Shin-Ichiro; Koyoshi, Rie; Shiga, Yuhei; Miyase, Yuiko; Norimatsu, Kenji; Nakamura, Ayumi; Adachi, Sen; Kuwano, Takashi; Sugihara, Makoto; Ike, Amane; Nishikawa, Hiroaki; Saku, Keijiro

2015-11-01

We investigated the relationship between the severity and presence of coronary artery disease (CAD) and a difference in systolic and diastolic blood pressure (SBP and DBP) between arms or between lower limbs. We enrolled 277 patients who underwent coronary angiography. We calculated the absolute (|right BP (rt. BP) - left BP (lt. BP)|) and relative (rt. BP - lt. BP) differences in SBP or DBP between arms or between lower limbs, and assessed the severity of CAD in terms of the Gensini score. The absolute difference in DBP between arms in the CAD group was significantly lower than that in the non-CAD group, whereas the absolute difference in DBP between lower limbs in the CAD group was significantly higher. There were no differences in the absolute or relative difference in SBP between arms or lower limbs between the groups. The absolute difference in DBP between arms decreased as the Gensini score increased. In a logistic regression analysis, the presence of CAD was independently associated with the absolute difference in DBP between arms, in addition to male, family history, dyslipidemia, diabetes mellitus and hypertension. The absolute difference in DBP between arms in addition to traditional factors may be a critical risk factor for the presence of CAD.

Regulation of coronary blood flow. Effect of coronary artery stenosis.

PubMed

Duncker, D J; Merkus, D

2004-12-01

The consistently high level of myocardial oxygen extraction requires tight control of coronary blood flow, because an increase in myocardial oxygen demand, as occurs during exercise, cannot be obtained by a further increase in oxygen extraction. Consequently, adequate control of coronary vascular resistance is critical. Coronary resistance vessel tone is the result of a myriad of vasodilator and vasoconstrictor influences, which are exerted by the myocardium, endothelium and neurohumoral status. Unraveling of the integrative mechanisms controlling metabolic vasodilation has been difficult, more than likely due to the redundancy design of vasomotor control. In contrast to the traditional view that myocardial ischemia produced by a coronary artery stenosis causes maximal microvascular dilation, more recent studies have shown that the coronary microvessels retain some degree of vasodilator reserve during ischemia and remain responsive to vasoconstrictor stimuli. These observations raise the question of whether pharmacologic vasodilators acting at the microvascular level might be therapeutically useful. The critical property of effective vasodilator therapy requires selective dilation of small arteries, while avoiding coronary steal by not interfering with metabolic vasoregulation at the level of the arterioles.

Challenges in secondary prevention after acute myocardial infarction: A call for action.

PubMed

Piepoli, Massimo F; Corrà, Ugo; Dendale, Paul; Frederix, Ines; Prescott, Eva; Schmid, Jean Paul; Cupples, Margaret; Deaton, Christi; Doherty, Patrick; Giannuzzi, Pantaleo; Graham, Ian; Hansen, Tina Birgitte; Jennings, Catriona; Landmesser, Ulf; Marques-Vidal, Pedro; Vrints, Christiaan; Walker, David; Bueno, Hector; Fitzsimons, Donna; Pelliccia, Antonio

2017-06-01

Worldwide, each year more than 7 million people experience myocardial infarction, in which one-year mortality rates are now in the range of 10%, but vary with patient characteristics. The consequences are even more dramatic: among patients who survive, 20% suffer a second cardiovascular event in the first year and approximately 50% of major coronary events occur in those with a previous hospital discharge diagnosis of ischaemic heart disease. The people behind these numbers spur this call for action. Prevention after myocardial infarction is crucial to reduce risk and suffering. Evidence-based interventions include optimal medical treatment with anti-platelets and statins, achievement of blood pressure, lipid and blood glucose targets, and appropriate lifestyle changes. The European Society of Cardiology and its constituent bodies are determined to embrace this challenge by developing a consensus document in which the existing gaps for secondary prevention strategies are reviewed. Effective interventions in relation to the patients, healthcare providers and healthcare systems are proposed and discussed. Finally, innovative strategies in hospital as well as in outpatient and long-term settings are endorsed.

Sacubitril and valsartan protect from experimental myocardial infarction by ameliorating oxidative damage in Wistar rats.

PubMed

Imran, Mohd; Hassan, Md Quamrul; Akhtar, Md Sayeed; Rahman, Obaid; Akhtar, M; Najmi, Abul Kalam

2018-03-29

Sacubitril (SAC), a neprilysin inhibitor prevent degradation of neprilysin and activate cGMP signaling pathways leading to rise in blood volume concurrent to blood pressure by means of vasoactive peptides, adrenomedullin, and bradykinin. The aim of this study was to evaluate the anti-ischemic effects of SAC through inhibiting neprilysin in isoproterenol (ISO) induced myocardial infarction (MI) in Wistar albino rats. ISO (85 mg/kg) was injected subcutaneously at the end of 14 days pre-treatment with SAC and valsartan (VAL). Biochemical investigation revealed that SAC along with VAL significantly prevented the antioxidant enzymes (SOD, Catalase, GR, GPx, GST, and GSH) degradation and malondialdehyde (MDA) induced by ISO intoxication in Wistar rats. Along with this, cardiac biomarkers (LDH, CK-MB, ALT, AST, and ALP) were also significantly ameliorated by SACand VAL in ISO-treated rats. Concurrently, decreased infarction area (IA)and marked reduction in myofibril damage by SACand VAL further supported its protective benefits in MI. Taken together, the results suggest that inhibition of enzyme neprilysin alleviated the ISO induces myocardial damage mediated by its strong antioxidant potential.

Protective effects of circulating microvesicles derived from myocardial ischemic rats on apoptosis of cardiomyocytes in myocardial ischemia/reperfusion injury.

PubMed

Wang, Yao; Wei, Su; Wang, Yi-Lu; Liu, Miao; Shang, Man; Zhang, Qi; Wu, Yan-Na; Liu, Ming-Lin; Song, Jun-Qiu; Liu, Yan-Xia

2017-08-15

To investigate the effects of circulating microvesicles derived from myocardial ischemia (I-MVs) on apoptosis in myocardial ischemia/reperfusion (I/R) injury in rats. I-MVs from rats undergoing myocardial left anterior descending (LAD) coronary artery ligation were isolated by ultracentrifugation from circulating blood and characterized by flow cytometry. I-MVs were administered intravenously (4.8 mg/kg) at 5 min before reperfusion procedure in I/R injury model which was induced by 30-min of ischemia and 120-min of reperfusion of LAD in rats. Treatment with I-MVssignificantly reduced the size of myocardial infarction, the activities of serum CK-MB and LDH, and the number of apoptotic cardiomyocytes. The activities of caspase 3, caspase 9 and caspase 12 in myocardium were also decreased significantly with I-MVs treatment. Moreover, the expression of Bax was decreased but Bcl-2 was increased. The expression of glucose regulated protein 78 (GRP78), sarco/endoplasmic reticulum Ca 2+ -ATPase 2 (SERCA2) and phosphorylated phospholamban (p-PLB) were increased after being treated with I-MVs. I-MVs could protect hearts from I/R injury in rats through SERCA2 and p-PLB of calcium regulatory proteins to alleviate intrinsic myocardial apoptosis including mitochondrial and endoplasmic reticulum pathways.

In vivo mouse myocardial (31)P MRS using three-dimensional image-selected in vivo spectroscopy (3D ISIS): technical considerations and biochemical validations.

PubMed

Bakermans, Adrianus J; Abdurrachim, Desiree; van Nierop, Bastiaan J; Koeman, Anneke; van der Kroon, Inge; Baartscheer, Antonius; Schumacher, Cees A; Strijkers, Gustav J; Houten, Sander M; Zuurbier, Coert J; Nicolay, Klaas; Prompers, Jeanine J

2015-10-01

(31)P MRS provides a unique non-invasive window into myocardial energy homeostasis. Mouse models of cardiac disease are widely used in preclinical studies, but the application of (31)P MRS in the in vivo mouse heart has been limited. The small-sized, fast-beating mouse heart imposes challenges regarding localized signal acquisition devoid of contamination with signal originating from surrounding tissues. Here, we report the implementation and validation of three-dimensional image-selected in vivo spectroscopy (3D ISIS) for localized (31)P MRS of the in vivo mouse heart at 9.4 T. Cardiac (31)P MR spectra were acquired in vivo in healthy mice (n = 9) and in transverse aortic constricted (TAC) mice (n = 8) using respiratory-gated, cardiac-triggered 3D ISIS. Localization and potential signal contamination were assessed with (31)P MRS experiments in the anterior myocardial wall, liver, skeletal muscle and blood. For healthy hearts, results were validated against ex vivo biochemical assays. Effects of isoflurane anesthesia were assessed by measuring in vivo hemodynamics and blood gases. The myocardial energy status, assessed via the phosphocreatine (PCr) to adenosine 5'-triphosphate (ATP) ratio, was approximately 25% lower in TAC mice compared with controls (0.76 ± 0.13 versus 1.00 ± 0.15; P < 0.01). Localization with one-dimensional (1D) ISIS resulted in two-fold higher PCr/ATP ratios than measured with 3D ISIS, because of the high PCr levels of chest skeletal muscle that contaminate the 1D ISIS measurements. Ex vivo determinations of the myocardial PCr/ATP ratio (0.94 ± 0.24; n = 8) confirmed the in vivo observations in control mice. Heart rate (497 ± 76 beats/min), mean arterial pressure (90 ± 3.3 mmHg) and blood oxygen saturation (96.2 ± 0.6%) during the experimental conditions of in vivo (31)P MRS were within the normal physiological range. Our results show that respiratory-gated, cardiac-triggered 3D ISIS allows for non-invasive assessments of in vivo mouse myocardial energy homeostasis with (31)P MRS under physiological conditions. Copyright © 2015 John Wiley & Sons, Ltd.

Creatine kinase MB isoenzyme in dermatomyositis: a noncardiac source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Larca, L.J.; Coppola, J.T.; Honig, S.

1981-03-01

Three patients with polymyositis had elevated serum levels of creatine kinase MB isoenzyme. The presence of this isoenzyme is used extensively to diagnose myocardial infarction, but the isoenzyme is also found in sera of patients with primary muscular and neuromuscular disorders. Researchers studied cardiac function in two of our patients with electrocardiograms, technetium stannous pyrophosphate scanning, and technetium 99m-labeled erythrocyte gated blood pool imaging and in the third patient by postmortem examination. There was no evidence of myocardial involvement to account for the high serum levels of isoenzyme. Creatine kinase MB in the sera of patients with polymyositis does notmore » necessarily indicate myocardial necrosis.« less

Intracoronary bivalirudin for no reflow reversal: a second chance to treat this disorder?

PubMed

Cortese, Bernardo; Picchi, Andrea; Micheli, Andrea; Limbruno, Ugo

2009-07-01

No reflow, defined as failure to restore normal myocardial blood flow despite removal of coronary obstruction, is a not rare complication of ST-elevation acute myocardial infarction. We here describe the case of an old patient experiencing inferior and right ventricle myocardial infarction complicated by cardiogenic shock, anaemia and thrombocytopenia. We managed it with urgent PCI using thrombus aspirator, that determined onset of no reflow, that we successfully managed with intracoronary bivalirudin. We showed how bivalirudin, a drug whose use is increasing in the catheterization laboratories, could be safely used via the intracoronary route to treat no reflow phenomenon due to distal microembolization in a complex patient.

Computational studies of transthoracic and transvenous defibrillation in a detailed 3-D human thorax model.

PubMed

Jorgenson, D B; Haynor, D R; Bardy, G H; Kim, Y

1995-02-01

A method for constructing and solving detailed patient-specific 3-D finite element models of the human thorax is presented for use in defibrillation studies. The method utilizes the patient's own X-ray CT scan and a simplified meshing scheme to quickly and efficiently generate a model typically composed of approximately 400,000 elements. A parameter sensitivity study on one human thorax model to examine the effects of variation in assigned tissue resistivity values, level of anatomical detail included in the model, and number of CT slices used to produce the model is presented. Of the seven tissue types examined, the average left ventricular (LV) myocardial voltage gradient was most sensitive to the values of myocardial and blood resistivity. Incorrectly simplifying the model, for example modeling the heart as a homogeneous structure by ignoring the blood in the chambers, caused the average LV myocardial voltage gradient to increase by 12%. The sensitivity of the model to variations in electrode size and position was also examined. Small changes (< 2.0 cm) in electrode position caused average LV myocardial voltage gradient values to increase by up to 12%. We conclude that patient-specific 3-D finite element modeling of human thoracic electric fields is feasible and may reduce the empiric approach to insertion of implantable defibrillators and improve transthoracic defibrillation techniques.

Protective effect of the combinations of glycyrrhizic, ferulic and cinnamic acid pretreatment on myocardial ischemia-reperfusion injury in rats

PubMed Central

GAO, YUQIN; HAO, JIPING; ZHANG, HONGKAO; QIAN, GUOQIANG; JIANG, RENWANG; HU, JING; WANG, JIANING; LEI, ZHANG; ZHAO, GUOPING

2015-01-01

The aim of this study was to find an effective drug cocktail pretreatment to protect myocardial tissue of the heart from ischemia-reperfusion (I/R) injury. The mechanisms underlying the effects of the drug cocktail were subsequently explored in order to expand the application of Dang-gui-si-ni-tang (DGSN), a Traditional Chinese Medicine. The active components of DGSN in the serum following oral administration were investigated using high-performance liquid chromatography. The activity of superoxide dismutase (SOD) and malondialdehyde (MDA) levels were then analyzed to show the effect of the active components in the treatment of myocardial I/R injury. An L16 (44) orthogonal experiment was utilized to determine the most effective cocktail mix and the mechanism underlying the effect of this mix on myocardial I/R injury was investigated. It was observed that FCG, a mixture of glycyrrhizic (50 mg/kg), cinnamic (200 mg/kg) and ferulic (300 mg/kg) acid, was the optimal drug cocktail present in DGSN. This was absorbed into the blood following oral administration and was shown to decrease MDA levels and increase the activity of SOD. In conclusion, the findings suggest that FCG, a combination of active ingredients in the DGSN decoction, can be absorbed into the blood and protect the myocardium from I/R injury. PMID:25574212

Myocardial Reloading after Extracorporeal Membrane Oxygenation Alters Substrate Metabolism While Promoting Protein Synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kajimoto, Masaki; Priddy, Colleen M.; Ledee, Dolena

2013-08-19

Extracorporeal membrane oxygenation (ECMO) unloads the heart providing a bridge to recovery in children after myocardial stunning. Mortality after ECMO remains high.Cardiac substrate and amino acid requirements upon weaning are unknown and may impact recovery. We assessed the hypothesis that ventricular reloading modulates both substrate entry into the citric acid cycle (CAC) and myocardial protein synthesis. Fourteen immature piglets (7.8-15.6 kg) were separated into 2 groups based on ventricular loading status: 8 hour-ECMO (UNLOAD) and post-wean from ECMO (RELOAD). We infused [2-13C]-pyruvate as an oxidative substrate and [13C6]-L-leucine, as a tracer of amino acid oxidation and protein synthesis into themore » coronary artery. RELOAD showed marked elevations in myocardial oxygen consumption above baseline and UNLOAD. Pyruvate uptake was markedly increased though RELOAD decreased pyruvate contribution to oxidative CAC metabolism.RELOAD also increased absolute concentrations of all CAC intermediates, while maintaining or increasing 13C-molar percent enrichment. RELOAD also significantly increased cardiac fractional protein synthesis rates by >70% over UNLOAD. Conclusions: RELOAD produced high energy metabolic requirement and rebound protein synthesis. Relative pyruvate decarboxylation decreased with RELOAD while promoting anaplerotic pyruvate carboxylation and amino acid incorporation into protein rather than to the CAC for oxidation. These perturbations may serve as therapeutic targets to improve contractile function after ECMO.« less

The Brazilian Family Health Program and Secondary Stroke and Myocardial Infarction Prevention: A 6-Year Cohort Study

PubMed Central

Franco, Selma; Longo, Alexandre; Moro, Carla; Buss, Talita A.; Collares, Daniel; Werlich, Roberta; Dadan, Danieli D.; Fissmer, Cristiane S.; Aragão, Ana; Ferst, Priscilla; Palharini, Felipe G.; Eluf-Neto, Jose; Fonseca, Luiz A. M.; Whiteley, William N.; Gonçalves, Anderson R. R.

2012-01-01

Objectives. We compared the incidence of recurrent or fatal cardiovascular disease in patients using Brazil’s government-run Family Health Program (FHP) with those using non-FHP models of care. Methods. From 2005 to 2010, we followed outpatients discharged from city public hospitals after a first ever stroke for stroke recurrence and myocardial infarction, using data from all city hospitals, death certificates, and outpatient monitoring in state-run and private units. Results. In the follow-up period, 103 patients in the FHP units and 138 in the non-FHP units had exclusively state-run care. Stroke or myocardial infarction occurred in 30.1% of patients in the FHP group and 36.2% of patients in non-FHP care (rate ratio [RR] = 0.85; 95% confidence interval [CI] = 0.61, 1.18; P = .39); 37.9% of patients in FHP care and 54.3% in non-FHP care (RR = 0.68; 95% CI = 0.50, 0.92; P = .01) died. FHP use was associated with lower hazard of death from all causes (hazard ratio [HR] = 0.58; P = .005) after adjusting for age and stroke severity. The absolute risk reduction for death by all causes was 16.4%. Conclusions. FHP care is more effective than is non-FHP care at preventing death from secondary stroke and myocardial infarction. PMID:23078478

Role of nitric oxide and adenosine in control of coronary blood flow in exercising dogs.

PubMed

Tune, J D; Richmond, K N; Gorman, M W; Feigl, E O

2000-06-27

Inhibition of nitric oxide (NO) synthesis results in very little change in coronary blood flow, but this is thought to be because cardiac adenosine concentration increases to compensate for the loss of NO vasodilation. Accordingly, in the present study, adenosine measurements were made before and during NO synthesis inhibition during exercise. Experiments were performed in chronically instrumented dogs at rest and during graded treadmill exercise before and during inhibition of NO synthesis with N(omega)-nitro-L-arginine (L-NNA, 35 mg/kg IV). Before inhibition of NO synthesis, myocardial oxygen consumption increased approximately 3.7-fold, and coronary blood flow increased approximately 3.2-fold from rest to the highest level of exercise, and this was not changed by NO synthesis inhibition. Coronary venous oxygen tension was modestly reduced by L-NNA at all levels of myocardial oxygen consumption. However, the slope of the relationship between myocardial oxygen consumption and coronary venous oxygen tension was not altered by L-NNA. Inhibition of NO synthesis did not increase coronary venous plasma or estimated interstitial adenosine concentration. During exercise, estimated interstitial adenosine remained well below the threshold concentration necessary for coronary vasodilation before or after L-NNA. NO causes a modest coronary vasodilation at rest and during exercise but does not act as a local metabolic vasodilator. Adenosine does not mediate a compensatory local metabolic coronary vasodilation when NO synthesis is inhibited.

Myocardial Infarction. Pathological Relevance and Relationship with Coronary Risk Factors.

PubMed

Leone, Aurelio

2017-01-01

Three types of necrosis characterize MI: coagulation necrosis, typically due to a coronarogenic mechanism, coagulative myocytolysis with formation of contract bands as an effect of sympathetic nervous system and adrenergic stimulation, and colliquative myocytolysis, characterized by myocardial fiber lysis, which is a close result of hydrolytic enzyme activity deriving from the material reaching the infarct area. Although a multifactorial etiology may be identified, nevertheless coronary alterations, which are a consequence of atherosclerotic plaque formation and complications with a reduced blood flow supply to the myocardium, are the benchmark of MI. Evidence indicates a close relationship between the MI and some coronary risk factors, associated with this pathologic pattern with a different, but high rate. Precipitating events to cause acute myocardial pathology need, however, to develop an acute myocardial infarction. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Positron Emission Tomography of the Heart

DOE R&D Accomplishments Database

Schelbert, H. R.; Phelps, M. E.; Kuhl, D. E.

1979-01-01

Positron emission computed tomography (PCT) represents an important new tool for the noninvasive evaluation and, more importantly, quantification of myocardial performance. Most currently available techniques permit assessment of only one aspect of cardiac function, i.e., myocardial perfusion by gamma scintillation camera imaging with Thallium-201 or left ventricular function by echocardiography or radionuclide angiocardiography. With PCT it may become possible to study all three major segments of myocardial performance, i.e., regional blood flow, mechanical function and, most importantly, myocardial metabolism. Each of these segments can either be evaluated separately or in combination. This report briefly describes the principles and technological advantages of the imaging device, reviews currently available radioactive tracers and how they can be employed for the assessment of flow, function and metabolism; and, lastly, discusses possible applications of PCT for the study of cardiac physiology or its potential role in the diagnosis of cardiac disease.

Calibration of diffuse correlation spectroscopy blood flow index with venous-occlusion diffuse optical spectroscopy in skeletal muscle

PubMed Central

Li, Zhe; Baker, Wesley B.; Parthasarathy, Ashwin B.; Ko, Tiffany S.; Wang, Detian; Schenkel, Steven; Durduran, Turgut; Li, Gang; Yodh, Arjun G.

2015-01-01

Abstract. We investigate and assess the utility of a simple scheme for continuous absolute blood flow monitoring based on diffuse correlation spectroscopy (DCS). The scheme calibrates DCS using venous-occlusion diffuse optical spectroscopy (VO-DOS) measurements of arm muscle tissue at a single time-point. A calibration coefficient (γ) for the arm is determined, permitting conversion of DCS blood flow indices to absolute blood flow units, and a study of healthy adults (N=10) is carried out to ascertain the variability of γ. The average DCS calibration coefficient for the right (i.e., dominant) arm was γ=(1.24±0.15)×108 (mL·100  mL−1·min−1)/(cm2/s). However, variability can be significant and is apparent in our site-to-site and day-to-day repeated measurements. The peak hyperemic blood flow overshoot relative to baseline resting flow was also studied following arm-cuff ischemia; excellent agreement between VO-DOS and DCS was found (R2=0.95, slope=0.94±0.07, mean difference=−0.10±0.45). Finally, we show that incorporation of subject-specific absolute optical properties significantly improves blood flow calibration accuracy. PMID:26720870

Prognostic significance of myocardial energy expenditure and myocardial efficiency in patients with heart failure with reduced ejection fraction.

PubMed

Cetin, Mehmet S; Ozcan Cetin, Elif H; Canpolat, Ugur; Sasmaz, Hatice; Temizhan, Ahmet; Aydogdu, Sinan

2018-02-01

In heart failure with reduced ejection fraction (HFrEF) patients, myocardial blood flow (MBF), myocardial energy expenditure (MEE), myocardial efficiency has been poorly evaluated because of the necessity of invasive procedures in the determination of these parameters. Transthoracic echocardiography (TTE) can provide reliable data for MEE, MBF (via coronary sinus (CS) flows). Also, myocardial efficiency can be evaluated by the MEE to MBF ratio. We aim to assess MBF, MEE and energy efficiency and the prognostic value of these parameters in HFrEF. In this prospective study, a total of 80 patients with HFrEF due to either ischemic or non-ischemic etiology and 20 healthy control subjects were included. Median follow-up duration was 901 (27-1004) days. MBF was calculated via coronary sinus blood flow. MEE was measured from circumferential end-systolic stress, stroke volume and left ventricular ejection time. MEE to MBF ratio was determined as MEf. Primary composite end-point (CEP) was cardiovascular mortality, heart transplantation or mechanical circulatory support. MEE and MEf were lower and MBF per minute was higher in HF group compared to control subjects whereas MBF per 100 g left ventricular mass was not different. MEE and MEf have significantly negative correlation with troponin I, BNP, uric acid and positive correlation with epicardial fat thickness. In Cox regression analysis, per one calorie decrease of MEE was associated 4.3 times increased risk [HR 4.396 (95% CI 1.230-15.716)] and per one percent decrease of MEf was associated 3.3 times increased risk of CEP [HR 3.343 (95% CI 1.025-10.905)]. Our study demonstrated that while MEE and MEf diminished in HFrEF, MBF preserved with the symptomatic progression of HF. MEE and MEf were found to be associated with important prognostic markers and independent predictors of CEP in HFrEF. Evaluation of MEE, MBF and MEf with echocardiography may provide an additional data regarding prognostic assessment of HFrEF population.

Differential MR Delayed Enhancement Patterns of Chronic Myocardial Infarction between Extracellular and Intravascular Contrast Media

PubMed Central

Wang, Jian; Xiang, Bo; Lin, Hung Yu; Liu, Hongyu; Freed, Darren; Arora, Rakesh C.; Tian, Ganghong

2015-01-01

Objectives Because the distribution volume and mechanism of extracellular and intravascular MR contrast media differ considerably, the enhancement pattern of chronic myocardial infarction with extracellular or intravascular media might also be different. This study aims to investigate the differences in MR enhancement patterns of chronic myocardial infarction between extracellular and intravascular contrast media. Materials and Methods Twenty pigs with myocardial infarction underwent cine MRI, first pass perfusion MRI and delayed enhancement MRI with extracellular or intravascular media at four weeks after coronary occlusion. Myocardial blood flow (MBF) was determined with microsphere measurement. The infarction histopathological changes were evaluated by hematoxylin and eosin staining and Masson's trichrome method. Results Cine MRI revealed the reduced wall thickening in chronic infarction compared with normal myocardium. Moreover, significant wall thinning in chronic infarction was observed in cine MRI. Peak first-pass signal intensity didn’t significantly differ between chronic infarction and normal myocardium no matter what kinds of contrast media. At the following delayed enhancement phase, extracellular media-enhanced signal intensity was significantly higher in chronic infarction than in normal myocardium. Conversely, intravascular media-enhanced signal intensity was almost equivalent among chronic infarction and normal myocardium. At four weeks after infarction, MBF in chronic infarction approached to that in normal myocardium. Large thick-walled vessels were detected at peri-infarction zones. The cardiomyocytes were replaced by scar tissue consisting of dilated blood vessels and discrete fibers of collagen. Conclusions Chronic infarction was characterized by the significantly reduced wall thickening and the definite wall thinning. First-pass myocardial perfusion defect was not detected in chronic infarction with two media due to the significantly recovered MBF and well-developed collateral vessels. Infarction remodeling enlarged the extracellular compartment, which was available for extracellular media but not accessible to intravascular media. Extracellular media identified chronic infarction as the hyper-enhancement; nonetheless, intravascular media didn’t provide delayed enhancement. PMID:25816056

Evaluation of first-draw whole blood, point-of-care cardiac markers in the context of the universal definition of myocardial infarction: a comparison of a multimarker panel to troponin alone and to testing in the central laboratory.

PubMed

Lee-Lewandrowski, Elizabeth; Januzzi, James L; Grisson, Ricky; Mohammed, Asim A; Lewandrowski, Grant; Lewandrowski, Kent

2011-04-01

Previous studies evaluating point-of-care testing (POCT) for cardiac biomarkers did not use current recommendations for troponin cutoff values or recognize the recent universal definition of acute myocardial infarction. Traditionally, achieving optimal sensitivity for the detection of myocardial injury on initial presentation required combining cardiac troponin and/or creatine kinase isoenzyme MB with an early marker, usually myoglobin. In recent years, the performance of central laboratory combining cardiac troponin assays has improved significantly, potentially obviating the need for a multimarker panel to achieve optimum sensitivity. To compare 2 commonly used POCT strategies to a fourth generation, central laboratory cardiac troponin T assay on first-draw specimens from patients being evaluated for acute myocardial infarction in the emergency department. The 2 strategies included a traditional POCT multimarker panel and a newer POCT method using cardiac troponin I alone. Blood specimens from 204 patients presenting to the emergency department with signs and/or symptoms of myocardial ischemia were measured on the 2 POCT systems and by a central laboratory method. The diagnosis for each patient was determined by retrospective chart review. The cardiac troponin T assasy alone was more sensitive for acute myocardial infarction than the multimarker POCT panel with equal or better specificity. When compared with a POCT troponin I, the cardiac troponin T was also more sensitive, but this difference was not significant. The POCT troponin I alone also had the same sensitivity as the multimarker panel. Testing for combining cardiac troponin alone using newer, commercially available, central laboratory or POCT assays performed with equal or greater sensitivity to acute myocardial infarction as the older, traditional, multimarker panel. In the near future, high-sensitivity, central laboratory troponins will be available for routine clinical use. As a result, the quality gap between central laboratories and older POCT methods will continue to widen, unless the performance of the POCT methods is improved.

Preliminary report of 48-hours Atosiban administration in spontaneous preterm labor - Doppler blood flow assessment of placental and fetal circulation.

PubMed

Grzesiak, Mariusz; Wilczynski, Jan

2013-01-01

The aims were to investigate whether there are any changes in placental and fetal circulation during Atosiban tocolysis within the first 48 hours of therapy. Detailed Doppler evaluation of placental and fetal circulation was performed prior to Atosiban administration and thereafter at 24 and 48 hours. Maternal heart rate and the pulsatility index (PI) in both uterine arteries (R-UtA, L-UtA) were assessed. Fetal heart rate (FHR), the resistance (RI) and pulsatility index (PI) of umbilical (UA) and middle cerebral artery (MCA) were measured. Additionally cerebroplacental ratio was calculated. E-wave/A-wave ratio (E/A) for atrioventricular valves, the myocardial performance index (MPI) and shortening fraction (SF) for both ventricles were calculated for both ventricles independently. To determine changes over time in all study variables analysis of variance (ANOVA) for repeated measurements followed by Tukey-Kramer's post hoc test was used. The effects of additional clinical covariates were checked. Maternal heart rate and blood flow in (R-UtA/L-UtA) were not altered significantly during Atosiban administration. No significant changes in FHR as well as Doppler parameters (RI, PI, PSV) in UA and MCA were recorded after 24/48 hours of tocolytic treatment. The mean values of cerebroplacental ratio (CPR) remained unaltered during treatment. Detailed evaluation of fetal cardiac function parameters (E/A, SF, MPI) calculated independently for both ventricles, revealed no significant changes over the time. To our best knowledge this study has been first evaluation of placental and fetal circulation with assessment of cardiac hemodynamic function during 48-hours administration of Atosiban. This kind of tocolysis treatment seems not to alter uterine nor fetal arterial blood flow pattern seriously. Hemodynamic cardiac activity in fetuses has remained unaffected. We cannot conclude definitely that there are absolutely no changes in the fetal hemodynamic condition due to Atosiban. Further studies should be performed to verify its possible influence on fetal venous blood flow.

Hemolysis induced by PMIVSD occluder.

PubMed

Rao, D Sheshagiri; Barik, Ramachandra; Siva Prasad, Akula

2016-09-01

Hemolysis related to occluder, prosthetic valve, and prosthetic ring used for mitral valve annuloplasty are not very unusual. However, hemolysis related to transcathetor closure of post-myocardial infarction ventricular septal defect (PMIVSD) is infrequent. A close follow-up for spontaneous resolution with or without blood transfusion has been reported in a few cases. Occasionally, surgical retrieval is unavoidable or lifelong blood transfusion is required if surgery cannot be done because of higher risk. In this illustration, we have showed a close follow-up of a case of hemolysis induced by atrial septal occluder used for VSD closure after myocardial infarction. Despite successful device closure of PMIVSD which is difficult, a close watch is needed for complications like residual leak, device embolization, and hemolysis. Copyright © 2016 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Cardiovascular magnetic resonance profiling of coronary atherosclerosis: vessel wall remodelling and related myocardial blood flow alterations.

PubMed

Jahnke, Cosima; Manka, Robert; Kozerke, Sebastian; Schnackenburg, Bernhard; Gebker, Rolf; Marx, Nikolaus; Paetsch, Ingo

2014-12-01

To determine the association between coronary vessel wall morphology and haemodynamic consequences to the myocardium using a combined cardiovascular magnetic resonance (CMR) imaging protocol. Non-invasive CMR profiling of coronary atherosclerotic wall changes and related myocardial blood flow impairment has not been established yet. Sixty-three patients (45 men, 61.5 ± 10.7 years) with suspected or known coronary artery disease underwent 3.0 Tesla CMR imaging. The combined CMR protocol consisted of the following imaging modules at rest: 3D vessel wall imaging and flow measurement of the proximal right coronary artery (RCA), myocardial T2*, and first-pass perfusion imaging. During adenosine stress coronary flow, T2* and first-pass perfusion imaging were repeated. Coronary X-ray angiography classified patient groups: (i) all-smooth (n = 19); (ii) luminal irregular (diameter reduction < 30%; n = 35); and (iii) stenosed RCA (diameter reduction ≥ 50%; n = 9). The ratio of CMR-derived vessel wall area-to-lumen area significantly increased stepwise for the comparison of all-smooth vs. luminal irregular vs. stenosed RCA (1.9 ± 0.6 vs. 2.6 ± 0.6 vs. 3.6 ± 0.9, P < 0.01). Epicardial coronary flow reserve exhibited a stepwise significant decrease (3.4 ± 0.5 vs. 2.9 ± 0.7 vs. 1.7 ± 0.3, P < 0.01). On the myocardial level, stress-induced percentage gain of T2* values (ΔT2*) was significantly decreased between groups (29.2 ± 10.6 vs. 9.0 ± 9.8 vs. 2.2 ± 11.8%, P < 0.01) while perfusion reserve index decreased in the presence of stenosed RCA only (2.2 ± 0.6 vs. 2.0 ± 0.4 vs. 1.3 ± 0.3, P = ns and P < 0.01, respectively). The proposed comprehensive CMR imaging protocol provided a non-invasive approach for direct assessment of coronary vessel wall remodelling and resultant pathophysiological consequences on the level of epicardial coronary and myocardial blood flow in patients. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Radionuclide imaging of myocardial infarction using Tc-99m TBI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holman, B.L.; Campbell, S.; Kirshenbaum, J.M.

The cationic complex Tc-99m t-butylisonitrile (TBI) concentrates in the myocardial tissue of several animal species. Its myocardial distribution is proportional to blood flow both in zones of ischemia and in normal myocardium at rest. Planar, tomographic, and gated myocardial images have been obtained using Tc-99m TBI in the human. The authors investigated the potential application of Tc-99m TBI imaging to detect and localize myocardial infarction. Four subjects without clinical evidence of cardiovascular disease and five patients with ECG evidence of previous myocardial infarction were studied. Tc-99m TBI (10mCi) was injected intravenously with the patient in a resting state with planarmore » imaging in the anterior, 30 and 70 degree LAO projections beginning one hr after injection. The distribution of the tracer was homogeneous throughout the left ventricular wall in the normal subjects. Regional perfusion defects were present in 4/5 of the patients with myocardial infarction. Location of the defects corresponded to the location of the infarct using ECG criteria (2 inferoposterior and 2 anterior). The patient in whom the Tc-99m TBI image appeared normal had sustained a subendocardial myocardial infarct which could not be localized by ECG; the other 4 pts had transmural infarcts. Anterior and 30 degree LAO images were of excellent quality in all cases; there was overlap of the liver on the inferior wall of the left ventricle on the 70 degree LAO views. The authors conclude that accurate perfusion imaging may be possible using Tc-99m TBI in patients with transmural myocardial infarction.« less

Effect of intensive structured care on individual blood pressure targets in primary care: multicentre randomised controlled trial.

PubMed

Stewart, Simon; Carrington, Melinda J; Swemmer, Carla H; Anderson, Craig; Kurstjens, Nicol P; Amerena, John; Brown, Alex; Burrell, Louise M; de Looze, Ferdinandus J; Harris, Mark; Hung, Joseph; Krum, Henry; Nelson, Mark; Schlaich, Markus; Stocks, Nigel P; Jennings, Garry L

2012-11-20

To determine the effectiveness of intensive structured care to optimise blood pressure control based on individual absolute risk targets in primary care. Pragmatic multicentre randomised controlled trial. General practices throughout Australia, except Northern Territory, 2009-11. Of 2185 patients from 119 general practices who were eligible for drug treatment for hypertension according to national guidelines 416 (19.0%) achieved their individual blood pressure target during a 28 day run-in period of monotherapy. After exclusions, 1562 participants not at target blood pressure (systolic 150 (SD 17) mm Hg, diastolic 88 (SD 11) mm Hg) were randomised (1:2 ratio) to usual care (n=524) or the intervention (n=1038). Computer assisted clinical profiling and risk target setting (all participants) with intensified follow-up and stepwise drug titration (initial angiotensin receptor blocker monotherapy or two forms of combination therapy using angiotensin receptor blockers) for those randomised to the intervention. The control group received usual care. The primary outcome was individual blood pressure target achieved at 26 weeks. Secondary outcomes were change in mean sitting systolic and diastolic blood pressure, absolute risk for cardiovascular disease within five years based on the Framingham risk score, and proportion and rate of adverse events. On an intention to treat basis, there was an 8.8% absolute difference in individual blood pressure target achieved at 26 weeks in favour of the intervention group compared with usual care group (358/988 (36.2%) v 138/504 (27.4%)): adjusted relative risk 1.28 (95% confidence interval 1.10 to 1.49, P=0.0013). There was also a 9.5% absolute difference in favour of the intervention group for achieving the classic blood pressure target of ≤ 140/90 mm Hg (627/988 (63.5%) v 272/504 (54.0%)): adjusted relative risk 1.18 (1.07 to 1.29, P<0.001). The intervention group achieved a mean adjusted reduction in systolic blood pressure of 13.2 mm Hg (95% confidence interval -12.3 to -14.2 mm Hg) and diastolic blood pressure of 7.7 mm Hg (-7.1 to -8.3 mm Hg) v 10.1 mm Hg (-8.8 to 11.3 mm Hg) and 5.5 mm Hg (-4.7 to -6.2 mm Hg) in the usual care group (P<0.001). Among 1141 participants in whom five year absolute cardiovascular risk scores were calculated from baseline to the 26 week follow-up, the reduction in risk scores was greater in the intervention group than usual care group (14.7% (SD 9.3%) to 10.9% (SD 8.0%); difference -3.7% (SD 4.5%) and 15.0% (SD 10.1%) to 12.4% (SD 9.4%); -2.6% (SD 4.5%): adjusted mean difference -1.13% (95% confidence interval -0.69% to -1.63%; P<0.001). Owing to adverse events 82 (7.9%) participants in the intervention group and 10 (1.9%) in the usual care group had their drug treatment modified. In a primary care setting intensive structured care resulted in higher levels of blood pressure control, with clinically lower blood pressure and absolute risk of future cardiovascular events overall and with more people achieving their target blood pressure. An important gap in treatment remains though and applying intensive management and achieving currently advocated risk based blood pressure targets is challenging.

Cardiac contraction motion compensation in gated myocardial perfusion SPECT: A comparative study.

PubMed

Salehi, Narges; Rahmim, Arman; Fatemizadeh, Emad; Akbarzadeh, Afshin; Farahani, Mohammad Hossein; Farzanefar, Saeed; Ay, Mohammad Reza

2018-05-01

Cardiac contraction significantly degrades quality and quantitative accuracy of gated myocardial perfusion SPECT (MPS) images. In this study, we aimed to explore different techniques in motion-compensated temporal processing of MPS images and their impact on image quality and quantitative accuracy. 50 patients without known heart condition underwent gated MPS. 3D motion compensation methods using Motion Freezing by Cedars Sinai (MF), Log-domain Diffeomorphic Demons (LDD) and Free-Form Deformation (FFD) were applied to warp all image phases to fit the end-diastolic (ED) phase. Afterwards, myocardial wall thickness, myocardial to blood pool contrast, and image contrast-to noise ratio (CNR) were measured in summed images with no motion compensation (NoMC) and compensated images (MF, LDD and FFD). Total Perfusion Defect (TPD) was derived from Cedars-Sinai software, on the basis of sex-specific normal limits. Left ventricle (LV) lateral wall thickness was reduced after applying motion compensation (p < 0.05). Myocardial to blood pool contrast and CNR in compensated images were greater than NoMC (p < 0.05). TPD_LDD was in good agreement with the corresponding TPD_MF (p = 0.13). All methods have improved image quality and quantitative performance relative to NoMC. LDD and FFD are fully automatic and do not require any manual intervention, while MF is dependent on contour definition. In terms of diagnostic parameters LDD is in good agreement with MF which is a clinically accepted method. Further investigation along with diagnostic reference standards, in order to specify diagnostic value of each technique is recommended. Copyright © 2018 Associazione Italiana di Fisica Medica. All rights reserved.

Canines as sentinel species for assessing chronic exposures to air pollutants: part 2. Cardiac pathology.

PubMed

Calderón-Garcidueñas, L; Gambling, T M; Acuña, H; García, R; Osnaya, N; Monroy, S; Villarreal-Calderón, A; Carson, J; Koren, H S; Devlin, R B

2001-06-01

The principal objective of this study is to evaluate by light and electron microscopy (LM, EM) the heart tissues in stray southwest and northeast metropolitan Mexico City (SWMMC, NEMMC) dogs and compare their findings to those from 3 less polluted cities (Cuernavaca, Tlaxcala, and Tuxpam). Clinically healthy mongrel dogs, including 109 from highly polluted SWMMC and NEMMC, and 43 dogs from less polluted cities were studied. Dogs residing in cities with lower levels of pollutants showed little or no cardiac abnormalities. Mexico City and Cuernavaca dogs exhibited LM myocardial alterations including apoptotic myocytes, endothelial and immune effector cells, degranulated mast cells associated with scattered foci of mononuclear cells in left and right ventricles and interventricular septum, and clusters of adipocytes interspersed with mononuclear cells. Vascular changes included scattered polymorphonuclear leukocytes (PMN) margination and microthrombi in capillaries, and small venous and arteriolar blood vessels. Small veins exhibited smooth muscle cell hyperplasia, and arteriolar blood vessels showed deposition of particulate matter (PM) in the media and adventitia. Unmyelinated nerve fibers showed endoneural and epineural degranulated mast cells. EM examination of myocardial mast cells showed distended and abundant rough endoplasmic reticulum with few secretory granules. Myocardial capillaries exhibited fibrin deposition and their endothelial cells displayed increased luminal and abluminal pinocytic activity and the formation of anemone-like protrusions of the endothelium into the lumen. A close association between myocardial findings, lung epithelial and endothelial pathology, and chronic inflammatory lung changes was noted. The myocardial changes described in dogs exposed to ambient air pollutants may form the basis for developing hypothesis-driven mechanistic studies that might explain the epidemiological data of increased cardiovascular morbidity and mortality in people exposed to air pollutants.

Cardiac T1 mapping in congenital heart disease: bolus vs. infusion protocols for measurements of myocardial extracellular volume fraction.

PubMed

Al-Wakeel-Marquard, Nadya; Rastin, Sanaz; Muench, Frédéric; O H-Ici, Darach; Yilmaz, Sevim; Berger, Felix; Kuehne, Titus; Messroghli, Daniel R

2017-12-01

Myocardial extracellular volume fraction (ECV) reflecting diffuse myocardial fibrosis can be measured with T1 mapping cardiovascular magnetic resonance (CMR) before and after the application of a gadolinium-based extracellular contrast agent. The equilibrium between blood and myocardium contrast concentration required for ECV measurements can be obtained with a primed contrast infusion (equilibrium contrast-CMR). We hypothesized that equilibrium can also be achieved with a single contrast bolus to accurately measure diffuse myocardial fibrosis in patients with congenital heart disease (CHD). Healthy controls (n = 17; median age 24.0 years) and patients with CHD (n = 19; 25.0 years) were prospectively enrolled. Using modified Look-Locker inversion recovery T1 mapping before, 15 min after bolus injection, and during constant infusion of gadolinium-DOTA, T1 values were obtained for blood pool and myocardium of the left ventricle (LV), the interventricular septum (IVS), and the right ventricle (RV) in a single midventricular plane in short axis or in transverse orientation. ECV of LV, IVS and RV by bolus-only and bolus-infusion correlated significantly in CHD patients (r = 0.94, 0.95, and 0.74; p < 0.01, respectively) and healthy controls (r = 0.96, 0.89, and 0.64; p < 0.05, respectively). Bland-Altman plots revealed no significant bias between the techniques for any of the analyzed regions. ECV of LV and RV myocardium measured by bolus-only T1 mapping agrees well with bolus-infusion measurements in patients with CHD. The use of a bolus-only approach facilitates the integration of ECV measurements into existing CMR imaging protocols, allowing for assessment of diffuse myocardial fibrosis in CHD in clinical routine.

Tissue-Informative Mechanism for Wearable Non-invasive Continuous Blood Pressure Monitoring

NASA Astrophysics Data System (ADS)

Woo, Sung Hun; Choi, Yun Young; Kim, Dae Jung; Bien, Franklin; Kim, Jae Joon

2014-10-01

Accurate continuous direct measurement of the blood pressure is currently available thru direct invasive methods via intravascular needles, and is mostly limited to use during surgical procedures or in the intensive care unit (ICU). Non-invasive methods that are mostly based on auscultation or cuff oscillometric principles do provide relatively accurate measurement of blood pressure. However, they mostly involve physical inconveniences such as pressure or stress on the human body. Here, we introduce a new non-invasive mechanism of tissue-informative measurement, where an experimental phenomenon called subcutaneous tissue pressure equilibrium is revealed and related for application in detection of absolute blood pressure. A prototype was experimentally verified to provide an absolute blood pressure measurement by wearing a watch-type measurement module that does not cause any discomfort. This work is supposed to contribute remarkably to the advancement of continuous non-invasive mobile devices for 24-7 daily-life ambulatory blood-pressure monitoring.

Energy Drinks and Myocardial Ischemia: A Review of Case Reports.

PubMed

Lippi, Giuseppe; Cervellin, Gianfranco; Sanchis-Gomar, Fabian

2016-07-01

The use and abuse of energy drinks (EDs) is constantly increasing worldwide. We performed a systematic search in Medline, Scopus and Web of Science to identify evidence about the potential link between these beverages and myocardial ischemia. Overall, 8 case reports could be detected, all of which described a realistic association between large intake of EDs and episodes of myocardial ischemia. Interestingly, no additional triggers of myocardial ischemia other than energy drinks could be identified in the vast majority of cases. Some plausible explanations can be brought in support of this association. Most of the biological effects of EDs are seemingly mediated by a positive inotropic effect on cardiac function, which entails increase in heart rate, cardiac output and contractility, stroke volume and arterial blood pressure. Additional biological abnormalities reported after EDs intake include increased platelet aggregation, endothelial dysfunction, hyperglycemia as well as an increase in total cholesterol, triglycerides and low-density lipoprotein cholesterol. Although a causal relationship between large consumption of EDs and myocardial ischemia cannot be definitely established so far, concerns about the cardiovascular risk of excessive consumption of these beverages are seemingly justified.

3D perfusion mapping in the intact mouse heart after myocardial infarction using myocardial contrast echocardiography

NASA Astrophysics Data System (ADS)

Li, Yinbo; Yang, Zequan; French, Brent A.; Hossack, John A.

2005-04-01

An intact mouse model of surgically-induced myocardial infarction (MI) caused by permanent occlusion of the Left Anterior Descending (LAD) coronary artery was studied. Normal mice with no occlusion were also studied as controls. For each mouse, contrast enhanced ultrasound images of the heart were acquired in parallel cross-sections perpendicular to the sternum at millimeter increments. For accurate 3D reconstruction, ECG gating and a tri-axial adjustable micromanipulator were used for temporal and spatial registration. Ultrasound images at steady-state of blood refilling were color-coded in each slice to show relative perfusion. Myocardial perfusion defects and necrosis were also examined postmortem by staining with Phthalo blue and TTC red dyes. Good correlation (R>0.93) in perfused area size was observed between in vivo measurements and histological staining. A 3D multi-slice model and a 3D rendering of perfusion distribution were created and showed a promising match with postmortem results, lending further credence to its use as a more comprehensive and more reliable tool for in vivo assessment of myocardial perfusion than 2D tomographic analysis.

21 CFR 862.1500 - Malic dehydrogenase test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... plasma. Malic dehydrogenase measurements are used in the diagnosis and treatment of muscle and liver diseases, myocardial infarctions, cancer, and blood disorders such as myelogenous (produced in the bone...

21 CFR 862.1500 - Malic dehydrogenase test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... plasma. Malic dehydrogenase measurements are used in the diagnosis and treatment of muscle and liver diseases, myocardial infarctions, cancer, and blood disorders such as myelogenous (produced in the bone...

21 CFR 862.1500 - Malic dehydrogenase test system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... plasma. Malic dehydrogenase measurements are used in the diagnosis and treatment of muscle and liver diseases, myocardial infarctions, cancer, and blood disorders such as myelogenous (produced in the bone...

[Absolute numbers of peripheral blood CD34+ hematopoietic stem cells prior to a leukapheresis procedure as a parameter predicting the efficiency of stem cell collection].

PubMed

Galtseva, I V; Davydova, Yu O; Gaponova, T V; Kapranov, N M; Kuzmina, L A; Troitskaya, V V; Gribanova, E O; Kravchenko, S K; Mangasarova, Ya K; Zvonkov, E E; Parovichnikova, E N; Mendeleeva, L P; Savchenko, V G

To identify a parameter predicting a collection of at least 2·106 CD34+ hematopoietic stem cells (HSC)/kg body weight per leukapheresis (LA) procedure. The investigation included 189 patients with hematological malignancies and 3 HSC donors, who underwent mobilization of stem cells with their subsequent collection by LA. Absolute numbers of peripheral blood leukocytes and CD34+ cells before a LA procedure, as well as a number of CD34+ cells/kg body weight (BW) in the LA product stored on the same day were determined in each patient (donor). There was no correlation between the number of leukocytes and that of stored CD34+ cells/kg BW. There was a close correlation between the count of peripheral blood CD34+ cells prior to LA and that of collected CD34+ cells calculated with reference to kg BW. The optimal absolute blood CD34+ cell count was estimated to 20 per µl, at which a LA procedure makes it possible to collect 2·106 or more CD34+ cells/kg BW.

Changes of jugular venous blood temperature associated with measurements of cerebral blood flow using the transcerebral double-indicator dilution technique.

PubMed

Mielck, F; Bräuer, A; Radke, O; Hanekop, G; Loesch, S; Friedrich, M; Hilgers, R; Sonntag, H

2004-04-01

The transcerebral double-indicator dilution technique is a recently developed method to measure global cerebral blood flow at bedside. It is based on bolus injection of ice-cold indocyanine green dye and simultaneous recording of resulting thermo- and dye-dilution curves in the aorta and the jugular bulb. However, with this method 40 mL of ice-cold solution is administered as a bolus. Therefore, this prospective clinical study was performed to elucidate the effects of repeated administration of indicator on absolute blood temperature and on cerebral blood flow and metabolism. The investigation was performed in nine male patients scheduled for elective coronary artery bypass grafting. Absolute blood temperature was measured in the jugular bulb and in the aorta before and after repeated measurements using the transcerebral double-indicator dilution technique. During the investigated time course, the blood temperature in the jugular bulb, compared to the aorta, was significantly higher with a mean difference of 0.21 degrees C. The administration of an ice-cold bolus reduced the mean blood temperature by 0.06 degrees C in the jugular bulb as well as in the aorta. After the transcerebral double-indicator dilution measurements a temperature recovery to baseline conditions was not observed during the investigated time period. Cerebral blood flow and cerebral metabolism did not change during the investigated time period. Repeated measurements with the transcerebral double-indicator dilution technique do not affect absolute jugular bulb blood temperatures negatively. Global cerebral blood flow and metabolism measurements remain unaltered. However, accuracy and resolution of this technique is not high enough to detect the effect of minor changes of physiological variables.

Single-scan rest/stress imaging: validation in a porcine model with 18F-Flurpiridaz.

PubMed

Guehl, Nicolas J; Normandin, Marc D; Wooten, Dustin W; Rozen, Guy; Sitek, Arkadiusk; Ruskin, Jeremy; Shoup, Timothy M; Ptaszek, Leon M; El Fakhri, Georges; Alpert, Nathaniel M

2017-08-01

18 F-labeled myocardial flow agents are becoming available for clinical application but the ∼2 hour half-life of 18 F complicates their clinical application for rest-stress measurements. The goal of this work is to evaluate in a pig model a single-scan method which provides quantitative rest-stress blood flow in less than 15 minutes. Single-scan rest-stress measurements were made using 18 F-Flurpiridaz. Nine scans were performed in healthy pigs and seven scans were performed in injured pigs. A two-injection, single-scan protocol was used in which an adenosine infusion was started 4 minutes after the first injection of 18 F-Flurpiridaz and followed either 3 or 6 minutes later by a second radiotracer injection. In two pigs, microsphere flow measurements were made at rest and during stress. Dynamic images were reoriented into the short axis view, and regions of interest (ROIs) for the 17 myocardial segments were defined in bull's eye fashion. PET data were fitted with MGH2, a kinetic model with time varying kinetic parameters, in which blood flow changes abruptly with the introduction of adenosine. Rest and stress myocardial blood flow (MBF) were estimated simultaneously. The first 12-14 minutes of rest-stress PET data were fitted in detail by the MGH2 model, yielding MBF measurement with a mean precision of 0.035 ml/min/cc. Mean myocardial blood flow across pigs was 0.61 ± 0.11 mL/min/cc at rest and 1.06 ± 0.19 mL/min/cc at stress in healthy pigs and 0.36 ± 0.20 mL/min/cc at rest and 0.62 ± 0.24 mL/min/cc at stress in the ischemic area. Good agreement was obtained with microsphere flow measurement (slope = 1.061 ± 0.017, intercept = 0.051 ± 0.017, mean difference 0.096 ± 0.18 ml/min/cc). Accurate rest and stress blood flow estimation can be obtained in less than 15 min of PET acquisition. The method is practical and easy to implement suggesting the possibility of clinical translation.

Dynamic 3D analysis of myocardial sympathetic innervation: an experimental study using 123I-MIBG and a CZT camera.

PubMed

Giorgetti, Assuero; Burchielli, Silvia; Positano, Vincenzo; Kovalski, Gil; Quaranta, Angela; Genovesi, Dario; Tredici, Manuel; Duce, Valerio; Landini, Luigi; Trivella, Maria Giovanna; Marzullo, Paolo

2015-03-01

Data on the in vivo myocardial kinetics of (123)I-metaiodobenzylguanidine ((123)I-MIBG) are scarce and have always been obtained using planar acquisitions. To clarify the normal kinetics of (123)I-MIBG in vivo over time, we designed an experimental protocol using a 3-dimensional (3D) dynamic approach with a cadmium zinc telluride (CZT) camera. We studied 6 anesthetized pigs (mean body weight, 37 ± 4 kg). Left ventricular myocardial perfusion and sympathetic innervation were assessed using (99m)Tc-tetrofosmin (26 ± 6 MBq), (123)I-MIBG (54 ± 14 MBq), and a CZT camera. A normal perfusion/function match on gated SPECT was the inclusion criterion. A dynamic acquisition in list mode started simultaneously with the bolus injection of (123)I-MIBG, and data were collected every 5 min for the first 20 min and then at acquisition steps of 30, 60, 90, and 120 min. Each step was reconstructed using dedicate software and reframed (60 s/frame). On the reconstructed transaxial slice that best showed the left ventricular cavity, regions of interest were drawn to obtain myocardial and blood pool activities. Myocardial time-activity curves were generated by interpolating data between contiguous acquisition steps, corrected for radiotracer decay and injected dose, and fitted to a bicompartmental model. Time to myocardial maximum signal intensity (MSI), MSI value, radiotracer retention index (RI, myocardial activity/blood pool integral), and washout rate were calculated. The mediastinal signal was measured and fitted to a linear model. The myocardial MSI of (123)I-MIBG was reached within 5.57 ± 4.23 min (range, 2-12 min). The mean MSI was 0.426% ± 0.092%. Myocardial RI decreased over time and reached point zero at 176 ± 31 min (range, 140-229 min). The ratio between myocardial and mediastinal signal at 15 and 125 min and extrapolated at 176 and 4 h was 5.45% ± 0.61%, 4.33% ± 1.23% (not statistically significant vs. 15 min), 3.95% ± 1.46% (P < 0.03 vs. 125 min), and 3.63% ± 1.64% (P < 0.03 vs. 176 min), respectively. Mean global washout rate at 125 min was 15% ± 14% (range, 0%-34%), and extrapolated data at 176 min and 4 h were 18% ± 18% (range, 0.49%-45%) and 25% ± 23% (range, 1.7%-56.2%; not statistically significant vs. 176 min), respectively. 3D dynamic analysis of (123)I-MIBG suggests that myocardial peak uptake is reached more quickly than previously described. Myocardial RI decreases over time and, on average, is null about 3 h after injection. The combination of an early peak and variations in delayed myocardial uptake could result in a wide physiologic range of washout rates. Mediastinal activity appears to be constant over time and significantly lower than previously described in planar studies, resulting in a higher heart-to-mediastinum ratio. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Polycythemia vera presenting as acute myocardial infarction: An unusual presentation

PubMed Central

Bahbahani, Hussain; Aljenaee, Khaled; Bella, Abdelhaleem

2014-01-01

Acute myocardial infarction (AMI) is usually seen in the setting of atherosclerosis and its associated risk factors. Myocardial infarction in the young poses a particular challenge, as the disease is less likely, due to atherosclerosis. We report the case of a 37-year-old female patient who presented with ST segment elevation anterolateral AMI. The only abnormality on routine blood investigation was raised hemoglobin and hematocrit. After further testing, she was diagnosed according to the World Health Organization (WHO) criteria with polycythemia vera. This case illustrates the importance of recognizing polycythemia vera as an important cause of thrombosis, which can present initially as AMI, and to emphasize the early recognition of the disease in order to initiate appropriate management strategies. PMID:25544823

Diagnosis of myocardial ischemia combining multiphase postmortem CT-angiography, histology, and postmortem biochemistry.

PubMed

Vanhaebost, Jessica; Ducrot, Kewin; de Froidmont, Sébastien; Scarpelli, Maria Pia; Egger, Coraline; Baumann, Pia; Schmit, Gregory; Grabherr, Silke; Palmiere, Cristian

2017-02-01

The aim of this study was to assess whether the identification of pathological myocardial enhancement at multiphase postmortem computed tomography angiography was correlated with increased levels of troponin T and I in postmortem serum from femoral blood as well as morphological findings of myocardial ischemia. We further aimed to investigate whether autopsy cases characterized by increased troponin T and I concentrations as well as morphological findings of myocardial ischemia were also characterized by pathological myocardial enhancement at multiphase postmortem computed tomography angiography. Two different approaches were used. In one, 40 forensic autopsy cases that had pathological enhancement of the myocardium (mean Hounsfield units ≥95) observed at postmortem angiography were retrospectively selected. In the second approach, 40 forensic autopsy cases that had a cause of death attributed to acute myocardial ischemia were retrospectively selected. The preliminary results seem to indicate that the identification of a pathological enhancement of the myocardium at postmortem angiography is associated with the presence of increased levels of cardiac troponins in postmortem serum and morphological findings of ischemia. Analogously, a pathological enhancement of the myocardium at postmortem angiography can be retrospectively found in the great majority of autopsy cases characterized by increased cardiac troponin levels in postmortem serum and morphological findings of myocardial ischemia. Multiphase postmortem computed tomography angiography is a useful tool in the postmortem setting for investigating ischemically damaged myocardium.

Role of CD11b+Gr-1+ myeloid cells in AGEs-induced myocardial injury in a mice model of acute myocardial infarction.

PubMed

Yao, Tongqing; Lu, Wenbin; Zhu, Jian; Jin, Xian; Ma, Genshan; Wang, Yuepeng; Meng, Shu; Zhang, Yachen; Li, Yigang; Shen, Chengxing

2015-01-01

Polymorph neutrophils are the predominant inflammatory cells and play a crucial role on the pathogenesis of myocardial injury at the early stage of acute myocardial infarction (AMI). However, the precursors and the differentiation of neutrophils are not fully understood. Here we explored the role of CD11b+Gr-1+ myeloid-derived suppressor cells (MDSCs) on myocardial injury in the absence and presence of advanced glycation end-products (AGEs) in a mice model of AMI. Male C57BL/6J mice were selected. Fluorescent actived cell sortor (FACS) data demonstrated significantly increased CD11b+Gr-1+ MDSCs both in peripheral blood circulation and in the ischemic myocardium at 24 hours post AMI. Quantitative-real-time PCR results also revealed significantly upregulated CD11b and Ly6G mRNA expression in the ischemic myocardium. AGEs treatment further aggravated these changes in AMI mice but not in sham mice. Moreover, AGEs treatment also significantly increased infarction size and enhanced cardiomyocyte apoptosis. The mRNA expression of pro-inflammatory cytokine IL-6 and iNOS2 was also significantly increased in AMI + AGEs group compared to AMI group. These data suggest enhanced infiltration of MDSCs by AGEs contributes to aggravated myocardial injury in AMI mice, which might be one of the mechanisms responsible for severer myocardial injury in AMI patients complicating diabetes.

[Effect and mechanism of icariin on myocardial ischemia-reperfusion injury model in diabetes rats].

PubMed

Hu, Yan-wu; Liu, Kai; Yan, Meng-tong

2015-11-01

To study the therapeutic effect and possible mechanism of icariin on myocardial ischemia-reperfusion injury ( MIRI) model in diabetes rats. The model of diabetic rats were induced by Streptozotocin (STZ), then the model of MIRI was established by ligating the reversible left anterior descending coronary artery for 30 min, and then reperfusing for 120 min. totally 40 male SD were randomly divided into five groups: the control group (NS), the ischemia reperfusion group (NIR), the diabetes control group (MS), the diabetic ischemia reperfusion group (MIR) and the diabetic ischemia reperfusion with icariin group (MIRI). The changes in blood glucose, body weight and living status were observed; the enzyme activity of serum CK-MB, LDH, GSH-Px and myocardium SOD and the content MDA and NO in myocardium were detected; the myocardial pathological changes were observed by HE staining; the myocardial Caspase-3, the Bcl-2, Bax protein expressions were detected by Western blot. The result showed that the diabetes model was successfully replicated; myocardial ischemia-reperfusion injury was more serious in diabetes rats; icariin can increase NO, SOD, GSH-Px, Bcl-2 protein expression, decrease MDA formation, CK-MB and LDH activities and Caspase-3 and Bcl-2 protein expressions and myocardial damage. The result suggested that icariin may play a protective role against ischemia reperfusion myocardial injury in diabetes rats by resisting oxidative stress and inhibiting cell apoptosis.

Bundle Branch Block

MedlinePlus

... known cause. Causes can include: Left bundle branch block Heart attacks (myocardial infarction) Thickened, stiffened or weakened ... myocarditis) High blood pressure (hypertension) Right bundle branch block A heart abnormality that's present at birth (congenital) — ...

Myocardial blood flow reserve is impaired in patients with aortic valve calcification and unobstructed epicardial coronary arteries.

PubMed

Nel, Karen; Nam, Michael C Y; Anstey, Chris; Boos, Christopher J; Carlton, Edward; Senior, Roxy; Kaski, Juan Carlos; Khattab, Ahmed; Shamley, Delva; Byrne, Christopher D; Stanton, Tony; Greaves, Kim

2017-12-01

Although calcific aortic valve disease (CAVD) is associated with coronary atherosclerosis, it is not known whether early CAVD is associated with coronary microcirculatory dysfunction (CMD). We sought to investigate the relationship between myocardial blood flow reserve (MBFR) - a measure of CMD, and early CAVD in the absence of obstructive epicardial coronary artery disease. We also determined whether this relationship was independent of coronary artery disease (CAD) and hs-CRP, a marker of systemic inflammation. 183 patients with chest pain and unobstructed coronary arteries were studied. Aortic valve calcification score (AVCS), coronary total plaque length (TPL), and coronary calcium score were quantified from multislice CT. MBFR was assessed using vasodilator myocardial contrast echocardiography. Hs-CRP was measured from venous blood using a particle-enhanced immunoassay. Mean (±SD) participant age was 59.8 (9.6) years. Mean AVCS was 68 (258) AU, TPL was 15.6 (22.2) mm, and median coronary calcification score was 43.5AU. Mean MBFR was 2.20 (0.52). Mean hs-CRP was 2.52 (3.86) mg/l. Multivariable linear regression modelling incorporating demographics, coronary plaque characteristics, MBFR, and inflammatory markers, demonstrated that age (β=0.05, 95% CI: 0.02, 0.08, P=0.007), hs-CRP (β=0.09, CI: 0.02, 0.16, P=0.010) and diabetes (β=1.03, CI: 0.08, 1.98, P=0.033), were positively associated with AVCS. MBFR (β=-0.87, CI: -1.44, -0.30, P=0.003), BMI (β=-0.11, CI: -0.21, -0.01, P=0.033), and LDL (β=-0.32, CI: -0.61, -0.03, P=0.029) were negatively associated with AVCS. TPL and coronary calcium score were not independently associated with AVCS when included in the regression model. Coronary microvascular function as determined by measurement of myocardial blood flow reserve is independently associated with early CAVD. This effect is independent of the presence of coronary artery disease and also systemic inflammation. Copyright © 2017 Elsevier B.V. All rights reserved.

Relationship between residual blood flow in the infarct-related artery and scintigraphic infarct size, myocardial salvage, and functional recovery in patients with acute myocardial infarction.

PubMed

Ndrepepa, Gjin; Kastrati, Adnan; Schwaiger, Markus; Mehilli, Julinda; Markwardt, Christina; Dibra, Alban; Dirschinger, Josef; Schömig, Albert

2005-11-01

In patients with acute myocardial infarction (AMI) before primary coronary stenting with adjunct glycoprotein IIb/IIIa receptor blockade, whether residual blood flow in the infarct-related artery (IRA) affects infarct size or myocardial salvage is not known. This study included 118 patients with ST-segment elevation AMI who received coronary stenting plus abciximab. SPECT studies were performed before and 7-14 d after stenting. Patients were divided into a group with initial Thrombolysis in Myocardial Infarction (TIMI) flow grade < or = 1 (77 patients) and a group with initial TIMI flow grade > 1 (41 patients). The initial median perfusion defect and (in brackets) the 25th and 75th percentiles were 29.1% [21.0%; 52.0%] of the left ventricle in patients with TIMI flow grade < or = 1, versus 16.5% [8.0%; 33.1%] of the left ventricle in patients with TIMI flow grade > 1 (P < 0.001). Baseline left ventricular ejection fraction (54.0% [45.0; 63.0] vs. 57.0% [40.0; 62.0], P = 0.623) or extension of hypokinetic region (28.0 [14.0; 41.0] hypokinetic chords vs. 24.0 [13.0; 39.0] hypokinetic chords, P = 0.643) did not differ significantly between the group with TIMI flow grade < or = 1 and the group with TIMI flow grade > 1. Final infarct size was 11.0% [6.1%; 23.5%] of the left ventricle in the group with TIMI flow grade < = 1, versus 6.0% [2.0%; 12.8%] of the left ventricle in the group with TIMI flow > 1 (P = 0.008). Salvage index was 0.58 [0.38; 0.76] in the group with TIMI flow grade < or = 1, versus 0.61 [0.36; 0.74] in the group with TIMI flow grade > 1 (P = 0.952). At the day 14 angiography, patients with TIMI flow grade > 1 had better left ventricular ejection fraction (61.0% [54.0%; 68.0%] vs. 56.5% [42.9%; 65.0%]; P = 0.03) and a smaller hypokinetic region (7 chords [0; 22.0] vs. 16 chords [2.5; 30.0]; P = 0.024) than did patients with TIMI flow grade < or = 1. Preserved blood flow in the IRA in patients with AMI is associated with a smaller area at risk, a smaller infarct, and better recovery of regional and global left ventricular function. The proportion of initial area at risk salvaged by coronary stenting does not seem to depend on residual blood flow in the IRA.

Interaction of the renin-angiotensin system and the renal nerves in the regulation of rat kidney function.

PubMed Central

Handa, R K; Johns, E J

1985-01-01

Stimulation of the renal sympathetic nerves in pentobarbitone anaesthetized rats achieved a 13% reduction in renal blood flow, did not change glomerular filtration rate, but reduced urine flow by 37%, absolute sodium excretion by 37%, and fractional sodium excretion by 34%. Following inhibition of converting enzyme with captopril (0.38 mmol kg-1 h-1), similar nerve stimulation reduced both renal blood flow and glomerular filtration rate by 16%, and although urine flow and absolute sodium excretion fell by 32 and 31%, respectively, the 18% fall in fractional sodium excretion was significantly less than that observed in the absence of captopril. Renal nerve stimulation at low levels, which did not change either renal blood flow or glomerular filtration rate, reduced urine flow, and absolute and fractional sodium excretions by 25, 26 and 23%, respectively. In animals receiving captopril at 0.38 mmol kg-1 h-1, low-level nerve stimulation caused small increases in glomerular filtration rate of 7% and urine flow of 12%, but did not change either absolute or fractional sodium excretions. At one-fifth the dose of captopril (0.076 mmol kg-1 h-1), low-level nerve stimulation did not change renal haemodynamics but decreased urine flow, and absolute and fractional sodium excretions by 10, 10 and 8%, respectively. These results showed that angiotensin II production was necessary for regulation of glomerular filtration rate in the face of modest neurally induced reductions in renal blood flow and was compatible with an intra-renal site of action of angiotensin II preferentially at the efferent arteriole. They also demonstrated that in the rat the action of the renal nerves to decrease sodium excretion was dependent on angiotensin II. PMID:3005558

Intraoperative IR imaging in the cardiac operating room

NASA Astrophysics Data System (ADS)

Szabo, Tamas; Fazekas, Levente; Horkay, Ferenc; Geller, Laslu; Gyongy, Tibor; Juhasz-Nagy, Alexander

1999-07-01

The high blood flow rate and the considerable metabolic activity render the myocardium a possible candidate for IR imaging. The study was aimed to test cardiothermography in evaluating arterial bypass graft patency and in assessing myocardial protection during open-heart surgery. Ten patients underwent arterial bypass grafting. Thermograms were obtained immediately before and after opening the grafts. As the bypasses were opened in hypothermia the warmer blood coming from the extracorporeal circulation readily delineated graft and coronary anatomy. By the end of the 5 min observation period, the revascularized area exhibited a temperature increase of 5.9 +/- 0.7 degrees C. The affectivity of antegrade cardioplegia was monitored in 38 patients undergoing either valve implantations or aorto- coronary bypass surgery. Thermographic imags were taken after sternotomy, before aortic cross-clamping and after administrating the 4 degrees C cardioplegic solution. Most of the patients displayed adequate myocardial cooling, moreover the bypass-group exhibited a more profound temperature-decrease. In conclusion, cardiothermography can visualize arterial grafts, recipient coronaries and collaterals seconds after opening by bypass, thus it properly evaluated arterial bypass graft patency. The obtained images could easily be analyzed for qualitative flow- and quantitative temperature changes. Myocardial protection could also be safely assessed with thermography.

Test-Retest Repeatability of Myocardial Blood Flow Measurements using Rubidium-82 Positron Emission Tomography

NASA Astrophysics Data System (ADS)

Efseaff, Matthew

Rubidium-82 positron emission tomography (PET) imaging has been proposed for routine myocardial blood flow (MBF) quantification. Few studies have investigated the test-retest repeatability of this method. Same-day repeatability of rest MBF imaging was optimized with a highly automated analysis program using image-derived input functions and a dual spillover correction (SOC). The effects of heterogeneous tracer infusion profiles and subject hemodynamics on test-retest repeatability were investigated at rest and during hyperemic stress. Factors affecting rest MBF repeatability included gender, suspected coronary artery disease, and dual SOC (p < 0.001). The best repeatability coefficient for same-day rest MBF was 0.20 mL/min/g using a six-minute scan-time, iterative reconstruction, dual SOC, resting rate-pressure-product (RPP) adjustment, and a left atrium image-derived input function. The serial study repeatabilities of the optimized protocol in subjects with homogeneous RPPs and tracer infusion profiles was 0.19 and 0.53 mL/min/g at rest and stress, and 0.95 for stress / rest myocardial flow reserve (MFR). Subjects with heterogeneous tracer infusion profiles and hemodynamic conditions had significantly less repeatable MBF measurements at rest, stress, and stress/rest flow reserve (p < 0.05).

Pharmacologic Effects of Cannabidiol on Acute Reperfused Myocardial Infarction in Rabbits: Evaluated With 3.0T Cardiac Magnetic Resonance Imaging and Histopathology.

PubMed

Feng, Yuanbo; Chen, Feng; Yin, Ting; Xia, Qian; Liu, Yewei; Huang, Gang; Zhang, Jian; Oyen, Raymond; Ni, Yicheng

2015-10-01

Cannabidiol (CBD) has anti-inflammatory effects. We explored its therapeutic effects on cardiac ischemia-reperfusion injury with an experimental imaging platform. Reperfused acute myocardial infarction (AMI) was induced in rabbits with a 90-minute coronary artery occlusion followed by 24-hour reperfusion. Before reperfusion, rabbits received 2 intravenous doses of 100 μg/kg CBD (n = 10) or vehicle (control, n = 10). Evans blue was intravenously injected for later detection of the AMI core. Cardiac magnetic resonance imaging was performed to evaluate cardiac morphology and function. After euthanasia, blood troponin I (cTnI) was assessed, and the heart was excised and infused with multifunctional red iodized oil dye. The heart was sliced for digital radiography to quantify the perfusion density rate, area at risk (AAR), and myocardial salvage index, followed by histomorphologic staining. Compared with controls, CBD treatment improved systolic wall thickening (P < 0.05), significantly increased blood flow in the AAR (P < 0.05), significantly decreased microvascular obstruction (P < 0.05), increased the perfusion density rate by 1.7-fold, lowered the AMI core/AAR ratio (P < 0.05), and increased the myocardial salvage index (P < 0.05). These improvements were associated with reductions in serum cTnI, cardiac leukocyte infiltration, and myocellular apoptosis (P < 0.05). Thus, CBD therapy reduced AMI size and facilitated restoration of left ventricular function. We demonstrated that this experimental platform has potential theragnostic utility.

Positron Emission Tomography-Determined Hyperemic Flow, Myocardial Flow Reserve, and Flow Gradient—Quo Vadis?

PubMed Central

Leucker, Thorsten M.; Valenta, Ines; Schindler, Thomas Hellmut

2017-01-01

Positron emission tomography/computed tomography (PET/CT) applied with positron-emitting flow tracers such as 13N-ammonia and 82Rubidium enables the quantification of both myocardial perfusion and myocardial blood flow (MBF) in milliliters per gram per minute for coronary artery disease (CAD) detection and characterization. The detection of a regional myocardial perfusion defect during vasomotor stress commonly identifies the culprit lesion or most severe epicardial narrowing, whereas adding regional hyperemic MBFs, myocardial flow reserve (MFR), and/or longitudinal flow decrease may also signify less severe but flow-limiting stenosis in multivessel CAD. The addition of regional hyperemic flow parameters, therefore, may afford a comprehensive identification and characterization of flow-limiting effects of multivessel CAD. The non-specific origin of decreases in hyperemic MBFs and MFR, however, prompts an evaluation and interpretation of regional flow in the appropriate context with the presence of obstructive CAD. Conversely, initial results of the assessment of a longitudinal hyperemic flow gradient suggest this novel flow parameter to be specifically related to increases in CAD caused epicardial resistance. The concurrent assessment of myocardial perfusion and several hyperemic flow parameters with PET/CT may indeed open novel avenues of precision medicine to guide coronary revascularization procedures that may potentially lead to a further improvement in cardiovascular outcomes in CAD patients. PMID:28770213

IL-6 signalling in patients with acute ST-elevation myocardial infarction

PubMed Central

Ritschel, Vibeke N.; Seljeflot, Ingebjørg; Arnesen, Harald; Halvorsen, Sigrun; Weiss, Thomas; Eritsland, Jan; Andersen, Geir Ø

2013-01-01

Cytokines of the IL-6 family have been related to infarct size and prognosis in patients with myocardial infarction. The aims of the present study were to elucidate possible associations between myocardial necrosis and left ventricular impairment and members of the IL-6 transsignalling system including soluble (s) IL-6R and (s) glycoprotein 130 (sgp130) in patients with ST-elevation myocardial infarction (STEMI) treated with primary PCI. In blood samples from 1028 STEMI patients, collected in-hosptial, we found significant correlations between peak TnT and IL-6 and CRP (p < 0.001, all) and between IL-6 and CRP and LV ejection fraction and NT-proBNP (p < 0.001, all). On the contrary, no significant associations were found between peak TnT and sgp130 or sIL-6R. Furthermore sgp130 was significantly elevated in diabetic patients and also associated with the glucometabolic state. In conclusion, circulating levels of IL-6 and CRP, but not the soluble forms of the receptor (sIL-6R) or the receptor signalling subunit (sgp130) were associated with the extent of myocardial necrosis. The biological importance of the IL-6/gp130-mediated signalling pathways in patients with acute myocardial infarction and dysglycemia should be further elucidated. PMID:24707455

Bovine Intestinal Alkaline Phosphatase Reduces Inflammation After Induction of Acute Myocardial Infarction in Mice.

PubMed

Fiechter, Danielle; Kats, Suzanne; Brands, Ruud; van Middelaar, Ben; Pasterkamp, Gerard; de Kleijn, Dominique; Seinen, Willem

2011-10-01

There has been increasing evidence suggesting that lipopolysaccharide or endotoxin may be an important activator of the innate immune system after acute myocardial infarction. Bovine intestinal alkaline phosphatase reduces inflammation in several endotoxin mediated diseases by dephosphorylation of the lipid A moiety of lipopolysaccharide. The aim of this study was to investigate the effect of bovine intestinal alkaline phosphatase on reducing inflammation after acute myocardial infarction. Just before permanent ligation of the left anterior descending coronary (LAD) artery to induce acute myocardial infarction in Balb/c mice, bovine intestinal alkaline phosphatase (bIAP) was administrated intravenously. After 4 hours, mice were sacrificed and the inflammatory response was assessed. Acute myocardial infarction induced the production of different cytokines, which were measured in blood. Treatment with bovine intestinal alkaline phosphatase resulted in a significant reduction of the pro-inflammatory cytokines IL-6, IL-1β and the chymase mouse mast cell protease-1. No difference in the production of the anti-inflammatory cytokine IL-10 was observed between the control group and the bovine intestinal alkaline phosphatase treated group. In a mouse model of permanent LAD coronary artery ligation, bIAP diminishes the pro-inflammatory responses but does not have an effect on the anti-inflammatory response in the acute phase after acute myocardial infarction.

Dunye Guanxinning Improves Acute Myocardial Ischemia-Reperfusion Injury by Inhibiting Neutrophil Infiltration and Caspase-1 Activity

PubMed Central

Zhang, Q. G.; Wang, S. R.; Chen, X. M.; Guo, H. N.

2018-01-01

Acute myocardial infarction is the most serious manifestation of cardiovascular disease, and it is a life-threatening condition. Dunye Guanxinning (DG) is a protective traditional Chinese patent herbal medicine with high clinical efficacy and suitable for the treatment of myocardial infarction. However, the mechanism through which it is beneficial is unclear. In this study, we hypothesized that DG improves acute myocardial ischemia-reperfusion injury by inhibiting neutrophil infiltration and caspase-1 activity. We found that DG administration decreased infarct size and cardiomyocyte apoptosis and improved left ventricular ejection fraction, fractional shortening, end-systolic volume index, end-systolic diameter, and carotid arterial blood flow output in rats. DG administration also improved hemorheological parameters, myocardial damage biomarkers, and oxidative stress indexes. The findings showed that DG administration inhibited neutrophil infiltration and reduced the serum interleukin-1 beta (IL-1β) level and myocardial IL-1β maturation. Moreover, DG administration inhibited caspase-1 activity and activated adenosine monophosphate-activated protein kinase (AMPK) phosphorylation in rat hearts. These results suggested that DG administration inhibits inflammasome activity and IL-1β release through the AMPK pathway. Our findings support the clinical efficacy of DG and partially reveal its mechanism, which is beneficial for understanding the therapeutic effects of this protective traditional Chinese patent drug. PMID:29674944

Intravenous Administration of Lycopene, a Tomato Extract, Protects against Myocardial Ischemia-Reperfusion Injury

PubMed Central

Tong, Chao; Peng, Chuan; Wang, Lianlian; Zhang, Li; Yang, Xiaotao; Xu, Ping; Li, Jinjin; Delplancke, Thibaut; Zhang, Hua; Qi, Hongbo

2016-01-01

Background: Oral uptake of lycopene has been shown to be beneficial for preventing myocardial ischemia-reperfusion (I/R) injury. However, the strong first-pass metabolism of lycopene influences its bioavailability and impedes its clinic application. In this study, we determined an intravenous (IV) administration dose of lycopene protects against myocardial infarction (MI) in a mouse model, and investigated the effects of acute lycopene administration on reactive oxygen species (ROS) production and related signaling pathways during myocardial I/R. Methods: In this study, we established both in vitro hypoxia/reoxygenation (H/R) cell model and in vivo regional myocardial I/R mouse model by ligating left anterior artery descending. TTC dual staining was used to assess I/R induced MI in the absence and presence of acute lycopene administration via tail vein injection. Results: Lycopene treatment (1 μM) before reoxygenation significantly reduced cardiomyocyte death induced by H/R. Intravenous administration of lycopene to achieve 1 μM concentration in circulating blood significantly suppressed MI, ROS production, and JNK phosphorylation in the cardiac tissue of mice during in vivo regional I/R. Conclusion: Elevating circulating lycopene to 1 μM via IV injection protects against myocardial I/R injury through inhibition of ROS accumulation and consequent inflammation in mice. PMID:26950150

Intravenous Administration of Lycopene, a Tomato Extract, Protects against Myocardial Ischemia-Reperfusion Injury.

PubMed

Tong, Chao; Peng, Chuan; Wang, Lianlian; Zhang, Li; Yang, Xiaotao; Xu, Ping; Li, Jinjin; Delplancke, Thibaut; Zhang, Hua; Qi, Hongbo

2016-03-03

Oral uptake of lycopene has been shown to be beneficial for preventing myocardial ischemia-reperfusion (I/R) injury. However, the strong first-pass metabolism of lycopene influences its bioavailability and impedes its clinic application. In this study, we determined an intravenous (IV) administration dose of lycopene protects against myocardial infarction (MI) in a mouse model, and investigated the effects of acute lycopene administration on reactive oxygen species (ROS) production and related signaling pathways during myocardial I/R. In this study, we established both in vitro hypoxia/reoxygenation (H/R) cell model and in vivo regional myocardial I/R mouse model by ligating left anterior artery descending. TTC dual staining was used to assess I/R induced MI in the absence and presence of acute lycopene administration via tail vein injection. Lycopene treatment (1 μM) before reoxygenation significantly reduced cardiomyocyte death induced by H/R. Intravenous administration of lycopene to achieve 1 μM concentration in circulating blood significantly suppressed MI, ROS production, and JNK phosphorylation in the cardiac tissue of mice during in vivo regional I/R. Elevating circulating lycopene to 1 μM via IV injection protects against myocardial I/R injury through inhibition of ROS accumulation and consequent inflammation in mice.

Effect of pacing-induced myocardial ischemia on platelet activation and fibrin formation in the coronary circulation.

PubMed

Nichols, A B; Gold, K D; Marcella, J J; Cannon, P J; Owen, J

1987-07-01

The effect of pacing-induced myocardial ischemia on platelet activation and fibrin formation was investigated in seven patients with severe proximal lesions of the left anterior descending coronary artery to determine if acute ischemia activates the coagulation system. Fibrin formation was assessed from plasma levels of fibrinopeptide A. Platelet activation was assessed by levels of platelet factor 4, beta-thromboglobulin and thromboxane B2. Plasma levels were measured before, during and after acute myocardial ischemia induced by rapid atrial pacing. Blood samples were collected from the ascending aorta and from the great cardiac vein through heparin-bonded catheters. The occurrence of anterior myocardial ischemia was established by electrocardiography and by myocardial lactate extraction. No significant transmyocardial gradients in the levels of fibrinopeptide A, platelet factor 4, beta-thromboglobulin or thromboxane B2 were found at rest, during ischemia or in the recovery period, and levels in the great cardiac vein did not change in response to ischemia. These data indicate that pacing-induced myocardial ischemia does not result in release of fibrinopeptide A, platelet factor 4, beta-thromboglobulin or thromboxane B2 into the coronary circulation, and imply that acute ischemia does not induce platelet activation or fibrin formation in the coronary circulation.

Measuring Time-Averaged Blood Pressure

NASA Technical Reports Server (NTRS)

Rothman, Neil S.

1988-01-01

Device measures time-averaged component of absolute blood pressure in artery. Includes compliant cuff around artery and external monitoring unit. Ceramic construction in monitoring unit suppresses ebb and flow of pressure-transmitting fluid in sensor chamber. Transducer measures only static component of blood pressure.

Myocardial 2D strain echocardiography and cardiac biomarkers in children during and shortly after anthracycline therapy for acute lymphoblastic leukaemia (ALL): a prospective study.

PubMed

Mavinkurve-Groothuis, Annelies M C; Marcus, Karen A; Pourier, Milanthy; Loonen, Jacqueline; Feuth, Ton; Hoogerbrugge, Peter M; de Korte, Chris L; Kapusta, Livia

2013-06-01

The aim of this study was to investigate myocardial 2D strain echocardiography and cardiac biomarkers in the assessment of cardiac function in children with acute lymphoblastic leukaemia (ALL) during and shortly after treatment with anthracyclines. Cardiac function of 60 children with ALL was prospectively studied with measurements of cardiac troponin T (cTnT) and N-terminal-pro-brain natriuretic peptide (NT-pro-BNP) and conventional and myocardial 2D strain echocardiography before start (T = 0), after 3 months (T = 1), and after 1 year (T = 2), and were compared with 60 healthy age-matched controls. None of the patients showed clinical signs of cardiac failure or abnormal fractional shortening. Cardiac function decreased significantly during treatment and was significantly decreased compared with normal controls. Cardiac troponin T levels were abnormal in 11% of the patients at T = 1 and were significantly related to increased time to global peak systolic longitudinal strain at T = 2 (P = 0.003). N-terminal-pro-brain natriuretic peptide levels were abnormal in 13% of patients at T = 1 and in 20% at T = 2, absolute values increased throughout treatment in 59%. Predictors for abnormal NT-pro-BNP at T = 2 were abnormal NT-pro-BNP at T = 0 and T = 1, for abnormal myocardial 2D strain parameters at T = 2 cumulative anthracycline dose and z-score of the diastolic left ventricular internal diameter at baseline. Children with newly diagnosed ALL showed decline of systolic and diastolic function during treatment with anthracyclines using cardiac biomarkers and myocardial 2D strain echocardiography. N-terminal-pro-brain natriuretic peptide levels were not related to echocardiographic strain parameters and cTnT was not a predictor for abnormal strain at T = 2.Therefore, the combination of cardiac biomarkers and myocardial 2D strain echocardiography is important in the assessment of cardiac function of children with ALL treated with anthracyclines.

Radionuclide Ventriculography or Radionuclide Angiography (MUGA Scan)

MedlinePlus

... Attack Heart Failure Myocardial Perfusion Imaging (MPI) Single Photon Emission Computed Tomography (SPECT) Positron Emission Tomography (PET) ... stroke. Popular Articles 1 Understanding Blood Pressure Readings 2 Sodium and Salt 3 Heart Attack Symptoms in ...

Menopause and myocardial infarction risk among employed women in relation to work and family psychosocial factors in Lithuania.

PubMed

Malinauskiene, Vilija; Tamosiunas, Abdonas

2010-05-01

To assess the relationship between menopause and age at menopause and the risk of the first non-fatal myocardial infarction taking into account the possible influence of psychosocial job characteristics, marital stress, level of social support, educational level, occupation, age and traditional ischemic heart disease risk factors. Population-based case-control study among 35-61 years old employed women in Kaunas, Lithuania. Totally 122 myocardial infarction cases and 371 controls were interviewed in 2001-2004. The logistic regression analysis was performed. Younger age at menopause (

Protective Effects of Ultramicronized Palmitoylethanolamide (PEA-um) in Myocardial Ischaemia and Reperfusion Injury in VIVO.

PubMed

Di Paola, Rosanna; Cordaro, Marika; Crupi, Rosalia; Siracusa, Rosalba; Campolo, Michela; Bruschetta, Giuseppe; Fusco, Roberta; Pugliatti, Pietro; Esposito, Emanuela; Cuzzocrea, Salvatore

2016-08-01

Myocardial infarction is the leading cause of death, occurs after prolonged ischemia of the coronary arteries. Restore blood flow is the first intervention help against heart attack. However, reperfusion of the arteries leads to ischemia/reperfusion injury (I/R). The fatty acid amide palmitoylethanolamide (PEA) is an endogenous compound widely present in living organisms, with analgesic and anti-inflammatory properties. The present study evaluated the effect of ultramicronized palmitoylethanolamide (PEA-um) treatment on the inflammatory process associated with myocardial I/R. Myocardial ischemia reperfusion injury was induced by occlusion of the left anterior descending coronary artery for 30 min followed by 2 h of reperfusion. PEA-um, was administered (10 mg/kg) 15 min after ischemia and 1 h after reperfusion. In this study, we demonstrated that PEA-um treatment reduces myocardial tissue injury, neutrophil infiltration, adhesion molecules (ICAM-1, P-selectin) expression, proinflammatory cytokines (TNF-α, IL-1β) production, nitrotyrosine and PAR formation, nuclear factor kB expression, and apoptosis (Fas-L, Bcl-2) activation. In addition to study whether the protective effect of PEA-um on myocardial ischemia reperfusion injury is also related to the activation of PPAR-α, in a separate set of experiments it has been performed myocardial I/R in PPARα mice. Genetic ablation of peroxisome proliferator activated receptor (PPAR)-α in PPAR-αKO mice exacerbated Myocardial ischemia reperfusion injury when compared with PPAR-αWT mice. PEA-um induced cardioprotection in PPAR-α wild-type mice, but the same effect cannot be observed in PPAR-αKO mice. Our results have clearly shown a modulation of the inflammatory process, associated with myocardial ischemia reperfusion injury, following administration of PEA-um.

Stopping versus continuing acetylsalicylic acid before coronary artery bypass surgery: A systematic review and meta-analysis of 14 randomized controlled trials with 4499 patients.

PubMed

Sá, Michel Pompeu Barros Oliveira; Soares, Artur Freire; Miranda, Rodrigo Gusmão Albuquerque; Araújo, Mayara Lopes; Menezes, Alexandre Motta; Silva, Frederico Pires Vasconcelos; Lima, Ricardo Carvalho

2017-11-01

This study aimed to evaluate the efficacy and safety of continuing versus stopping aspirin [acetylsalicylic acid (ASA)] preoperatively in patients undergoing coronary artery bypass graft surgery. MEDLINE, EMBASE, CENTRAL/Cochrane Controlled Trials Register (CCTR), ClinicalTrials.gov, Scientific Electronic Library Online (SciELO), Literatura Latino Americana em Ciências da Saúde (LILACS), Google Scholar and reference lists of relevant articles were searched for randomized controlled trials that reported efficacy outcomes of myocardial infarction and mortality, and safety outcomes of blood loss, packed red blood cell transfusion and surgical re-exploration were compared between groups. Fourteen studies fulfilled our eligibility criteria and included a total of 4499 patients (2329 for 'continuing ASA' and 2170 for 'stopping ASA'). In the pooled analysis, continuing aspirin therapy did not reduce the risk of myocardial infarction [risk ratio 0.834, 95% confidence interval (CI) 0.688-1.010; P = 0.063] or operative mortality (risk ratio 1.384, 95% CI 0.727-2.636; P = 0.323). Preoperative ASA increased postoperative chest tube drainage (mean difference 143 ml, 95% CI 39-248 ml; P = 0.007) and packed red blood cell transfusion (mean difference 142 ml, 95% CI 55-228; P = 0.001) but did not increase the risk of surgical re-exploration (risk ratio 1.316, 95% CI 0.910-1.905; P = 0.145). This meta-analysis found no statistically significant difference regarding the risk of operative mortality and myocardial infarction between the 'continuing ASA' and 'stopping ASA' strategies. On the other hand, the mean volume of blood loss and packed red blood cell transfusion was higher in the 'continuing ASA' group, but this finding did not translate into higher risk of reoperation for bleeding. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Increase in electrocardiographic R-waves after revascularization in patients with acute myocardial infarction.

PubMed

Isobe, Satoshi; Takada, Yasuo; Ando, Akitada; Ohshima, Satoru; Yamada, Kiyoyasu; Nanasato, Mamoru; Unno, Kazumasa; Ogawa, Takuo; Kondo, Takahisa; Izawa, Hideo; Inden, Yasuya; Hirai, Makoto; Murohara, Toyoaki

2006-11-01

The physiological mechanism of the increase in the electrocardiographic (ECG) R-wave voltage after revascularization in patients with acute myocardial infarction (MI) needs to be elucidated. One hundred and thirty-eight MI patients (83: anterior MI, 45: inferior MI, 10: lateral MI) underwent ECG and echocardiography in both the acute and subacute phases after emergency revascularization, as well as a resting thallium-201/iodine-123 15-p-iodophenyl-3-(R,S)-methyl pentadecanoic acid myocardial scintigraphy in the acute phase. The total sum of the R-wave voltage (SigmaR) was calculated over multiple leads on ECG for each infarcted lesion. Scintigraphic defect on each tracer was expressed as the percentage (%) defect of the total left ventricular (LV) myocardium. The % defect-discordance on both images in the acute phase and the % increase in SigmaR and the absolute increase in LV ejection fraction from the acute to the subacute phase (DeltaEF) were also calculated. The SigmaR in the subacute phase was significantly greater than that in the acute phase (p<0.0001). The % increase in SigmaR significantly correlated with the DeltaEF (r=0.57, p<0.0001). The % increase in SigmaR also correlated with the % defect-discordance (r=0.68, p<0.0001). The increase in the ECG R-wave voltage reflects not only the improvement in myocardial perfusion but also the presence of salvaged myocardium after revascularization in acute MI patients.

Numerical Simulation of Blood Flow in Human Artery Using (A, Q) and (A, u) Systems

NASA Astrophysics Data System (ADS)

Mungkasi, Sudi; Wijayanti Budiawan, Inge

2018-03-01

In this paper, we model blood flow in human artery in the form of (𝐴, 𝑄) and (𝐴, 𝑢) systems, then we use the Lax-Friedrichs finite volume method to find the numerical solution of each model. Here 𝐴 represents the cross sectional area of the artery, 𝑄 denotes the discharge of the blood flow, and 𝑢 is the velocity of the blood flow. We simulate the numerical scheme of each model and investigate how the blood pressure pulse propagates in human artery. Particularly, we use the residual of 𝐴 to determine which system is better numerically. We obtain that the (𝐴, 𝑄) system is better numerically than the (𝐴, 𝑢) system, because the absolute of the residual of 𝐴 using the (𝐴, 𝑄) system is smaller than the absolute of the residual of 𝐴 using the (𝐴, 𝑢) system.

Increasing Pyruvate Dehydrogenase Flux as a Treatment for Diabetic Cardiomyopathy: A Combined 13C Hyperpolarized Magnetic Resonance and Echocardiography Study.

PubMed

Le Page, Lydia M; Rider, Oliver J; Lewis, Andrew J; Ball, Vicky; Clarke, Kieran; Johansson, Edvin; Carr, Carolyn A; Heather, Lisa C; Tyler, Damian J

2015-08-01

Although diabetic cardiomyopathy is widely recognized, there are no specific treatments available. Altered myocardial substrate selection has emerged as a candidate mechanism behind the development of cardiac dysfunction in diabetes. As pyruvate dehydrogenase (PDH) activity appears central to the balance of substrate use, we aimed to investigate the relationship between PDH flux and myocardial function in a rodent model of type 2 diabetes and to explore whether or not increasing PDH flux, with dichloroacetate, would restore the balance of substrate use and improve cardiac function. All animals underwent in vivo hyperpolarized [1-(13)C]pyruvate magnetic resonance spectroscopy and echocardiography to assess cardiac PDH flux and function, respectively. Diabetic animals showed significantly higher blood glucose levels (10.8 ± 0.7 vs. 8.4 ± 0.5 mmol/L), lower PDH flux (0.005 ± 0.001 vs. 0.017 ± 0.002 s(-1)), and significantly impaired diastolic function (transmitral early diastolic peak velocity/early diastolic myocardial velocity ratio [E/E'] 12.2 ± 0.8 vs. 20 ± 2), which are in keeping with early diabetic cardiomyopathy. Twenty-eight days of treatment with dichloroacetate restored PDH flux to normal levels (0.018 ± 0.002 s(-1)), reversed diastolic dysfunction (E/E' 14 ± 1), and normalized blood glucose levels (7.5 ± 0.7 mmol/L). The treatment of diabetes with dichloroacetate therefore restored the balance of myocardial substrate selection, reversed diastolic dysfunction, and normalized blood glucose levels. This suggests that PDH modulation could be a novel therapy for the treatment and/or prevention of diabetic cardiomyopathy. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

[Copeptin and ischemia modified albumin in early diagnosis and prognosis of myocardial damage in acute organic phosphorus pesticide poisoning].

PubMed

Li, Jing; Zhang, Jianjun; Li, Na; Li, Jia; Liu, Juan; Liu, Qian

2015-03-01

To assess the value of combined detection of copeptin and ischemia modified albumin (IMA) in early diagnosis and prognostic evaluation of myocardial damage in patients with acute organic phosphorus pesticide poisoning (AOPP). A total of 126 AOPP patients were examined for blood copepin and IMA levels and myocardial injury markers within 1 h after admission. Copeptin and IMA levels significantly increased in patients with AOPP compared with those in the control subjects. Copeptin and IMA levels were significantly higher in severe AOPP cases than in mild to moderate cases (P<0.05). Logistic regression analysis showed that increased copeptin and IMA levels and severe complications of AOPP were associated with an increased risk of cardiovascular events. Early detection of copeptin and IMA levels has important clinical value in early diagnosis and prognostic evaluation of myocardial damage in patients with AOPP, and their levels are positively correlated with the severity of the condition.

CD8+CD28+ T cells might mediate injury of cardiomyocytes in acute myocardial infarction.

PubMed

Zhang, Lili; Wang, Zhiyan; Wang, Di; Zhu, Jumo; Wang, Yi

2018-06-07

CD8 + T cells accumulate in the necrotic myocardium of acute myocardial infarction (AMI). It is unclear whether CD8 + CD28 + T cells, a specific subset of CD8 + T cells, contribute to myocardial injury. In this study, 92 consecutive patients with AMI and 28 healthy control subjects were enrolled. The frequency of CD8 + CD28 + T cells in peripheral blood samples was assayed by flow cytometry. Plasma cardiac troponin I (TNI) and left ventricular ejection fraction (LVEF) were determined. Long-term prognosis of the patients was evaluated by major adverse cardiac and cerebrovascular events (MACCE) over a 12-month follow-up period. Our findings indicated that patients with AMI who presented with high numbers of CD8 + CD28 + T cells had an increased infarction size and aggravated ventricular function. We proposed that cytotoxic CD8 + CD28 + T cell-mediated myocardial necrosis may act as a novel and alternative pathway of AMI. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of trapidil in myocardial ischemia-reperfusion injury in rabbit.

PubMed

Liu, Mingjie; Sun, Qi; Wang, Qiang; Wang, Xiuying; Lin, Peng; Yang, Ming; Yan, Yuanyuan

2014-01-01

To evaluate the cardioprotective effects of trapidil on myocardial ischemia-reperfusion injury (MIRI) in rabbits. Rabbits were subjected to 40 min of myocardial ischemia followed by 120 min of reperfusion. Blood for superoxide dismutase (SOD) and malondialdehyde (MDA) were estimated. At the end of reperfusion, the rabbits were sacrificed and the hearts were isolated for histological examination. An apoptotic index (AI) was determined using the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end-labeling (TUNEL) method. The expression of apoptosis-related proteins Bax and Bcl-2 was analyzed using immunohistochemistry. Statistical analyses were performed by one-way analysis of variance (ANOVA), P < 0.05 considered statistically significant. Trapidil caused a significant (P < 0.05) increase in SOD activity, as decreased MDA levels and significantly (P < 0.05) reduced the expression of Bax as compared with the ischemia-reperfusion (IR) control group. Trapidil may attenuate the myocardial damage produced by IR injury and offer potential cardioprotective action.

Black-blood native T1 mapping: Blood signal suppression for reduced partial voluming in the myocardium.

PubMed

Weingärtner, Sebastian; Meßner, Nadja M; Zöllner, Frank G; Akçakaya, Mehmet; Schad, Lothar R

2017-08-01

To study the feasibility of black-blood contrast in native T 1 mapping for reduction of partial voluming at the blood-myocardium interface. A saturation pulse prepared heart-rate-independent inversion recovery (SAPPHIRE) T 1 mapping sequence was combined with motion-sensitized driven-equilibrium (MSDE) blood suppression for black-blood T 1 mapping at 3 Tesla. Phantom scans were performed to assess the T 1 time accuracy. In vivo black-blood and conventional SAPPHIRE T 1 mapping was performed in eight healthy subjects and analyzed for T 1 times, precision, and inter- and intraobserver variability. Furthermore, manually drawn regions of interest (ROIs) in all T 1 maps were dilated and eroded to analyze the dependence of septal T 1 times on the ROI thickness. Phantom results and in vivo myocardial T 1 times show comparable accuracy with black-blood compared to conventional SAPPHIRE (in vivo: black-blood: 1562 ± 56 ms vs. conventional: 1583 ± 58 ms, P = 0.20); Using black-blood SAPPHIRE precision was significantly lower (standard deviation: 133.9 ± 24.6 ms vs. 63.1 ± 6.4 ms, P < .0001), and blood T 1 time measurement was not possible. Significantly increased interobserver interclass correlation coefficient (ICC) (0.996 vs. 0.967, P = 0.011) and similar intraobserver ICC (0.979 vs. 0.939, P = 0.11) was obtained with the black-blood sequence. Conventional SAPPHIRE showed strong dependence on the ROI thickness (R 2 = 0.99). No such trend was observed using the black-blood approach (R 2 = 0.29). Black-blood SAPPHIRE successfully eliminates partial voluming at the blood pool in native myocardial T 1 mapping while providing accurate T 1 times, albeit at a reduced precision. Magn Reson Med 78:484-493, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Absolute and Relative Carnitine Deficiency in Patients on Hemodialysis and Peritoneal Dialysis.

PubMed

Naseri, Mitra; Mottaghi Moghadam Shahri, Hasan; Horri, Mohsen; Esmaeeli, Mohammad; Ghaneh Sherbaf, Fatemeh; Jahanshahi, Shohre; Moeenolroayaa, Giti; Rasoli, Zahra; Salemian, Farzaneh; Pour Hasan, Maryam

2016-01-01

Carnitine deficiency is commonly seen in dialysis patients. This study assessed the association dialysis and pediatric patients' characteristics with plasma carnitines levels. Plasma carnitine concentrations were measured by tandem mass spectrometry in 46 children on hemodialysis or peritoneal dialysis. The total carnitine, free carnitine (FC), and L-acyl carnitine (AC) levels of 40 µmol/L and less, less than 7 µmol/L, and less than 15 µmol/L were defined low, respectively. An FC less than 20 µmol/L and an AC/FC ratio greater than 0.4 were considered as absolute and relative carnitine deficiencies. The correlation between carnitines levels and AC/FC ratio and age, duration of dialysis, characteristics of dialysis, and blood urea nitrogen and serum albumin concentrations were assessed. Absolute carnitine deficiency, low total carnitine, and low AC concentrations were found in 66.7%, 82.6%, and 51% of the patients, respectively. All of the patients had relative carnitine deficiency. Carnitine measurements were not significantly different between the hemodialysis and peritoneal dialysis groups. More severe relative carnitine deficiency was found in those with lower blood urea nitrogen levels and those on peritoneal dialysis. No linear correlation was found between carnitine levels and age, duration of dialysis, characteristics of dialysis, serum albumin level, or blood urea nitrogen level. Absolute and relative carnitine deficiencies are common among children on dialysis. Patients with lower blood urea nitrogen levels and peritoneal dialysis patients are more prone to severe relative carnitine deficiency.

Myocardial Ischemia

MedlinePlus

... risk of high blood pressure and heart disease. Lack of physical activity. An inactive lifestyle contributes to obesity and is associated with higher cholesterol and triglyceride levels. People who get regular aerobic exercise have better cardiovascular fitness, which is associated with ...

Neonatal nucleated red blood cells in infants of overweight and obese mothers.

PubMed

Sheffer-Mimouni, Galit; Mimouni, Francis B; Dollberg, Shaul; Mandel, Dror; Deutsch, Varda; Littner, Yoav

2007-06-01

The perinatal outcome of the infant of obese mother is adversely affected and in theory, may involve fetal hypoxia. We hypothesized that an index of fetal hypoxia, the neonatal nucleated red blood cell (NRBC) count, is elevated in infants of overweight and obese mothers. Absolute NRBC counts taken during the first 12 hours of life in 41 infants of overweight and obese mothers were compared to 28 controls. Maternal body mass index and infant birthweight were significantly higher in the overweight and obese group (P < 0.01). Hematocrit, corrected white blood cell and lymphocyte counts did not differ between groups. The absolute NRBC count was higher (P = 0.01), and the platelet count lower (P = 0.05) in infants of overweight and obese mothers than in controls. In stepwise regression analysis, the absolute NRBC count in infants of overweight and obese mothers remained significantly higher even after taking into account birthweight or gestational age and Apgar scores (P < 0.02). Infants of overweight and obese mothers have increased nucleated red blood cells at birth compared with controls. We speculate that even apparently healthy fetuses of overweight and obese mothers are exposed to a subtle hypoxemic environment.

Reductions in finger blood flow induced by 125-Hz vibration: effect of location of contact with vibration.

PubMed

Ye, Ying; Griffin, Michael J

2016-04-01

This study investigated whether the reductions in finger blood flow induced by 125-Hz vibration applied to different locations on the hand depend on thresholds for perceiving vibration at these locations. Subjects attended three sessions during which vibration was applied to the right index finger, the right thenar eminence, or the left thenar eminence. Absolute thresholds for perceiving vibration at these locations were determined. Finger blood flow in the middle finger of both hands was then measured at 30-s intervals during five successive 5-min periods: (i) pre-exposure, (ii) pre-exposure with 2-N force, (iii) 2-N force with vibration, (iv) post-exposure with 2-N force, (v) recovery. During period (iii), vibration was applied at 15 dB above the absolute threshold for perceiving vibration at the right thenar eminence. Vibration at all three locations reduced finger blood flow on the exposed and unexposed hand, with greater reductions when vibrating the finger. Vibration-induced vasoconstriction was greatest for individuals with low thresholds and locations of excitation with low thresholds. Differences in vasoconstriction between subjects and between locations are consistent with the Pacinian channel mediating both absolute thresholds and vibration-induced vasoconstriction.

Differential loss of natural killer cell activity in patients with acute myocardial infarction and stable angina pectoris.

PubMed

Yan, Wenwen; Zhou, Lin; Wen, Siwan; Duan, Qianglin; Huang, Feifei; Tang, Yu; Liu, Xiaohong; Chai, Yongyan; Wang, Lemin

2015-01-01

To evaluate the activity of natural killer cells through their inhibitory and activating receptors and quantity in peripheral blood mononuclear cells extracted from patients with acute myocardial infarction, stable angina pectoris and the controls. 100 patients with myocardial infarction, 100 with stable angina, and 20 healthy volunteers were recruited into the study. 20 randomly chosen people per group were examined for the whole human genome microarray analysis to detect the gene expressions of all 40 inhibitory and activating natural killer cell receptors. Flow cytometry analysis was applied to all 200 patients to measure the quantity of natural killer cells. In myocardial infarction group, the mRNA expressions of six inhibitory receptors KIR2DL2, KIR3DL3, CD94, NKG2A, KLRB1, KLRG1, and eight activating receptors KIR2DS3, KIR2DS5, NKp30, NTB-A, CRACC, CD2, CD7 and CD96 were significantly down-regulated (P<0.05) compared with both angina patients and the controls. There was no statistical difference in receptor expressions between angina patients and control group. The quantity of natural killer cells was significantly decreased in both infarction and angina patients compared with normal range (P<0.001). The significant mRNAs down-regulation of several receptors in myocardial infarction group and reduction in the quantity of natural killer cells in both myocardial infarction and angina patients showed a quantitative loss and dysfunction of natural killer cells in myocardial infarction patients.

Effects of denopamine (TA-064), a new positive inotropic agent, on myocardial oxygen consumption and left ventricular dimension in anesthetized dogs.

PubMed

Ikeo, T; Nagao, T

1985-10-01

We compared the effects of denopamine (TA-064) and isoproterenol on hemodynamics, myocardial oxygen consumption and the left ventricular (LV) dimension in halothane-N2O anesthetized dogs. Denopamine (0.25-1 micrograms/kg/min, i.v., infusion X 15 min) produced a maximum increase in LV dp/dtmax by 64% of the control, without affecting aortic pressure significantly. Doses of isoproterenol (0.01-0.04 micrograms/kg/min, i.v., infusion X 15 min) were selected to produce a positive inotropic action similar to that of denopamine. Denopamine produced significantly less increasing effects in heart rate, cardiac output and myocardial oxygen consumption and had more reducing effects in LV internal diameter than isoproterenol, while isoproterenol tended to produce a more potent increase in coronary blood flow, but a smaller decrease in LV end-diastolic pressure than denopamine. PQ interval was similarly reduced. Denopamine caused no substantial increase in myocardial oxygen consumption at a lower dose, at which LV dp/dtmax was significantly increased. A weak effect of denopamine on myocardial oxygen consumption may result partly from a weak positive chronotropic effect and partly from a reduction of preload and cardiac size.

In silico analysis of the anti-hypertensive drugs impact on myocardial oxygen balance.

PubMed

Guala, A; Leone, D; Milan, A; Ridolfi, L

2017-06-01

Hypertension is a very common pathology, and its clinical treatment largely relies on different drugs. Some of these drugs exhibit specific protective functions in addition to those resulting from blood pressure reduction. In this work, we study the impact of commonly used anti-hypertensive drugs (RAAS, [Formula: see text] and calcium channel blockers) on myocardial oxygen supply-consumption balance, which plays a crucial role in type 2 myocardial infarction. To this aim, 42 wash-out hypertensive patients were selected, a number of measured data were used to set a validated multi-scale cardiovascular model to subject-specific conditions, and the administration of different drugs was suitably simulated. Our results ascribe the well-known major cardioprotective efficiency of [Formula: see text] blockers compared to other drugs to a positive change of myocardial oxygen balance due to the concomitant: (1) reduction in aortic systolic, diastolic and pulse pressures, (2) decrease in left ventricular work, diastolic cavity pressure and oxygen consumption, (3) increase in coronary flow and (4) ejection efficiency improvement. RAAS blockers share several positive outcomes with [Formula: see text] blockers, although to a reduced extent. In contrast, calcium channel blockers seem to induce some potentially negative effects on the myocardial oxygen balance.

Reduced coronary flow and resistance reserve in primary scleroderma myocardial disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nitenberg, A.; Foult, J.M.; Kahan, A.

1986-08-01

The maximum coronary vasodilator capacity after intravenous dipyridamole (0.14 mg X kg-1 X min-1 X 4 minutes) was studied in seven patients with primary scleroderma myocardial disease and compared to that of seven control subjects. Hemodynamic data and left ventricular angiographic data were not different in the two groups. The coronary flow reserve was evaluated by the dipyridamole/basal coronary sinus blood flow ratio (D/B CSBF) and the coronary resistance reserve by the dipyridamole/basal coronary resistance ratio (D/B CR). Coronary reserve was greatly impaired in the group with primary scleroderma myocardial disease: D/B CSBF was lower than in the control groupmore » (2.54 +/- 1.37 vs 4.01 +/- 0.56, respectively; p less than 0.05) and D/B CR was higher than in the control group (0.47 +/- 0.25 vs 0.23 +/- 0.04, respectively; p less than 0.05). Such a decreased coronary flow and resistance reserve in patients with primary scleroderma myocardial disease was not explained by an alteration of left ventricular function. It may be an important contributing factor in the pathogenesis of primary scleroderma myocardial disease.« less

Myocardial blood flow: Roentgen videodensitometry techniques

NASA Technical Reports Server (NTRS)

Smith, H. C.; Robb, R. A.; Wood, E. H.

1975-01-01

The current status of roentgen videodensitometric techniques that provide an objective assessment of blood flow at selected sites within the coronary circulation were described. Roentgen videodensitometry employs conventional radiopaque indicators, radiological equipment and coronary angiographic techniques. Roentgen videodensitometry techniques developed in the laboratory during the past nine years, and for the past three years were applied to analysis of angiograms in the clinical cardiac catheterization laboratory.

DNA double-strand breaks in blood lymphocytes induced by two-day 99mTc-MIBI myocardial perfusion scintigraphy.

PubMed

Rief, Matthias; Hartmann, Lisa; Geisel, Dominik; Richter, Felicitas; Brenner, Winfried; Dewey, Marc

2018-07-01

To investigate DNA double-strand breaks (DSBs) in blood lymphocytes induced by two-day 99m Tc-MIBI myocardial perfusion scintigraphy (MPS) using y-H2AX immunofluorescence microscopy and to correlate the results with 99m Tc activity in blood samples. Eleven patients who underwent two-day MPS were included. DSB blood sampling was performed before and 5min, 1h and 24h after the first and second radiotracer injections. 99m Tc activity was measured in each blood sample. For immunofluorescence microscopy, distinct foci representing DSBs were quantified in lymphocytes after staining for the phosphorylated histone variant y-H2AX. The 99m Tc-MIBI activity measured on days one and two was similar (254±25 and 258±27 MBq; p=0.594). Compared with baseline DSB foci (0.09±0.05/cell), a significant increase was found at 5min (0.19±0.04/cell) and 1h (0.18±0.04/cell) after the first injection and at 5min and 1h after the second injection (0.21±0.03 and 0.19±0.04/cell, respectively; p=0.003 for both). At 24h after the first and second injections, the number of DSB foci had returned to baseline (0.06±0.02 and 0.12±0.05/cell, respectively). 99m Tc activity levels in peripheral blood samples correlated well with DSB counts (r=0.451). DSB counts reflect 99m Tc-MIBI activity after injection for two-day MPS, and might allow individual monitoring of biological effects of cardiac nuclear imaging. • Myocardial perfusion scintigraphy using 99m Tc induces time-dependent double-strand breaks (DSBs) • γ-H2AX immunofluorescence microscopy shows DSB as an early response to radiotracer injection • Activity measurements of 99m Tc correlate well with detected DSB • DSB foci induced by 99m Tc return to baseline 24h after radiotracer injection.

Routine implantation of cardioverter/defibrillator devices in patients aged 75 years and older with prior myocardial infarction and left ventricular ejection fraction < 30: antagonist viewpoint.

PubMed

Basta, Lofty L

2003-01-01

The Multicenter Automatic Defibrillator Implantation Trial (MADIT II) investigators assert that their results justify the placement of artificial implantable defibrillator cardioverter devices in patients aged 75 years and older with prior myocardial infarction and left ventricular dysfunction (ejection fraction of 30 or less). The authors claim that the results of the trial do not justify this conclusion. The majority of patients were male (84%) and aged 64+/-10 years. Also, 2.8% of patients assigned to the defibrillator group and 1.5% had their device removed. Of the latter subgroup, nine patients (1.3%) received a heart transplant. Twelve had their artificial implantable defibrillator cardioverter device deactivated mostly because of terminal illness. Although the study results show a significant reduction in mortality over the control group (absolute reduction=5.6%), almost the same percentage required hospitalization because of manifestation of congestive heart failure (absolute value 5%; p=0.09). Also, 1.8% had lead problems, 0.7% had infections, and the benefits were only seen after the first year. Caution is needed before the results of this study are applied to a much older cohort comprised mainly of women in whom heart transplant is contraindicated and who have multiple health problems, including cognitive impairment. Artificial implantable cardioverter/defibrillator devices are expensive and this study's results need to be duplicated in other comparable cohorts.

Myocardial Fibrosis in Competitive Triathletes Detected by Contrast-Enhanced CMR Correlates With Exercise-Induced Hypertension and Competition History.

PubMed

Tahir, Enver; Starekova, Jitka; Muellerleile, Kai; von Stritzky, Alexandra; Münch, Julia; Avanesov, Maxim; Weinrich, Julius M; Stehning, Christian; Bohnen, Sebastian; Radunski, Ulf K; Freiwald, Eric; Blankenberg, Stefan; Adam, Gerhard; Pressler, Axel; Patten, Monica; Lund, Gunnar K

2017-12-08

This study analyzed the presence of myocardial fibrosis detected by late gadolinium-enhancement (LGE) cardiac magnetic resonance (CMR) in correlation with the performance of competitive triathletes objectified by an exercise test and individual competition history. Myocardial fibrosis detected by LGE CMR has been reported to occur in 0% to 50% of asymptomatic athletes. However, the cause and mechanisms of myocardial fibrosis are unclear. Eighty-three asymptomatic triathletes undergoing >10 training h per week (43 ± 10 years of age; 65% male) and 36 sedentary controls were studied by using LGE and extracellular volume (ECV) CMR. Parameters of physical fitness were measured by spiroergometry. Triathletes reported their lifetime competition results. LGE CMR revealed focal nonischemic myocardial fibrosis in 9 of 54 (17%) male triathletes (LGE + ) but in none of the female triathletes (p < 0.05). LGE + triathletes had higher peak exercise systolic blood pressure (213 ± 24 mm Hg) than LGE - triathletes (194 ± 26 mm Hg; p < 0.05). Furthermore, left ventricular mass index was higher in LGE + triathletes (93 ± 7 g/m 2 ) than in LGE - triathletes (84 ± 11 g/m 2 ; p < 0.05). ECV in LGE - myocardium was higher in LGE + triathletes (26.3 ± 1.8%) than in LGE - triathletes (24.4 ± 2.2%; p < 0.05). LGE + triathletes completed longer cumulative distances in swimming and cycling races and participated more often in middle and Iron Man distances than LGE - triathletes. A cycling race distance of >1,880 km completed during competition had the highest accuracy to predict LGE, with an area under the curve value of 0.876 (p < 0.0001), resulting in high sensitivity (89%) and specificity (79%). Multivariate analysis identified peak exercise systolic blood pressure (p < 0.05) and the swimming race distance (p < 0.01) as independent predictors of LGE presence. Myocardial fibrosis in asymptomatic triathletes seems to be associated with exercise-induced hypertension and the race distances. There appears to be a safe upper limit, beyond which exercise may result in myocardial fibrosis. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Partitioned fluid-solid coupling for cardiovascular blood flow: left-ventricular fluid mechanics.

PubMed

Krittian, Sebastian; Janoske, Uwe; Oertel, Herbert; Böhlke, Thomas

2010-04-01

We present a 3D code-coupling approach which has been specialized towards cardiovascular blood flow. For the first time, the prescribed geometry movement of the cardiovascular flow model KaHMo (Karlsruhe Heart Model) has been replaced by a myocardial composite model. Deformation is driven by fluid forces and myocardial response, i.e., both its contractile and constitutive behavior. Whereas the arbitrary Lagrangian-Eulerian formulation (ALE) of the Navier-Stokes equations is discretized by finite volumes (FVM), the solid mechanical finite elasticity equations are discretized by a finite element (FEM) approach. Taking advantage of specialized numerical solution strategies for non-matching fluid and solid domain meshes, an iterative data-exchange guarantees the interface equilibrium of the underlying governing equations. The focus of this work is on left-ventricular fluid-structure interaction based on patient-specific magnetic resonance imaging datasets. Multi-physical phenomena are described by temporal visualization and characteristic FSI numbers. The results gained show flow patterns that are in good agreement with previous observations. A deeper understanding of cavity deformation, blood flow, and their vital interaction can help to improve surgical treatment and clinical therapy planning.

The effect of heart motion on parameter bias in dynamic cardiac SPECT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ross, S.G.; Gullberg, G.T.; Huesman, R.H.

1996-12-31

Dynamic cardiac SPECT can be used to estimate kinetic rate parameters which describe the wash-in and wash-out of tracer activity between the blood and the myocardial tissue. These kinetic parameters can in turn be correlated to myocardial perfusion. There are, however, many physical aspects associated with dynamic SPECT which can introduce errors into the estimates. This paper describes a study which investigates the effect of heart motion on kinetic parameter estimates. Dynamic SPECT simulations are performed using a beating version of the MCAT phantom. The results demonstrate that cardiac motion has a significant effect on the blood, tissue, and backgroundmore » content of regions of interest. This in turn affects estimates of wash-in, while it has very little effect on estimates of wash-out. The effect of cardiac motion on parameter estimates appears not to be as great as effects introduced by photon noise and geometric collimator response. It is also shown that cardiac motion results in little extravascular contamination of the left ventricle blood region of interest.« less

Therapeutic Effects of Breviscapine in Cardiovascular Diseases: A Review.

PubMed

Gao, Jialiang; Chen, Guang; He, Haoqiang; Liu, Chao; Xiong, Xingjiang; Li, Jun; Wang, Jie

2017-01-01

Breviscapine is a crude extract of several flavonoids of Erigeron breviscapus (Vant.) Hand.-Mazz. , containing more than 85% of scutellarin, which has been traditionally used in China as an activating blood circulation medicine to improve cerebral blood supply. Accumulating evidence from various in vivo and in vitro studies has shown that breviscapine exerts a broad range of cardiovascular pharmacological effects, including vasodilation, protection against ischaemia/reperfusion (I/R), anti-inflammation, anticoagulation, antithrombosis, endothelial protection, myocardial protection, reduction of smooth muscle cell migration and proliferation, anticardiac remodeling, antiarrhythmia, blood lipid reduction, and improvement of erectile dysfunction. In addition, several clinical studies have reported that breviscapine could be used in conjunction with Western medicine for cardiovascular diseases (CVDs) including coronary heart disease, myocardial infarction, hypertension, atrial fibrillation, hyperlipidaemia, viral myocarditis, chronic heart failure, and pulmonary heart disease. However, the protective effects of breviscapine on CVDs based on experimental studies along with its underlying mechanisms have not been reviewed systematically. This paper reviewed the underlying pharmacological mechanisms in the cardioprotective effects of breviscapine and elucidated its clinical applications.

Therapeutic Effects of Breviscapine in Cardiovascular Diseases: A Review

PubMed Central

Gao, Jialiang; Chen, Guang; He, Haoqiang; Liu, Chao; Xiong, Xingjiang; Li, Jun; Wang, Jie

2017-01-01

Breviscapine is a crude extract of several flavonoids of Erigeron breviscapus (Vant.) Hand.-Mazz., containing more than 85% of scutellarin, which has been traditionally used in China as an activating blood circulation medicine to improve cerebral blood supply. Accumulating evidence from various in vivo and in vitro studies has shown that breviscapine exerts a broad range of cardiovascular pharmacological effects, including vasodilation, protection against ischaemia/reperfusion (I/R), anti-inflammation, anticoagulation, antithrombosis, endothelial protection, myocardial protection, reduction of smooth muscle cell migration and proliferation, anticardiac remodeling, antiarrhythmia, blood lipid reduction, and improvement of erectile dysfunction. In addition, several clinical studies have reported that breviscapine could be used in conjunction with Western medicine for cardiovascular diseases (CVDs) including coronary heart disease, myocardial infarction, hypertension, atrial fibrillation, hyperlipidaemia, viral myocarditis, chronic heart failure, and pulmonary heart disease. However, the protective effects of breviscapine on CVDs based on experimental studies along with its underlying mechanisms have not been reviewed systematically. This paper reviewed the underlying pharmacological mechanisms in the cardioprotective effects of breviscapine and elucidated its clinical applications. PMID:28588491

COOL AMI EU pilot trial: a multicentre, prospective, randomised controlled trial to assess cooling as an adjunctive therapy to percutaneous intervention in patients with acute myocardial infarction.

PubMed

Noc, Marko; Erlinge, David; Neskovic, Aleksandar N; Kafedzic, Srdjan; Merkely, Béla; Zima, Endre; Fister, Misa; Petrović, Milovan; Čanković, Milenko; Veress, Gábor; Laanmets, Peep; Pern, Teele; Vukcevic, Vladan; Dedovic, Vladimir; Średniawa, Beata; Świątkowski, Andrzej; Keeble, Thomas R; Davies, John R; Warenits, Alexandra-Maria; Olivecrona, Göran; Peruga, Jan Zbigniew; Ciszewski, Michal; Horvath, Ivan; Edes, Istvan; Nagy, Gergely Gyorgy; Aradi, Daniel; Holzer, Michael

2017-08-04

We aimed to investigate the rapid induction of therapeutic hypothermia using the ZOLL Proteus Intravascular Temperature Management System in patients with anterior ST-elevation myocardial infarction (STEMI) without cardiac arrest. A total of 50 patients were randomised; 22 patients (88%; 95% confidence interval [CI]: 69-97%) in the hypothermia group and 23 patients (92%; 95% CI: 74-99) in the control group completed cardiac magnetic resonance imaging at four to six days and 30-day follow-up. Intravascular temperature at coronary guidewire crossing after 20.5 minutes of endovascular cooling decreased to 33.6°C (range 31.9-35.5°C). There was a 17-minute (95% CI: 4.6-29.8 min) cooling-related delay to reperfusion. In "per protocol" analysis, median infarct size/left ventricular mass was 16.7% in the hypothermia group versus 23.8% in the control group (absolute reduction 7.1%, relative reduction 30%; p=0.31) and median left ventricular ejection fraction (LVEF) was 42% in the hypothermia group and 40% in the control group (absolute reduction 2.4%, relative reduction 6%; p=0.36). Except for self-terminating paroxysmal atrial fibrillation (32% versus 8%; p=0.074), there was no excess of adverse events in the hypothermia group. We rapidly and safely cooled patients with anterior STEMI to 33.6°C at the time of coronary guidewire crossing. This is ≥1.1°C lower than in previous cooling studies. Except for self-terminating atrial fibrillation, there was no excess of adverse events and no clinically important cooling-related delay to reperfusion. A statistically non-significant numerical 7.1% absolute and 30% relative reduction in infarct size warrants a pivotal trial powered for efficacy.

Usefulness of Single Photon Emission Computed Tomography/Computed Tomography Fusion-Hybrid Imaging to Evaluate Coronary Artery Disorders in Patients with a History of Kawasaki Disease.

PubMed

Abe, Masanori; Fukazawa, Ryuji; Ogawa, Shunichi; Watanabe, Makoto; Fukushima, Yoshimitsu; Kiriyama, Tomonari; Hayashi, Hiromitsu; Itoh, Yasuhiko

2016-01-01

The coronary arterial lesions of Kawasaki disease are mainly dilative lesions, aneurysms, and stenotic lesions formed before, after, and between aneurysms; these lesions develop in multiple branches resulting in complex coronary hemodynamics. Diagnosis of myocardial ischemia and infarction and evaluation of the culprit coronary arteries and regions is critical to evaluating the treatment and prognosis of patients. This study used hybrid imaging, in which multidetector computed tomographic (CT) images for coronary CT angiography (CCTA) and stress myocardial perfusion single-photon emission CT (SPECT) images were fused. We investigated the diagnosis of blood vessels and regions responsible for myocardial ischemia and infarction in patients with complex coronary arterial lesions; in addition, we evaluated myocardial lesions that developed directly under giant coronary artery aneurysms. The subjects were 17 patients with Kawasaki disease with multiple coronary arterial lesions (median age, 18.0 years; 16 male). Both CCTA using 64-row CT and adenosine-loading myocardial SPECT were performed. Three branches, the right coronary artery (RCA), left anterior descending branch (LAD), and left circumflex branch, were evaluated with the conventional side-by-side interpretation, in which the images were lined up for diagnosis, and hybrid imaging, in which the CCTA and SPECT images were fused with computer processing. In addition, the myocardial lesions directly under giant coronary artery aneurysms were investigated with fusion imaging. Images sufficient for evaluation were acquired in all 17 patients. In the RCA, coronary arterial lesions were detected with CCTA in 16 patients. The evaluations were consistent between the side-by-side and fusion interpretation in 14 patients, and the blood vessel responsible for the myocardial ischemic region was identified in 2 patients. In the left circumflex branch, coronary arterial lesions were confirmed with 3-dimensional CT in 5 patients, and the the culprit coronary arteries for myocardial ischemia/infarction were confirmed with the fusion interpretation but not with the side-by-side interpretation. In the LAD, coronary arterial lesions were present in all patients, and the diagnosis was made with the fusion interpretation in 10 patients. In the LAD, small-range infarct lesions were detected directly under the giant coronary artery aneurysm in 8 patients, but were not confirmed with the side-by-side interpretation. Fusion imaging was capable of accurately evaluating myocardial ischemia/infarction as cardiovascular sequelae of Kawasaki disease and confirming the culprit coronary arteries. In addition, analysis of fusion images confirmed that small-range infarct lesions were concomitantly present directly under giant coronary artery aneurysms in the anterior descending coronary artery.

Challenges for the prevention of primary and secondary stroke: the importance of lowering blood pressure and total cardiovascular risk.

PubMed

Chalmers, J; Chapman, N

2001-01-01

It is well established that blood pressure lowering is effective for the primary prevention of stroke and other cardiovascular disorders in subjects with blood pressures as low as 140/90 mmHg, and up to 80 years of age. Despite this knowledge, blood pressure levels are controlled in less than 25% of the hypertensive population worldwide. It has taken longer to prove that blood pressure lowering is equally effective for the prevention of recurrent stroke. The results of PROGRESS (Perindopril Protection Against Recurrent Stroke Study) have confirmed that a perindopril-based regimen in subjects with cerebrovascular disease substantially reduces the incidence of secondary stroke and primary myocardial infarction. It is daunting to recall that it has taken almost two decades for beta-blockers to be widely used for the secondary prevention of myocardial infarction, since widespread use of the PROGRESS regimen would prevent more than half a million strokes worldwide each year. The real challenge now is to implement novel and effective strategies for the control of blood pressure and other cardiovascular risk factors worldwide. Strategies should include lifestyle measures, such as stopping smoking, exercise and reducing overweight. There is a real need to identify hypertensive subjects and treat them with blood pressure lowering drugs for primary prevention. In subjects with established cardiovascular disease, consideration should be given to a range of proven interventions for secondary prevention, such as blood pressure lowering, irrespective of current blood pressure, anti-platelet drugs, statins for lowering cholesterol and glycaemic control in diabetics. Among new strategies to lower overall cardiovascular risk, consideration should be given to the development of single-pill combinations of drugs of known efficacy, including various combinations of ACE inhibitors, diuretics, beta-blockers, aspirin and statins, among others.

Assessment of myocardial metabolic flexibility and work efficiency in human type 2 diabetes using 16-[18F]fluoro-4-thiapalmitate, a novel PET fatty acid tracer

PubMed Central

Hutchins, G. D.; Perry, K.; Territo, W.; Chisholm, R.; Acton, A.; Glick-Wilson, B.; Considine, R. V.; Moberly, S.; DeGrado, T. R.

2015-01-01

Altered myocardial fuel selection likely underlies cardiac disease risk in diabetes, affecting oxygen demand and myocardial metabolic flexibility. We investigated myocardial fuel selection and metabolic flexibility in human type 2 diabetes mellitus (T2DM), using positron emission tomography to measure rates of myocardial fatty acid oxidation {16-[18F]fluoro-4-thia-palmitate (FTP)} and myocardial perfusion and total oxidation ([11C]acetate). Participants underwent paired studies under fasting conditions, comparing 3-h insulin + glucose euglycemic clamp conditions (120 mU·m−2·min−1) to 3-h saline infusion. Lean controls (n = 10) were compared with glycemically controlled volunteers with T2DM (n = 8). Insulin augmented heart rate, blood pressure, and stroke index in both groups (all P < 0.01) and significantly increased myocardial oxygen consumption (P = 0.04) and perfusion (P = 0.01) in both groups. Insulin suppressed available nonesterified fatty acids (P < 0.0001), but fatty acid concentrations were higher in T2DM under both conditions (P < 0.001). Insulin-induced suppression of fatty acid oxidation was seen in both groups (P < 0.0001). However, fatty acid oxidation rates were higher under both conditions in T2DM (P = 0.003). Myocardial work efficiency was lower in T2DM (P = 0.006) and decreased in both groups with the insulin-induced increase in work and shift in fuel utilization (P = 0.01). Augmented fatty acid oxidation is present under baseline and insulin-treated conditions in T2DM, with impaired insulin-induced shifts away from fatty acid oxidation. This is accompanied by reduced work efficiency, possibly due to greater oxygen consumption with fatty acid metabolism. These observations suggest that improved fatty acid suppression, or reductions in myocardial fatty acid uptake and retention, could be therapeutic targets to improve myocardial ischemia tolerance in T2DM. PMID:26732686

Assessment of myocardial metabolic flexibility and work efficiency in human type 2 diabetes using 16-[18F]fluoro-4-thiapalmitate, a novel PET fatty acid tracer.

PubMed

Mather, K J; Hutchins, G D; Perry, K; Territo, W; Chisholm, R; Acton, A; Glick-Wilson, B; Considine, R V; Moberly, S; DeGrado, T R

2016-03-15

Altered myocardial fuel selection likely underlies cardiac disease risk in diabetes, affecting oxygen demand and myocardial metabolic flexibility. We investigated myocardial fuel selection and metabolic flexibility in human type 2 diabetes mellitus (T2DM), using positron emission tomography to measure rates of myocardial fatty acid oxidation {16-[(18)F]fluoro-4-thia-palmitate (FTP)} and myocardial perfusion and total oxidation ([(11)C]acetate). Participants underwent paired studies under fasting conditions, comparing 3-h insulin + glucose euglycemic clamp conditions (120 mU·m(-2)·min(-1)) to 3-h saline infusion. Lean controls (n = 10) were compared with glycemically controlled volunteers with T2DM (n = 8). Insulin augmented heart rate, blood pressure, and stroke index in both groups (all P < 0.01) and significantly increased myocardial oxygen consumption (P = 0.04) and perfusion (P = 0.01) in both groups. Insulin suppressed available nonesterified fatty acids (P < 0.0001), but fatty acid concentrations were higher in T2DM under both conditions (P < 0.001). Insulin-induced suppression of fatty acid oxidation was seen in both groups (P < 0.0001). However, fatty acid oxidation rates were higher under both conditions in T2DM (P = 0.003). Myocardial work efficiency was lower in T2DM (P = 0.006) and decreased in both groups with the insulin-induced increase in work and shift in fuel utilization (P = 0.01). Augmented fatty acid oxidation is present under baseline and insulin-treated conditions in T2DM, with impaired insulin-induced shifts away from fatty acid oxidation. This is accompanied by reduced work efficiency, possibly due to greater oxygen consumption with fatty acid metabolism. These observations suggest that improved fatty acid suppression, or reductions in myocardial fatty acid uptake and retention, could be therapeutic targets to improve myocardial ischemia tolerance in T2DM. Copyright © 2016 the American Physiological Society.

Mechanistic insights and characterization of sickle cell disease-associated cardiomyopathy.

PubMed

Desai, Ankit A; Patel, Amit R; Ahmad, Homaa; Groth, John V; Thiruvoipati, Thejasvi; Turner, Kristen; Yodwut, Chattanong; Czobor, Peter; Artz, Nicole; Machado, Roberto F; Garcia, Joe G N; Lang, Roberto M

2014-05-01

Cardiovascular disease is an important cause of morbidity and mortality in sickle cell disease (SCD). We sought to characterize sickle cell cardiomyopathy using multimodality noninvasive cardiovascular testing and identify potential causative mechanisms. Stable adults with SCD (n=38) and healthy controls (n=13) prospectively underwent same day multiparametric cardiovascular magnetic resonance (cine, T2* iron, vasodilator first pass myocardial perfusion, and late gadolinium enhancement imaging), transthoracic echocardiography, and applanation tonometry. Compared with controls, patients with SCD had severe dilation of the left ventricle (124±27 vs 79±12 mL/m(2)), right ventricle (127±28 vs 83±14 mL/m(2)), left atrium (65±16 vs 41±9 mL/m(2)), and right atrium (78±17 vs 56±17 mL/m(2); P<0.01 for all). Patients with SCD also had a 21% lower myocardial perfusion reserve index than control subjects (1.47±0.34 vs 1.87±0.37; P=0.034). A significant subset of patients with SCD (25%) had evidence of late gadolinium enhancement, whereas only 1 patient had evidence of myocardial iron overload. Diastolic dysfunction was present in 26% of patients with SCD compared with 8% in controls. Estimated filling pressures (E/e', 9.3±2.7 vs 7.3±2.0; P=0.0288) were higher in patients with SCD. Left ventricular dilation and the presence of late gadolinium enhancement were inversely correlated to hepatic T2* times (ie, hepatic iron overload because of frequent blood transfusions; P<0.05 for both), whereas diastolic dysfunction and increased filling pressures were correlated to aortic stiffness (augmentation pressure and index, P<0.05 for all). Sickle cell cardiomyopathy is characterized by 4-chamber dilation and in some patients myocardial fibrosis, abnormal perfusion reserve, diastolic dysfunction, and only rarely myocardial iron overload. Left ventricular dilation and myocardial fibrosis are associated with increased blood transfusion requirements, whereas left ventricular diastolic dysfunction is predominantly correlated with increased aortic stiffness. http://www.clinicaltrials.gov. Unique identifier: NCT01044901. © 2014 American Heart Association, Inc.

Platelet counts on admission affect coronary flow, myocardial perfusion and left ventricular systolic function after primary percutaneous coronary intervention.

PubMed

Sharif, Dawod; Abu-Salem, Mira; Sharif-Rasslan, Amal; Rosenschein, Uri

2017-10-01

Patients with acute ST-elevation myocardial infarction (STEMI) and increased platelet count treated by fibrinolysis have worse outcomes. The aim of this study was to test the hypothesis that platelet blood count at admission in patients with acute STEMI treated by primary percutaneous coronary intervention affects coronary flow, myocardial perfusion and recovery of left ventricular systolic function. A total of 174 patients presenting with acute anterior STEMI and treated with primary percutaneous coronary intervention were included and divided into subgroups of admission platelet blood count of <200 K, 200-300 K, 300-400 K and >400 K. Evaluation of coronary artery flow and myocardial blush grade was performed according to the TIMI criteria. Electrocardiographic ST elevation resolution post-primary percutaneous coronary intervention was evaluated. Doppler echocardiographic evaluation of left anterior descending coronary artery velocities early and late after primary percutaneous coronary intervention and assessment of left ventricular ejection fraction and wall motion score index (WMSI) of left ventricular and left anterior descending coronary artery territory were performed. Post-primary percutaneous coronary intervention TIMI, myocardial blush grade and ST elevation resolution were similar in all groups. Patients with platelet counts <200 K had higher peak diastolic left anterior descending coronary artery velocity both early and late after primary percutaneous coronary intervention, and higher prevalence of left anterior descending coronary artery velocity deceleration time exceeding 600 ms, (45.5% vs. 40%, P<0.05). Patients with platelet counts >400 K presented with worse left ventricular ejection fraction, left ventricular WMSI and left anterior descending coronary artery WMSI, and before discharge this subgroup had worse left ventricular WMSI and left anterior descending coronary artery WMSI, P<0.01. Patients with anterior STEMI treated by primary percutaneous coronary intervention with lower admission platelet count had higher left anterior descending coronary artery diastolic velocities, better myocardial perfusion with more patients having left anterior descending coronary artery-descending coronary artery velocity deceleration time >600 ms. Patients with higher platelet counts had lower left ventricular systolic function both at admission and before discharge.

Underestimation of myocardial blood flow by dynamic perfusion CT: Explanations by two-compartment model analysis and limited temporal sampling of dynamic CT.

PubMed

Ishida, Masaki; Kitagawa, Kakuya; Ichihara, Takashi; Natsume, Takahiro; Nakayama, Ryohei; Nagasawa, Naoki; Kubooka, Makiko; Ito, Tatsuro; Uno, Mio; Goto, Yoshitaka; Nagata, Motonori; Sakuma, Hajime

2016-01-01

Previous studies using dynamic perfusion CT and volume perfusion CT (VPCT) software consistently underestimated the stress myocardial blood flow (MBF) in normal myocardium to be 1.1-1.4 ml/min/g, whilst the O 15-water PET studies demonstrated the normal stress MBF of 3-5 ml/min/g. We hypothesized that the MBF determined by VPCT (MBF-VPCT) is actually presenting the blood-to-myocardium transfer constant, K1. In this study, we determined K1 using Patlak plot (K1-Patlak) and compared the results with MBF-VPCT. 17 patients (66 ± 9 years, 7 males) with suspected coronary artery disease (CAD) underwent stress dynamic perfusion CT, followed by rest coronary CT angiography (CTA). Arterial input and myocardial output curves were analyzed with Patlak plot to quantify myocardial K1. Significant CAD was defined as >50% stenosis on CTA. A simulation study was also performed to investigate the influence of limited temporal sampling in dynamic CT acquisition on K1 using the undersampling data generated from MRI. There were 3 patients with normal CTA, 7 patients with non-significant CAD, and 7 patients with significant CAD. K1-patlak was 0.98 ± 0.35 (range 0.22-1.67) ml/min/g, whereas MBF-VPCT was 0.83 ± 0.23 (range 0.34-1.40) ml/min/g. There was a linear relationship between them: (MBF-VPCT) = 0.58 x (K1-patlak) + 0.27 (r(2) = 0.65, p < 0.001). The simulation study done on MRI data demonstrated that Patlak plot substantially underestimated true K1 by 41% when true K1 was 2.0 ml/min/g with the temporal sampling of 2RR for arterial input and 4RR for myocardial output functions. The results of our study are generating hypothesis that MBF-VPCT is likely to be calculating K1-patlak equivalent, not MBF. In addition, these values may be substantially underestimated because of limited temporal sampling rate. Copyright © 2016 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Regulation of Coronary Blood Flow in Health and Ischemic Heart Disease

PubMed Central

Duncker, Dirk J.; Koller, Akos; Merkus, Daphne; Canty, John M.

2018-01-01

The major factors determining myocardial perfusion and oxygen delivery have been elucidated over the past several decades, and this knowledge has been incorporated into the management of patients with ischemic heart disease (IHD). The basic understanding of the fluid mechanical behavior of coronary stenoses has also been translated to the cardiac catheterization laboratory where measurements of coronary pressure distal to a stenosis and coronary flow are routinely obtained. However, the role of perturbations in coronary microvascular structure and function, due to myocardial hypertrophy or coronary microvascular dysfunction, in IHD is becoming increasingly recognized. Future studies should therefore be aimed at further improving our understanding of the integrated coronary microvascular mechanisms that control coronary blood flow, and of the underlying causes and mechanisms of coronary microvascular dysfunction. This knowledge will be essential to further improve the treatment of patients with IHD. PMID:25475073

ATLS Hypovolemic Shock Classification by Prediction of Blood Loss in Rats Using Regression Models.

PubMed

Choi, Soo Beom; Choi, Joon Yul; Park, Jee Soo; Kim, Deok Won

2016-07-01

In our previous study, our input data set consisted of 78 rats, the blood loss in percent as a dependent variable, and 11 independent variables (heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure, pulse pressure, respiration rate, temperature, perfusion index, lactate concentration, shock index, and new index (lactate concentration/perfusion)). The machine learning methods for multicategory classification were applied to a rat model in acute hemorrhage to predict the four Advanced Trauma Life Support (ATLS) hypovolemic shock classes for triage in our previous study. However, multicategory classification is much more difficult and complicated than binary classification. We introduce a simple approach for classifying ATLS hypovolaemic shock class by predicting blood loss in percent using support vector regression and multivariate linear regression (MLR). We also compared the performance of the classification models using absolute and relative vital signs. The accuracies of support vector regression and MLR models with relative values by predicting blood loss in percent were 88.5% and 84.6%, respectively. These were better than the best accuracy of 80.8% of the direct multicategory classification using the support vector machine one-versus-one model in our previous study for the same validation data set. Moreover, the simple MLR models with both absolute and relative values could provide possibility of the future clinical decision support system for ATLS classification. The perfusion index and new index were more appropriate with relative changes than absolute values.

The distribution of blood eosinophil levels in a Japanese COPD clinical trial database and in the rest of the world.

PubMed

Barnes, Neil; Ishii, Takeo; Hizawa, Nobuyuki; Midwinter, Dawn; James, Mark; Hilton, Emma; Jones, Paul W

2018-01-01

Blood eosinophil measurements may help to guide physicians on the use of inhaled corticosteroids (ICS) for patients with chronic obstructive pulmonary disease (COPD). Emerging data suggest that COPD patients with higher blood eosinophil counts may be at higher risk of exacerbations and more likely to benefit from combined ICS/long-acting beta 2 -agonist (LABA) treatment than therapy with a LABA alone. This analysis describes the distribution of blood eosinophil count at baseline in Japanese COPD patients in comparison with non-Japanese COPD patients. A post hoc analysis of eosinophil distribution by percentage and absolute cell count was performed across 12 Phase II-IV COPD clinical studies (seven Japanese studies [N=848 available absolute eosinophil counts] and five global studies [N=5,397 available eosinophil counts] that included 246 Japanese patients resident in Japan with available counts). Blood eosinophil distributions were assessed at baseline, before blinded treatment assignment. Among Japanese patients, the median (interquartile range) absolute eosinophil count was 170 cells/mm 3 (100-280 cells/mm 3 ). Overall, 612/1,094 Japanese patients (56%) had an absolute eosinophil count ≥150 cells/mm 3 and 902/1,304 Japanese patients (69%) had a percentage eosinophil ≥2%. Among non-Japanese patients, these values were 160 (100-250) cells/mm 3 , 2,842/5,151 patients (55%), and 2,937/5,155 patients (57%), respectively. The eosinophil distribution among Japanese patients was similar to that among non-Japanese patients. Within multi-country studies with similar inclusion criteria, the eosinophil count was numerically lower in Japanese compared with non-Japanese patients (median 120 vs 160 cells/mm 3 ). The eosinophil distribution in Japanese patients seems comparable to that of non-Japanese patients; although within multi-country studies, there was a slightly lower median eosinophil count for Japanese patients compared with non-Japanese patients. These findings suggest that blood eosinophil data from global studies are of relevance in Japan.

Effect of antiischemic therapy on coronary flow reserve and the pressure-maximal coronary flow relationship in anesthetized swine.

PubMed

McFalls, E O; Duncker, D J; Sassen, L M; Gho, B C; Verdouw, P D

1991-12-01

The effect of nifedipine (0.5, 1.0, and 2.0 micrograms/kg/min), metoprolol (0.1, 0.5, and 1.0 mg/kg), the beta 1-selective adrenoceptor partial agonist epanolol (10, 50, and 200 micrograms/kg), or equivalent volumes of isotonic saline (n = 6, in each group), on coronary blood flow capacity were studied in anesthetized swine. Intracoronary bolus injections of adenosine (20 micrograms/kg/0.2 ml) were administered without and during three levels of coronary stenosis, prior to and following each dose of drug, to obtain maximal coronary blood flows at different perfusion pressures in the autoregulatory range. Coronary perfusion pressures were varied by partial inflation of a balloon around the left anterior descending coronary artery. Special care was taken that the stenoses not lead to myocardial ischemia. Three indices of coronary blood flow capacity were used: absolute coronary flow reserve (ACFR, the ratio of maximal to resting coronary blood flow), the slope and the extrapolated pressure at zero flow (Pzf) of the pressure-maximal coronary flow (PMCF) relationship, and relative coronary flow reserve (RCFR, the ratio of maximal coronary blood flow with a stenosis to maximal coronary blood flow without a stenosis) at two of the three levels of stenosis. Nifedipine decreased ACFR from 4.5 +/- 1.9 to 1.9 +/- 0.3 (mean +/- SD; p less than 0.05), reflecting in part the increase in resting coronary blood flow. The nifedipine-induced changes in maximal coronary blood flow were not only due to a drop in perfusion pressure, as the slope of the PMCF relationship decreased from 2.27 +/- 0.49 ml/(min.mm Hg) to 1.54 +/- 0.51 ml/(min.mm Hg) (p less than 0.05), and Pzf decreased from 30 +/- 4 mm Hg to 20 +/- 7 mm Hg (p less than 0.05). Consequently, calculated maximal coronary blood flow was attenuated from 114 +/- 31 ml/min to 93 +/- 37 ml/min at 80 mm Hg, but was enhanced from 23 +/- 13 to 37 +/- 24 ml/min at 40 mm Hg coronary perfusion pressure. In concert with the change in the PMCF relationship, RCFR at equivalent severe stenosis increased from 0.33 +/- 0.06 to 0.47 +/- 0.10 (p less than 0.05). No changes were observed with metoprolol, epanolol, or saline. The effect of nifedipine on the PMCF relationship not only provides a mechanism for the drug's antiischemic action, but should also be considered in the interpretation of coronary flow reserve measurements in patients on nifedipine treatment.

Quantification of regional myocardial blood flow estimation with three-dimensional dynamic rubidium-82 PET and modified spillover correction model.

PubMed

Katoh, Chietsugu; Yoshinaga, Keiichiro; Klein, Ran; Kasai, Katsuhiko; Tomiyama, Yuuki; Manabe, Osamu; Naya, Masanao; Sakakibara, Mamoru; Tsutsui, Hiroyuki; deKemp, Robert A; Tamaki, Nagara

2012-08-01

Myocardial blood flow (MBF) estimation with (82)Rubidium ((82)Rb) positron emission tomography (PET) is technically difficult because of the high spillover between regions of interest, especially due to the long positron range. We sought to develop a new algorithm to reduce the spillover in image-derived blood activity curves, using non-uniform weighted least-squares fitting. Fourteen volunteers underwent imaging with both 3-dimensional (3D) (82)Rb and (15)O-water PET at rest and during pharmacological stress. Whole left ventricular (LV) (82)Rb MBF was estimated using a one-compartment model, including a myocardium-to-blood spillover correction to estimate the corresponding blood input function Ca(t)(whole). Regional K1 values were calculated using this uniform global input function, which simplifies equations and enables robust estimation of MBF. To assess the robustness of the modified algorithm, inter-operator repeatability of 3D (82)Rb MBF was compared with a previously established method. Whole LV correlation of (82)Rb MBF with (15)O-water MBF was better (P < .01) with the modified spillover correction method (r = 0.92 vs r = 0.60). The modified method also yielded significantly improved inter-operator repeatability of regional MBF quantification (r = 0.89) versus the established method (r = 0.82) (P < .01). A uniform global input function can suppress LV spillover into the image-derived blood input function, resulting in improved precision for MBF quantification with 3D (82)Rb PET.

Haemodynamic responses and changes of haemostatic risk factors in cold-adapted humans.

PubMed

De Lorenzo, F; Kadziola, Z; Mukherjee, M; Saba, N; Kakkar, V V

1999-09-01

Epidemiological studies have shown an increase in acute myocardial infarctions or deaths due to myocardial infarction in colder weather; the mechanisms most likely involve increased blood levels of haemostatic risk factors, and increases in arterial blood pressure and heart rate. We studied the relationship between cold adaptation, haemostatic risk factors and haemodynamic variables. Cold adaptation was obtained by a programme of immersion of the whole body up to the neck in a water-filled bath, the temperature of which was gradually decreased from 22 degrees C to 14 degrees C, time of exposure being increased from 5 to 20 min over a period of 90 days. We studied 428 patients (44% men) and measured blood levels of fibrinogen, plasminogen activator inhibitor 1 (PAI-1), tissue plasminogen activator antigen (t-PA), plasma viscosity, von Willebrand factor, D-dimer and platelet count, both at baseline and after 90 days of daily immersion. There were significant reductions in von Willebrand factor (-3%; p < 0.001), and plasma viscosity (-3.0 s; p < 0.001), and a mild but significant increase in PAI-1 (+0.3 IU/ml; p = 0.02). The pressure rate product (systolic blood pressure x heart rate) was also significantly lower after cold adaptation (-310; p = 0.004). Cold adaptation, compared with exposure to cold weather, induces different haemodynamic responses and changes of blood levels of haemostatic risk factors.

Overexpression of MMP-9 and its inhibitors in blood mononuclear cells after myocardial infarction--is it associated with depressive symptomatology?

PubMed

Jönsson, Simon; Lundberg, Anna K; Jonasson, Lena

2014-01-01

Matrix metalloproteinase (MMP)-9 may play a central role in the development and progression of atherosclerosis. Emerging evidence also indicates an association between MMP-9 and depressive symptomatology. Here, we investigated whether expression of MMP-9 and its inhibitors in blood mononuclear cells and plasma were related to depressive symptoms in patients with a recent myocardial infarction (MI). Blood sampling was performed between 6 and 18 months after MI in 57 patients. Forty-one clinically healthy subjects were included as controls. Gene expression of MMP-9 and its main tissue inhibitors TIMP-1 and -2 were analyzed in freshly isolated or cultured blood mononuclear cells. Corresponding protein levels were assessed in cell supernatants and plasma. In post-MI patients, mRNA levels of MMP-9 and TIMP-1 and -2 were significantly higher than in controls while protein levels in cell supernatants and plasma did not differ between groups. The Center for Epidemiological Studies - Depression (CES-D) scale was used to assess depressive symptomatology. Repeated assessments during the first 18 months after MI showed significantly higher CES-D scores in patients compared with controls. However, there were no relationships between depressive mood and any of the measurements of MMP-9 or TIMPs. Our findings indicate that overexpression of MMP-9 and TIMPs in blood mononuclear cells and elevated depressive symptoms represent two unrelated phenomena after MI.

Molecular tissue changes in early myocardial ischemia: from pathophysiology to the identification of new diagnostic markers.

PubMed

Aljakna, Aleksandra; Fracasso, Tony; Sabatasso, Sara

2018-03-01

Diagnosing early myocardial ischemia (the initial 4 to 6 h after interruption of blood flow to part of the myocardium) remains a challenge for clinical and forensic pathologists. Several immunohistochemical markers have been proposed for improving postmortem detection of early myocardial ischemia; however, no single marker appears to be both sufficiently specific as well as sensitive. This review summarizes the diverse categories of molecular tissue markers that have been investigated in human autopsy samples with acute myocardial infarction as well as in the well-established and widely used in vivo animal model of early myocardial ischemia (permanent ligation of the coronary artery). Recently identified markers appearing during the initial 2 h of myocardial ischemia are highlighted. Among them, only six were tested for specificity (C5b-9, hypoxia-inducible factor 1-alpha, vascular endothelial growth factor, heart fatty acid binding protein, connexin 43, and JunB). Despite the discovery of several potentially promising markers (in terms of early expression and specificity), many of them remain to be tested and validated for application in routine diagnostics in clinical and forensic pathology. In particular, research investigating the postmortem stability of these markers is required before any might be implemented into routine diagnostics. Establishing a standardized panel of immunohistochemical markers may be more useful for improving sensitivity and specificity than searching for a single marker.

Titanium dioxide nanoparticle-induced cytotoxicity and the underlying mechanism in mouse myocardial cells

NASA Astrophysics Data System (ADS)

Zhou, Yingjun; Hong, Fashui; Wang, Ling

2017-11-01

Exposure to fine particulate matter (PM) is known to cause cardiovascular disease. While extensive research has focused on the risk of atmospheric PM to public health, particularly heart disease, limited studies to date have attempted to clarify the molecular mechanisms underlying myocardial cell damage caused by exposure to titanium dioxide nanoparticles (TiO2 NPs). Data from the current investigation showed that TiO2 NPs are deposited in myocardial mitochondria via the blood circulation accompanied by obvious ultrastructural changes and impairment of mitochondrial structure and function in mouse myocardial cells, including reduction in mitochondrial membrane potential and ATP production, aggravation of oxidative stress along with increased levels of reactive oxygen species, malondialdehyde and protein carbonyl, and decreased glutathione content and enzymatic activities, including superoxide dismutase and glutathione peroxidase. Furthermore, TiO2 NPs induced a significant decrease in the activities of complex I, complex II, complex III, complex IV, succinate dehydrogenase, NADH oxidase, Ca2+-ATPase, Na+/K+-ATPase, and Ca2+/Mg2+-ATPase, and upregulation of cytokine expression (including cytochrome c, caspase-3, and p-JNK) in mitochondria-mediated apoptosis while downregulating Bcl-2 expression in mouse myocardial cells. Our results collectively indicate that chronic exposure to TiO2 NPs induces damage in mitochondrial structure and function as well as mitochondria-mediated apoptosis in mouse myocardial cells, which may be closely associated with heart disease in animals and humans.

Bovine Intestinal Alkaline Phosphatase Reduces Inflammation After Induction of Acute Myocardial Infarction in Mice

PubMed Central

Fiechter, Danielle; Kats, Suzanne; Brands, Ruud; van Middelaar, Ben; Pasterkamp, Gerard; de Kleijn, Dominique; Seinen, Willem

2011-01-01

Background There has been increasing evidence suggesting that lipopolysaccharide or endotoxin may be an important activator of the innate immune system after acute myocardial infarction. Bovine intestinal alkaline phosphatase reduces inflammation in several endotoxin mediated diseases by dephosphorylation of the lipid A moiety of lipopolysaccharide. The aim of this study was to investigate the effect of bovine intestinal alkaline phosphatase on reducing inflammation after acute myocardial infarction. Methods Just before permanent ligation of the left anterior descending coronary (LAD) artery to induce acute myocardial infarction in Balb/c mice, bovine intestinal alkaline phosphatase (bIAP) was administrated intravenously. After 4 hours, mice were sacrificed and the inflammatory response was assessed. Acute myocardial infarction induced the production of different cytokines, which were measured in blood. Results Treatment with bovine intestinal alkaline phosphatase resulted in a significant reduction of the pro-inflammatory cytokines IL-6, IL-1β and the chymase mouse mast cell protease-1. No difference in the production of the anti-inflammatory cytokine IL-10 was observed between the control group and the bovine intestinal alkaline phosphatase treated group. Conclusion In a mouse model of permanent LAD coronary artery ligation, bIAP diminishes the pro-inflammatory responses but does not have an effect on the anti-inflammatory response in the acute phase after acute myocardial infarction. PMID:28357012

Repeatable noninvasive measurement of mouse myocardial glucose uptake with 18F-FDG: evaluation of tracer kinetics in a type 1 diabetes model.

PubMed

Thorn, Stephanie L; deKemp, Robert A; Dumouchel, Tyler; Klein, Ran; Renaud, Jennifer M; Wells, R Glenn; Gollob, Michael H; Beanlands, Rob S; DaSilva, Jean N

2013-09-01

A noninvasive and repeatable method for assessing mouse myocardial glucose uptake with (18)F-FDG PET and Patlak kinetic analysis was systematically assessed using the vena cava image-derived blood input function (IDIF). Contrast CT and computer modeling was used to determine the vena cava recovery coefficient. Vena cava IDIF (n = 7) was compared with the left ventricular cavity IDIF, with blood and liver activity measured ex vivo at 60 min. The test-retest repeatability (n = 9) of Patlak influx constant K(i) at 10-40 min was assessed quantitatively using Bland-Altman analysis. Myocardial glucose uptake rates (rMGU) using the vena cava IDIF were calculated at baseline (n = 8), after induction of type 1 diabetes (streptozotocin [50 mg/kg] intraperitoneally, 5 d), and after acute insulin stimulation (0.08 mU/kg of body weight intraperitoneally). These changes were analyzed with a standardized uptake value calculation at 20 and 40 min after injection to correlate to the Patlak time interval. The proximal mouse vena cava diameter was 2.54 ± 0.30 mm. The estimated recovery coefficient, calculated using nonlinear image reconstruction, decreased from 0.76 initially (time 0 to peak activity) to 0.61 for the duration of the scan. There was a 17% difference in the image-derived vena cava blood activity at 60 min, compared with the ex vivo blood activity measured in the γ-counter. The coefficient of variability for Patlak K(i) values between mice was found to be 23% with the proposed method, compared with 51% when using the left ventricular cavity IDIF (P < 0.05). No significant bias in K(i) was found between repeated scans with a coefficient of repeatability of 0.16 mL/min/g. Calculated rMGU values were reduced by 60% in type 1 diabetic mice from baseline scans (P < 0.03, ANOVA), with a subsequent increase of 40% to a level not significantly different from baseline after acute insulin treatment. These results were confirmed with a standardized uptake value measured at 20 and 40 min. The mouse vena cava IDIF provides repeatable assessment of the blood time-activity curve for Patlak kinetic modeling of rMGU. An expected significant reduction in myocardial glucose uptake was demonstrated in a type 1 diabetic mouse model, with significant recovery after acute insulin treatment, using a mouse vena cava IDIF approach.

Milrinone and levosimendan during porcine myocardial ischemia -- no effects on calcium overload and metabolism.

PubMed

Axelsson, B; Johansson, G; Abrahamsson, P; Gupta, A; Tydén, H; Wouters, P; Haney, M

2013-07-01

Although inotropic stimulation is considered harmful in the presence of myocardial ischaemia, both calcium sensitisers and phosphodiesterase inhibitors may offer cardioprotection. We hypothesise that these cardioprotective effects are related to an acute alteration of myocardial metabolism. We studied in vivo effects of milrinone and levosimendan on calcium overload and ischaemic markers using left ventricular microdialysis in pigs with acute myocardial ischaemia. Anaesthetised juvenile pigs, average weight 36 kg, were randomised to one of three intravenous treatment groups: milrinone 50 μg/kg bolus plus infusion 0.5 μg/kg/min (n = 7), levosimendan 24 μg/kg plus infusion 0.2 μg/kg/min (n = 7), or placebo (n = 6) for 60 min prior to and during a 45 min acute regional coronary occlusion. Systemic and myocardial haemodynamics were assessed, and microdialysis was performed with catheters positioned in the left ventricular wall. (45) Ca(2+) was included in the microperfusate in order to assess local calcium uptake into myocardial cells. The microdialysate was analysed for glucose, lactate, pyruvate, glycerol, and for (45) Ca(2+) recovery. During ischaemia, there were no differences in microdialysate-measured parameters between control animals and milrinone- or levosimendan-treated groups. In the pre-ischaemic period, arterial blood pressure decreased in all groups while myocardial oxygen consumption remained stable. These findings reject the hypothesis of an immediate energy-conserving effect of milrinone and levosimendan during acute myocardial ischaemia. On the other hand, the data show that inotropic support with milrinone and levosimendan does not worsen the metabolic parameters that were measured in the ischaemic myocardium. © 2013 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Left ventricular energy model predicts adverse events in women with suspected myocardial ischemia: results from the NHLBI-sponsored women’s ischemia syndrome evaluation (WISE) study

PubMed Central

Weinberg, Nicole; Pohost, Gerald M.; Bairey Merz, C. Noel; Shaw, Leslee J.; Sopko, George; Fuisz, Anthon; Rogers, William J.; Walsh, Edward G.; Johnson, B. Delia; Sharaf, Barry L.; Pepine, Carl J.; Mankad, Sunil; Reis, Steven E.; Rayarao, Geetha; Vido, Diane A.; Bittner, Vera; Tauxe, Lindsey; Olson, Marian B.; Kelsey, Sheryl F.; Biederman, Robert WW

2013-01-01

Objectives To assess the prognostic value of a left ventricular energy-model in women with suspected myocardial ischemia. Background The prognostic value of internal energy utilization (IEU) of the left ventricle in women with suspected myocardial ischemia is unknown. Methods Women [n=227, mean age 59±12 years (range, 31-86 years)], with symptoms of myocardial ischemia, underwent myocardial perfusion imaging (MPI) assessment for regional perfusion defects along with measurement of ventricular volumes separately by gated Single Photon Emission Computed Tomography (SPECT) (n=207) and magnetic resonance imaging (MRI) (n=203). During follow-up (40±17 months), time to first major adverse cardiovascular event (MACE, death, myocardial infarction or hospitalization for congestive heart failure) was analyzed using MRI and gated SPECT variables. Results Adverse events occurred in 31 (14%). Multivariable Cox models were formed for each modality: IEU and wall thickness by MRI (Chi-squared 34, P<0.005) and IEU and systolic blood pressure by gated SEPCT (Chi-squared 34, P<0.005). The models remained predictive after adjustment for age, disease history and Framingham risk score. For each Cox model, patients were categorized as high-risk if the model hazard was positive and not high-risk otherwise. Kaplan-Meier analysis of time to MACE was performed for high-risk vs. not high-risk for MR (log rank 25.3, P<0.001) and gated SEPCT (log rank 18.2, P<0.001) models. Conclusions Among women with suspected myocardial ischemia a high internal energy utilization has higher prognostic value than either a low EF or the presence of a myocardial perfusion defect assessed using two independent modalities of MR or gated SPECT. PMID:24015377

Management of Patient Care in Hemodialysis While Focusing on Cardiovascular Disease Events and the Atypical Role of Hyper- and/or Hypotension: A Systematic Review

PubMed Central

Khan, Amer Hayat; Syed Sulaiman, Syed Azhar; Khan, Irfanullah

2016-01-01

Background. Hemodialysis related hemodynamic instability is a major but an underestimated issue. Moreover, cardiovascular events are the leading cause of morbidity and mortality associated with blood pressure in hemodialysis patients. However, there have been many controversies regarding the role and management of hyper- and/or hypotension during hemodialysis that needs to be addressed. Objective. To critically review the available published data on the atypical role of hyper- and/or hypotension in cardiovascular associated morbidity and mortality in patients on hemodialysis and to understand the discrepancies in this context. Methods. A comprehensive search of literature employing electronic as well as manual sources and screening 2783 papers published between Jan 1980 and Oct 2015 was conducted to collect, identify, and analyze relevant information through peer-reviewed research articles, systematic reviews, and other published works. The cardiovascular events, including accelerated atherosclerotic cardiovascular disease (ASCVD), stroke, heart failure, myocardial infarction, myocardial ischemia, and stress induced myocardial dysfunction, leading to death were considered relevant. Results. A total of 23 published articles met the inclusion criteria and were included for in-depth review and analysis to finalize a comprehensive systematic review article. All the studies showed a significant association between the blood pressure and cardiovascular disease events in hemodialysis patients. Conclusions. Both intradialytic hypertension/hypotension episodes are major risk factors for cardiovascular mortality with a high percentage of probable causality; however, clinicians are faced with a dilemma on how to evaluate blood pressure and treat this condition. PMID:27833921

Effects of imposed acid-base derangement on the cardiovascular effects and pharmacokinetics of bupivacaine and thiopental.

PubMed

Mather, Laurence E; Ladd, Leigh A; Copeland, Susan E; Chang, Dennis H-T

2004-06-01

By changing physicochemical properties such as effective lipophilicity, changes in blood pH could alter the distribution, elimination, and effects of weakly ionizing drugs. The authors examined the outcome of imposed acid-base derangement on cardiovascular effects and myocardial and whole body pharmacokinetics of bupivacaine, a weak base, and thiopental, a weak acid. Intravenous infusions of rac-bupivacaine HCl (37.5 mg) or rac-thiopental sodium (250 mg, subanesthetic dose) were administered over 3 min to previously instrumented conscious ewes with normal blood pH, acidemia imposed by lactic acid infusion, or alkalemia imposed by bicarbonate infusion. Hemodynamic and electrocardiographic effects were recorded; arterial and coronary sinus drug blood concentrations were analyzed by chiral high-performance liquid chromatography. Bupivacaine decreased myocardial contractility, coronary perfusion, heart rate, and cardiac output; however, cardiac output and stroke volume were not as affected by bupivacaine with acidemia. Thiopental decreased myocardial contractility and stroke volume and increased heart rate; acidemia enhanced the tachycardia and produced a greater decrease in stroke volume than with alkalemia. Taken as a whole, the cardiovascular changes were not systematically modified by acid-base derangement. Overall, the tissue distribution of bupivacaine was favored by alkalemia, but thiopental pharmacokinetics were essentially unaffected by acid-base derangement. Acid-base derangement did not influence the kinetics of either drug enantioselectively. At the doses used, the hemodynamic and electrocardiographic effects of bupivacaine and thiopental were not systematically modified by acid-base derangement, nor were there changes in regional or whole body pharmacokinetics of either drug that were clearly related to acid-base status.

Ex-vivo expanded umbilical cord blood stem cells retain capacity for myocardial regeneration.

PubMed

Schlechta, Bernhard; Wiedemann, Dominik; Kittinger, Clemens; Jandrositz, Anita; Bonaros, Nikolaos E; Huber, Johannes C; Preisegger, Karl-Heinz; Kocher, Alfred A

2010-01-01

Umbilical cord blood (UCB) is a source of human hematopoietic precursor cells (HPCs), a stem cell (SC) type that has been used in several trials for myocardial repair. A certain minimal number of cells is required for measurable regeneration and a major challenge of SC-based regenerative therapy constitutes ex-vivo expansion of the primitive cell compartment. The aim of this study was to investigate the ex-vivo expansion potential of UCB-derived HPCs and the ability of these expanded cells to migrate to the site of damage and improve ventricular function in a rodent model of myocardial infarction (MI). UCB-derived HPCs, defined by coexpression of CD133 and CD34, were expanded using various cytokine combinations. MI was induced by left anterior descending artery ligation in nude rats. Cells were injected intravenously 2 days after infarction. The combination of SC factor, thrombopoietin, flt3-ligand and interleukin-6 was found to be the most effective for inducing proliferation of HPCs. The migratory capacity of expanded HPCs was similar to that of non-expanded HPCs and improvement of ejection fraction was significant in both groups, with a relative increase of >60%. UCB-derived HPCs can be reproducibly expanded ex-vivo and retain their potential to improve cardiac function post-MI. (Circ J 2010; 74: 188 - 194).

Hemoglobin oxygen affinty in patients with low-output heart failure and cardiogenic shock after acute myocardial infaraction.

PubMed

Agostoni, A; Lotto, A; Stabilini, R; Bernasconi, C; Gerli, G; Gattinoni, L; Lapichino, G; Sslvadé, P

1975-06-01

The aim of this study was to determine the oxigen affinity actually present in vivo in blood from patients with acute myocardial infarction. Patients with uncomplicated acute myocardial infarction had normal value of P50 in vivo (partial pressure of oxygen at which 50 percent of the hemoglobin is saturated with oxygen at fixed levels of pHand PC02 present in vivo). Also the values of P50 in vivo of blood from patients with low cardiac output with mild or severe heart failured did not differ from the normal mean. This was the consequence of an increase of 2, 3-diphosphoglycerate levels (which reduces the oxygen affinity of hemoglobin) and of the immediate effect of alkalosis (Bohr effect). By contrast, the values of P50 in vivo were significantly increased in patients with cardiogenic shock. This could be ascribed to the state of acute acidiosis present in these patients. In these conditions the changes in the values of P50 in vivo play an important role in the oxygen delivery to the tissues. However, high values of P50 do not enhance oxygen delivery when a severe arterial hypoxemia (P02 smaller than 40-45 mm Hg) is also present.

Experimental lead poisoning in bald eagles

USGS Publications Warehouse

Pattee, H.; Wiemeyer, S.; Hoffman, P.; Carpenter, J.; Sileo, L.

1979-01-01

Captive, crippled bald eagles unsuitable for release were fed lead shot to determine diagnostic criteria for lead poisoning. The eagles were fluoroscoped and bled periodically to determine shot retention and blood delta--aminolevulinic acid dehydratase activity. Microscopic examination revealed renal tubular degeneration, arterial fibrinoid necrosis and myocardial necrosis. Acid-fast intra-nuclear inclusion bodies were not found in proximal convoluted tubule cells. Analyses of blood and toxicological data are not yet complete.

Experimental lead-shot poisoning in bald eagles

USGS Publications Warehouse

Pattee, O.H.; Wiemeyer, Stanley N.; Mulhern, B.M.; Sileo, L.; Carpenter, J.W.

1981-01-01

Captive, crippled bald eagles unsuitable for release were fed lead shot to determine diagnostic criteria for lead poisoning. The eagles were fluoroscoped and bled periodically to determine shot retention and blood delta--aminolevulinic acid dehydratase activity. Microscopic examination revealed renal tubular degeneration, arterial fibrinoid necrosis and myocardial necrosis. Acid-fast intra-nuclear inclusion bodies were not found in proximal convoluted tubule cells. Analyses of blood and toxicological data are not yet complete.

[Pharmacodynamics Study on Gualou Xiebai Dropping Pills and Its Medicinal Ingredients in Prescription].

PubMed

Yan, Hai-yan; Zou, Chun-cai; Wei, Mei-ling; Gao, Zheng-zheng; Yang, Yang

2015-03-01

To study the pharmacodynamics of Gualou Xiebai Dropping Pills and its medicinal ingredients in prescription on anti-myocardial ischemia. SPF Rats were divided randomly into eleven groups with ten rats in each group and half male and half female, the rats were respectively given the physiological saline(blank group and model group), Gualou, Xiebai, Gualou Xiebai Baijiutang (all equivalent to the crude herb of 22. 5 g/kg), Gualou Xiebai. Dropping Pills in the doses of 3. 75,11. 25,22. 5,33. 75 and 45 g/kg and Compound Danshen Drop Pills of 0. 085 g/kg by gavage one time a day for seven days. Except blank group, other rats were given by intraperitoneal injection of isoproterenol to establish myocardial ischemia models, changes of ST segments in ECG were observed in all groups, and the levels of SOD, NO, HDL-C, MDA, CAT, LDH and CK in blood plasma were detected, and the pathological changes of myocardial tissues were observed under light microscope by HE staining. Compared with model group, ST segments in ECG dropped markedly at different time point which included 10,11 and 12 (P <0. 05) in Gualou Xiebai Drop Pills groups of 22. 5, 33. 75 and 45 g/kg, time points were more than those of other groups. Gualou Xiebai Dropping Pills groups of 22. 5 and 33. 75 g/kg improved the levels of SOD, MDA, CAT, NO, HDL-C, LDH and CK in blood plasma in model rats significantly (P <0. 01 or P <0. 05). Gualou Xeibai Dropping Pills improved the pathological changes of myocardial tissues at all dosages. Gualou Xiebai Drop Pills can effectively restrain the acute myocardial ischemia induced by isoproterenol in rats, compared with Gualou, Xiebai or Gualou Xiebai Baijiutang, Gualou Xiebai Drop Pills obtains a favourable effect.

Cardiac troponin I degradation in serum of patients with hypertrophic obstructive cardiomyopathy undergoing percutaneous septal ablation.

PubMed

Madsen, Lene H; Lund, Terje; Grieg, Zanina; Nygaard, Ståle; Holmvang, Lene; Jurlander, Birgit; Grande, Peer; Christensen, Geir; Atar, Dan

2009-01-01

Troponin has become the most important marker for diagnosing acute myocardial infarction, yet knowledge is scarce regarding appearance of specific degradation fragments in the blood. We have recently described the appearance of intact cardiac troponin I (cTnI) and 7 degradation products in patients suffering from ST-elevation myocardial infarction (STEMI) using Western blot analysis. However, the time resolution in STEMI patients is hampered by the rather vague time point 'onset of pain'. We therefore sought to utilize a time-wise more reliable model of human myocardial necrosis: percutaneous transluminal septal myocardial ablation (PTSMA) of hypertrophic obstructive cardiomyopathy (HOCM). Here the iatrogenic induction of myocardial necrosis occurs in vivo, allowing us to investigate degradation of cTnI by the second. Blood samples were obtained from 8 patients with HOCM just prior to initiation of PTSMA and up to 50 h following the procedure. Western blot analysis was performed with subsequent analysis of relative intensities of the bands as compared to the degradation of cTnI in STEMI patients from the ASSENT-2 troponin substudy. We demonstrate intact cTnI and 9 degradation products [molecular weight (MW) 12.0-23.5 kDa]. The bands were comparable in MW to degradation fragments in STEMI. Their early rise in intensity, occurring within few minutes after the alcohol injection, emphasizes how susceptible troponin bands are to chemical/ischemic insults. Moreover, two additional bands were visible in the PTSMA population. This work describes the degradation products of troponin I in HOCM patients undergoing PTSMA. The detected bands appear fast and are similar to degradations following STEMI. This model contributes to our knowledge of the degradation patterns of troponin in disease states, and may thus play a role in the interpretation of elevated troponin levels. Copyright 2009 S. Karger AG, Basel.

Quantitative myocardial perfusion from static cardiac and dynamic arterial CT

NASA Astrophysics Data System (ADS)

Bindschadler, Michael; Branch, Kelley R.; Alessio, Adam M.

2018-05-01

Quantitative myocardial blood flow (MBF) estimation by dynamic contrast enhanced cardiac computed tomography (CT) requires multi-frame acquisition of contrast transit through the blood pool and myocardium to inform the arterial input and tissue response functions. Both the input and the tissue response functions for the entire myocardium are sampled with each acquisition. However, the long breath holds and frequent sampling can result in significant motion artifacts and relatively high radiation dose. To address these limitations, we propose and evaluate a new static cardiac and dynamic arterial (SCDA) quantitative MBF approach where (1) the input function is well sampled using either prediction from pre-scan timing bolus data or measured from dynamic thin slice ‘bolus tracking’ acquisitions, and (2) the whole-heart tissue response data is limited to one contrast enhanced CT acquisition. A perfusion model uses the dynamic arterial input function to generate a family of possible myocardial contrast enhancement curves corresponding to a range of MBF values. Combined with the timing of the single whole-heart acquisition, these curves generate a lookup table relating myocardial contrast enhancement to quantitative MBF. We tested the SCDA approach in 28 patients that underwent a full dynamic CT protocol both at rest and vasodilator stress conditions. Using measured input function plus single (enhanced CT only) or plus double (enhanced and contrast free baseline CT’s) myocardial acquisitions yielded MBF estimates with root mean square (RMS) error of 1.2 ml/min/g and 0.35 ml/min/g, and radiation dose reductions of 90% and 83%, respectively. The prediction of the input function based on timing bolus data and the static acquisition had an RMS error compared to the measured input function of 26.0% which led to MBF estimation errors greater than threefold higher than using the measured input function. SCDA presents a new, simplified approach for quantitative perfusion imaging with an acquisition strategy offering substantial radiation dose and computational complexity savings over dynamic CT.

Investigating the effect of remote ischaemic preconditioning on biomarkers of stress and injury-related signalling in patients having isolated coronary artery bypass grafting or aortic valve replacement using cardiopulmonary bypass: study protocol for a randomized controlled trial.

PubMed

Fiorentino, Francesca; Angelini, Gianni D; Suleiman, M-Saadeh; Rahman, Alima; Anderson, Jon; Bryan, Alan J; Culliford, Lucy A; Moscarelli, Marco; Punjabi, Prakash P; Reeves, Barnaby C

2015-04-23

Ischaemia-reperfusion injury occurs during heart surgery that uses cardiopulmonary bypass (CPB) and cardioplegic arrest. It is hypothesised that remote ischaemic preconditioning (RIPC) protects the heart against such injury. Despite the numerous studies investigating the protective effects of RIPC, there is still uncertainty about the interpretation of the findings as well as conflicting results between studies. The objective of this trial is to investigate the cardioprotective effect of RIPC in patients having coronary artery bypass grafting (CABG) or aortic valve replacement surgery. This will be achieved by estimating the effect of the intervention in the two groups of pathologies and by investigating the signalling mechanisms that may underpin the cardioprotective effect. A two-centre randomised controlled trial will be used to investigate the effects of RIPC in two pathologies: patients having isolated CABG and those having aortic valve replacement surgery (AVR) with CPB. Participants will be randomised to RIPC or control (sham RIPC), stratified by surgical stratum. The intervention will be delivered by a research nurse. Data will be collected by a research nurse blinded to the intervention. The patient and the theatre staff are also blinded to the allocation. Markers of myocardial injury and inflammation will be measured in myocardial biopsies and in blood samples at different times. This trial is designed to investigate whether RIPC will reduce myocardial injury and inflammation following heart surgery and whether there is a difference in effect between participants having CABG or AVR. This trial is a unique opportunity to study the mechanisms associated with RIPC using human myocardial tissue and blood, and to relate these to the extent of myocardial injury/protection. Current Controlled Trials ISRCTN33084113 (25 March 2013).

Low-Level Tragus Stimulation for the Treatment of Ischemia and Reperfusion Injury in Patients With ST-Segment Elevation Myocardial Infarction: A Proof-of-Concept Study.

PubMed

Yu, Lilei; Huang, Bing; Po, Sunny S; Tan, Tuantuan; Wang, Menglong; Zhou, Liping; Meng, Guannan; Yuan, Shenxu; Zhou, Xiaoya; Li, Xuefei; Wang, Zhuo; Wang, Songyun; Jiang, Hong

2017-08-14

The aim of this study was to investigate whether low-level tragus stimulation (LL-TS) treatment could reduce myocardial ischemia-reperfusion injury in patients with ST-segment elevation myocardial infarction (STEMI). The authors' previous studies suggested that LL-TS could reduce the size of myocardial injury induced by ischemia. Patients who presented with STEMI within 12 h of symptom onset, treated with primary percutaneous coronary intervention, were randomized to the LL-TS group (n = 47) or the control group (with sham stimulation [n = 48]). LL-TS, 50% lower than the electric current that slowed the sinus rate, was delivered to the right tragus once the patients arrived in the catheterization room and lasted for 2 h after balloon dilatation (reperfusion). All patients were followed for 7 days. The occurrence of reperfusion-related arrhythmia, blood levels of creatine kinase-MB, myoglobin, N-terminal pro-B-type natriuretic peptide and inflammatory markers, and echocardiographic characteristics were evaluated. The incidence of reperfusion-related ventricular arrhythmia during the first 24 h was significantly attenuated by LL-TS. In addition, the area under the curve for creatine kinase-MB and myoglobin over 72 h was smaller in the LL-TS group than the control group. Furthermore, blood levels of inflammatory markers were decreased by LL-TS. Cardiac function, as demonstrated by the level of N-terminal pro-B-type natriuretic peptide, the left ventricular ejection fraction, and the wall motion index, was markedly improved by LL-TS. LL-TS reduces myocardial ischemia-reperfusion injury in patients with STEMI. This proof-of-concept study raises the possibility that this noninvasive strategy may be used to treat patients with STEMI undergoing primary percutaneous coronary intervention. Copyright © 2017. Published by Elsevier Inc.

Effects of Nitroglycerin on Regional Myocardial Blood Flow in Coronary Artery Disease

PubMed Central

Horwitz, Lawrence D.; Gorlin, Richard; Taylor, Warren J.; Kemp, Harvey G.

1971-01-01

Regional myocardial blood flow before and after sublingual nitroglycerin was measured in 10 patients with coronary artery disease. During thoracotomy, 133Xe was injected directly into the subepicardium in diseased regions of the anterior left ventricular wall, and washout rates were recorded with a scintillation counter. All disappearance curves were closely approximated by two exponential decays analyzed as two parallel flow systems by the compartmental method. The appearance of a double exponential decay pattern in diseased regions suggests that the slow phase was associated with collateral blood flow, although nonhomogeneous myocardium-to-blood partition coefficients for xenon cannot be excluded. Nitroglycerin increased the rapid phase flow in 9 of 10 patients and the slow flow in 7 of 10 patients. Average flow increased in 9 of the 10 patients (P < 0.01). Mean rapid phase flow in the control state was 110 ml/100 g per min and after nitroglycerin increased to 132 ml/100 g per min (P < 0.01); slow phase flow increased from 12 ml/100 g per min to 15 ml/100 g per min (P < 0.05). It is concluded that, under these conditions, nitroglycerin improves perfusion in regions of diseased myocardium in patients with coronary artery disease. PMID:4999635

Direct parametric reconstruction in dynamic PET myocardial perfusion imaging: in vivo studies.

PubMed

Petibon, Yoann; Rakvongthai, Yothin; El Fakhri, Georges; Ouyang, Jinsong

2017-05-07

Dynamic PET myocardial perfusion imaging (MPI) used in conjunction with tracer kinetic modeling enables the quantification of absolute myocardial blood flow (MBF). However, MBF maps computed using the traditional indirect method (i.e. post-reconstruction voxel-wise fitting of kinetic model to PET time-activity-curves-TACs) suffer from poor signal-to-noise ratio (SNR). Direct reconstruction of kinetic parameters from raw PET projection data has been shown to offer parametric images with higher SNR compared to the indirect method. The aim of this study was to extend and evaluate the performance of a direct parametric reconstruction method using in vivo dynamic PET MPI data for the purpose of quantifying MBF. Dynamic PET MPI studies were performed on two healthy pigs using a Siemens Biograph mMR scanner. List-mode PET data for each animal were acquired following a bolus injection of ~7-8 mCi of 18 F-flurpiridaz, a myocardial perfusion agent. Fully-3D dynamic PET sinograms were obtained by sorting the coincidence events into 16 temporal frames covering ~5 min after radiotracer administration. Additionally, eight independent noise realizations of both scans-each containing 1/8th of the total number of events-were generated from the original list-mode data. Dynamic sinograms were then used to compute parametric maps using the conventional indirect method and the proposed direct method. For both methods, a one-tissue compartment model accounting for spillover from the left and right ventricle blood-pools was used to describe the kinetics of 18 F-flurpiridaz. An image-derived arterial input function obtained from a TAC taken in the left ventricle cavity was used for tracer kinetic analysis. For the indirect method, frame-by-frame images were estimated using two fully-3D reconstruction techniques: the standard ordered subset expectation maximization (OSEM) reconstruction algorithm on one side, and the one-step late maximum a posteriori (OSL-MAP) algorithm on the other side, which incorporates a quadratic penalty function. The parametric images were then calculated using voxel-wise weighted least-square fitting of the reconstructed myocardial PET TACs. For the direct method, parametric images were estimated directly from the dynamic PET sinograms using a maximum a posteriori (MAP) parametric reconstruction algorithm which optimizes an objective function comprised of the Poisson log-likelihood term, the kinetic model and a quadratic penalty function. Maximization of the objective function with respect to each set of parameters was achieved using a preconditioned conjugate gradient algorithm with a specifically developed pre-conditioner. The performance of the direct method was evaluated by comparing voxel- and segment-wise estimates of [Formula: see text], the tracer transport rate (ml · min -1 · ml -1 ), to those obtained using the indirect method applied to both OSEM and OSL-MAP dynamic reconstructions. The proposed direct reconstruction method produced [Formula: see text] maps with visibly lower noise than the indirect method based on OSEM and OSL-MAP reconstructions. At normal count levels, the direct method was shown to outperform the indirect method based on OSL-MAP in the sense that at matched level of bias, reduced regional noise levels were obtained. At lower count levels, the direct method produced [Formula: see text] estimates with significantly lower standard deviation across noise realizations than the indirect method based on OSL-MAP at matched bias level. In all cases, the direct method yielded lower noise and standard deviation than the indirect method based on OSEM. Overall, the proposed direct reconstruction offered a better bias-variance tradeoff than the indirect method applied to either OSEM and OSL-MAP. Direct parametric reconstruction as applied to in vivo dynamic PET MPI data is therefore a promising method for producing MBF maps with lower variance.

Direct parametric reconstruction in dynamic PET myocardial perfusion imaging: in-vivo studies

PubMed Central

Petibon, Yoann; Rakvongthai, Yothin; Fakhri, Georges El; Ouyang, Jinsong

2017-01-01

Dynamic PET myocardial perfusion imaging (MPI) used in conjunction with tracer kinetic modeling enables the quantification of absolute myocardial blood flow (MBF). However, MBF maps computed using the traditional indirect method (i.e. post-reconstruction voxel-wise fitting of kinetic model to PET time-activity-curves -TACs) suffer from poor signal-to-noise ratio (SNR). Direct reconstruction of kinetic parameters from raw PET projection data has been shown to offer parametric images with higher SNR compared to the indirect method. The aim of this study was to extend and evaluate the performance of a direct parametric reconstruction method using in-vivo dynamic PET MPI data for the purpose of quantifying MBF. Dynamic PET MPI studies were performed on two healthy pigs using a Siemens Biograph mMR scanner. List-mode PET data for each animal were acquired following a bolus injection of ~7-8 mCi of 18F-flurpiridaz, a myocardial perfusion agent. Fully-3D dynamic PET sinograms were obtained by sorting the coincidence events into 16 temporal frames covering ~5 min after radiotracer administration. Additionally, eight independent noise realizations of both scans - each containing 1/8th of the total number of events - were generated from the original list-mode data. Dynamic sinograms were then used to compute parametric maps using the conventional indirect method and the proposed direct method. For both methods, a one-tissue compartment model accounting for spillover from the left and right ventricle blood-pools was used to describe the kinetics of 18F-flurpiridaz. An image-derived arterial input function obtained from a TAC taken in the left ventricle cavity was used for tracer kinetic analysis. For the indirect method, frame-by-frame images were estimated using two fully-3D reconstruction techniques: the standard Ordered Subset Expectation Maximization (OSEM) reconstruction algorithm on one side, and the One-Step Late Maximum a Posteriori (OSL-MAP) algorithm on the other side, which incorporates a quadratic penalty function. The parametric images were then calculated using voxel-wise weighted least-square fitting of the reconstructed myocardial PET TACs. For the direct method, parametric images were estimated directly from the dynamic PET sinograms using a maximum a posteriori (MAP) parametric reconstruction algorithm which optimizes an objective function comprised of the Poisson log-likelihood term, the kinetic model and a quadratic penalty function. Maximization of the objective function with respect to each set of parameters was achieved using a preconditioned conjugate gradient algorithm with a specifically developed pre-conditioner. The performance of the direct method was evaluated by comparing voxel- and segment-wise estimates of K1, the tracer transport rate (mL.min−1.mL−1), to those obtained using the indirect method applied to both OSEM and OSL-MAP dynamic reconstructions. The proposed direct reconstruction method produced K1 maps with visibly lower noise than the indirect method based on OSEM and OSL-MAP reconstructions. At normal count levels, the direct method was shown to outperform the indirect method based on OSL-MAP in the sense that at matched level of bias, reduced regional noise levels were obtained. At lower count levels, the direct method produced K1 estimates with significantly lower standard deviation across noise realizations than the indirect method based on OSL-MAP at matched bias level. In all cases, the direct method yielded lower noise and standard deviation than the indirect method based on OSEM. Overall, the proposed direct reconstruction offered a better bias-variance tradeoff than the indirect method applied to either OSEM and OSL-MAP. Direct parametric reconstruction as applied to in-vivo dynamic PET MPI data is therefore a promising method for producing MBF maps with lower variance. PMID:28379843

Direct parametric reconstruction in dynamic PET myocardial perfusion imaging: in vivo studies

NASA Astrophysics Data System (ADS)

Petibon, Yoann; Rakvongthai, Yothin; El Fakhri, Georges; Ouyang, Jinsong

2017-05-01

Dynamic PET myocardial perfusion imaging (MPI) used in conjunction with tracer kinetic modeling enables the quantification of absolute myocardial blood flow (MBF). However, MBF maps computed using the traditional indirect method (i.e. post-reconstruction voxel-wise fitting of kinetic model to PET time-activity-curves-TACs) suffer from poor signal-to-noise ratio (SNR). Direct reconstruction of kinetic parameters from raw PET projection data has been shown to offer parametric images with higher SNR compared to the indirect method. The aim of this study was to extend and evaluate the performance of a direct parametric reconstruction method using in vivo dynamic PET MPI data for the purpose of quantifying MBF. Dynamic PET MPI studies were performed on two healthy pigs using a Siemens Biograph mMR scanner. List-mode PET data for each animal were acquired following a bolus injection of ~7-8 mCi of 18F-flurpiridaz, a myocardial perfusion agent. Fully-3D dynamic PET sinograms were obtained by sorting the coincidence events into 16 temporal frames covering ~5 min after radiotracer administration. Additionally, eight independent noise realizations of both scans—each containing 1/8th of the total number of events—were generated from the original list-mode data. Dynamic sinograms were then used to compute parametric maps using the conventional indirect method and the proposed direct method. For both methods, a one-tissue compartment model accounting for spillover from the left and right ventricle blood-pools was used to describe the kinetics of 18F-flurpiridaz. An image-derived arterial input function obtained from a TAC taken in the left ventricle cavity was used for tracer kinetic analysis. For the indirect method, frame-by-frame images were estimated using two fully-3D reconstruction techniques: the standard ordered subset expectation maximization (OSEM) reconstruction algorithm on one side, and the one-step late maximum a posteriori (OSL-MAP) algorithm on the other side, which incorporates a quadratic penalty function. The parametric images were then calculated using voxel-wise weighted least-square fitting of the reconstructed myocardial PET TACs. For the direct method, parametric images were estimated directly from the dynamic PET sinograms using a maximum a posteriori (MAP) parametric reconstruction algorithm which optimizes an objective function comprised of the Poisson log-likelihood term, the kinetic model and a quadratic penalty function. Maximization of the objective function with respect to each set of parameters was achieved using a preconditioned conjugate gradient algorithm with a specifically developed pre-conditioner. The performance of the direct method was evaluated by comparing voxel- and segment-wise estimates of {{K}1} , the tracer transport rate (ml · min-1 · ml-1), to those obtained using the indirect method applied to both OSEM and OSL-MAP dynamic reconstructions. The proposed direct reconstruction method produced {{K}1} maps with visibly lower noise than the indirect method based on OSEM and OSL-MAP reconstructions. At normal count levels, the direct method was shown to outperform the indirect method based on OSL-MAP in the sense that at matched level of bias, reduced regional noise levels were obtained. At lower count levels, the direct method produced {{K}1} estimates with significantly lower standard deviation across noise realizations than the indirect method based on OSL-MAP at matched bias level. In all cases, the direct method yielded lower noise and standard deviation than the indirect method based on OSEM. Overall, the proposed direct reconstruction offered a better bias-variance tradeoff than the indirect method applied to either OSEM and OSL-MAP. Direct parametric reconstruction as applied to in vivo dynamic PET MPI data is therefore a promising method for producing MBF maps with lower variance.

Dark blood late enhancement imaging.

PubMed

Kellman, Peter; Xue, Hui; Olivieri, Laura J; Cross, Russell R; Grant, Elena K; Fontana, Marianna; Ugander, Martin; Moon, James C; Hansen, Michael S

2016-11-07

Bright blood late gadolinium enhancement (LGE) imaging typically achieves excellent contrast between infarcted and normal myocardium. However, the contrast between the myocardial infarction (MI) and the blood pool is frequently suboptimal. A large fraction of infarctions caused by coronary artery disease are sub-endocardial and thus adjacent to the blood pool. It is not infrequent that sub-endocardial MIs are difficult to detect or clearly delineate. In this present work, an inversion recovery (IR) T2 preparation was combined with single shot steady state free precession imaging and respiratory motion corrected averaging to achieve dark blood LGE images with good signal to noise ratio while maintaining the desired spatial and temporal resolution. In this manner, imaging was conducted free-breathing, which has benefits for image quality, patient comfort, and clinical workflow in both adults and children. Furthermore, by using a phase sensitive inversion recovery reconstruction the blood signal may be made darker than the myocardium (i.e., negative signal values) thereby providing contrast between the blood and both the MI and remote myocardium. In the proposed approach, a single T1-map scout was used to measure the myocardial and blood T1 using a MOdified Look-Locker Inversion recovery (MOLLI) protocol and all protocol parameters were automatically calculated from these values within the sequence thereby simplifying the user interface. The contrast to noise ratio (CNR) between MI and remote myocardium was measured in n = 30 subjects with subendocardial MI using both bright blood and dark blood protocols. The CNR for the dark blood protocol had a 13 % loss compared to the bright blood protocol. The CNR between the MI and blood pool was positive for all dark blood cases, and was negative in 63 % of the bright blood cases. The conspicuity of subendocardial fibrosis and MI was greatly improved by dark blood (DB) PSIR as well as the delineation of the subendocardial border. Free-breathing, dark blood PSIR LGE imaging was demonstrated to improve the visualization of subendocardial MI and fibrosis in cases with low contrast with adjacent blood pool. The proposed method also improves visualization of thin walled fibrous structures such as atrial walls and valves, as well as papillary muscles.

Benazepril plus amlodipine or hydrochlorothiazide for hypertension in high-risk patients.

PubMed

Jamerson, Kenneth; Weber, Michael A; Bakris, George L; Dahlöf, Björn; Pitt, Bertram; Shi, Victor; Hester, Allen; Gupte, Jitendra; Gatlin, Marjorie; Velazquez, Eric J

2008-12-04

The optimal combination drug therapy for hypertension is not established, although current U.S. guidelines recommend inclusion of a diuretic. We hypothesized that treatment with the combination of an angiotensin-converting-enzyme (ACE) inhibitor and a dihydropyridine calcium-channel blocker would be more effective in reducing the rate of cardiovascular events than treatment with an ACE inhibitor plus a thiazide diuretic. In a randomized, double-blind trial, we assigned 11,506 patients with hypertension who were at high risk for cardiovascular events to receive treatment with either benazepril plus amlodipine or benazepril plus hydrochlorothiazide. The primary end point was the composite of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, hospitalization for angina, resuscitation after sudden cardiac arrest, and coronary revascularization. The baseline characteristics of the two groups were similar. The trial was terminated early after a mean follow-up of 36 months, when the boundary of the prespecified stopping rule was exceeded. Mean blood pressures after dose adjustment were 131.6/73.3 mm Hg in the benazepril-amlodipine group and 132.5/74.4 mm Hg in the benazepril-hydrochlorothiazide group. There were 552 primary-outcome events in the benazepril-amlodipine group (9.6%) and 679 in the benazepril-hydrochlorothiazide group (11.8%), representing an absolute risk reduction with benazepril-amlodipine therapy of 2.2% and a relative risk reduction of 19.6% (hazard ratio, 0.80, 95% confidence interval [CI], 0.72 to 0.90; P<0.001). For the secondary end point of death from cardiovascular causes, nonfatal myocardial infarction, and nonfatal stroke, the hazard ratio was 0.79 (95% CI, 0.67 to 0.92; P=0.002). Rates of adverse events were consistent with those observed from clinical experience with the study drugs. The benazepril-amlodipine combination was superior to the benazepril-hydrochlorothiazide combination in reducing cardiovascular events in patients with hypertension who were at high risk for such events. (ClinicalTrials.gov number, NCT00170950.) 2008 Massachusetts Medical Society

Left atrial enlargement increases the risk of major adverse cardiac events independent of coronary vasodilator capacity.

PubMed

Koh, Angela S; Murthy, Venkatesh L; Sitek, Arkadiusz; Gayed, Peter; Bruyere, John; Wu, Justina; Di Carli, Marcelo F; Dorbala, Sharmila

2015-09-01

Longstanding uncontrolled atherogenic risk factors may contribute to left atrial (LA) hypertension, LA enlargement (LAE) and coronary vascular dysfunction. Together they may better identify risk of major adverse cardiac events (MACE). The aim of this study was to test the hypothesis that chronic LA hypertension as assessed by LAE modifies the relationship between coronary vascular function and MACE. In 508 unselected subjects with a normal clinical (82)Rb PET/CT, ejection fraction ≥40 %, no prior coronary artery disease, valve disease or atrial fibrillation, LAE was determined based on LA volumes estimated from the hybrid perfusion and CT transmission scan images and indexed to body surface area. Absolute myocardial blood flow and global coronary flow reserve (CFR) were calculated. Subjects were systematically followed-up for the primary end-point - MACE - a composite of all-cause death, myocardial infarction, hospitalization for heart failure, stroke, coronary artery disease progression or revascularization. During a median follow-up of 862 days, 65 of the subjects experienced a composite event. Compared with subjects with normal LA size, subjects with LAE showed significantly lower CFR (2.25 ± 0.83 vs. 1.95 ± 0.80, p = 0.01). LAE independently and incrementally predicted MACE even after accounting for clinical risk factors, medication use, stress left ventricular ejection fraction, stress left ventricular end-diastolic volume index and CFR (chi-squared statistic increased from 30.9 to 48.3; p = 0.001). Among subjects with normal CFR, those with LAE had significantly worse event-free survival (risk adjusted HR 5.4, 95 % CI 2.3 - 12.8, p < 0.0001). LAE and reduced CFR are related but distinct cardiovascular adaptations to atherogenic risk factors. LAE is a risk marker for MACE independent of clinical factors and left ventricular volumes; individuals with LAE may be at risk of MACE despite normal coronary vascular function.

How Should Blood Glucose Meter System Analytical Performance Be Assessed?

PubMed

Simmons, David A

2015-08-31

Blood glucose meter system analytical performance is assessed by comparing pairs of meter system and reference instrument blood glucose measurements measured over time and across a broad array of glucose values. Consequently, no single, complete, and ideal parameter can fully describe the difference between meter system and reference results. Instead, a number of assessment tools, both graphical (eg, regression plots, modified Bland-Altman plots, and error grid analysis) and tabular (eg, International Organization for Standardization guidelines, mean absolute difference, and mean absolute relative difference) have been developed to evaluate meter system performance. The strengths and weaknesses of these methods of presenting meter system performance data, including a new method known as Radar Plots, are described here. © 2015 Diabetes Technology Society.

Association between control to target blood pressures and healthy lifestyle factors among Japanese hypertensive patients: longitudinal data analysis from Fukushima Research of Hypertension (FRESH).

PubMed

Yokokawa, Hirohide; Goto, Aya; Sanada, Hironobu; Watanabe, Tsuyoshi; Felder, Robin A; Jose, Pedro A; Yasumura, Seiji

2014-01-01

To determine success rates in controlling target blood pressures longitudinally by measuring several factors, including lifestyle characteristics associated with uncontrolled blood pressures for target treatment goals. This prospective observational cohort study (September 2008-September 2010) collected information on blood pressure control status and healthy lifestyle factors listed in Breslow's seven health practices through medical records and self-administered questionnaires from 884 of the 1264 Japanese hypertensive patients initially registered in the FRESH study. Multivariate analysis adjusted for associated factors was performed to estimate the association between lifestyle change and "uncontrolled blood pressures" at the final follow-up survey. Median age and proportion of men were 73 years and 39.1%, respectively. All survey failure rates were 37.6% among non-elderly patients (<65 years of age) without diabetes mellitus or chronic kidney disease, and 35.0% among patients with these diseases or myocardial infarction. Maintaining a healthy lifestyle was a protective factor against uncontrolled blood pressures in multivariate analysis. Obesity and smoking status were associated with uncontrolled blood pressures, and exercise frequency was borderline significance. The number of participants with healthy responses for these factors remained relatively low during follow up. Our study revealed low rates of controlled blood pressures, especially in non-elderly patients without diabetes mellitus or chronic kidney disease, and patients with these diseases or myocardial infarction. Our data indicate the need to maintain a healthy lifestyle, in particular, ideal body weight and adequate exercise frequency, for better hypertension management according to treatment guidelines. Copyright © 2013 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

Omega-6 and omega-3 polyunsaturated fatty acid levels are reduced in whole blood of Italian patients with a recent myocardial infarction: the AGE-IM study.

PubMed

Marangoni, Franca; Novo, Giuseppina; Perna, Giampiero; Perrone Filardi, Pasquale; Pirelli, Salvatore; Ceroti, Marco; Querci, Andrea; Poli, Andrea

2014-02-01

The relationship between whole blood fatty acids and myocardial infarction (MI) risk has not been analyzed in detail, especially in Mediterranean countries. The AGE-IM (Acidi Grassi Essenziali e Infarto Miocardico) study was planned to examine the relationships between MI, whole blood fatty acids and the diet in an Italian cohort. 119 Patients with a recent MI and 103 control subjects were enrolled in the study. The whole blood fatty acid composition was determined; information on anthropometrics, biochemical parameters and blood pressure values were also obtained. Diet composition was assessed using a validated food frequency questionnaire from 86 cases and 72 controls. Total PUFA, omega-6 and omega-3 PUFA (as percentage of whole blood fatty acids) were significantly lower in MI patients than in matched controls, whereas saturated and monounsaturated fatty acids were higher in cases. MI infarction risk significantly and steadily decreased with increasing levels of total PUFA (OR: 0.14) and of total omega-6 and omega-3 (OR: 0.15 and 0.37, respectively). No correlation was identified between dietary fats and MI risk or between whole blood fatty acid levels and dietary nutrients and fats. Percentage levels of total PUFA, total omega-3 PUFA and total omega-6 PUFA are lower in MI patients than in matched control subjects in the AGE-IM cohort. These data support a favorable association not only of whole blood percentage levels of total omega-3, but also of total omega-6, with cardiovascular risk. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

New evidence on the importance of the renin-angiotensin system in the treatment of higher-risk patients with hypertension.

PubMed

Sleight, Peter; Yusuf, Salim

2003-09-01

We reviewed the drug treatment of hypertension in the light of recent trials. beta-Blockers and diuretics clearly reduce mortality, strokes, and coronary heart disease (CHD) in hypertension. Recent trials assessed whether newer agents that block the renin-angiotensin-aldosterone system, or calcium blockers, offer any additional advantage, or have benefits in high-risk individuals with conventionally 'normal' blood pressure. The recent ALLHAT study claimed no differences in CHD or mortality when chlorthalidone, amlodipine, and lisinopril were compared. However, the decrease in blood pressure was not the same with the three agents, and a substantial proportion of patients enrolled did not have clinical disease. In contrast, the LIFE study (comparing losartan and a beta-blocker) and the ANBP-2 study [comparing angiotensin-converting enzyme (ACE) inhibition and a diuretic] reduced blood pressure similarly, yet demonstrated benefits in favour of angiotensin II type 1 receptor blockers (ARBs) and ACE inhibitors. Other trials indicated similar advantages of ACE inhibitors or ARBs in patients with diabetic nephropathy. Among high-risk patients with initial blood pressure in the 'normal' range, ACE inhibitors significantly reduce clinical events (mortality, strokes, and myocardial infarction), despite modest decreases in blood pressure, suggesting that additional mechanisms are responsible. Recent results of the Prospective Studies Collaboration show lower risk, even in the normal blood pressure range; high-risk patients will benefit further from ACE inhibitors and ARBs (and beta-blockers after myocardial infarction). Data for other blood pressure decreasing agents are unavailable in such populations. We conclude that blood pressure decreasing per se is of clinical benefit, but drugs that block the renin-angiotensin system offer additional advantages. Drug choice is best determined by the patient's clinical condition.

Protective effect of N-acetylcysteine activated carbon release microcapsule on myocardial ischemia-reperfusion injury in rats

PubMed Central

Cai, Zhaobin; Shi, Tingting; Zhuang, Rangxiao; Fang, Hongying; Jiang, Xiaojie; Shao, Yidan; Zhou, Hongping

2018-01-01

With the development of science and technology, and development of artery bypass, methods such as cardiopulmonary cerebral resuscitation have been practiced in recent years. Despite this, some methods fail to promote or recover the function of tissues and organs, and in some cases, may aggravate dysfunction and structural damage to tissues. The latter is typical of ischemia-reperfusion (IR) injury. Lipid peroxidation mediated by free radicals is an important process of myocardial IR injury. Myocardial IR has been demonstrated to induce the formation of large numbers of free radicals in rats, which promotes the peroxidation of lipids within unsaturated fatty acids in the myocardial cell membrane. Markers of lipid peroxidation include malondialdehyde, superoxide dismutase and lactic dehydrogenase. Recent studies have demonstrated that N-acetylcysteine (NAC) is able to dilate blood vessels, prevent oxidative damage, improve immunity, inhibit apoptosis and the inflammatory response and promote glutathione synthesis in cells. NAC also improves the systolic function of myocardial cells and cardiac function, prevents myocardial apoptosis, protects ventricular remodeling and vascular remodeling, reduces opiomelanocortin levels in the serum and increases the content of nitric oxide in the serum, thus improving vascular endothelial function. Therefore, NAC has potent pharmacological activity; however, the relatively fast metabolism of NAC, along with its large clinical dose and low bioavailability, limit its applications. The present study combined NAC with medicinal activated carbons, and prepared N-acetylcysteine activated carbon sustained-release microcapsules (ACNACs) to overcome the limitations of NAC. It was demonstrated that ACNACs exerted greater effective protective effects than NAC alone on myocardial IR injury in rats. PMID:29434769

Effects on infarct size and left ventricular function of early intravenous injection of anistreplase in acute myocardial infarction. The APSIM Study Investigators.

PubMed

Bassand, J P; Bernard, Y; Lusson, J R; Machecourt, J; Cassagnes, J; Borel, E

1990-03-01

A total of 231 patients suffering from a first acute myocardial infarction were randomly allocated within 4 hours following the onset of symptoms either to anistreplase or anisoylated plasminogen streptokinase activator complex (APSAC), 30 U over 5 minutes, or to conventional heparin therapy, 5000 IU in bolus injection. Heparin was reintroduced in both groups 4 h after initial therapy at a dosage of 500 IU/kg per day. A total of 112 patients received anistreplase and 119 received heparin within a mean period of 188 +/- 62 min following the onset of symptoms. Infarct size was estimated from single photon emission computerized tomography and expressed in percentage of the total myocardial volume. The patency rate of the infarct-related artery was 77% in the anistreplase group and 36% in the heparin group (p less than 0.001). Left ventricular ejection fraction determined from contrast angiography was significantly higher in the anistreplase group than in the heparin group (6 absolute percentage point difference). A significant 31% reduction in infarct size was found in the anistreplase group (33% for the anterior wall infarction subgroup [p less than 0.05] and 16% for the inferior wall infarction subgroup, NS). A close inverse relation was found between the values of left ventricular ejection fraction and infarct size (r = -.73, p less than 0.01). In conclusion, early infusion of anistreplase in acute myocardial infarction produced a high early patency rate, a significant limitation of infarct size, and a significant preservation of left ventricular systolic function, mainly in the anterior wall infarctions.

Risk of acute myocardial infarction after the death of a significant person in one's life: the Determinants of Myocardial Infarction Onset Study.

PubMed

Mostofsky, Elizabeth; Maclure, Malcolm; Sherwood, Jane B; Tofler, Geoffrey H; Muller, James E; Mittleman, Murray A

2012-01-24

Acute psychological stress is associated with an abrupt increase in the risk of cardiovascular events. Intense grief in the days after the death of a significant person may trigger the onset of acute myocardial infarction (MI), but this relationship has not been systematically studied. We conducted a case-crossover analysis of 1985 participants from the multicenter Determinants of Myocardial Infarction Onset Study interviewed during index hospitalization for an acute MI between 1989 and 1994. We compared the observed number of deaths in the days preceding MI symptom onset with its expected frequency based on each patient's control information, defined as the occurrence of deaths in the period from 1 to 6 months before infarction. Among the 1985 subjects, 270 (13.6%) experienced the loss of a significant person in the prior 6 months, including 19 within 1 day of their MI. The incidence rate of acute MI onset was elevated 21.1-fold (95% confidence interval, 13.1-34.1) within 24 hours of the death of a significant person and declined steadily on each subsequent day. The absolute risk of MI within 1 week of the death of a significant person is 1 excess MI per 1394 exposed individuals at low (5%) 10-year MI risk and 1 per 320 among individuals at high (20%) 10-year risk. Grief over the death of a significant person was associated with an acutely increased risk of MI in the subsequent days. The impact may be greatest among individuals at high cardiovascular risk.

Ga-67 citrate myocardial uptake in a patient with AIDS, toxoplasmosis, and myocarditis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Memel, D.S.; DeRogatis, A.J.; William, D.C.

1991-05-01

A 38-year-old man with AIDS presented with fever of unknown origin, splenomegaly, anemia, and thrombocytopenia. Admission laboratory data revealed a positive toxoplasmosis titer in the blood. The initial chest x-ray showed small bilateral pleural effusions, a normal cardiac silhouette, no infiltrates, and no interstitial edema. Ga-67 imaging revealed markedly abnormal uptake in the myocardium. A diagnosis of toxoplasmosis myocarditis was made based on laboratory and imaging data. The patient was treated for toxoplasmosis. No myocardial uptake of tracer was demonstrated on a follow-up Ga-67 scan, performed after completion of treatment for toxoplasmosis.

Impact of motion and partial volume effects correction on PET myocardial perfusion imaging using simultaneous PET-MR

NASA Astrophysics Data System (ADS)

Petibon, Yoann; Guehl, Nicolas J.; Reese, Timothy G.; Ebrahimi, Behzad; Normandin, Marc D.; Shoup, Timothy M.; Alpert, Nathaniel M.; El Fakhri, Georges; Ouyang, Jinsong

2017-01-01

PET is an established modality for myocardial perfusion imaging (MPI) which enables quantification of absolute myocardial blood flow (MBF) using dynamic imaging and kinetic modeling. However, heart motion and partial volume effects (PVE) significantly limit the spatial resolution and quantitative accuracy of PET MPI. Simultaneous PET-MR offers a solution to the motion problem in PET by enabling MR-based motion correction of PET data. The aim of this study was to develop a motion and PVE correction methodology for PET MPI using simultaneous PET-MR, and to assess its impact on both static and dynamic PET MPI using 18F-Flurpiridaz, a novel 18F-labeled perfusion tracer. Two dynamic 18F-Flurpiridaz MPI scans were performed on healthy pigs using a PET-MR scanner. Cardiac motion was tracked using a dedicated tagged-MRI (tMR) sequence. Motion fields were estimated using non-rigid registration of tMR images and used to calculate motion-dependent attenuation maps. Motion correction of PET data was achieved by incorporating tMR-based motion fields and motion-dependent attenuation coefficients into image reconstruction. Dynamic and static PET datasets were created for each scan. Each dataset was reconstructed as (i) Ungated, (ii) Gated (end-diastolic phase), and (iii) Motion-Corrected (MoCo), each without and with point spread function (PSF) modeling for PVE correction. Myocardium-to-blood concentration ratios (MBR) and apparent wall thickness were calculated to assess image quality for static MPI. For dynamic MPI, segment- and voxel-wise MBF values were estimated by non-linear fitting of a 2-tissue compartment model to tissue time-activity-curves. MoCo and Gating respectively decreased mean apparent wall thickness by 15.1% and 14.4% and increased MBR by 20.3% and 13.6% compared to Ungated images (P  <  0.01). Combined motion and PSF correction (MoCo-PSF) yielded 30.9% (15.7%) lower wall thickness and 82.2% (20.5%) higher MBR compared to Ungated data reconstructed without (with) PSF modeling (P  <  0.01). For dynamic PET, mean MBF across all segments were comparable for MoCo (0.72  ±  0.21 ml/min/ml) and Gating (0.69  ±  0.18 ml/min/ml). Ungated data yielded significantly lower mean MBF (0.59  ±  0.16 ml/min/ml). Mean MBF for MoCo-PSF was 0.80  ±  0.22 ml/min/ml, which was 37.9% (25.0%) higher than that obtained from Ungated data without (with) PSF correction (P  <  0.01). The developed methodology holds promise to improve the image quality and sensitivity of PET MPI studies performed using PET-MR.

Cardiovascular effects of sildenafil citrate and recommendations for its use.

PubMed

Kloner, R A; Zusman, R M

1999-09-09

Sildenafil citrate is the first orally active therapy proved to be effective and safe treatment for erectile dysfunction (ED). Because men with cardiovascular disease are at increased risk of developing ED, and because ED and cardiovascular disease share important risk factors, attention has focused recently on the use of sildenafil in these men. When used in combination with nitroglycerin and other nitric oxide (NO) donors, sildenafil may potentiate major drops in blood pressure. Use of nitrate antianginal agents are an absolute contraindication to sildenafil use. In normotensive men and in men receiving antihypertensive medications evaluated in Phase II/III clinical trials, sildenafil use at the recommended doses (25-100 mg 1 hour before sexual intercourse and no more than once daily) was associated with modest, transient reductions in blood pressure and negligible effects on heart rate. In a more recent study, sildenafil was well tolerated in patients receiving antihypertensive medications and was not associated with major decreases in blood pressure. From the time of its approval in the United States in March 1998 through mid-November 1998, with approximately 6 million prescriptions written, 130 deaths were reported by the US Food and Drug Administration (FDA). Seventy-seven of the men who died had documented cardiovascular events. Sixteen men took or were administered nitroglycerin or an organic nitrate; 3 others had nitroglycerin in their possession. Physician prescribing guidelines issued by the American College of Cardiology/American Heart Association (ACC/AHA) recommend caution when prescribing sildenafil to men with certain cardiovascular conditions, liver or kidney disease, and to those taking medications that may prolong sildenafil's half-life (e.g., erythromycin or cimetidine). Those with known or suspected coronary artery disease may benefit from an exercise test to determine whether resumption of sexual activity with use of sildenafil is likely to be associated with an increased risk of myocardial ischemia.

Regulation of coronary blood flow during exercise.

PubMed

Duncker, Dirk J; Bache, Robert J

2008-07-01

Exercise is the most important physiological stimulus for increased myocardial oxygen demand. The requirement of exercising muscle for increased blood flow necessitates an increase in cardiac output that results in increases in the three main determinants of myocardial oxygen demand: heart rate, myocardial contractility, and ventricular work. The approximately sixfold increase in oxygen demands of the left ventricle during heavy exercise is met principally by augmenting coronary blood flow (~5-fold), as hemoglobin concentration and oxygen extraction (which is already 70-80% at rest) increase only modestly in most species. In contrast, in the right ventricle, oxygen extraction is lower at rest and increases substantially during exercise, similar to skeletal muscle, suggesting fundamental differences in blood flow regulation between these two cardiac chambers. The increase in heart rate also increases the relative time spent in systole, thereby increasing the net extravascular compressive forces acting on the microvasculature within the wall of the left ventricle, in particular in its subendocardial layers. Hence, appropriate adjustment of coronary vascular resistance is critical for the cardiac response to exercise. Coronary resistance vessel tone results from the culmination of myriad vasodilator and vasoconstrictors influences, including neurohormones and endothelial and myocardial factors. Unraveling of the integrative mechanisms controlling coronary vasodilation in response to exercise has been difficult, in part due to the redundancies in coronary vasomotor control and differences between animal species. Exercise training is associated with adaptations in the coronary microvasculature including increased arteriolar densities and/or diameters, which provide a morphometric basis for the observed increase in peak coronary blood flow rates in exercise-trained animals. In larger animals trained by treadmill exercise, the formation of new capillaries maintains capillary density at a level commensurate with the degree of exercise-induced physiological myocardial hypertrophy. Nevertheless, training alters the distribution of coronary vascular resistance so that more capillaries are recruited, resulting in an increase in the permeability-surface area product without a change in capillary numerical density. Maintenance of alpha- and ss-adrenergic tone in the presence of lower circulating catecholamine levels appears to be due to increased receptor responsiveness to adrenergic stimulation. Exercise training also alters local control of coronary resistance vessels. Thus arterioles exhibit increased myogenic tone, likely due to a calcium-dependent protein kinase C signaling-mediated alteration in voltage-gated calcium channel activity in response to stretch. Conversely, training augments endothelium-dependent vasodilation throughout the coronary microcirculation. This enhanced responsiveness appears to result principally from an increased expression of nitric oxide (NO) synthase. Finally, physical conditioning decreases extravascular compressive forces at rest and at comparable levels of exercise, mainly because of a decrease in heart rate. Impedance to coronary inflow due to an epicardial coronary artery stenosis results in marked redistribution of myocardial blood flow during exercise away from the subendocardium towards the subepicardium. However, in contrast to the traditional view that myocardial ischemia causes maximal microvascular dilation, more recent studies have shown that the coronary microvessels retain some degree of vasodilator reserve during exercise-induced ischemia and remain responsive to vasoconstrictor stimuli. These observations have required reassessment of the principal sites of resistance to blood flow in the microcirculation. A significant fraction of resistance is located in small arteries that are outside the metabolic control of the myocardium but are sensitive to shear and nitrovasodilators. The coronary collateral system embodies a dynamic network of interarterial vessels that can undergo both long- and short-term adjustments that can modulate blood flow to the dependent myocardium. Long-term adjustments including recruitment and growth of collateral vessels in response to arterial occlusion are time dependent and determine the maximum blood flow rates available to the collateral-dependent vascular bed during exercise. Rapid short-term adjustments result from active vasomotor activity of the collateral vessels. Mature coronary collateral vessels are responsive to vasodilators such as nitroglycerin and atrial natriuretic peptide, and to vasoconstrictors such as vasopressin, angiotensin II, and the platelet products serotonin and thromboxane A(2). During exercise, ss-adrenergic activity and endothelium-derived NO and prostanoids exert vasodilator influences on coronary collateral vessels. Importantly, alterations in collateral vasomotor tone, e.g., by exogenous vasopressin, inhibition of endogenous NO or prostanoid production, or increasing local adenosine production can modify collateral conductance, thereby influencing the blood supply to the dependent myocardium. In addition, vasomotor activity in the resistance vessels of the collateral perfused vascular bed can influence the volume and distribution of blood flow within the collateral zone. Finally, there is evidence that vasomotor control of resistance vessels in the normally perfused regions of collateralized hearts is altered, indicating that the vascular adaptations in hearts with a flow-limiting coronary obstruction occur at a global as well as a regional level. Exercise training does not stimulate growth of coronary collateral vessels in the normal heart. However, if exercise produces ischemia, which would be absent or minimal under resting conditions, there is evidence that collateral growth can be enhanced. In addition to ischemia, the pressure gradient between vascular beds, which is a determinant of the flow rate and therefore the shear stress on the collateral vessel endothelium, may also be important in stimulating growth of collateral vessels.

Identification of ADAMTS7 as a novel locus for coronary atherosclerosis and association of ABO with myocardial infarction in the presence of coronary atherosclerosis: two genome-wide association studies.

PubMed

Reilly, Muredach P; Li, Mingyao; He, Jing; Ferguson, Jane F; Stylianou, Ioannis M; Mehta, Nehal N; Burnett, Mary Susan; Devaney, Joseph M; Knouff, Christopher W; Thompson, John R; Horne, Benjamin D; Stewart, Alexandre F R; Assimes, Themistocles L; Wild, Philipp S; Allayee, Hooman; Nitschke, Patrick Linsel; Patel, Riyaz S; Martinelli, Nicola; Girelli, Domenico; Quyyumi, Arshed A; Anderson, Jeffrey L; Erdmann, Jeanette; Hall, Alistair S; Schunkert, Heribert; Quertermous, Thomas; Blankenberg, Stefan; Hazen, Stanley L; Roberts, Robert; Kathiresan, Sekar; Samani, Nilesh J; Epstein, Stephen E; Rader, Daniel J

2011-01-29

We tested whether genetic factors distinctly contribute to either development of coronary atherosclerosis or, specifically, to myocardial infarction in existing coronary atherosclerosis. We did two genome-wide association studies (GWAS) with coronary angiographic phenotyping in participants of European ancestry. To identify loci that predispose to angiographic coronary artery disease (CAD), we compared individuals who had this disorder (n=12,393) with those who did not (controls, n=7383). To identify loci that predispose to myocardial infarction, we compared patients who had angiographic CAD and myocardial infarction (n=5783) with those who had angiographic CAD but no myocardial infarction (n=3644). In the comparison of patients with angiographic CAD versus controls, we identified a novel locus, ADAMTS7 (p=4·98×10(-13)). In the comparison of patients with angiographic CAD who had myocardial infarction versus those with angiographic CAD but no myocardial infarction, we identified a novel association at the ABO locus (p=7·62×10(-9)). The ABO association was attributable to the glycotransferase-deficient enzyme that encodes the ABO blood group O phenotype previously proposed to protect against myocardial infarction. Our findings indicate that specific genetic predispositions promote the development of coronary atherosclerosis whereas others lead to myocardial infarction in the presence of coronary atherosclerosis. The relation to specific CAD phenotypes might modify how novel loci are applied in personalised risk assessment and used in the development of novel therapies for CAD. The PennCath and MedStar studies were supported by the Cardiovascular Institute of the University of Pennsylvania, by the MedStar Health Research Institute at Washington Hospital Center and by a research grant from GlaxoSmithKline. The funding and support for the other cohorts contributing to the paper are described in the webappendix. Copyright © 2011 Elsevier Ltd. All rights reserved.

Know the Warning Signs of a Heart Attack

MedlinePlus

... No. 22 Know the Warning Signs of a Heart Attack What is a heart attack? Aheart attack happens when the blood vessels that ... hurting your heart muscle. Another name for a heart attack is myocardial infarction, or MI. If you have ...

Impact of glycemic variability on the occurrence of periprocedural myocardial infarction and major adverse cardiovascular events (MACE) after coronary intervention in patients with stable angina pectoris at 6months follow-up.

PubMed

Xia, Jinggang; Xu, Ji; Hu, Shaodong; Hao, Hengjian; Yin, Chunlin; Xu, Dong

2017-08-01

We explored the impact of glycemic variability on the occurrence of periprocedural myocardial infarction and major adverse cardiovascular events (MACE) after coronary intervention in patients with stable angina pectoris (SAP) at 6months follow-up. From May 2015 to April 2016, a total of 746 patients with SAP were divided to high glycemic variability group (H group) (n=261) and low glycemic variability group (L group) (n=485). The primary end point was incidence of periprocedural myocardial infarction and MACE at 6months follow-up. The occurrence of periprocedural myocardial infarction occurred in 18.8% of patients in H group and in 12.4% in L group (P=0.03). The incidence of MACE at 6months follow-up was 9.6% in H group and 4.5% in L group (P=0.01). Multivariable analysis suggested that high glycemic variability conferred a 53% risk increment of 6months follow-up MACE (odds ratio 2.13, 95% confidence interval 1.85-5.38; P=0.01). The trial shows that higher blood glucose variability was correlated with higher incidence of periprocedural myocardial infarction and MACE at 6months follow-up. Copyright © 2017. Published by Elsevier B.V.

Evaluation of (99)  (m)TcN-MPO as a new myocardial perfusion imaging agent in normal dogs and in an acute myocardial infarction canine model: comparison with (99)  (m)Tc-sestamibi.

PubMed

Bu, Lihong; Li, Renfei; Jin, Zhongnan; Wen, Xiaofei; Liu, Shuang; Yang, Baofeng; Shen, Baozhong; Chen, Xiaoyuan

2011-02-01

(99)  (m)TcN-MPO ([(99)  (m)TcN(mpo)(PNP5)](+): mpo = 2-mercaptopyridine oxide and PNP5 = N-ethoxyethyl-N,N-bis[2-(bis(3-methoxypropyl)phosphino)ethyl]amine) is a cationic (99)  (m)Tc-nitrido complex, which has favorable biodistribution and myocardial uptake with rapid liver clearance in Sprague Dawley rats. The objective of this study was to compare the biodistribution and pharmacokinetics of (99)  (m)TcN-MPO and (99)  (m)Tc-Sestamibi in normal dogs, and to evaluate the potential of (99)  (m)TcN-MPO as a myocardial perfusion agent in canines with acute myocardial infarction. Five normal mongrel dogs were injected intravenously with (99)  (m)TcN-MPO. Venous blood samples were collected via a femoral vein catheter at 0.5, 1, 2, 3, 4, 5, 10, 20, 30, 40, 60, and 90 min post-injection (p.i.). Anterior-posterior planar images were acquired by γ-camera at 10, 20, 30, 60, 90, and 120 min p.i. Regions of interest (ROIs) were drawn around the heart, liver, and lungs. The heart/liver and heart/lung ratios were calculated by dividing the mean counts in heart ROI by the mean counts in the liver and lung ROI, respectively. For comparison, (99)  (m)Tc-sestamibi was also evaluated in the same five dogs. The interval period between the two examinations was 1 week to eliminate possible interference between these two radiotracers. In addition, single positron emission computed tomography (SPECT) images in the canine infarct model were collected 24 h after myocardial infarction at 30 and 60 min after the administration of (99)  (m)TcN-MPO (n = 4) or (99)  (m)Tc-Sestamibi (n = 4). It was found that (99)  (m)TcN-MPO and (99)  (m)Tc-Sestamibi displayed very similar blood clearance characteristics during the first 90 min p.i. Both (99)  (m)TcN-MPO and (99)  (m)Tc-Sestamibi had a rapid blood clearance with less than 50% of initial radioactivity remaining at 1 min and less than 5% at 30 min p.i. (99)  (m)TcN-MPO and (99)  (m)Tc-Sestamibi both showed good heart/lung contrast. The heart/liver ratio of (99)  (m)TcN-MPO increased with time (0.53 ± 0.06 at 10 min, 0.90 ± 0.062 at 30 min, and 1.22 ± 0.06 at 60 min p.i.), whereas the heart/liver ratio of (99)  (m)Tc-Sestamibi remained low at all time points (0.50 ± 0.03 at 10 min, 0.64 ± 0.03 at 30 min, and 0.60 ± 0.02 at 60 min p.i.). SPECT imaging studies in canines with acute myocardial infarction indicated that good visualization of the left ventricular wall and perfusion defects could be achieved at 30 min after administration of (99)  (m)TcN-MPO but not after (99)  (m)Tc-Sestamibi. The combination of reasonable heart uptake with rapid hepatobiliary excretion makes (99)  (m)TcN-MPO a promising new radiotracer for myocardial perfusion imaging.

Hemorheological abnormalities in human arterial hypertension

NASA Astrophysics Data System (ADS)

Lo Presti, Rosalia; Hopps, Eugenia; Caimi, Gregorio

2014-05-01

Blood rheology is impaired in hypertensive patients. The alteration involves blood and plasma viscosity, and the erythrocyte behaviour is often abnormal. The hemorheological pattern appears to be related to some pathophysiological mechanisms of hypertension and to organ damage, in particular left ventricular hypertrophy and myocardial ischemia. Abnormalities have been observed in erythrocyte membrane fluidity, explored by fluorescence spectroscopy and electron spin resonance. This may be relevant for red cell flow in microvessels and oxygen delivery to tissues. Although blood viscosity is not a direct target of antihypertensive therapy, the rheological properties of blood play a role in the pathophysiology of arterial hypertension and its vascular complications.

Temporal Progression of Pneumonic Plague in Blood of Nonhuman Primate: A Transcriptomic Analysis

DTIC Science & Technology

2016-03-22

urea nitrogen (BUN), Fig 2. Potentially activated and inhibited GoI-Time enriched pathways across the time course. The canonical pathways enriched by up...journal.pone.0151788 March 22, 2016 8 / 21 The quantitative measurements of Y. pestis present in the exposed animals’ blood and urine samples and...leukocytes (S5B Fig), formation of cellular inclusion bodies, synthesis of extracellular matrix, and myocardial and liver failure. Protein ubiquitination

Cardiovascular magnetic resonance assessment of acute cardiovascular effects of voluntary apnoea in elite divers.

PubMed

Eichhorn, L; Doerner, J; Luetkens, J A; Lunkenheimer, J M; Dolscheid-Pommerich, R C; Erdfelder, F; Fimmers, R; Nadal, J; Stoffel-Wagner, B; Schild, H H; Hoeft, A; Zur, B; Naehle, C P

2018-06-18

Prolonged breath holding results in hypoxemia and hypercapnia. Compensatory mechanisms help maintain adequate oxygen supply to hypoxia sensitive organs, but burden the cardiovascular system. The aim was to investigate human compensatory mechanisms and their effects on the cardiovascular system with regard to cardiac function and morphology, blood flow redistribution, serum biomarkers of the adrenergic system and myocardial injury markers following prolonged apnoea. Seventeen elite apnoea divers performed maximal breath-hold during cardiovascular magnetic resonance imaging (CMR). Two breath-hold sessions were performed to assess (1) cardiac function, myocardial tissue properties and (2) blood flow. In between CMR sessions, a head MRI was performed for the assessment of signs of silent brain ischemia. Urine and blood samples were analysed prior to and up to 4 h after the first breath-hold. Mean breath-hold time was 297 ± 52 s. Left ventricular (LV) end-systolic, end-diastolic, and stroke volume increased significantly (p < 0.05). Peripheral oxygen saturation, LV ejection fraction, LV fractional shortening, and heart rate decreased significantly (p < 0.05). Blood distribution was diverted to cerebral regions with no significant changes in the descending aorta. Catecholamine levels, high-sensitivity cardiac troponin, and NT-pro-BNP levels increased significantly, but did not reach pathological levels. Compensatory effects of prolonged apnoea substantially burden the cardiovascular system. CMR tissue characterisation did not reveal acute myocardial injury, indicating that the resulting cardiovascular stress does not exceed compensatory physiological limits in healthy subjects. However, these compensatory mechanisms could overly tax those limits in subjects with pre-existing cardiac disease. For divers interested in competetive apnoea diving, a comprehensive medical exam with a special focus on the cardiovascular system may be warranted. This prospective single-centre study was approved by the institutional ethics committee review board. It was retrospectively registered under ClinicalTrials.gov (Trial registration: NCT02280226 . Registered 29 October 2014).

Effects of hypoxia on cochlear blood flow in mice evaluated using Doppler optical microangiography.

PubMed

Dziennis, Suzan; Reif, Roberto; Zhi, Zhongwei; Nuttall, Alfred L; Wang, Ruikang K

2012-10-01

Reduced cochlear blood flow (CoBF) is a main contributor to hearing loss. Studying CoBF has remained a challenge due to the lack of available tools. Doppler optical microangiography (DOMAG), a method to quantify single-vessel absolute blood flow, and laser Doppler flowmetry (LDF), a method for measuring the relative blood flow within a large volume of tissue, were used for determining the changes in CoBF due to systemic hypoxia in mice. DOMAG determined the change in blood flow in the apical turn (AT) with single-vessel resolution, while LDF averaged the change in the blood flow within a large volume of the cochlea (hemisphere with ∼1 to 1.5 mm radius). Hypoxia was induced by decreasing the concentration of oxygen-inspired gas, so that the oxygen saturation was reduced from >95% to ∼80%. DOMAG determined that during hypoxia the blood flow in two areas of the AT near and far from the helicotrema were increased and decreased, respectively. The LDF detected a decrease in blood flow within a larger volume of the cochlea (several turns averaged together). Therefore, the use of DOMAG as a tool for studying cochlear blood flow due to its ability to determine absolute flow values with single-vessel resolution was proposed.

Effects of hypoxia on cochlear blood flow in mice evaluated using Doppler optical microangiography

NASA Astrophysics Data System (ADS)

Dziennis, Suzan; Reif, Roberto; Zhi, Zhongwei; Nuttall, Alfred L.; Wang, Ruikang K.

2012-10-01

Reduced cochlear blood flow (CoBF) is a main contributor to hearing loss. Studying CoBF has remained a challenge due to the lack of available tools. Doppler optical microangiography (DOMAG), a method to quantify single-vessel absolute blood flow, and laser Doppler flowmetry (LDF), a method for measuring the relative blood flow within a large volume of tissue, were used for determining the changes in CoBF due to systemic hypoxia in mice. DOMAG determined the change in blood flow in the apical turn (AT) with single-vessel resolution, while LDF averaged the change in the blood flow within a large volume of the cochlea (hemisphere with ˜1 to 1.5 mm radius). Hypoxia was induced by decreasing the concentration of oxygen-inspired gas, so that the oxygen saturation was reduced from >95% to ˜80%. DOMAG determined that during hypoxia the blood flow in two areas of the AT near and far from the helicotrema were increased and decreased, respectively. The LDF detected a decrease in blood flow within a larger volume of the cochlea (several turns averaged together). Therefore, the use of DOMAG as a tool for studying cochlear blood flow due to its ability to determine absolute flow values with single-vessel resolution was proposed.

Measurement of cardiac troponin I utilizing a point of care analyzer in healthy alpacas.

PubMed

Blass, Keith A; Kraus, Marc S; Rishniw, Mark; Mann, Sabine; Mitchell, Lisa M; Divers, Thomas J

2011-12-01

Myocardial disease in camelids is poorly characterized. Nutritional (selenium deficiency) and toxic (ionophore toxicity) myocardial disease have been reported in camelids. Diagnosis and management of these and other myocardial diseases might be enhanced by evaluating cardiac troponin I (cTnI) concentrations. No information about cTnI reference intervals in camelids is currently available. (A) To determine cTnI concentrations obtained using a point of care i-STAT(®)1 analyzer (Heska Corporation) in healthy alpacas; (B) to compare alpaca cTnI concentrations between heparinized whole blood and plasma samples and between 2 different storage conditions (4 °C for 24 h or -80 °C for 30 days); (C) to examine assay reproducibility using the i-STAT(®)1. 23 healthy alpacas were evaluated. Blood and plasma samples were analyzed by the i-STAT(®)1 within 1 h of collection. Aliquots of plasma were stored at either 4 °C for 24 h or -80 °C for 30 days, and then analyzed. Assay reproducibility was determined by comparing 2 plasma or whole blood cTnI concentrations measured on the same sample over a 10 min period. Analyzer-specific plasma cTnI concentrations in clinically normal alpacas had a median of <0.02 ng/mL (range: <0.02 ng/mL to 0.07 ng/mL). Plasma and whole blood concentrations showed good agreement. Storage did not affect cTnI concentrations (p > 0.75). Plasma cTnI concentrations had coefficient of repeatability of 0.02 ng/mL. The i-STAT(®)1 can measure cTnI in alpacas on both plasma and whole blood and provides similar values for both samples. Storage at 4 °C for 24 h or -80 °C for 30 days does not affect estimates of plasma cTnI. Evaluation of cTnI might be of value in assessing cardiac disease in this species. Copyright © 2011 Elsevier B.V. All rights reserved.

Application of Large-Scale Aptamer-Based Proteomic Profiling to Planned Myocardial Infarctions.

PubMed

Jacob, Jaison; Ngo, Debby; Finkel, Nancy; Pitts, Rebecca; Gleim, Scott; Benson, Mark D; Keyes, Michelle J; Farrell, Laurie A; Morgan, Thomas; Jennings, Lori L; Gerszten, Robert E

2018-03-20

Emerging proteomic technologies using novel affinity-based reagents allow for efficient multiplexing with high-sample throughput. To identify early biomarkers of myocardial injury, we recently applied an aptamer-based proteomic profiling platform that measures 1129 proteins to samples from patients undergoing septal alcohol ablation for hypertrophic cardiomyopathy, a human model of planned myocardial injury. Here, we examined the scalability of this approach using a markedly expanded platform to study a far broader range of human proteins in the context of myocardial injury. We applied a highly multiplexed, expanded proteomic technique that uses single-stranded DNA aptamers to assay 4783 human proteins (4137 distinct human gene targets) to derivation and validation cohorts of planned myocardial injury, individuals with spontaneous myocardial infarction, and at-risk controls. We found 376 target proteins that significantly changed in the blood after planned myocardial injury in a derivation cohort (n=20; P <1.05E-05, 1-way repeated measures analysis of variance, Bonferroni threshold). Two hundred forty-seven of these proteins were validated in an independent planned myocardial injury cohort (n=15; P <1.33E-04, 1-way repeated measures analysis of variance); >90% were directionally consistent and reached nominal significance in the validation cohort. Among the validated proteins that were increased within 1 hour after planned myocardial injury, 29 were also elevated in patients with spontaneous myocardial infarction (n=63; P <6.17E-04). Many of the novel markers identified in our study are intracellular proteins not previously identified in the peripheral circulation or have functional roles relevant to myocardial injury. For example, the cardiac LIM protein, cysteine- and glycine-rich protein 3, is thought to mediate cardiac mechanotransduction and stress responses, whereas the mitochondrial ATP synthase F 0 subunit component is a vasoactive peptide on its release from cells. Last, we performed aptamer-affinity enrichment coupled with mass spectrometry to technically verify aptamer specificity for a subset of the new biomarkers. Our results demonstrate the feasibility of large-scale aptamer multiplexing at a level that has not previously been reported and with sample throughput that greatly exceeds other existing proteomic methods. The expanded aptamer-based proteomic platform provides a unique opportunity for biomarker and pathway discovery after myocardial injury. © 2017 American Heart Association, Inc.

Myocardial Oxidative Stress in Infants Undergoing Cardiac Surgery.

PubMed

Sznycer-Taub, Nathaniel; Mackie, Stewart; Peng, Yun-Wen; Donohue, Janet; Yu, Sunkyung; Aiyagari, Ranjit; Charpie, John

2016-04-01

Cardiac surgery for congenital heart disease often necessitates a period of myocardial ischemia during cardiopulmonary bypass and cardioplegic arrest, followed by reperfusion after aortic cross-clamp removal. In experimental models, myocardial ischemia-reperfusion is associated with significant oxidative stress and ventricular dysfunction. A prospective observational study was conducted in infants (<1 year) who underwent elective surgical repair of a ventricular septal defect (VSD) or tetralogy of Fallot (TOF). Blood samples were drawn following anesthetic induction (baseline) and directly from the coronary sinus at 1, 3, 5, and 10 min following aortic cross-clamp removal. Samples were analyzed for oxidant stress using assays for thiobarbituric acid-reactive substances, protein carbonyl, 8-isoprostane, and total antioxidant capacity. For each subject, raw assay data were normalized to individual baseline samples and expressed as fold-change from baseline. Results were compared using a one-sample t test with Bonferroni correction for multiple comparisons. Sixteen patients (ten with TOF and six with VSD) were enrolled in the study, and there were no major postoperative complications observed. For the entire cohort, there was an immediate, rapid increase in myocardial oxidative stress that was sustained for 10 min following aortic cross-clamp removal in all biomarker assays (all P < 0.01), except total antioxidant capacity. Infant cardiac surgery is associated with a rapid, robust, and time-dependent increase in myocardial oxidant stress as measured from the coronary sinus in vivo. Future studies with larger enrollment are necessary to assess any association between myocardial oxidative stress and early postoperative outcomes.

Myocardial effective transverse relaxation time T2* Correlates with left ventricular wall thickness: A 7.0 T MRI study.

PubMed

Huelnhagen, Till; Hezel, Fabian; Serradas Duarte, Teresa; Pohlmann, Andreas; Oezerdem, Celal; Flemming, Bert; Seeliger, Erdmann; Prothmann, Marcel; Schulz-Menger, Jeanette; Niendorf, Thoralf

2017-06-01

Myocardial effective relaxation time T2* is commonly regarded as a surrogate for myocardial tissue oxygenation. However, it is legitimate to assume that there are multiple factors that influence T2*. To this end, this study investigates the relationship between T2* and cardiac macromorphology given by left ventricular (LV) wall thickness and left ventricular radius, and provides interpretation of the results in the physiological context. High spatio-temporally resolved myocardial CINE T2* mapping was performed in 10 healthy volunteers using a 7.0 Tesla (T) full-body MRI system. Ventricular septal wall thickness, left ventricular inner radius, and T2* were analyzed. Macroscopic magnetic field changes were elucidated using cardiac phase-resolved magnetic field maps. Ventricular septal T2* changes periodically over the cardiac cycle, increasing in systole and decreasing in diastole. Ventricular septal wall thickness and T2* showed a significant positive correlation, whereas the inner LV radius and T2* were negatively correlated. The effect of macroscopic magnetic field gradients on T2* can be considered minor in the ventricular septum. Our findings suggest that myocardial T2* is related to tissue blood volume fraction. Temporally resolved T2* mapping could be beneficial for myocardial tissue characterization and for understanding cardiac (patho)physiology in vivo. Magn Reson Med 77:2381-2389, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Pseudoinfarction pattern in a patient with hyperkalemia, diabetic ketoacidosis and normal coronary vessels: a case report.

PubMed

Ziakas, Antonios; Basagiannis, Christos; Stiliadis, Ioannis

2010-04-26

A rare electrocardiographic finding of hyperkalemia is ST segment elevation or the so called 'pseudoinfarction' pattern. It has been suggested that hyperkalemia causes the 'pseudoinfarction' pattern not only through its direct myocardial effects, but also through other mechanisms, such as anoxia, acidosis, and coronary artery spasm. A 33-year-old Caucasian woman with insulin-treated diabetes presented with continuous epigastric pain of four hours duration. Her coronary heart disease risk factors apart from diabetes included hypercholesterolemia and smoking. Her initial electrocardiogram revealed ST segment elevation in the anteroseptal leads consistent with anterior myocardial infarction. Blood tests revealed hyperglycemia, hyperkalemia, metabolic acidosis and urine ketones, while a bed-side cardiac echocardiogram showed no segmental wall motion abnormality. We provisionally diagnosed diabetic ketoacidosis that was possibly precipitated by acute myocardial infarction, as there were findings in favor of (epigastric pain, electrocardiogram pattern, presence of 3 coronary heart disease risk factors) and against (young age, normal echocardiogram) the diagnosis of acute myocardial infarction. We performed cardiac angiography in order to exclude an anterior acute myocardial infarction, which could lead to myocardial damage and possible severe complications should there be a delay in treatment. Angiography revealed normal coronary arteries. During the procedure, ST segment elevation in the anteroseptal leads was still present in our patient's electrocardiogram results. ST segment elevation is a rare manifestation of hyperkalemia. In our patient, coronary spasm did not contribute to such an electrocardiography finding.

Crisis management during anaesthesia: myocardial ischaemia and infarction.

PubMed

Ludbrook, G L; Webb, R K; Currie, M; Watterson, L M

2005-06-01

Myocardial ischaemia and infarction are significant perioperative complications which are associated with poor patient outcome. Anaesthetic practice should therefore focus, particularly in the at risk patient, on their prevention, their accurate detection, on the identification of precipitating factors, and on rapid effective management. To examine the role of a previously described core algorithm "COVER ABCD-A SWIFT CHECK" supplemented by a specific sub-algorithm for myocardial ischaemia and infarction in the management of myocardial ischaemia and/or infarction occurring in association with anaesthesia. The potential performance of this structured approach for each of the relevant incidents among the first 4000 reported to the Australian Incident Monitoring Study (AIMS) was compared with the actual management as reported by the anaesthetists involved. Of the 125 incidents retrieved from the 4000 reports, 40 (1%) were considered to demonstrate myocardial infarction or ischaemia. The use of the structured approach described in this paper would have led to appropriate management in 90% of cases, with the remaining 10% requiring other sub-algorithms. It was considered that the application of this structured approach would have led to earlier recognition and/or better management of the problem in 45% of cases. Close and continuous monitoring of patients at risk of myocardial ischaemia during anaesthesia is necessary, using optimal ECG lead configurations, but sensitivity of this monitoring is not 100%. Coronary vasodilatation with glyceryl trinitrate (GTN) should not be withheld when indicated and the early use of beta blocking drugs should be considered even with normal blood pressures and heart rates.

Pharmacological prevention of reperfusion injury in acute myocardial infarction. A potential role for adenosine as a therapeutic agent.

PubMed

Quintana, Miguel; Kahan, Thomas; Hjemdahl, Paul

2004-01-01

The concept of reperfusion injury, although first recognized from animal studies, is now recognized as a clinical phenomenon that may result in microvascular damage, no-reflow phenomenon, myocardial stunning, myocardial hibernation and ischemic preconditioning. The final consequence of this event is left ventricular (LV) systolic dysfunction leading to increased morbidity and mortality. The typical clinical case of reperfusion injury occurs in acute myocardial infarction (MI) with ST segment elevation in which an occlusion of a major epicardial coronary artery is followed by recanalization of the artery. This may occur either spontaneously or by means of thrombolysis and/or by primary percutaneous coronary intervention (PCI) with efficient platelet inhibition by aspirin (acetylsalicylic acid), clopidogrel and glycoprotein IIb/IIIa inhibitors. Although the pathophysiology of reperfusion injury is complex, the major role that neutrophils play in this process is well known. Neutrophils generate free radicals, degranulation products, arachidonic acid metabolites and platelet-activating factors that interact with endothelial cells, inducing endothelial injury and neutralization of nitrous oxide vasodilator capacity. Adenosine, through its multi-targeted pharmacological actions, is able to inhibit some of the above-mentioned detrimental effects. The net protective of adenosine in in vivo models of reperfusion injury is the reduction of the infarct size, the improvement of the regional myocardial blood flow and of the regional function of the ischemic area. Additionally, adenosine preserves the post-ischemic coronary flow reserve, coronary blood flow and the post-ischemic regional contractility. In small-scale studies in patients with acute MI, treatment with adenosine has been associated with smaller infarcts, less no-reflow phenomenon and improved LV function. During elective PCI adenosine reduced ST segment shifts, lactate production and ischemic symptoms. During the last years, three relatively large placebo-controlled clinical trials have been conducted: Acute Myocardial Infarction Study of Adenosine Trial (AMISTAD) I and II and Attenuation by Adenosine of Cardiac Complications (ATTACC). In the AMISTAD trials, the final infarct size was reduced and the LV systolic function was improved by adenosine treatment, mainly in patients with anterior MI localization. However, morbidity and mortality were not affected. In the ATTACC study, the LV systolic function was not affected by adenosine, however, trends towards improved survival were observed in patients with anterior MI localization. The possibility of obtaining a Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow in the infarct-related artery in up to 95% of patients with acute MI (increasing the occurrence of reperfusion injury) has turned back the interest towards the protection of myocardial cells from the impending ischemic and reperfusion injury in which adenosine alone or together with other cardio-protective agents may exert important clinical effects.

Regional myocardial shape and dimensions of the working isolated canine left ventricle

NASA Technical Reports Server (NTRS)

Ritman, E.; Tsuiki, K.; Donald, D.; Wood, E. H.

1975-01-01

Angiographic experiments were performed on isolated canine left ventricle preparations using donor dog to supply blood to the coronary circulation via a rotary pump to control coronary flow. The angiographic record was transferred from video tape to video disk for detailed uninterrupted sequential analysis at a frequency of 60 fields/sec. It is shown that the use of a biplane X-ray technique and a metabolically supported isolated canine left ventricle preparation provides an angiographically ideal means of measuring the mechanical dynamics of the myocardium while the intact left ventricular myocardial structure and electrical activation pattern retain most of the in situ ventricular characteristics. In particular, biplane X-ray angiography of the left ventricle can provide estimates of total ventricular function such as ejection fraction, stroke volume, and myocardial mass correct to within 15% under the angiographically ideal conditions of the preparation.

Stem cells--clinical application and perspectives.

PubMed

Brehm, Michael; Zeus, Tobias; Strauer, Bodo Eckehard

2002-11-01

Augmentation of myocardial performance in experimental models of therapeutic infarction and heart failure has been achieved by transplantation of exogenous cells into damaged myocardium. The quest for suitable donor cells has prompted research into the use of both embryonic stem cells and adult somatic stem cells. Recently, there has been a growing body of evidence that multipotent somatic stem cells in adult bone marrow exhibit tremendous functional plasticity and can reprogram in a new environmental tissue niche to give rise to cell lineages specific for new organ site. This phenomenon has made huge impact on myocardial biology, while multipotent adult bone marrow hematopoeitic stem cells and mesechymal stem cells can repopulate infarcted rodent myocardium and differentiate into both cardiomyocytes and new blood vessels. These data, coupled with the identification of a putative primitive cardiac stem cell population in the adult human heart, may open the way for novel therapeutic modalities for enhancing myocardial performance and treating heart failure.

Nuclear medicine and imaging research: quantitative studies in radiopharmaceutical science. Comprehensive progress report, January 1, 1980-December 31, 1982

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beck, R.N.; Cooper, M.C.

1982-06-01

This 3-y report cites progress in the following areas of radiopharmaceutical research: cyclotron operations; /sup 51/Mn for myocardial localization; /sup 82/Rb for heart imaging; /sup 15/O-labelled H/sub 2/O and molecular oxygen; studies on /sup 11/C-2-deoxyglucose localization; /sup 13/NH/sub 3/ measurements of myocardial perfusion; /sup 130/Cs myocardial imaging; heart motion studies; labelled amino acids for pancreatic imaging; /sup 11/C-hexamethonium for cartilage imaging; /sup 11/C-cholic acid pharmacology; blood element labelling with /sup 115m/In; /sup 75/Br studies; extrapolation of animal data to humans; in vivo quantification of radioactivity; fetal and neonatal radiation effects from radiopharmaceuticals administered to pregnant and lactating mice; and verificationmore » of MIRD absorbed dose calculations for some organ-incorporated radionuclides. (ERB)« less

Fractional flow reserve-guided management in stable coronary disease and acute myocardial infarction: recent developments

PubMed Central

Berry, Colin; Corcoran, David; Hennigan, Barry; Watkins, Stuart; Layland, Jamie; Oldroyd, Keith G.

2015-01-01

Coronary artery disease (CAD) is a leading global cause of morbidity and mortality, and improvements in the diagnosis and treatment of CAD can reduce the health and economic burden of this condition. Fractional flow reserve (FFR) is an evidence-based diagnostic test of the physiological significance of a coronary artery stenosis. Fractional flow reserve is a pressure-derived index of the maximal achievable myocardial blood flow in the presence of an epicardial coronary stenosis as a ratio to maximum achievable flow if that artery were normal. When compared with standard angiography-guided management, FFR disclosure is impactful on the decision for revascularization and clinical outcomes. In this article, we review recent developments with FFR in patients with stable CAD and recent myocardial infarction. Specifically, we review novel developments in our understanding of CAD pathophysiology, diagnostic applications, prognostic studies, clinical trials, and clinical guidelines. PMID:26038588

Should the patient with coronary artery disease use sildenafil?

PubMed

Cheitlin, Melvin D

2003-01-01

Since the etiology of erectile dysfunction is frequently related to endothelial dysfunction, a problem in common with much vascular disease, erectile dysfunction disproportionately affects patients with cardiovascular disease. With the development of phosphodiesterase 5 inhibitors, the first of which was sildenafil (Viagra), an effective oral medication became available. The question of safety of these drugs, especially in patients with latent or overt coronary artery disease, is of concern. Sildenafil relaxes smooth muscle and therefore lowers systolic and diastolic blood pressure slightly. With organic nitrates, the drop in blood pressure is potentiated, at times dangerously, thereby making it contraindicated to take nitrates within 24 hours of using sildenafil. In double-blind, placebo-controlled trials, there was no difference between sildenafil subjects and control patients in the incidence of myocardial infarction, cardiovascular, and total deaths. Coronary disease patients with stable angina, controlled on medications, were included in the trials. Therefore, sildenafil, as a drug, is safe in such patients. With a patient with coronary artery disease suddenly engaging in the physical exercise associated with sexual intercourse, there is the danger of increased risk of precipitating myocardial infarction or death. The cardiovascular metabolic cost of sexual activity is reviewed and appears to be approximately at the level of 3-5 metabolic equivalents of exercise. Sexual activity occurs within 2 hours of the onset of an acute myocardial infarction in <1.0% of patients. Although sexual intercourse is estimated to increase the risk of myocardial infarction by a factor of 2x, there is still only a very small increase in risk, a risk acceptable to patients who feel their quality of life will be markedly improved by their ability to engage in sexual activity.

Effect of K+ATP channel and adenosine receptor blockade during rest and exercise in congestive heart failure.

PubMed

Traverse, Jay H; Chen, YingJie; Hou, MingXiao; Li, Yunfang; Bache, Robert J

2007-06-08

K(+)(ATP) channels are important metabolic regulators of coronary blood flow (CBF) that are activated in the setting of reduced levels of ATP or perfusion pressure. In the normal heart, blockade of K(+)(ATP) channels results in a approximately 20% reduction in resting CBF but does not impair the increase in CBF that occurs during exercise. In contrast, adenosine receptor blockade fails to alter CBF or myocardial oxygen consumption (MVO(2)) in the normal heart but contributes to the increase in CBF during exercise when vascular K(+)(ATP) channels are blocked. Congestive heart failure (CHF) is associated with a decrease in CBF that is matched to a decrease in MVO(2) suggesting downregulation of myocardial energy utilization. Because myocardial ATP levels and coronary perfusion pressure are reduced in CHF, this study was undertaken to examine the role of K(+)(ATP) channels and adenosine in dogs with pacing-induced CHF. Myocardial blood flow (MBF) and MVO(2) were measured during rest and treadmill exercise before and after K(+)(ATP) channel blockade with glibenclamide (50 microg/kg/min ic) or adenosine receptor blockade with 8-phenyltheophylline (8-PT; 5 mg/kg iv). Inhibition of K(+)(ATP) channels resulted in a decrease in CBF and MVO(2) at rest and during exercise without a change in the relationship between CBF and MVO(2). In contrast, adenosine receptor blockade caused a significant increase in CBF that occurred secondary to an increase of MVO(2). These findings demonstrate that coronary K(+)(ATP) channel activity contribute to the regulation of resting MBF in CHF, and that endogenous adenosine may act to inhibit MVO(2) in the failing heart.

A mathematical model for active contraction in healthy and failing myocytes and left ventricles.

PubMed

Cai, Li; Wang, Yongheng; Gao, Hao; Li, Yiqiang; Luo, Xiaoyu

2017-01-01

Cardiovascular disease is one of the leading causes of death worldwide, in particular myocardial dysfunction, which may lead to heart failure eventually. Understanding the electro-mechanics of the heart will help in developing more effective clinical treatments. In this paper, we present a multi-scale electro-mechanics model of the left ventricle (LV). The Holzapfel-Ogden constitutive law was used to describe the passive myocardial response in tissue level, a modified Grandi-Pasqualini-Bers model was adopted to model calcium dynamics in individual myocytes, and the active tension was described using the Niederer-Hunter-Smith myofilament model. We first studied the electro-mechanics coupling in a single myocyte in the healthy and diseased left ventricle, and then the single cell model was embedded in a dynamic LV model to investigate the compensation mechanism of LV pump function due to myocardial dysfunction caused by abnormality in cellular calcium dynamics. The multi-scale LV model was solved using an in-house developed hybrid immersed boundary method with finite element extension. The predictions of the healthy LV model agreed well with the clinical measurements and other studies, and likewise, the results in the failing states were also consistent with clinical observations. In particular, we found that a low level of intracellular Ca2+ transient in myocytes can result in LV pump function failure even with increased myocardial contractility, decreased systolic blood pressure, and increased diastolic filling pressure, even though they will increase LV stroke volume. Our work suggested that treatments targeted at increased contractility and lowering the systolic blood pressure alone are not sufficient in preventing LV pump dysfunction, restoring a balanced physiological Ca2+ handling mechanism is necessary.

Reduced Myocardial Flow Reserve by Positron Emission Tomography Predicts Cardiovascular Events After Cardiac Transplantation.

PubMed

Konerman, Matthew C; Lazarus, John J; Weinberg, Richard L; Shah, Ravi V; Ghannam, Michael; Hummel, Scott L; Corbett, James R; Ficaro, Edward P; Aaronson, Keith D; Colvin, Monica M; Koelling, Todd M; Murthy, Venkatesh L

2018-06-01

We evaluated the diagnostic and prognostic value of quantification of myocardial flow reserve (MFR) with positron emission tomography (PET) in orthotopic heart transplant patients. We retrospectively identified orthotopic heart transplant patients who underwent rubidium-82 cardiac PET imaging. The primary outcome was the composite of cardiovascular death, acute coronary syndrome, coronary revascularization, and heart failure hospitalization. Cox regression was used to evaluate the association of MFR with the primary outcome. The relationship of MFR and cardiac allograft vasculopathy severity in patients with angiography within 1 year of PET imaging was assessed using Spearman rank correlation and logistic regression. A total of 117 patients (median age, 60 years; 71% men) were identified. Twenty-one of 62 patients (34%) who underwent angiography before PET had cardiac allograft vasculopathy. The median time from orthotopic heart transplant to PET imaging was 6.4 years (median global MFR, 2.31). After a median of 1.4 years, 22 patients (19%) experienced the primary outcome. On an unadjusted basis, global MFR (hazard ratio, 0.22 per unit increase; 95% confidence interval, 0.09-0.50; P <0.001) and stress myocardial blood flow (hazard ratio, 0.48 per unit increase; 95% confidence interval, 0.29-0.79; P =0.004) were associated with the primary outcome. Decreased MFR independently predicted the primary outcome after adjustment for other variables. In 42 patients who underwent angiography within 12 months of PET, MFR and stress myocardial blood flow were associated with moderate-severe cardiac allograft vasculopathy (International Society of Heart and Lung Transplantation grade 2-3). MFR assessed by cardiac rubidium-82 PET imaging is a predictor of cardiovascular events after orthotopic heart transplant and is associated with cardiac allograft vasculopathy severity. © 2018 American Heart Association, Inc.

Comparing short versus standard-length balloon for intra-aortic counterpulsation: results from a porcine model of myocardial ischaemia-reperfusion.

PubMed

Gelsomino, Sandro; Lozekoot, Pieter W J; Lorusso, Roberto; de Jong, Monique M J; Parise, Orlando; Matteucci, Francesco; Lucà, Fabiana; La Meir, Mark; Gensini, Gian Franco; Maessen, Jos G

2016-05-01

We compare a short and a standard-size balloon with same filling volumes to verify the differences in terms of visceral flow, coronary circulation and haemodynamic performance during aortic counterpulsation in an animal model of myocardial ischaemia-reperfusion injury. Eighteen healthy pigs underwent 120-min ligation of the left anterior descending coronary artery followed by 6 h of reperfusion, and they were randomly assigned to have intra-aortic balloon counterpulsation (IABP) with a 40-ml short-balloon (n = 6) or a 40-ml standard-length balloon (n = 6), or to undergo no IABP implantation (controls, n = 6). Haemodynamics and visceral and coronary flows were measured at baseline (t0), at 2 h of ischaemia (t1) and every hour thereafter until 6 h of reperfusion (from tR1 to tR6), respectively. Mesenteric flows increased significantly at tR1 only in the short-balloon group (P < 0.001) and it was constantly higher than in the standard-balloon group regardless of mean arterial pressure, systemic vascular resistance and cardiac output (CO; all, P < 0.001). Renal blood flows were significantly increased during IABP treatment with values constantly and significantly higher in short balloons at any following experimental step (all, P < 0.05). IABP improved CO and coronary blood flow, and reduced afterload, myocardial resistances and myocardial oxygen consumption without differences between the short and the standard-length balloon (all, P > 0.05). The short balloon prevents visceral ischaemia and, compared with the standard-size balloon, it does not lose IABP beneficial cardiac and coronary-related effects. Further studies are warranted to confirm our findings. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Effect of Ranolazine on Left Ventricular Dyssynchrony in Patients with Coronary Artery Disease

PubMed Central

Venkataraman, Rajesh; Chen, Ji; Garcia, Ernest V.; Belardinelli, Luiz; Hage, Fadi G.; Heo, Jaekyeong; Iskandrian, Ami E.

2012-01-01

We previously reported that ranolazine improved exercise myocardial perfusion. Ranolazine ameliorates myocardial ischemia by augmenting myocardial blood flow; likely due to a reduction in extra-vascular compression of small vessels. We hypothesized that ranolazine could improve left ventricular (LV) dyssynchrony as assessed by phase analysis of gated SPECT myocardial perfusion imaging (MPI). Patients (n=32) with known or suspected coronary artery disease and reversible perfusion defects on a clinically indicated stress MPI were re-studied 4 weeks after ranolazine (500–1000 mg orally twice daily) was added to their conventional treatment in an open-label trial (data previously reported). The LV systolic and diastolic dyssynchrony indices were obtained using automated phase analysis before and after ranolazine. There were no significant changes in heart rate and blood pressure (at rest or during stress) after treatment. The perfusion pattern improved in 13 of 18 patients who had exercise testing but in only 3 of 14 patients who had vasodilator stress testing. There were no significant changes in LV ejection fraction or volumes after treatment. The systolic and diastolic LV dyssynchrony improved after ranolazine therapy; there was a significant decrease in systolic phase standard deviation (SD) (21±17 vs. 18±13, P=0.04), systolic bandwidth (BW) (69±60 vs. 53±38, P=0.03), diastolic SD (29±18 vs. 24±15, P=0.047) and diastolic BW (91±61 vs. 72±45, P=0.02). In conclusion, this is the first study to show improvement in diastolic and systolic LV synchrony with ranolazine as measured by automated phase analysis of gated SPECT MPI. PMID:22884560

Cardioprotective medication use and risk factor control among US adults with unrecognized myocardial infarction: the REasons for Geographic And Racial Differences in Stroke (REGARDS) study

PubMed Central

Levitan, Emily B; Gamboa, Christopher; Safford, Monika M; Rizk, Dana V; Brown, Todd M; Soliman, Elsayed Z; Muntner, Paul

2013-01-01

Background Individuals with unrecognized myocardial infarction (UMI) have similar risks for cardiovascular events and mortality as those with recognized myocardial infarction (RMI). The prevalence of cardioprotective medication use and blood pressure and low-density lipoprotein cholesterol control among individuals with UMI is unknown. Methods Participants from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study who were recruited between May 2004 and October 2007 received baseline twelve-lead electrocardiograms (n = 21,036). Myocardial infarction (MI) status was characterized as no MI, UMI (electrocardiogram abnormalities consistent with MI without self-reported history; n = 949; 4.5%), and RMI (self-reported history of MI; n = 1574; 7.5%). Results For participants with no MI, UMI, and RMI, prevalence of use was 38.4%, 44.4%, and 75.7% for aspirin; 18.0%, 25.8%, and 57.2% for beta blockers; 31.7%, 38.7%, and 55.0% for angiotensin converting enzyme inhibitors or angiotensin receptor blockers; and 28.1%, 33.9%, and 64.1% for statins, respectively. Participants with RMI were 35% more likely to have low-density lipoprotein cholesterol < 100 mg/dL than participants with UMI (prevalence ratio = 1.35, 95% confidence interval 1.19–1.52). Blood pressure control (,140/90 mmHg) was similar between RMI and UMI groups (prevalence ratio = 1.03, 95% confidence interval 0.93–1.13). Conclusion Although participants with UMI were somewhat more likely to use cardioprotective medications than those with no MI, they were less likely to use cardioprotective medications and to have controlled low-density lipoprotein cholesterol than participants with RMI. Increasing appropriate treatment and risk factor control among individuals with UMI may reduce risk of mortality and future cardiovascular events. PMID:23404361

The effects of combined versus selective adrenergic blockade on left ventricular and systemic hemodynamics, myocardial substrate preference, and regional perfusion in conscious dogs with dilated cardiomyopathy.

PubMed

Nikolaidis, Lazaros A; Poornima, Indu; Parikh, Pratik; Magovern, Megan; Shen, You-Tang; Shannon, Richard P

2006-05-02

Given that adverse effects of chronic sympathetic activation are mediated by all three adrenergic receptor subtypes (beta1, beta2, alpha1), we examined the effects of standard doses of carvedilol and metoprolol succinate (metoprolol controlled release/extended release [CR/XL]) on hemodynamics, myocardial metabolism, and regional organ perfusion. Both beta1 selective and combined adrenergic blockade reduce morbidity and mortality in heart failure. Whether there are advantages of one class over the other remains controversial, even in the wake of the Carvedilol Or Metoprolol European Trial (COMET). Similarly, the mechanistic basis for the relative differences is incompletely understood. Thirty-three conscious, chronically instrumented dogs with pacing-induced (240 min(-1) for 4 weeks) dilated cardiomyopathy (DCM) were randomized to carvedilol (25 mg twice daily, Coreg, Glaxo Smith Kline, Research Triangle, North Carolina) or metoprolol succinate (100 mg qd, Toprol XL, Astra Zeneca, Wilmington, Delaware). Left ventricular and systemic hemodynamics, myocardial substrate uptake, and norepinephrine spillover were measured before and after three days of treatment. Regional (renal, hepatic, skeletal muscle) blood flows were measured using neutron-activated microspheres. Both agents had comparable heart rate effects. However, carvedilol-treated dogs showed significantly greater increases in stroke volume and cardiac output and decreases in left ventricular end-diastolic pressure and systemic vascular resistance. Carvedilol increased renal, hepatic, and skeletal muscle blood flow. Carvedilol increased myocardial glucose uptake and suppressed norepinephrine and glucagon. Carvedilol antagonized the response to exogenous norepinephrine to a greater extent than metoprolol CR/XL. At doses inducing comparable heart rate reductions, short-term treatment with carvedilol had superior hemodynamic and metabolic effects compared with metoprolol CR/XL. These data suggest important advantages of blocking all three adrenergic receptor subtypes in DCM.

Serum Tumor Necrosis Factor-alpha associates with Myocardial Oxygen Demand and Exercise Tolerance in Postmenopausal Women.

PubMed

Carter, Stephen J; Bryan, David R; Neumeier, William H; Glasser, Stephen P; Hunter, Gary R

2018-01-01

The functional implications of serum tumor necrosis factor-alpha (TNF-α), a marker of oxidative stress, on hemodynamic parameters at rest and during physical exertion are unclear. The aims of this investigation were to examine the independent associations of TNF-α on myocardial oxygen demand at rest and during submaximal exercise, while also evaluating the association of TNF-α on exercise tolerance. Forty, postmenopausal women, provided blood samples and completed a modified-Balke protocol to measure maximal oxygen uptake (VO 2max ). Large artery compliance was measured by pulse contour analyses while rate-pressure product (RPP), an index of myocardial oxygen demand, was measured at rest and during two submaximal workloads (i.e., ≈55% and ≈75% VO 2max ). RPP was calculated by dividing the product of heart rate and systolic blood pressure (via auscultation) by 100. Exercise tolerance corresponded with the cessation of the graded exercise test. During higher-intensity exertion, ≈75% VO 2max , multiple linear regression revealed a positive association ( r = 0.43; p = 0.015) between TNF-α and RPP while adjusting for maximal heart rate, VO 2max , large artery compliance, and percent body fat. Path analyses revealed a significant indirect effect of large artery compliance on exercise tolerance through TNF-α, β = 0.13, CI [0.03, 0.35], indicating greater levels of TNF-α associated with poorer exercise tolerance. These data suggest TNF-α independently associates with myocardial oxygen demand during physical exertion, thus highlighting the utility of higher-intensity efforts to expose important phenomena not apparent at rest. TNF-α also appears to be indirectly associated with the link between large artery compliance and exercise tolerance.

Myocardial perfusion and oxidative stress after 21% vs. 100% oxygen ventilation and uninterrupted chest compressions in severely asphyxiated piglets.

PubMed

Solevåg, Anne Lee; Schmölzer, Georg M; O'Reilly, Megan; Lu, Min; Lee, Tze-Fun; Hornberger, Lisa K; Nakstad, Britt; Cheung, Po-Yin

2016-09-01

Despite the minimal evidence, neonatal resuscitation guidelines recommend using 100% oxygen when chest compressions (CC) are needed. Uninterrupted CC in adult cardiopulmonary resuscitation (CPR) may improve CPR hemodynamics. We aimed to examine 21% oxygen (air) vs. 100% oxygen in 3:1 CC:ventilation (C:V) CPR or continuous CC with asynchronous ventilation (CCaV) in asphyxiated newborn piglets following cardiac arrest. Piglets (1-3 days old) were progressively asphyxiated until cardiac arrest and randomized to 4 experimental groups (n=8 each): air and 3:1 C:V CPR, 100% oxygen and 3:1 C:V CPR, air and CCaV, or 100% oxygen and CCaV. Time to return of spontaneous circulation (ROSC), mortality, and clinical and biochemical parameters were compared between groups. We used echocardiography to measure left ventricular (LV) stroke volume at baseline, at 30min and 4h after ROSC. Left common carotid artery blood pressure was measured continuously. Time to ROSC (heart rate ≥100min(-1)) ranged from 75 to 592s and mortality 50-75%, with no differences between groups. Resuscitation with air was associated with higher LV stroke volume after ROSC and less myocardial oxidative stress compared to 100% oxygen groups. CCaV was associated with lower mean arterial blood pressure after ROSC and higher myocardial lactate than those of 3:1 C:V CPR. In neonatal asphyxia-induced cardiac arrest, using air during CC may reduce myocardial oxidative stress and improve cardiac function compared to 100% oxygen. Although overall recovery may be similar, CCaV may impair tissue perfusion compared to 3:1 C:V CPR. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

[Myocardial uptake ratio of iodine-123 labeled beta-methyl iodophenylpentadecanoic acid (123I-BMIPP) in relation to the concentration of the substrates of energy].

PubMed

Tsuchimochi, S; Tamaki, N; Kawamoto, M; Tadamura, E; Fujita, T; Nohara, R; Matsumori, A; Sasayama, S; Yonekura, Y; Konishi, J

1995-06-01

Iodine-123 beta-methyl iodophenylpentadecanoic acid (BMIPP) has been used for evaluating myocardial fatty acid metabolism in vivo. The whole body BMIPP imaging was acquired in 26 patients (11 with HCM, 11 with CAD and 4 with DCM) to calculate % uptake in the myocardium and to correlate its uptake with biochemical data, including blood sugar (BS), nonesterified fatty acid (NEFA) and insulin in the blood. BMIPP was administered at rest with overnight fasting state, and the anterior and posterior whole body imaging was performed one hour later. The background corrected whole myocardial counts were calculated to obtain %BMIPP uptake. In addition, the heart to mediastinum count ratio (H/M ratio) was calculated from the mean counts in the heart and the upper mediastinum in the anterior view. The %BMIPP uptake was 3.70 +/- 1.22% and H/M ratio was 2.30 +/- 0.23. The patients with DCM showed higher %BMIPP uptake values (DCM = 5.58 +/- 0.67% vs. CAD = 3.09 +/- 0.97% and HCM = 3.63 +/- 0.86%, both p < 0.01), but similar values of H/M ratio with other patients (DCM = 2.43 +/- 0.20, CAD = 2.22 +/- 0.25 and HCM = 2.32 +/- 0.20). Although the biochemical data varied at the time of the tracer administration, they were not significantly correlated with the %BMIPP uptake or H/M ratio. However, there was a significant correlation between %BMIPP uptake and H/M ratio with the correlation coefficient of 0.80 (p < 0.001). We conclude that the myocardial uptake of BMIPP is not influenced by the plasma substrate level under the fasting state.

Exercise-induced myocardial ischemia in patients with coronary artery disease: lack of evidence for platelet activation or fibrin formation in peripheral venous blood.

PubMed

Marcella, J J; Nichols, A B; Johnson, L L; Owen, J; Reison, D S; Kaplan, K L; Cannon, P J

1983-05-01

The hypothesis that exercise-induced myocardial ischemia is associated with abnormal platelet activation and fibrin formation or dissolution was tested in patients with coronary artery disease undergoing upright bicycle stress testing. In vivo platelet activation was assessed by radioimmunoassay of platelet factor 4, beta-thrombo-globulin and thromboxane B2. In vivo fibrin formation was assessed by radioimmunoassay of fibrinopeptide A, and fibrinolysis was assessed by radioimmunoassay of thrombin-increasable fibrinopeptide B which reflects plasmin cleavage of fibrin I. Peripheral venous concentrations of these substances were measured in 10 normal subjects and 13 patients with coronary artery disease at rest and during symptom-limited peak exercise. Platelet factor 4, beta-thromboglobulin and thromboxane B2 concentrations were correlated with rest and exercise catecholamine concentrations to determine if exercise-induced elevation of norepinephrine and epinephrine enhances platelet activation. Left ventricular end-diastolic and end-systolic volumes, ejection fraction and segmental wall motion were measured at rest and during peak exercise by first pass radionuclide angiography. All patients with coronary artery disease had documented exercise-induced myocardial ischemia manifested by angina pectoris, ischemic electrocardiographic changes, left ventricular segmental dyssynergy and a reduction in ejection fraction. Rest and peak exercise plasma concentrations were not significantly different for platelet factor 4, beta-thromboglobulin, thromboxane B2, fibrinopeptide A and thrombin-increasable fibrinopeptide B. Peripheral venous concentrations of norepinephrine and epinephrine increased significantly (p less than 0.001) in both groups of patients. The elevated catecholamine levels did not lead to detectable platelet activation. This study demonstrates that enhanced platelet activation, thromboxane release and fibrin formation or dissolution are not detectable in peripheral venous blood of patients with coronary disease during exercise-induced myocardial ischemia.

Assessment of myocardial metabolic rate of glucose by means of Bayesian ICA and Markov Chain Monte Carlo methods in small animal PET imaging

NASA Astrophysics Data System (ADS)

Berradja, Khadidja; Boughanmi, Nabil

2016-09-01

In dynamic cardiac PET FDG studies the assessment of myocardial metabolic rate of glucose (MMRG) requires the knowledge of the blood input function (IF). IF can be obtained by manual or automatic blood sampling and cross calibrated with PET. These procedures are cumbersome, invasive and generate uncertainties. The IF is contaminated by spillover of radioactivity from the adjacent myocardium and this could cause important error in the estimated MMRG. In this study, we show that the IF can be extracted from the images in a rat heart study with 18F-fluorodeoxyglucose (18F-FDG) by means of Independent Component Analysis (ICA) based on Bayesian theory and Markov Chain Monte Carlo (MCMC) sampling method (BICA). Images of the heart from rats were acquired with the Sherbrooke small animal PET scanner. A region of interest (ROI) was drawn around the rat image and decomposed into blood and tissue using BICA. The Statistical study showed that there is a significant difference (p < 0.05) between MMRG obtained with IF extracted by BICA with respect to IF extracted from measured images corrupted with spillover.

Fluid phase biopsy for detection and characterization of circulating endothelial cells in myocardial infarction

NASA Astrophysics Data System (ADS)

Bethel, Kelly; Luttgen, Madelyn S.; Damani, Samir; Kolatkar, Anand; Lamy, Rachelle; Sabouri-Ghomi, Mohsen; Topol, Sarah; Topol, Eric J.; Kuhn, Peter

2014-02-01

Elevated levels of circulating endothelial cells (CECs) occur in response to various pathological conditions including myocardial infarction (MI). Here, we adapted a fluid phase biopsy technology platform that successfully detects circulating tumor cells in the blood of cancer patients (HD-CTC assay), to create a high-definition circulating endothelial cell (HD-CEC) assay for the detection and characterization of CECs. Peripheral blood samples were collected from 79 MI patients, 25 healthy controls and six patients undergoing vascular surgery (VS). CECs were defined by positive staining for DAPI, CD146 and von Willebrand Factor and negative staining for CD45. In addition, CECs exhibited distinct morphological features that enable differentiation from surrounding white blood cells. CECs were found both as individual cells and as aggregates. CEC numbers were higher in MI patients compared with healthy controls. VS patients had lower CEC counts when compared with MI patients but were not different from healthy controls. Both HD-CEC and CellSearch® assays could discriminate MI patients from healthy controls with comparable accuracy but the HD-CEC assay exhibited higher specificity while maintaining high sensitivity. Our HD-CEC assay may be used as a robust diagnostic biomarker in MI patients.

Patient-specific assessment of left ventricular thrombogenesis risk after acute myocardial infarction: a pilot clinical study

NASA Astrophysics Data System (ADS)

Rossini, L.; Khan, A.; Del Alamo, J. C.; Martinez-Legazpi, P.; Pérez Del Villar, C.; Benito, Y.; Yotti, R.; Barrio, A.; Delgado-Montero, A.; Gonzalez-Mansilla, A.; Fernandez-Avilés, F.; Bermejo, J.

2016-11-01

Left ventricular thrombosis (LVT) is a major complication of acute myocardial infarction (AMI). In these patients, the benefits of chronic anticoagulation therapy need to be balanced with its pro-hemorrhagic effects. Blood stasis in the cardiac chambers, a risk factor for LVT, is not addressed in current clinical practice. We recently developed a method to quantitatively assess the blood residence time (RT) inside the left ventricle (LV) based on 2D color-Doppler velocimetry (echo-CDV). Using time-resolved blood velocity fields acquired non-invasively, we integrate a modified advection equation to map intraventricular stasis regions. Here, we present how this tool can be used to estimate the risk of LVT in patients with AMI. 73 patients with a first anterior-AMI were studied by echo-CDV and RT analysis within 72h from admission and at a 5-month follow-up. Patients who eventually develop LVT showed early abnormalities of intraventricular RT: the apical region with RT>2s was significantly larger, had a higher RT and a longer wall contact length. Thus, quantitative analysis of intraventricular flow based on echocardiography may provide subclinical markers of LV thrombosis risk to guide clinical decision making.

Essential Hypotension and Allostasis Registry

ClinicalTrials.gov

2018-03-30

Blood Pressure; Depression; Panic Attack; Fibromyalgia; POTS; Inappropriate Sinus Tachycardia; Coronary Heart Disease; Acute Coronary Syndrome (ACS); Acute Myocardial Infarction (AMI); Cerebrovascular Disease (CVD); Transient Ischemic Attack (TIA); Atrial Fibrillation; Diabetes Mellitus; Cancer; Systolic Heart Failure; Diastolic Heart Failure; Chronic Fatigue Syndrome; Syncope; Vasovagal Syncope

Differences of serum interleukin-6 levels in normotensive and preeclampsia women

NASA Astrophysics Data System (ADS)

Lumbanraja, S. N.; Junitasari, R.; Pasaribu, H. P.

2018-03-01

Red cell distribution width (RDW) has been shown higher with the increase of inflammatory activity. As CD4 count is not available in all cities in Indonesia, RDW was hoped to be the next promising marker to predict the progression of HIV infection. This study aims to find the association of RDW with aCD4 count in HIV-positive reproductive women in Indonesia. It was a prospective cross sectional study enrolled 37 consented outpatients HIV-positive reproductive women in Haji Adam Malik General Hospital, Medan, Indonesia. A 10 mL blood was taken, separated into two tubes for complete blood count and CD4 count. Data were collected and analyzed with SPSS 19.Mean CD4 absolute was lowest in >14.5% RDW group but without statistical significance. By classify CD4 absolute count, CD4 absolute ≤350/mm3 showed significantly higher RDW than CD4 absolute >350/mm3 (13.98±2.10% vs 12.79±0.88% p=0.02). No correlation was between RDW and CD4 absolute, as well as, with CD4%.In conclusion, high RDW can be a promising marker to predict the low CD4 count in HIV-positive reproductive women within antiretroviral therapy.

TU-G-BRA-08: BEST IN PHYSICS (JOINT IMAGING-THERAPY): Hybrid PET-MRI Imaging of Acute Radiation Induced Cardiac Toxicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

El-Sherif, O; Xhaferllari, I; Gaede, S

Purpose: To identify the presence of low-dose radiation induced cardiac toxicity in a canine model using hybrid positron emission tomography (PET) and magnetic resonance imaging (MRI). Methods: Research ethics board approval was obtained for a longitudinal imaging study of 5 canines after cardiac irradiation. Animals were imaged at baseline, 1 week post cardiac irradiation, and 1 month post cardiac irradiation using a hybrid PET- MRI system (Biograph mMR, Siemens Healthcare). The imaging protocol was designed to assess acute changes in myocardial perfusion and inflammation. Myocardial perfusion imaging was performed using N13-ammonia tracer followed by a dynamic PET acquisition scan. Amore » compartmental tracer kinetic model was used for absolute perfusion quantification. Myocardial inflammation imaging was performed using F18-fluorodeoxyglucose (FDG) tracer. The standard uptake value (SUV) over a region encompassing the whole heart was used to compare FDG scans. All animals received a simulation CT scan (GE Medical Systems) for radiation treatment planning. Radiation treatment plans were created using the Pinncale3 treatment planning system (Philips Radiation Oncology Systems) and designed to resemble the typical cardiac exposure during left-sided breast cancer radiotherapy. Cardiac irradiations were performed in a single fraction using a TrueBeam linear accelerator (Varian Medical Systems). Results: The delivered dose (mean ± standard deviation) to heart was 1.8±0.2 Gy. Reductions in myocardial stress perfusion relative to baseline were observed in 2 of the 5 animals 1 month post radiation. A global inflammatory response 1 month post radiation was observed in 4 of the 5 animals. The calculated SUV at 1 month post radiation was significantly higher (p=0.05) than the baseline SUV. Conclusion: Low doses of cardiac irradiation (< 2 Gy) may lead to myocardial perfusion defects and a global inflammatory response that can be detectable as early as 1 month post irradiation using hybrid PET-MRI imaging techniques.« less

The Comparison of the Outcomes between Primary PCI, Fibrinolysis, and No Reperfusion in Patients ≥ 75 Years Old with ST-Segment Elevation Myocardial Infarction: Results from the Chinese Acute Myocardial Infarction (CAMI) Registry.

PubMed

Peiyuan, He; Jingang, Yang; Haiyan, Xu; Xiaojin, Gao; Ying, Xian; Yuan, Wu; Wei, Li; Yang, Wang; Xinran, Tang; Ruohua, Yan; Chen, Jin; Lei, Song; Xuan, Zhang; Rui, Fu; Yunqing, Ye; Qiuting, Dong; Hui, Sun; Xinxin, Yan; Runlin, Gao; Yuejin, Yang

2016-01-01

Only a few randomized trials have analyzed the clinical outcomes of elderly ST-segment elevation myocardial infarction (STEMI) patients (≥ 75 years old). Therefore, the best reperfusion strategy has not been well established. An observational study focused on clinical outcomes was performed in this population. Based on the national registry on STEMI patients, the in-hospital outcomes of elderly patients with different reperfusion strategies were compared. The primary endpoint was defined as death. Secondary endpoints included recurrent myocardial infarction, ischemia driven revascularization, myocardial infarction related complications, and major bleeding. Multivariable regression analysis was performed to adjust for the baseline disparities between the groups. Patients who had primary percutaneous coronary intervention (PCI) or fibrinolysis were relatively younger. They came to hospital earlier, and had lower risk of death compared with patients who had no reperfusion. The guideline recommended medications were more frequently used in patients with primary PCI during the hospitalization and at discharge. The rates of death were 7.7%, 15.0%, and 19.9% respectively, with primary PCI, fibrinolysis, and no reperfusion (P < 0.001). Patients having primary PCI also had lower rates of heart failure, mechanical complications, and cardiac arrest compared with fibrinolysis and no reperfusion (P < 0.05). The rates of hemorrhage stroke (0.3%, 0.6%, and 0.1%) and other major bleeding (3.0%, 5.0%, and 3.1%) were similar in the primary PCI, fibrinolysis, and no reperfusion group (P > 0.05). In the multivariable regression analysis, primary PCI outweighs no reperfusion in predicting the in-hospital death in patients ≥ 75 years old. However, fibrinolysis does not. Early reperfusion, especially primary PCI was safe and effective with absolute reduction of mortality compared with no reperfusion. However, certain randomized trials were encouraged to support the conclusion.

The mitochondria-targeting peptide elamipretide diminishes circulating HtrA2 in ST-segment elevation myocardial infarction.

PubMed

Hortmann, Marcus; Robinson, Samuel; Mohr, Moritz; Mauler, Maximillian; Stallmann, Daniela; Reinöhl, Jochen; Duerschmied, Daniel; Peter, Karlheinz; Carr, James; Gibson, C Michael; Bode, Christoph; Ahrens, Ingo

2017-05-01

The extent of myocardial damage in patients with ST-segment elevation myocardial infarction (STEMI) depends on both the time to reperfusion as well as injury induced by ischaemia-reperfusion resulting in a cascade of cellular and humoral reactions. As a consequence of ischaemia-reperfusion in the heart, the high-temperature requirement serine peptidase 2 (HtrA2) is translocated from the mitochondria to the cytosol, whereupon it induces protease activity-dependent apoptosis mediated via caspases. Myocardial damage induced by reperfusion cannot be monitored due to a current lack in specific biomarkers. We examined the serum level of HtrA2 as a potentially novel biomarker for mitochondrial-induced cardiomyocyte apoptosis. After informed consent, peripheral blood was obtained from patients ( n=19) with first-time acute anterior STEMI after percutaneous coronary intervention. Within this group, 10 of the patients received the mitochondria-targeting peptide elamipretide (phase 2a clinical study EMBRACE (NCT01572909)). Blood was also obtained from a control group of healthy donors ( n=16). The serum level of HtrA2 was measured by an enzyme-linked immunosorbent assay (ELISA). In a murine model of myocardial ischaemia-reperfusion injury, HtrA2 was determined in plasma by ELISA after left anterior descending artery occlusion. HtrA2 median was significantly increased in patients with STEMI compared to healthy controls 392.4 (240.7-502.8) pg/mL vs. 1805.5 (981.3-2220.1) pg/mL ( P⩽0.05). Elamipretide significantly reduced the HtrA2 median serum level after myocardial infarction 1805.5 (981.3-2220.1) pg/mL vs. 496.5 (379.4-703.8) pg/mL ( P⩽0.05). Left anterior descending artery occlusion in mice significantly increased HtrA2 mean in plasma (117.4 fg/ml±SEM 28.1 vs. 525.2 fg/ml±SEM 96; P⩽0.05). Compared to healthy controls, we found significantly increased serum levels of HtrA2 in patients with STEMI. The result was validated in a murine model of myocardial ischaemia-reperfusion injury. In humans the increased serum level was significantly reduced by the mitochondria-targeting peptide elamipretide. In conclusion, HtrA2 is detectable in serum of patients with STEMI and might present a novel biomarker for mitochondrial-induced cardiomyocyte apoptosis. Consequently, HtrA2 may also show promise as a biomarker for the identification of ischaemia-reperfusion injury. However, this must be validated in a lager clinical trial.

Projected Impact of a Sodium Consumption Reduction Initiative in Argentina: An Analysis from the CVD Policy Model – Argentina

PubMed Central

Konfino, Jonatan; Mekonnen, Tekeshe A.; Coxson, Pamela G.; Ferrante, Daniel; Bibbins-Domingo, Kirsten

2013-01-01

Background Cardiovascular disease (CVD) is the leading cause of death in adults in Argentina. Sodium reduction policies targeting processed foods were implemented in 2011 in Argentina, but the impact has not been evaluated. The aims of this study are to use Argentina-specific data on sodium excretion and project the impact of Argentina’s sodium reduction policies under two scenarios - the 2-year intervention currently being undertaken or a more persistent 10 year sodium reduction strategy. Methods We used Argentina-specific data on sodium excretion by sex and projected the impact of the current strategy on sodium consumption and blood pressure decrease. We assessed the projected impact of sodium reduction policies on CVD using the Cardiovascular Disease (CVD) Policy Model, adapted to Argentina, modeling two alternative policy scenarios over the next decade. Results Our study finds that the initiative to reduce sodium consumption currently in place in Argentina will have substantial impact on CVD over the next 10 years. Under the current proposed policy of 2-year sodium reduction, the mean sodium consumption is projected to decrease by 319–387 mg/day. This decrease is expected to translate into an absolute reduction of systolic blood pressure from 0.93 mmHg to 1.81 mmHg. This would avert about 19,000 all-cause mortality, 13,000 total myocardial infarctions, and 10,000 total strokes over the next decade. A more persistent sodium reduction strategy would yield even greater CVD benefits. Conclusion The impact of the Argentinean initiative would be effective in substantially reducing mortality and morbidity from CVD. This paper provides evidence-based support to continue implementing strategies to reduce sodium consumption at a population level. PMID:24040085

Cardiovascular Response to Recreational Hockey in Middle-Aged Men.

PubMed

Goodman, Zack A; Thomas, Scott G; Wald, Robert C; Goodman, Jack M

2017-06-15

The present study examined the hemodynamic response to recreational pick-up hockey relative to maximal exercise testing in middle-aged men. A total of 23 men with a mean age of 53 ± 7 years were studied. Graded exercise testing on a cycle ergometer determined maximal oxygen consumption, blood pressure (BP), and heart rate (HR). Ambulatory BP and Holter electrocardiographic monitoring was performed during one of their weekly hockey games (mean duration = 45 ± 7.2 minutes): for "On-Ice" responses (PLAY; data recorded while standing immediately after a shift; 8.0 ± 1.4 shifts per game) and during seated recovery (BENCH), 15 minutes after the game. On-Ice HRs and BPs were significantly higher than values obtained during maximal cycle exercise, respectively (HR 174 ± 8.9 vs 163 ± 11.0 beats/min) (systolic blood pressure 202 ± 20 vs 173 ± 31 mm Hg; p <0.05). Both systolic and diastolic blood pressures decreased significantly throughout the duration of the game, whereas HR increased from 139 ± 20 to 155 ± 16 beats/min during the game. The myocardial oxygen demand (myocardial time tension index) increased significantly during PLAY concurrent with a decrease in estimated myocardial oxygen supply (diastolic pressure time index), with the endocardial viability ratio during PLAY demonstrating a significant decrease during the third quarter of the game (1.25 ± 0.24) versus the first quarter (1.56 ± 0.30), which remained depressed 15 minutes post-game (p <0.05). In conclusion, recreational pick-up hockey in middle-aged men is an extremely vigorous interval exercise with increasing relative intensity as the game progresses. Hockey elicits peak BPs and HRs that can exceed values observed during maximal exercise testing and is characterized by progressive increases in myocardial oxygen demand and lowered supply during PLAY and BENCH time. Given the progressive and high cardiovascular demands, caution is warranted when estimating the cardiovascular demands of hockey from clinical stress testing, particularly in those whom coronary reserve may be compromised. Copyright © 2017 Elsevier Inc. All rights reserved.

Is cold or warm blood cardioplegia superior for myocardial protection?

PubMed Central

Abah, Udo; Roberts, Patrick Garfjeld; Ishaq, Muhammad; De Silva, Ravi

2012-01-01

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether the use of warm or cold blood cardioplegia has superior myocardial protection. More than 192 papers were found using the reported search, of which 20 represented the best evidence to answer the clinical question. The authors, journal, date, country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. A good breadth of high-level evidence addressing this clinical dilemma is available, including a recent meta-analysis and multiple large randomized clinical trials. Yet despite this level of evidence, no clear significant clinical benefit has been demonstrated by warm or cold blood cardioplegia. This suggests that neither method is significantly superior and that both provide similar efficacy of myocardial protection. The meta-analysis, including 41 randomized control trials (5879 patients in total), concluded that although a lower cardiac enzyme release and improved postoperative cardiac index was demonstrated in the warm cardioplegia group, this benefit was not reflected in clinical outcomes, which were similar in both groups. This theme of benefit in biochemical markers, physiological metrics and non-fatal postoperative events in the warm cardioplegia group ran throughout the literature, in particular the ‘Warm Heart investigators’ who conducted a randomized trial of 1732 patients, demonstrated a reduction in postoperative low output syndrome (6.1 versus 9.3%, P = 0.01) in the warm cardioplegia group, but no significant drop in 30-day all-cause mortality (1.4 versus 2.5%, P = 0.12). However, their later follow-up indicates non-fatal postoperative events predict reduced late survival, independent of cardioplegia. A minority of studies suggested a benefit of cold cardioplegia over warm in particular patient subgroups: One group conducted a retrospective study of 520 patients who required prolonged aortic cross-clamp times, results demonstrated less myocardial damage and reduced postoperative cardiac mortality and morbidity in the cold group. The clinical bottom line is that warm and cold cardioplegia result in similar short-term mortality. However, large studies have shown that warm cardioplegia reduces adverse post-operative events; the significance of which is unclear. PMID:22402501

Comprehensive characterisation of hypertensive heart disease left ventricular phenotypes

PubMed Central

Rodrigues, Jonathan C L; Amadu, Antonio Matteo; Dastidar, Amardeep Ghosh; Szantho, Gergley V; Lyen, Stephen M; Godsave, Cattleya; Ratcliffe, Laura E K; Burchell, Amy E; Hart, Emma C; Hamilton, Mark C K; Nightingale, Angus K; Paton, Julian F R; Manghat, Nathan E; Bucciarelli-Ducci, Chiara

2016-01-01

Objective Myocardial intracellular/extracellular structure and aortic function were assessed among hypertensive left ventricular (LV) phenotypes using cardiovascular magnetic resonance (CMR). Methods An observational study from consecutive tertiary hypertension clinic patients referred for CMR (1.5 T) was performed. Four LV phenotypes were defined: (1) normal with normal indexed LV mass (LVM) and LVM to volume ratio (M/V), (2) concentric remodelling with normal LVM but elevated M/V, (3) concentric LV hypertrophy (LVH) with elevated LVM but normal indexed end-diastolic volume (EDV) or (4) eccentric LVH with elevated LVM and EDV. Extracellular volume fraction was measured using T1-mapping. Circumferential strain was calculated by voxel-tracking. Aortic distensibility was derived from high-resolution aortic cines and contemporaneous blood pressure measurements. Results 88 hypertensive patients (49±14 years, 57% men, systolic blood pressure (SBP): 167±30 mm Hg, diastolic blood pressure (DBP): 96±14 mm Hg) were compared with 29 age-matched/sex-matched controls (47±14 years, 59% men, SBP: 128±12 mm Hg, DBP: 79±10 mm Hg). LVH resulted from increased myocardial cell volume (eccentric LVH: 78±19 mL/m2 vs concentric LVH: 73±15 mL/m2 vs concentric remodelling: 55±9 mL/m2, p<0.05, respectively) and interstitial fibrosis (eccentric LVH: 33±10 mL/m2 vs concentric LVH: 30±10 mL/m2 vs concentricremodelling: 19±2 mL/m2, p<0.05, respectively). LVH had worst circumferential impairment (eccentric LVH: −12.8±4.6% vs concentric LVH: −15.5±3.1% vs concentric remodelling: –17.1±3.2%, p<0.05, respectively). Concentric remodelling was associated with reduced aortic distensibility, but not with large intracellular/interstitial expansion or myocardial dysfunction versus controls. Conclusions Myocardial interstitial fibrosis varies across hypertensive LV phenotypes with functional consequences. Eccentric LVH has the most fibrosis and systolic impairment. Concentric remodelling is only associated with abnormal aortic function. Understanding these differences may help tailor future antihypertensive treatments. PMID:27260191

Apparatus and method for processing Korotkov sounds. [for blood pressure measurement

NASA Technical Reports Server (NTRS)

Golden, D. P., Jr.; Hoffler, G. W.; Wolthuis, R. A. (Inventor)

1974-01-01

A Korotkov sound processor, used in a noninvasive automatic blood measuring system where the brachial artery is occluded by an inflatable cuff, is disclosed. The Korotkoff sound associated with the systolic event is determined when the ratio of the absolute value of a voltage signal, representing Korotkov sounds in the range of 18 to 26 Hz to a maximum absolute peak value of the unfiltered signals, first equals or exceeds a value of 0.45. Korotkov sound associated with the diastolic event is determined when a ratio of the voltage signal of the Korotkov sounds in the range of 40 to 60 Hz to the absolute peak value of such signals within a single measurement cycle first falls below a value of 0.17. The processor signals the occurrence of the systolic and diastolic events and these signals can be used to control a recorder to record pressure values for these events.

Mechanical assistance by intra-aortic balloon pump counterpulsation during reperfusion increases coronary blood flow and mitigates the no-reflow phenomenon: an experimental study.

PubMed

Pierrakos, Charalampos N; Bonios, Michael J; Drakos, Stavros G; Charitos, Efstratios I; Tsolakis, Elias J; Ntalianis, Argirios; Nanas, Serafim N; Charitos, Christos E; Nanas, John N; Terrovitis, John V

2011-09-01

The effects of the intra-aortic balloon pump (IABP) counterpulsation on the extent of myocardial infarction (MI), the no-reflow phenomenon (NRP), and coronary blood flow (CBF) during reperfusion in an ischemia-reperfusion experimental model have not been clarified. Eleven pigs underwent occlusion of the mid left anterior descending coronary artery for 1 h, followed by reperfusion for 2 h. CBF, distal to the occlusion site, was measured. In six experiments, IABP support began 10 min before, and continued throughout reperfusion (IABP Group). Five pigs without IABP support served as controls. At the end of each experiment, the myocardial area at risk (MAR) of infarction and the extent of MI and NRP were measured. Hemodynamic measurements at baseline and during coronary occlusion were similar in both groups. During reperfusion, systolic aortic blood pressure was significantly lower in the IABP Group than in controls. In the IABP Group, CBF reached a peak at 5 min of reperfusion, gradually decreased, but remained higher than at baseline, and significantly higher than in controls throughout the 2 h of reperfusion. In controls, CBF increased significantly above baseline immediately after the onset of reperfusion, then returned to baseline within 90 min. The extent of NRP (37 ± 25% vs. 68 ± 17%, P = 0.047) and MI (39 ± 23% vs. 67 ± 13%, P = 0.036), both expressed as percentage of MAR, was significantly less in the IABP group than in controls. After prolonged myocardial ischemia, IABP assistance started just 10 min before and throughout reperfusion increased CBF and limited infarct size and extent of NRP. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Is cardiovascular disease in patients with diabetes associated with serum levels of MMP-2, LOX, and the elastin degradation products ELM and ELM-2?

PubMed

Preil, Simone Andrea Rørdam; Thorsen, Anne-Sofie Faarvang; Christiansen, Anne Lindegaard; Poulsen, Mikael Kjær; Karsdal, Morten Asser; Leeming, Diana Julie; Rasmussen, Lars Melholt

2017-11-01

Diabetes mellitus type 2 (T2DM) is a significant risk factor for the development of cardiovascular diseases (CVDs). In a previous microarray study of internal mammary arteries from patients with and without T2DM, we observed several elastin-related genes with altered mRNA-expression in diabetic patients, namely matrix metalloproteinase 2 (MMP-2), lysyl oxidase (LOX) and elastin itself. In this study we investigate whether the serum concentrations of elastin-related proteins correlate to signs of CVD in patients with T2DM. Blood samples from 302 type 2 diabetic patients were analysed for MMP-2, LOX, and the elastin degradation products ELM and ELM2. The results were investigated for correlations to signs of CVD in different vascular territories, as determined by myocardial perfusion scintigraphy, carotid artery thickness and ankle-brachial blood pressure index. T2DM patients with peripheral arterial disease (low ankle-brachial index) (PAD) display higher levels of MMP-2 and ELM compared to patients without PAD. However, none of the proteins or degradation products correlated with myocardial ischemia or a combined measure of CVD-signs, including myocardial ischemia, increased carotid thickness and decreased ankle-brachial blood pressure. Our results suggest that the diabetic environment affects the circulating amounts of MMP-2 and ELM in patients with PAD. However, the same connection could not be seen in diabetic patients with CVD broadly identified in three vascular territories. LOX and ELM-2 did not correlate to any type of CVD. Overall, serum levels of elastin-related molecules are only remotely related to CVD in type 2 diabetes.

Mortality in patients with TIMI 3 flow after PCI in relation to time delay to reperfusion.

PubMed

Vichova, Teodora; Maly, Marek; Ulman, Jaroslav; Motovska, Zuzana

2016-03-01

Percutaneous coronary intervention (PCI) performed within 12 h from symptom onset enables complete blood flow restoration in infarct-related artery in 90% of patients. Nevertheless, even with complete restoration of epicardial blood flow in culprit vessel (postprocedural Thrombolysis in Myocardial Infarction (TIMI) flow grade 3), myocardial perfusion at tissue level may be insufficient. We hypothesized that the outcome of patients with STEMI/bundle branch block (BBB)-myocardial infarction and post-PCI TIMI 3 flow is related to the time to reperfusion. Observational study based on a retrospective analysis of population of 635 consecutive patients with STEMI/BBB-MI and post-PCI TIMI 3 flow from January 2009 to December 2011 (mean age 63 years, 69.6% males). Mortality of patients was evaluated in relation to the time from symptom onset to reperfusion. A total of 83 patients (13.07%) with postprocedural TIMI 3 flow after PCI had died at 1-year follow-up. Median TD in patients who survived was 3.92 h (iqr 5.43), in patients who died 6.0 h (iqr 11.42), P = 0.004. Multiple logistic regression analysis identified time delay ≥ 9 h as significantly related to 1-year mortality of patients with STEMI/BBB-MI and post-PCI TIMI 3 flow (OR 1.958, P = 0.026). Other significant variables associated with mortality in multivariate regression analysis were: left ventricle ejection fraction < 30% (P = 0.006), age > 65 years (P < 0.001), Killip class >2 (P <0.001), female gender (P = 0.019), and creatinine clearance < 30 mL/min (P < 0.001). Time delay to reperfusion is significantly related to 1-year mortality of patients with STEMI/BBB-MI and complete restoration of epicardial blood flow in culprit vessel after PCI.

Reliability of the rapid bedside whole-blood quantitative cardiac troponin T assay in the diagnosis of myocardial injury in patients with acute coronary syndrome.

PubMed

Saadeddin, Salam; Habbab, Mohammed; Siddieg, Hisham; Fayomi, Mahmoud; Dafterdar, Rofaida

2004-03-01

A rapid bedside whole-blood quantitative cTnT assay has recently been developed. We evaluated the reliability of this test for the diagnosis of myocardial injury in patients with acute coronary syndrome (ACS). Whole-blood cTnT levels were measured in 96 patients with ACS using the Roche Cardiac Reader(R) rapid bedside assay device, and the results were compared with serum cTnT levels in the same patients measured by the Roche Elecsys(R) Immunoanalyzer. There were 50 patients with clinical evidence of myocardial injury and 56 without. From the qualitative point of view (reporting negative or positive tests), the results of the rapid bedside tests were identical to those obtained by the serum immunoanalyzer. From quantitative the point of view, the rapid bedside tests could not measure exact values below 0.1 ng/ml (reported negative) or above 2.0 ng/ml (reported >2.0). The measurements made by the rapid bedside tests within the range of 0.1 to 2.0 ng/ml correlated well with those of the serum immunoanalyzer (Cardiac Reader(R) cTnT=0.61, Elecsys(R) cTnT+0.12; r=0.88), but their mean values were significantly lower (1.20I0.71 vs. 1.41I1.03, p=0.0007). The rapid bedside cTnT assay correlates well with immunoanalyzer measurements between the values of 0.1 and 2.0 ng/ml. However, they tend to give significantly lower values and fail to give exact values below 0.1 and above 2.0 ng/ml, which may affect their performance in monitoring and managing patients with ACS, and limit their use in predicting outcome.

Splenic release of platelets contributes to increased circulating platelet size and inflammation after myocardial infarction.

PubMed

Gao, Xiao-Ming; Moore, Xiao-Lei; Liu, Yang; Wang, Xin-Yu; Han, Li-Ping; Su, Yidan; Tsai, Alan; Xu, Qi; Zhang, Ming; Lambert, Gavin W; Kiriazis, Helen; Gao, Wei; Dart, Anthony M; Du, Xiao-Jun

2016-07-01

Acute myocardial infarction (AMI) is characterized by a rapid increase in circulating platelet size but the mechanism for this is unclear. Large platelets are hyperactive and associated with adverse clinical outcomes. We determined mean platelet volume (MPV) and platelet-monocyte conjugation (PMC) using blood samples from patients, and blood and the spleen from mice with AMI. We further measured changes in platelet size, PMC, cardiac and splenic contents of platelets and leucocyte infiltration into the mouse heart. In AMI patients, circulating MPV and PMC increased at 1-3 h post-MI and MPV returned to reference levels within 24 h after admission. In mice with MI, increases in platelet size and PMC became evident within 12 h and were sustained up to 72 h. Splenic platelets are bigger than circulating platelets in normal or infarct mice. At 24 h post-MI, splenic platelet storage was halved whereas cardiac platelets increased by 4-fold. Splenectomy attenuated all changes observed in the blood, reduced leucocyte and platelet accumulation in the infarct myocardium, limited infarct size and alleviated cardiac dilatation and dysfunction. AMI-induced elevated circulating levels of adenosine diphosphate and catecholamines in both human and the mouse, which may trigger splenic platelet release. Pharmacological inhibition of angiotensin-converting enzyme, β1-adrenergic receptor or platelet P2Y12 receptor reduced platelet abundance in the murine infarct myocardium albeit having diverse effects on platelet size and PMC. In conclusion, AMI evokes release of splenic platelets, which contributes to the increase in platelet size and PMC and facilitates myocardial accumulation of platelets and leucocytes, thereby promoting post-infarct inflammation. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

Overweight female rats selectively breed for low aerobic capacity exhibit increased myocardial fibrosis and diastolic dysfunction

PubMed Central

Johnson, Megan S.; Ma, Lixin; Pulakat, Lakshmi; Mugerfeld, Irina; Hayden, Melvin R.; Garro, Mona; Knight, William; Britton, Steven L.; Koch, Lauren G.; Sowers, James R.

2012-01-01

The statistical association between endurance exercise capacity and cardiovascular disease suggests that impaired aerobic metabolism underlies the cardiovascular disease risk in men and women. To explore this connection, we applied divergent artificial selection in rats to develop low-capacity runner (LCR) and high-capacity runner (HCR) rats and found that disease risks segregated strongly with low running capacity. Here, we tested if inborn low aerobic capacity promotes differential sex-related cardiovascular effects. Compared with HCR males (HCR-M), LCR males (LCR-M) were overweight by 34% and had heavier retroperitoneal, epididymal, and omental fat pads; LCR females (LCR-F) were 20% heavier than HCR females (HCR-F), and their retroperitoneal, but not perireproductive or omental, fat pads were heavier as well. Unlike HCR-M, blood pressure was elevated in LCR-M, and this was accompanied by left ventricular (LV) hypertrophy. Like HCR-F, LCR-F exhibited normal blood pressure and LV weight as well as increased spontaneous cage activity compared with males. Despite normal blood pressures, LCR-F exhibited increased myocardial interstitial fibrosis and diastolic dysfunction, as indicated by increased LV stiffness, a decrease in the initial filling rate, and an increase in diastolic relaxation time. Although females exhibited increased arterial stiffness, ejection fraction was normal. Increased interstitial fibrosis and diastolic dysfunction in LCR-F was accompanied by the lowest protein levels of phosphorylated AMP-actived protein kinase [phospho-AMPK (Thr172)] and silent information regulator 1. Thus, the combination of risk factors, including female sex, intrinsic low aerobic capacity, and overweightness, promote myocardial stiffness/fibrosis sufficient to induce diastolic dysfunction in the absence of hypertension and LV hypertrophy. PMID:22345570

The absolute counting of red cell-derived microparticles with red cell bead by flow rate based assay.

PubMed

Nantakomol, Duangdao; Imwong, Malika; Soontarawirat, Ingfar; Kotjanya, Duangporn; Khakhai, Chulalak; Ohashi, Jun; Nuchnoi, Pornlada

2009-05-01

Activation of red blood cell is associated with the formation of red cell-derived microparticles (RMPs). Analysis of circulating RMPs is becoming more refined and clinically useful. A quantitative Trucount tube method is the conventional method uses for quantitating RMPs. In this study, we validated a quantitative method called "flow rate based assay using red cell bead (FCB)" to measure circulating RMPs in the peripheral blood of healthy subjects. Citrated blood samples collected from 30 cases of healthy subjects were determined the RMPs count by using double labeling of annexin V-FITC and anti-glycophorin A-PE. The absolute RMPs numbers were measured by FCB, and the results were compared with the Trucount or with flow rate based calibration (FR). Statistical correlation and agreement were analyzed using linear regression and Bland-Altman analysis. There was no significant difference in the absolute number of RMPs quantitated by FCB when compared with those two reference methods including the Trucount tube and FR method. The absolute RMPs count obtained from FCB method was highly correlated with those obtained from Trucount tube (r(2) = 0.98, mean bias 4 cell/microl, limit of agreement [LOA] -20.3 to 28.3 cell/microl), and FR method (r(2) = 1, mean bias 10.3 cell/microl, and LOA -5.5 to 26.2 cell/microl). This study demonstrates that FCB is suitable and more affordable for RMPs quantitation in the clinical samples. This method is a low cost and interchangeable to latex bead-based method for generating the absolute counts in the resource-limited areas. (c) 2008 Clinical Cytometry Society.

Quantification of absolute blood velocity using LDA

NASA Astrophysics Data System (ADS)

Borozdova, M. A.; Fedosov, I. V.; Tuchin, V. V.

2018-04-01

We developed novel schematics of a Laser Doppler anemometer where measuring volume is comparable with the red blood cell (RBC) size and a small period of interference fringes improves device resolution. The technique was used to estimate Doppler frequency shift at flow velocity measurements. It has been shown that technique is applicable for measurements in whole blood.

Gualou Xiebai Decoction, a Traditional Chinese Medicine, Prevents Cardiac Reperfusion Injury of Hyperlipidemia Rat via Energy Modulation.

PubMed

Yan, Lu-Lu; Zhang, Wei-Yang; Wei, Xiao-Hong; Yan, Li; Pan, Chun-Shui; Yu, Yang; Fan, Jing-Yu; Liu, Yu-Ying; Zhou, Hua; Han, Jing-Yan; Yao, Xin-Sheng

2018-01-01

Background: Gualou Xiebai Decoction (GLXB) is a classic prescription of Chinese medicine used for the treatment of cardiac problems. The present study was designed to explore the effect and mechanism of GLXB on ischemia/reperfusion (I/R) induced disorders in myocardial structure and function, focusing on the regulation of energy metabolism and the RhoA/ROCK pathway. Methods: After hyperlipidemic rat model was established by oral administration of high fat diet, the rats were treated with GLXB for 6 weeks and subjected to 30 min occlusion of the left anterior descending coronary artery (LADCA) followed by 90 min reperfusion to elicit I/R challenge. Myocardial infarct size was assessed by Evans blue-TTC staining. Myocardial blood flow (MBF) and cardiac function were evaluated. Enzyme-linked immunosorbent assay was performed to examine the content of ATP, ADP, AMP, CK, CK-MB, LDH, cTnT, cTnI, and IL-6. Double staining of F-actin and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling was conducted to assess myocardial apoptosis. Expressions of ATP synthase subunit δ (ATP 5D), and RhoA and ROCK were determined by Western blotting. Results: Administration with GLXB at high dose for 6 weeks protected heart against I/R-induced MBF decrease, myocardial infarction and apoptosis, ameliorated I/R-caused impairment of cardiac function and myocardial structure, restored the decrease in the ratio of ADP/ATP and AMP/ATP, and the expression of ATP 5D with inhibiting the expression of RhoA and ROCK. Conclusions: Treatment with GLXB effectively protects myocardial structure and function from I/R challenge, possibly via regulating energy metabolism involving inactivation of RhoA/ROCK signaling pathway.

Aspirin Use for the Primary Prevention of Myocardial Infarction Among Men in North Carolina, 2013

PubMed Central

Tchwenko, Samuel; Perry, Geraldine S.

2015-01-01

Introduction The US Preventive Services Task Force recommends aspirin use for men aged 45 to 79, when the potential benefit of preventing myocardial infarctions outweighs the potential harm of gastrointestinal hemorrhage. We determined prevalence and predictors of aspirin use for primary prevention of myocardial infarction vis-à-vis risk among men aged 45 to 79 in North Carolina. Methods The study used data for men aged 45 to 79 without contraindications to aspirin use or a history of cardiovascular disease from the 2013 North Carolina Behavioral Risk Factor Surveillance System survey. Stratification by risk of myocardial infarction was based on history of diabetes, high cholesterol, high blood pressure, and smoking. Analyses were performed in Stata version 13.0 (StataCorp LP); survey commands were used to account for complex sampling design. Results Most respondents, 74.2% (95% confidence interval [CI], 71.2%–77.0%), had at least one risk factor for myocardial infarction. Prevalence of aspirin use among respondents with risk factors was 44.8% (95% CI, 41.0–48.5) and was significantly higher than the prevalence among respondents without risk factors (prevalence ratio: 1.44 [95% CI, 1.17–1.78]). No significant linear dose (number of risk factors)–response (taking aspirin) relationship was found (P for trend = .25). Older age predicted (P = .03) aspirin use among respondents with at least one myocardial infarction risk factor. Conclusion Most men aged 45 to 79 in North Carolina have at least one risk factor for myocardial infarction, but less than half use aspirin. Interventions aimed at boosting aspirin use are needed among at-risk men in North Carolina. PMID:26583574

Myocardial infarction in young men. Study of risk factors in nine countries.

PubMed Central

Dolder, M A; Oliver, M F

1975-01-01

In order to determine whether the development of myocardial infarction in different countries is associated with different risk factors, 240 male survivors, aged 40 or less, were studied in nine countries. In the seven centres in developed countries (Auckland, Melbourne, Los Angles/Atlanta, Cape Town, Tel Avic, Heidelberg, and Edinburgh) there was a high procedure of risk factors, particularly of hyperlipidaemia and cigarette smoking. The prevalence of hypertension, obesity, hyperglycaemia, and hyperuricaemia varied from centre to centre. Risk factors were less prevalent in Bombay and Singapore: the most common risks operating in Bombay seemed to be cigarette smoking and hyperglycaemia, while in Singpore cigarette smoking was the commonest. The mean age of the whole group was 35.4 years. Serum cholesterol levels of 7.25 mmol/l (280 mg/dl) or more were present in 25 per cent of all patients, serum triglyceride levels of 2.26 mmol/l )l200 mg/dl) or more in 35 per cent. 80 per cent of the patients were smokers, and 15 per cent were either for hypertension before myocardial infarction or had a raised blood pressure after myocardial infarction. Obesity was found in 19 per cent of all patients and serum uric acid levels over 0.5 mmol/l (8.5 mg/dl) in 17 per cent. 10 per cent of all patients were either treated for diabetes mellitus before myocardial infarction or showed an abnormal glucose tolerance after myocardial infarction. This collaborative study may help, by showing differences in the prevalence of risk factors, to indicate to each centre and to national and to international organizations, the direction for their future studies into the causation and prevention of myocardial infarction in young men. PMID:1137658

Enalapril protects against myocardial ischemia/reperfusion injury in a swine model of cardiac arrest and resuscitation

PubMed Central

Wang, Guoxing; Zhang, Qian; Yuan, Wei; Wu, Junyuan; Li, Chunsheng

2016-01-01

There is strong evidence to suggest that angiotensin-converting enzyme inhibitors (ACEIs) protect against local myocardial ischemia/reperfusion (I/R) injury. This study was designed to explore whether ACEIs exert cardioprotective effects in a swine model of cardiac arrest (CA) and resuscitation. Male pigs were randomly assigned to three groups: sham-operated group, saline treatment group and enalapril treatment group. Thirty minutes after drug infusion, the animals in the saline and enalapril groups were subjected to ventricular fibrillation (8 min) followed by cardiopulmonary resuscitation (up to 30 min). Cardiac function was monitored, and myocardial tissue and blood were collected for analysis. Enalapril pre-treatment did not improve cardiac function or the 6-h survival rate after CA and resuscitation; however, this intervention ameliorated myocardial ultrastructural damage, reduced the level of plasma cardiac troponin I and decreased myocardial apoptosis. Plasma angiotensin (Ang) II and Ang-(1–7) levels were enhanced in the model of CA and resuscitation. Enalapril reduced the plasma Ang II level at 4 and 6 h after the return of spontaneous circulation whereas enalapril did not affect the plasma Ang-(1–7) level. Enalapril pre-treatment decreased the myocardial mRNA and protein expression of angiotensin-converting enzyme (ACE). Enalapril treatment also reduced the myocardial ACE/ACE2 ratio, both at the mRNA and the protein level. Enalapril pre-treatment did not affect the upregulation of ACE2, Ang II type 1 receptor (AT1R) and MAS after CA and resuscitation. Taken together, these findings suggest that enalapril protects against ischemic injury through the attenuation of the ACE/Ang II/AT1R axis after CA and resuscitation in pigs. These results suggest the potential therapeutic value of ACEIs in patients with CA. PMID:27633002

Risk for myocardial infarction and stroke after community-acquired bacteremia: a 20-year population-based cohort study.

PubMed

Dalager-Pedersen, Michael; Søgaard, Mette; Schønheyder, Henrik Carl; Nielsen, Henrik; Thomsen, Reimar Wernich

2014-04-01

Infections may trigger acute cardiovascular events, but the risk after community-acquired bacteremia is unknown. We assessed the risk for acute myocardial infarction and ischemic stroke within 1 year of community-acquired bacteremia. This population-based cohort study was conducted in Northern Denmark. We included 4389 hospitalized medical patients with positive blood cultures obtained on the day of admission. Patients hospitalized with bacteremia were matched with up to 10 general population controls and up to 5 acutely admitted nonbacteremic controls, matched on age, sex, and calendar time. All incident events of myocardial infarction and stroke during the following 365 days were ascertained from population-based healthcare databases. Multivariable regression analyses were used to assess relative risks with 95% confidence intervals (CIs) for myocardial infarction and stroke among bacteremia patients and their controls. The risk for myocardial infarction or stroke was greatly increased within 30 days of community-acquired bacteremia: 3.6% versus 0.2% among population controls (adjusted relative risk, 20.86; 95% CI, 15.38-28.29) and 1.7% among hospitalized controls (adjusted relative risk, 2.18; 95% CI, 1.80-2.65). The risks for myocardial infarction or stroke remained modestly increased from 31 to 180 days after bacteremia in comparison with population controls (adjusted hazard ratio, 1.64; 95% CI, 1.18-2.27), but not versus hospitalized controls (adjusted hazard ratio, 0.95; 95% CI, 0.69-1.32). No differences in cardiovascular risk were seen after >6 months. Increased 30-day risks were consistently found for a variety of etiologic agents and infectious foci. Community-acquired bacteremia is associated with increased short-term risk of myocardial infarction and stroke.

Effects of Chronic and Acute Zinc Supplementation on Myocardial Ischemia-Reperfusion Injury in Rats.

PubMed

Ozyıldırım, Serhan; Baltaci, Abdulkerim Kasim; Sahna, Engin; Mogulkoc, Rasim

2017-07-01

The present study aims to explore the effects of chronic and acute zinc sulfate supplementation on myocardial ischemia-reperfusion injury in rats. The study registered 50 adult male rats which were divided into five groups in equal numbers as follows: group 1, normal control; group 2, sham; group 3, myocardial ischemia reperfusion (My/IR): the group which was fed on a normal diet and in which myocardial I/R was induced; group 4, myocardial ischemia reperfusion + chronic zinc: (5 mg/kg i.p. zinc sulfate for 15 days); and group 5, myocardial ischemia reperfusion + acute zinc: the group which was administered 15 mg/kg i.p. zinc sulfate an hour before the operation and in which myocardial I/R was induced. The collected blood and cardiac tissue samples were analyzed using spectrophotometric method to determine levels of MDA, as an indicator of tissue injury, and GSH, as an indicator of antioxidant activity. The highest plasma and heart tissue MDA levels were measured in group 3 (p < 0.05). Group 5 had lower MDA values than group 3, while group 4 had significantly lower MDA values than groups 3 and 5 (p < 0.05). The highest erythrocyte GSH values were found in group 4 (p < 0.05). Erythrocyte GSH values in group 5 were higher than those in group 3 (p < 0.05). The highest GSH values in heart tissue were measured in group 4 (p < 0.05). The results of the study reveal that the antioxidant activity inhibited by elevated oxidative stress in heart ischemia reperfusion in rats is restored partially by acute zinc administration and markedly by chronic zinc supplementation.

The distribution of blood eosinophil levels in a Japanese COPD clinical trial database and in the rest of the world

PubMed Central

Ishii, Takeo; Hizawa, Nobuyuki; Midwinter, Dawn; James, Mark; Hilton, Emma; Jones, Paul W

2018-01-01

Background Blood eosinophil measurements may help to guide physicians on the use of inhaled corticosteroids (ICS) for patients with chronic obstructive pulmonary disease (COPD). Emerging data suggest that COPD patients with higher blood eosinophil counts may be at higher risk of exacerbations and more likely to benefit from combined ICS/long-acting beta2-agonist (LABA) treatment than therapy with a LABA alone. This analysis describes the distribution of blood eosinophil count at baseline in Japanese COPD patients in comparison with non-Japanese COPD patients. Methods A post hoc analysis of eosinophil distribution by percentage and absolute cell count was performed across 12 Phase II–IV COPD clinical studies (seven Japanese studies [N=848 available absolute eosinophil counts] and five global studies [N=5,397 available eosinophil counts] that included 246 Japanese patients resident in Japan with available counts). Blood eosinophil distributions were assessed at baseline, before blinded treatment assignment. Findings Among Japanese patients, the median (interquartile range) absolute eosinophil count was 170 cells/mm3 (100–280 cells/mm3). Overall, 612/1,094 Japanese patients (56%) had an absolute eosinophil count ≥150 cells/mm3 and 902/1,304 Japanese patients (69%) had a percentage eosinophil ≥2%. Among non-Japanese patients, these values were 160 (100–250) cells/mm3, 2,842/5,151 patients (55%), and 2,937/5,155 patients (57%), respectively. The eosinophil distribution among Japanese patients was similar to that among non-Japanese patients. Within multi-country studies with similar inclusion criteria, the eosinophil count was numerically lower in Japanese compared with non-Japanese patients (median 120 vs 160 cells/mm3). Interpretation The eosinophil distribution in Japanese patients seems comparable to that of non-Japanese patients; although within multi-country studies, there was a slightly lower median eosinophil count for Japanese patients compared with non-Japanese patients. These findings suggest that blood eosinophil data from global studies are of relevance in Japan. PMID:29440882

Abnormal myocardial fluid retention as an early manifestation of ischemic injury.

PubMed Central

Willerson, J. T.; Scales, F.; Mukherjee, A.; Platt, M.; Templeton, G. H.; Fink, G. S.; Buja, L. M.

1977-01-01

Fifty-seven isolated, blood perfused, continuously weighed canine hearts have been utilized to study the development of abnormal myocardial fluid retention during early myocardial ischemic injury. Inflatable balloon catheters were positioned around the left anterior descending coronary arteries (LAD) of 54 hearts or the proximal left circumflex coronary arteries of three hearts for study of the following intervals of coronary occlusion: a) 10 minutes followed by 20 minutes of reflow, b) 40 minutes followed by either no reflow or by 20 minutes of reflow, and c) 60 minutes without reflow. After 60 minutes of fixed coronary occlusion, histologic and ultrastructural examination revealed mild swelling of many ischemic cardiac muscle cells in the absence of interstitial edema, cardiac weight gain, and obvious structural defects in cell membrane integrity. After 40 minutes of coronary occlusion and 20 minutes of reflow, significant cardiac weight gain occurred in association with characteristic alterations in the ischemic region, including widespread interstitial edema and focal vascular congestion and hemorrhage and swelling of cardiac muscle cells. Focal structural defects in cell membrane integrity were also noted. The development of abnormal myocardial fluid retention after 40 minutes of LAD occlusion occurred in association with a significant reduction in sodium-potassium-ATPase activity in the ischemic area, but with no significant alteration in either creatine phosphokinase or citrate synthase activity in the same region. Despite the abnormal myocardial fluid retention in these hearts, it was possible pharmacologically to vasodilate coronary vessels with adenosine and nitroglycerin infusion to maintain a consistently high coronary flow following release of the coronary occlusion after 40 minutes and to even exceed initial hyperemic flow values following release of the occlusion when adenosine and nitroglycerin infusion was delayed until 15 minutes after reflow. Thus, the data indicate that impaired cell volume regulation and interstitial fluid accumulation and focal structural defects in cell membrane integrity are early manifestations of ischemic injury followed by reflow, but fail to establish a major role for the abnormal fluid retention in altering coronary blood flow prior to the development of extensive myocardial necrosis. In contrast, fixed coronary occlusion for 60 minutes results in mild intracellular swelling but no significant interstitial edema and no obvious structural defects in cell membrane integrity. Images Figure 1 Figure 5 Figure 6 Figure 2 Figure 3 Figure 4 PMID:139829

Automatic retinal blood vessel parameter calculation in spectral domain optical coherence tomography

NASA Astrophysics Data System (ADS)

Wehbe, Hassan; Ruggeri, Marco; Jiao, Shuliang; Gregori, Giovanni; Puliafito, Carmen A.

2007-02-01

Measurement of retinal blood vessel parameters like the blood blow in the vessels may have significant impact on the study and diagnosis of glaucoma, a leading blinding disease worldwide. Optical coherence tomography (OCT) is a noninvasive imaging technique that can provide not only microscopic structural imaging of the retina but also functional information like the blood flow velocity in the retina. The aim of this study is to automatically extract the parameters of retinal blood vessels like the 3D orientation, the vessel diameters, as well as the corresponding absolute blood flow velocity in the vessel. The parameters were extracted from circular OCT scans around the optic disc. By removing the surface reflection through simple segmentation of the circular OCT scans a blood vessel shadowgram can be generated. The lateral coordinates and the diameter of each blood vessel are extracted from the shadowgram through a series of signal processing. Upon determination of the lateral position and the vessel diameter, the coordinate in the depth direction of each blood vessel is calculated in combination with the Doppler information for the vessel. The extraction of the vessel coordinates and diameter makes it possible to calculate the orientation of the vessel in reference to the direction of the incident sample light, which in turn can be used to calculate the absolute blood flow velocity and the flow rate.

Increased coronary blood flow and cardiac contractile efficiency with intraaortic balloon counterpulsation in a porcine model of myocardial ischemia-reperfusion injury.

PubMed

Gelsomino, Sandro; Lucà, Fabiana; Renzulli, Attilio; Rubino, Antonino S; Romano, Salvatore Mario; van der Veen, Frederik H; Carella, Rocco; Maessen, Joseph G; Gensini, Gian Franco; Lorusso, Roberto

2011-01-01

The evaluation of the impact of intraaortic balloon pump (IABP) on postischemic coronary perfusion and myocardial contractile impairment has been so far limited to early reperfusion phase. Therefore, we analyzed the 24-hour effects of IABP on coronary blood flow (CBF) and left ventricular performance in an animal model of acute myocardial ischemia-reperfusion injury. Healthy swine (n = 20) underwent 120-minute ligation of the left anterior descending coronary artery followed by 24 hours of reperfusion. We randomly assigned the animals to have IABP placed in the descending aorta 5 minutes after reperfusion onset (n = 10) or to undergo no implantation (n = 10). We measured CBF, coronary resistance, cardiac cycle efficiency (CCE), and maximal pressure/time ratio before ischemia was induced and at 30 minutes and 1, 6, 12, and 24 hours after reperfusion began. During diastole, CBF was significantly increased in IABP compared with baseline and controls at all time points (all p < 0.001). This was also true during systole in IABP only for the first hour after reperfusion began. Additionally, both CCE and pressure/time ratio were significantly increased in IABP compared with baseline at 30 minutes and 1 hour after reperfusion began (p < 0.001). IABP was associated with enhanced CBF and cardiac efficiency in a model of acute ischemic-reperfusion injury.

Influence of polymeric microspheres on the myocardial oxygen partial pressure in the beating heart of pigs.

PubMed

Hiebl, B; Mrowietz, C; Lee, S; Braune, S; Knaut, M; Lendlein, A; Franke, R P; Jung, F

2011-07-01

Injection of labeled microspheres is an established method in animal models to analyze the capillary organ blood flow at different time points. However, the microspheres can lead to stenoses of the capillary lumen, which might affect tissue oxygen supply. Our study aimed to investigate the influence of repeated injections of microspheres into the left coronary artery on the tissue oxygen partial pressure (pO(2)) in the downstream supplied myocardium of Göttingen minipigs. Tests (n=6 pigs each) were performed with two differently sized microspheres (ø=10 ± 0.1 μm (M10) or ø=15 ± 0.15 μm (M15)) from polystyrene. The pO(2) was measured in the midmyocardium of the left and right ventricle for 6 min continuously after each of five injections (1 × 10(6) microspheres each). There was a time laps of 12 min between each injection. In addition, the influence of the carrier solution was analyzed solely in the identical time frame. pO(2) decreased significantly in the myocardial area supplied by the ramus interventricularis paraconalis after injection of M15 microspheres. In contrast, the application of the M10 microspheres did not change the myocardial pO(2). This finding suggests to use microspheres with diameters not exceeding 10 μm for the coronary blood flow assessment. Copyright © 2011 Elsevier Inc. All rights reserved.

Regulation of myocardial blood flow response to mental stress in healthy individuals.

PubMed

Schöder, H; Silverman, D H; Campisi, R; Sayre, J W; Phelps, M E; Schelbert, H R; Czernin, J

2000-02-01

Mental stress testing has been proposed as a noninvasive tool to evaluate endothelium-dependent coronary vasomotion. In patients with coronary artery disease, mental stress can induce myocardial ischemia. However, even the determinants of the physiological myocardial blood flow (MBF) response to mental stress are poorly understood. Twenty-four individuals (12 males/12 females, mean age 49 +/- 13 yr, range 31-74 yr) with a low likelihood for coronary artery disease were studied. Serum catecholamines, cardiac work, and MBF (measured quantitatively with N-13 ammonia and positron emission tomography) were assessed. During mental stress (arithmetic calculation) MBF increased significantly from 0.70 +/- 0.14 to 0.92 +/- 0.21 ml x min(-1) x g(-1) (P < 0.01). Mental stress caused significant increases (P < 0.01) in serum epinephrine (26 +/- 16 vs. 42 +/- 17 pg/ml), norepinephrine (272 +/- 139 vs. 322 +/- 136 pg/ml), and cardiac work [rate-pressure product (RPP) 8,011 +/- 1,884 vs. 10,416 +/- 2,711]. Stress-induced changes in cardiac work were correlated with changes in MBF (r = 0.72; P < 0.01). Multiple-regression analysis revealed stress-induced changes in the RPP as the only significant (P = 0.0001) predictor for the magnitude of mental stress-induced increases in MBF in healthy individuals. Data from this group of healthy individuals should prove useful to investigate coronary vasomotion in individuals at risk for or with documented coronary artery disease.

[Cacoa and dark chocolate in cardiovascular prevention?].

PubMed

Belz, G G; Mohr-Kahaly, S

2011-12-01

It has been shown that the consumption of cocoa has a positive influence on a number of cardiovascular surrogate parameters such as arterial vasodilatation and a moderate decrease in blood pressure in humans. In the blood, a decrease in platelet aggregation and an increase in angiogenetic progenitor cells was noted. Furthermore, anti-inflammatory effects, an amelioration of the lipid profile and glucose metabolism was described. An increase of endothelial NO production following the ingestion of the antioxidant cocoa flavanols catechin and epicatechin seems to be the leading mechanism causing these effects. In animal studies of myocardial reperfusion, a decrease in infarct size was noted. In several prospective cohort studies from Europe and the United States, a 50 % reduction of mortality mostly due to a reduction of myocardial infarction was published. Consumption up to about 25 g daily of a flavanol rich dark chocolate (ca. 85 % cocoa content) can be recommended for cardiovascular prevention. In this moderate dosage, the potentially harmful effects due to weight gain and cadmium intake will be minimal. However, controlled randomized trials with well defined clinical endpoints are needed to prove the positive effects described so far. At this point, in time based on the information described in this article, a moderate consumption of flavanol rich cocoa products seems to be effective in the prevention of coronary artery disease and myocardial infarction. © Georg Thieme Verlag KG Stuttgart · New York.

New angiotensin II type 1 receptor blocker, azilsartan, attenuates cardiac remodeling after myocardial infarction.

PubMed

Nakamura, Yuichi; Suzuki, Satoshi; Saitoh, Shu-ichi; Takeishi, Yasuchika

2013-01-01

After an acute myocardial infarction (MI), neurohumoral systems including renin-angiotensin-aldosterone system (RAAS) are activated which in turn aggravate cardiac remodeling. Angiotensin receptor blockers (ARBs) are useful drugs for suppression of RAAS. The purpose of this study was to evaluate a new ARB, azilsartan, for suppressing cardiac remodeling and progression to heart failure after MI. We created MI by left anterior descending coronary artery ligation in male mice, and these mice were orally administered saline (0.2 mL) in the control group (Group C), 0.1 mg/kg/d of azilsartan in the low dose group (Group L), and 1.0 mg/kg/d in the high dose group (Group H) everyday. Blood pressure was decreased in Group H, but not in Group L, compared to Group C. At 2 weeks after MI creation, infarct size and fibrotic change at the site remote to the myocardial infarcted area were attenuated in Group L and Group H compared to Group C. Echocardiography revealed that cardiac remodeling was suppressed in Group L and Group H compared to Group C. Increases of mRNA expression levels related to fibrotic change were attenuated in Group L and Group H compared to Group C. The new ARB, azilsartan, had a cardiac remodeling suppression effect after MI, and this effect was observed without blood pressure lowering.

Longitudinal optical monitoring of blood flow in breast tumors during neoadjuvant chemotherapy

NASA Astrophysics Data System (ADS)

Cochran, J. M.; Chung, S. H.; Leproux, A.; Baker, W. B.; Busch, D. R.; DeMichele, A. M.; Tchou, J.; Tromberg, B. J.; Yodh, A. G.

2017-06-01

We measure tissue blood flow markers in breast tumors during neoadjuvant chemotherapy and investigate their correlation to pathologic complete response in a pilot longitudinal patient study (n  =  4). Tumor blood flow is quantified optically by diffuse correlation spectroscopy (DCS), and tissue optical properties, blood oxygen saturation, and total hemoglobin concentration are derived from concurrent diffuse optical spectroscopic imaging (DOSI). The study represents the first longitudinal DCS measurement of neoadjuvant chemotherapy in humans over the entire course of treatment; it therefore offers a first correlation between DCS flow indices and pathologic complete response. The use of absolute optical properties measured by DOSI facilitates significant improvement of DCS blood flow calculation, which typically assumes optical properties based on literature values. Additionally, the combination of the DCS blood flow index and the tissue oxygen saturation from DOSI permits investigation of tissue oxygen metabolism. Pilot results from four patients suggest that lower blood flow in the lesion-bearing breast is correlated with pathologic complete response. Both absolute lesion blood flow and lesion flow relative to the contralateral breast exhibit potential for characterization of pathological response. This initial demonstration of the combined optical approach for chemotherapy monitoring provides incentive for more comprehensive studies in the future and can help power those investigations.

[Concordance between central venous and arterial blood gases in post-surgical myocardial revascularization patients in stable condition].

PubMed

Santos-Martínez, Luis Efren; Guevara-Carrasco, Marlene; Naranjo-Ricoy, Guillermo; Baranda-Tovar, Francisco Martín; Moreno-Ruíz, Luis Antonio; Herrera-Velázquez, Marco Antonio; Magaña-Serrano, José Antonio; Valencia-Sánchez, Jesús Salvador; Calderón-Abbo, Moisés Cutiel

2014-01-01

The concordance between the parameters of arterial and central venous blood gases has not been defined yet. We studied the concordance between both parameters in post-surgical myocardial revascularization patients in stable condition. Consecutive subjects were studied in a cross-sectional design. The position of the central venous catheter was performed and simultaneously we obtained arterial and central venous blood samples prior to discharge from the intensive care unit. Data are expressed according to Bland-Altman statistical method and the intraclass correlation coefficient. Statistical result was accepted at P<.05. Two hundred and six samples were studied of 103 post-surgical patients, pH and lactate had a mean difference (limits of agreement) 0.029±0.048 (-0018, 0.077) and -0.12±0.22 (-0.57, 0.33) respectively. The magnitude of the intraclass correlation coefficient was 0.904 and 0.943 respectively. The values related to oxygen pressure were 27.86±6.08 (15.9, 39.8) and oxygen saturation 33.02±6.13 (21, 45), with magnitude of 0.258 and 0.418 respectively. The best matching parameters between arterial and central venous blood samples were pH and lactate. Copyright © 2013 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

Pulmonary Exposure to Combustion Particulate Matter Induces Myocardial Mitochondrial injury and impaired tolerance to ischemia reoxygenation

EPA Science Inventory

Background and aim: Air pollution is associated with increased morbidity and mortality of acute and chronic coronary heart disease. This effect has been attributed to oxidative stress, thrombogenesis, elevation of blood pressure, inflammation and accelerated atherosclerosis. H...

Protection of Lotus Seedpod Proanthocyanidins on Organs and Tissues under High-intensity Excercise

PubMed Central

Mengyan, Zhang

2015-01-01

Lotus seedpod proanthocyanidins (LSPC) as a kind of polyphenols is widely used in medicines, cosmetics, health products. High-intensity exercise can cause damage to the body's organs and tissues. Different doses of LSPC is given to mice to check the function of protect effect to the body's organs and tissues under high-intensity exercise. The hemoglobin (HB) content, red blood cell (RBC) number and white blood cell (WBC) number were tested for mice after exercise. The activity of superoxide dismutase (SOD) and the contents of glutathione (GSH) and malondialdehyde (MDA) in muscle and viscera were evaluated. The result showed that LSPC can effectively reduce inflammation reaction in the body of mice with high intensity exercise, alleviate oxidative stress-induced injury of tissues and organs, and execute protective function on skeletal muscle and cardiac muscle. And the LSPC could enhance myocardial anti-oxygen and enzymatic activity which suggests the protective effects of resveratrol against exercise-induced myocardial damage in mice. PMID:26998176

Fluid-dynamics modelling of the human left ventricle with dynamic mesh for normal and myocardial infarction: preliminary study.

PubMed

Khalafvand, S S; Ng, E Y K; Zhong, L; Hung, T K

2012-08-01

Pulsating blood flow patterns in the left ventricular (LV) were computed for three normal subjects and three patients after myocardial infarction (MI). Cardiac magnetic resonance (MR) images were obtained, segmented and transformed into 25 frames of LV for a computational fluid dynamics (CFD) study. Multi-block structure meshes were generated for 25 frames and 75 intermediate grids. The complete LV cycle was modelled by using ANSYS-CFX 12. The flow patterns and pressure drops in the LV chamber of this study provided some useful information on intra-LV flow patterns with heart diseases. Copyright © 2012 Elsevier Ltd. All rights reserved.

The past, present and future of renin–angiotensin aldosterone system inhibition☆

PubMed Central

Mentz, Robert J.; Bakris, George L.; Waeber, Bernard; McMurray, John J.V.; Gheorghiade, Mihai; Ruilope, Luis M.; Maggioni, Aldo P.; Swedberg, Karl; Piña, Ileana L.; Fiuzat, Mona; O’Connor, Christopher M.; Zannad, Faiez; Pitt, Bertram

2014-01-01

The renin–angiotensin aldosterone system (RAAS) is central to the pathogenesis of cardiovascular disease. RAAS inhibition can reduce blood pressure, prevent target organ damage in hypertension and diabetes, and improve outcomes in patients with heart failure and/or myocardial infarction. This review presents the history of RAAS inhibition including a summary of key heart failure, myocardial infarction, hypertension and atrial fibrillation trials. Recent developments in RAAS inhibition are discussed including implementation and optimization of current drug therapies. Finally, ongoing clinical trials, opportunities for future trials and issues related to the barriers and approvability of novel RAAS inhibitors are highlighted. PMID:23121914

Noninvasive optical quantification of absolute blood flow, blood oxygenation, and oxygen consumption rate in exercising skeletal muscle

NASA Astrophysics Data System (ADS)

Gurley, Katelyn; Shang, Yu; Yu, Guoqiang

2012-07-01

This study investigates a method using novel hybrid diffuse optical spectroscopies [near-infrared spectroscopy (NIRS) and diffuse correlation spectroscopy (DCS)] to obtain continuous, noninvasive measurement of absolute blood flow (BF), blood oxygenation, and oxygen consumption rate (\\Vdot O2) in exercising skeletal muscle. Healthy subjects (n=9) performed a handgrip exercise to increase BF and \\Vdot O2 in forearm flexor muscles, while a hybrid optical probe on the skin surface directly monitored oxy-, deoxy-, and total hemoglobin concentrations ([HbO2], [Hb], and THC), tissue oxygen saturation (StO2), relative BF (rBF), and relative oxygen consumption rate (r\\Vdot O2). The rBF and r\\Vdot O2 signals were calibrated with absolute baseline BF and \\Vdot O2 obtained through venous and arterial occlusions, respectively. Known problems with muscle-fiber motion artifacts in optical measurements during exercise were mitigated using a novel gating algorithm that determined muscle contraction status based on control signals from a dynamometer. Results were consistent with previous findings in the literature. This study supports the application of NIRS/DCS technology to quantitatively evaluate hemodynamic and metabolic parameters in exercising skeletal muscle and holds promise for improving diagnosis and treatment evaluation for patients suffering from diseases affecting skeletal muscle and advancing fundamental understanding of muscle and exercise physiology.

Noninvasive optical quantification of absolute blood flow, blood oxygenation, and oxygen consumption rate in exercising skeletal muscle

PubMed Central

Gurley, Katelyn; Shang, Yu

2012-01-01

Abstract. This study investigates a method using novel hybrid diffuse optical spectroscopies [near-infrared spectroscopy (NIRS) and diffuse correlation spectroscopy (DCS)] to obtain continuous, noninvasive measurement of absolute blood flow (BF), blood oxygenation, and oxygen consumption rate (V˙O2) in exercising skeletal muscle. Healthy subjects (n=9) performed a handgrip exercise to increase BF and V˙O2 in forearm flexor muscles, while a hybrid optical probe on the skin surface directly monitored oxy-, deoxy-, and total hemoglobin concentrations ([HbO2], [Hb], and THC), tissue oxygen saturation (StO2), relative BF (rBF), and relative oxygen consumption rate (rV˙O2). The rBF and rV˙O2 signals were calibrated with absolute baseline BF and V˙O2 obtained through venous and arterial occlusions, respectively. Known problems with muscle-fiber motion artifacts in optical measurements during exercise were mitigated using a novel gating algorithm that determined muscle contraction status based on control signals from a dynamometer. Results were consistent with previous findings in the literature. This study supports the application of NIRS/DCS technology to quantitatively evaluate hemodynamic and metabolic parameters in exercising skeletal muscle and holds promise for improving diagnosis and treatment evaluation for patients suffering from diseases affecting skeletal muscle and advancing fundamental understanding of muscle and exercise physiology. PMID:22894482

Simultaneous determination of the intravenous and oral pharmacokinetic parameters of D,L-verapamil using stable isotope-labelled verapamil.

PubMed

Eichelbaum, M; Somogyi, A; von Unruh, G E; Dengler, H J

1981-01-01

Following i.v. administration, the plasma concentration-time curve of verapamil could best be described by either a mono- or biexponential equation. Total plasma clearance (1.26 1/min) approached liver blood flow (1.51/min), so it can be concluded that its clearance is liver blood flow-dependent. Although absorption was almost complete after oral administration, absolute bioavailability (20%) was low, due to extensive hepatic first-pass metabolism. The approach using stable isotope-labelled and unlabelled drug permits simultaneous administration by the intravascular and extravascular routes, thus allowing determination of absolute bioavailability in a single experiment.

Neonatal nucleated red blood cells in G6PD deficiency.

PubMed

Yeruchimovich, Mark; Shapira, Boris; Mimouni, Francis B; Dollberg, Shaul

2002-05-01

The objective of this study is to study the absolute number of nucleated red blood cells (RBC) at birth, an index of active fetal erythropoiesis, in infants with G6PD deficiency and in controls. We tested the hypothesis that hematocrit and hemoglobin would be lower, and absolute nucleated RBC counts higher, in the G6PD deficient and that these changes would be more prominent in infants exposed passively to fava bean through maternal diet. Thirty-two term infants with G6PD deficiency were compared with 30 term controls. Complete blood counts with manual differential counts were obtained within 12 hours of life. Absolute nucleated RBC and corrected leukocyte counts were computed from the Coulter results and the differential count. G6PD deficient patients did not differ from controls in terms of gestational age, birth weight, or Apgar scores or in any of the hematologic parameters studied, whether or not the mother reported fava beans consumption in the days prior to delivery. Although intrauterine hemolysis is possible in G6PD deficient fetuses exposed passively to fava beans, our study supports that such events must be very rare.

Hepatic Blood Perfusion Estimated by Dynamic Contrast-Enhanced Computed Tomography in Pigs Limitations of the Slope Method

PubMed Central

Winterdahl, Michael; Sørensen, Michael; Keiding, Susanne; Mortensen, Frank V.; Alstrup, Aage K. O.; Hansen, Søren B.; Munk, Ole L.

2012-01-01

Objective To determine whether dynamic contrast-enhanced computed tomography (DCE-CT) and the slope method can provide absolute measures of hepatic blood perfusion from hepatic artery (HA) and portal vein (PV) at experimentally varied blood flow rates. Materials and Methods Ten anesthetized 40-kg pigs underwent DCE-CT during periods of normocapnia (normal flow), hypocapnia (decreased flow), and hypercapnia (increased flow), which was induced by adjusting the ventilation. Reference blood flows in HA and PV were measured continuously by surgically-placed ultrasound transit-time flowmeters. For each capnic condition, the DCE-CT estimated absolute hepatic blood perfusion from HA and PV were calculated using the slope method and compared with flowmeter based absolute measurements of hepatic perfusions and relative errors were analyzed. Results The relative errors (mean±SEM) of the DCE-CT based perfusion estimates were −21±23% for HA and 81±31% for PV (normocapnia), 9±23% for HA and 92±42% for PV (hypocapnia), and 64±28% for HA and −2±20% for PV (hypercapnia). The mean relative errors for HA were not significantly different from zero during hypo- and normocapnia, and the DCE-CT slope method could detect relative changes in HA perfusion between scans. Infusion of contrast agent led to significantly increased hepatic blood perfusion, which biased the PV perfusion estimates. Conclusions Using the DCE-CT slope method, HA perfusion estimates were accurate at low and normal flow rates whereas PV perfusion estimates were inaccurate and imprecise. At high flow rate, both HA perfusion estimates were significantly biased. PMID:22836307

Effect of granulocyte colony stimulating EPC on cardiac function and myocardial energy expenditure in patients with heart failure after myocardial infarction.

PubMed

Zhao, Zilin; Luo, Jianchun; Ma, Lixian; Luo, Xia; Huang, Liangyan

2015-01-01

To study the changes of cardiac function and myocardial energy expenditure following treatment with granulocyte colony stimulating factor (G-CSF) in patients with heart failure after myocardial infarction. Thirty-eight patients with heart failure after myocardial infarction were randomized into G-CSF treatment group and control group. All the patients received conventional treatment (medication and interventional therapy), and the patients in treatment group were given additional G-CSF (600 μg/day) for 7 consecutive days. The plasma level of brain-type natriuretic peptide (BNP) and the number of endothelial progenitor cells (EPC) in the peripheral blood were detected before and at 7 days and 4 months after the treatment. The cardiac functions (LVEF, FS, LVIDs, PWTs, EDV, SV, ET) was evaluated by ultrasonic imaging before and at 2 weeks and 4 months after the treatment. The MEE and circumferential end-systolic wall stress (cESS) were calculated by correlation formula. The number of EPC was significantly higher in the treatment group than in the control group after the treatment especially at 7 days (P<0.01). In both groups, BNP level was lowered significantly after the treatment to recover the normal level (P<0.01). The cardiac functions and myocardial energy expenditure were improved in all the patients at 2 weeks and 4 months after the treatment, and the improvement was more obvious in the treatment group (P<0.05), especially in terms of the MEE and cESS was significantly lowered in the treatment group than in the control group after the treatment at 2 weeks (P<0.01), the LVEF and FS was significantly increased in the treatment group than in the control group after the treatment at 4 months (P<0.01). EPC mobilization by G-CSF can effectively improve the cardiac functions, lessen ventricular remodeling and reduce myocardial energy expenditure in patients with heart failure after myocardial infarction.

Carriers of the hypertrophic cardiomyopathy MYBPC3 mutation are characterized by reduced myocardial efficiency in the absence of hypertrophy and microvascular dysfunction.

PubMed

Timmer, Stefan A J; Germans, Tjeerd; Brouwer, Wessel P; Lubberink, Mark; van der Velden, Jolanda; Wilde, Arthur A M; Christiaans, Imke; Lammertsma, Adriaan A; Knaapen, Paul; van Rossum, Albert C

2011-12-01

Next to left ventricular (LV) hypertrophy, hypertrophic cardiomyopathy (HCM) is characterized by microvascular dysfunction and reduced myocardial external efficiency (MEE). Insights into the presence of these abnormalities as early markers of disease are of clinical importance in risk stratification, and development of therapeutic approaches. Therefore, the aim was to investigate myocardial perfusion and energetics in genotype-positive, phenotype-negative HCM subjects (carriers). Fifteen carriers of an MYBPC3 mutation underwent [(15)O]water positron emission tomography (PET) to assess myocardial blood flow (MBF). [(11)C]acetate PET was performed to obtain myocardial oxygen consumption (MVO(2)). By use of cardiovascular magnetic resonance imaging, LV volumes and mass were defined to calculate MEE, i.e. the ratio between external work and MVO(2). Eleven healthy, genotype-negative, family relatives underwent similar scanning protocols to serve as a control group. Left ventricular mass was comparable between carriers and controls (93 ± 25 vs. 99 ± 21 g, P= 0.85), as was MBF at rest (1.19 ± 0.34 vs. 1.18 ± 0.32 mL min(-1) g(-1), P= 0.92), and during hyperaemia (3.87 ± 0.75 vs. 3.96 ± 0.86 mL min(-1) g(-1), P= 0.77). Myocardial oxygen consumption averaged 0.137 ± 0.057 mL min(-1) g(-1) in carriers and was not significantly different from controls (0.125 ± 0.043 mL min(-1) g(-1), P= 0.29). Cardiac work, however, was slightly reduced in carriers (7398 ± 1384 vs. 9139 ± 2484 mmHg mL in controls, P= 0.08). As a consequence, MEE was significantly decreased in carriers (27 ± 10 vs. 36 ± 8% in controls, P= 0.02). Carriers display reduced myocardial work generation in relation to oxygen consumption, in the absence of hypertrophy and flow abnormalities. Hence, impaired myocardial energetics may constitute a primary component of HCM pathogenesis.

Peripheral Blood Lymphocyte Subset Counts in Pre-menopausal Women with Iron-Deficiency Anaemia

PubMed Central

Reza Keramati, Mohammad; Sadeghian, Mohammad Hadi; Ayatollahi, Hossein; Mahmoudi, Mahmoud; Khajedaluea, Mohammad; Tavasolian, Houman; Borzouei, Anahita

2011-01-01

Background: Iron-deficiency anaemia (IDA) is a major worldwide public health problem. Children and women of reproductive age are especially vulnerable to IDA, and it has been reported that these patients are more prone to infection. This study was done to evaluate alteration of lymphocyte subgroups in IDA. Methods: In this prospective study, we investigated lymphocyte subsets in pre-menopausal women with iron-deficiency anaemia; 50 normal subjects and 50 IDA (hypochromic microcytic) cases were enrolled. Experimental and control anticoagulated blood samples were evaluated using flow cytometry to determine the absolute and relative numbers of various lymphocyte subgroups. Finally, the results of the patient and control groups were compared. Results: Mean (SD) absolute counts of lymphocytes, CD3+ cells, CD3+/CD4+ subsets (T helper) and CD3+/CD8+ subsets (T cytotoxic) in the patient group were 2.08 (0.65) x 109/L, 1.53 (0.53) x 109/L, 0.87 (0.28) x 109/L, and 0.51 (0.24) x 109/L, respectively. The results showed significant differences between case and control groups in mean absolute counts of lymphocytes (P = 0.014), T lymphocytes (P = 0.009), helper T cells (P = 0.004), and cytotoxic T cells (P = 0.043). Conclusion: This study showed that absolute counts of peripheral blood T lymphocytes as a marker of cell-mediated immunity may be decreased in pre-menopausal women with iron-deficiency anaemia, and that these patients may be more prone to infection. PMID:22135572

Myocardial perfusion MRI with sliding-window conjugate-gradient HYPR.

PubMed

Ge, Lan; Kino, Aya; Griswold, Mark; Mistretta, Charles; Carr, James C; Li, Debiao

2009-10-01

First-pass perfusion MRI is a promising technique for detecting ischemic heart disease. However, the diagnostic value of the method is limited by the low spatial coverage, resolution, signal-to-noise ratio (SNR), and cardiac motion-related image artifacts. In this study we investigated the feasibility of using a method that combines sliding window and CG-HYPR methods (SW-CG-HYPR) to reduce the acquisition window for each slice while maintaining the temporal resolution of one frame per heartbeat in myocardial perfusion MRI. This method allows an increased number of slices, reduced motion artifacts, and preserves the relatively high SNR and spatial resolution of the "composite images." Results from eight volunteers demonstrate the feasibility of SW-CG-HYPR for accelerated myocardial perfusion imaging with accurate signal intensity changes of left ventricle blood pool and myocardium. Using this method the acquisition time per cardiac cycle was reduced by a factor of 4 and the number of slices was increased from 3 to 8 as compared to the conventional technique. The SNR of the myocardium at peak enhancement with SW-CG-HYPR (13.83 +/- 2.60) was significantly higher (P < 0.05) than the conventional turbo-FLASH protocol (8.40 +/- 1.62). Also, the spatial resolution of the myocardial perfection images was significantly improved. SW-CG-HYPR is a promising technique for myocardial perfusion MRI. (c) 2009 Wiley-Liss, Inc.

A Novel Positron Emission Tomography (PET) Approach to Monitor Cardiac Metabolic Pathway Remodeling in Response to Sunitinib Malate.

PubMed

O'Farrell, Alice C; Evans, Rhys; Silvola, Johanna M U; Miller, Ian S; Conroy, Emer; Hector, Suzanne; Cary, Maurice; Murray, David W; Jarzabek, Monika A; Maratha, Ashwini; Alamanou, Marina; Udupi, Girish Mallya; Shiels, Liam; Pallaud, Celine; Saraste, Antti; Liljenbäck, Heidi; Jauhiainen, Matti; Oikonen, Vesa; Ducret, Axel; Cutler, Paul; McAuliffe, Fionnuala M; Rousseau, Jacques A; Lecomte, Roger; Gascon, Suzanne; Arany, Zoltan; Ky, Bonnie; Force, Thomas; Knuuti, Juhani; Gallagher, William M; Roivainen, Anne; Byrne, Annette T

2017-01-01

Sunitinib is a tyrosine kinase inhibitor approved for the treatment of multiple solid tumors. However, cardiotoxicity is of increasing concern, with a need to develop rational mechanism driven approaches for the early detection of cardiac dysfunction. We sought to interrogate changes in cardiac energy substrate usage during sunitinib treatment, hypothesising that these changes could represent a strategy for the early detection of cardiotoxicity. Balb/CJ mice or Sprague-Dawley rats were treated orally for 4 weeks with 40 or 20 mg/kg/day sunitinib. Cardiac positron emission tomography (PET) was implemented to investigate alterations in myocardial glucose and oxidative metabolism. Following treatment, blood pressure increased, and left ventricular ejection fraction decreased. Cardiac [18F]-fluorodeoxyglucose (FDG)-PET revealed increased glucose uptake after 48 hours. [11C]Acetate-PET showed decreased myocardial perfusion following treatment. Electron microscopy revealed significant lipid accumulation in the myocardium. Proteomic analyses indicated that oxidative metabolism, fatty acid β-oxidation and mitochondrial dysfunction were among the top myocardial signalling pathways perturbed. Sunitinib treatment results in an increased reliance on glycolysis, increased myocardial lipid deposition and perturbed mitochondrial function, indicative of a fundamental energy crisis resulting in compromised myocardial energy metabolism and function. Our findings suggest that a cardiac PET strategy may represent a rational approach to non-invasively monitor metabolic pathway remodeling following sunitinib treatment.

A Novel Positron Emission Tomography (PET) Approach to Monitor Cardiac Metabolic Pathway Remodeling in Response to Sunitinib Malate

PubMed Central

Silvola, Johanna M. U.; Miller, Ian S.; Conroy, Emer; Hector, Suzanne; Cary, Maurice; Murray, David W.; Jarzabek, Monika A.; Maratha, Ashwini; Alamanou, Marina; Udupi, Girish Mallya; Shiels, Liam; Pallaud, Celine; Saraste, Antti; Liljenbäck, Heidi; Jauhiainen, Matti; Oikonen, Vesa; Ducret, Axel; Cutler, Paul; McAuliffe, Fionnuala M.; Rousseau, Jacques A.; Lecomte, Roger; Gascon, Suzanne; Arany, Zoltan; Ky, Bonnie; Force, Thomas; Knuuti, Juhani; Gallagher, William M.; Roivainen, Anne; Byrne, Annette T.

2017-01-01

Sunitinib is a tyrosine kinase inhibitor approved for the treatment of multiple solid tumors. However, cardiotoxicity is of increasing concern, with a need to develop rational mechanism driven approaches for the early detection of cardiac dysfunction. We sought to interrogate changes in cardiac energy substrate usage during sunitinib treatment, hypothesising that these changes could represent a strategy for the early detection of cardiotoxicity. Balb/CJ mice or Sprague-Dawley rats were treated orally for 4 weeks with 40 or 20 mg/kg/day sunitinib. Cardiac positron emission tomography (PET) was implemented to investigate alterations in myocardial glucose and oxidative metabolism. Following treatment, blood pressure increased, and left ventricular ejection fraction decreased. Cardiac [18F]-fluorodeoxyglucose (FDG)-PET revealed increased glucose uptake after 48 hours. [11C]Acetate-PET showed decreased myocardial perfusion following treatment. Electron microscopy revealed significant lipid accumulation in the myocardium. Proteomic analyses indicated that oxidative metabolism, fatty acid β-oxidation and mitochondrial dysfunction were among the top myocardial signalling pathways perturbed. Sunitinib treatment results in an increased reliance on glycolysis, increased myocardial lipid deposition and perturbed mitochondrial function, indicative of a fundamental energy crisis resulting in compromised myocardial energy metabolism and function. Our findings suggest that a cardiac PET strategy may represent a rational approach to non-invasively monitor metabolic pathway remodeling following sunitinib treatment. PMID:28129334

Oral administration of L-arginine in patients with angina or following myocardial infarction may be protective by increasing plasma superoxide dismutase and total thiols with reduction in serum cholesterol and xanthine oxidase

PubMed Central

Tripathi, Pratima; Chandra, M

2009-01-01

Administration of L-arginine has been shown to control ischemic injury by producing nitric oxide which dilates the vessels and thus maintains proper blood flow to the myocardium. In the present study attempt has been made to determine whether oral administration of L-arginine has any effect on oxidant/antioxidant homeostasis in ischemic myocardial patients [represented by the patients of acute angina (AA) and acute myocardial infarction (MI)]. L-arginine has antioxidant and antiapoptotic properties, decreases endothelin-1 expression and improves endothelial function, thereby controlling oxidative injury caused during myocardial ischemic syndrome. Effect of L-arginine administration on the status of free radical scavenging enzymes, pro-oxidant enzyme and antioxidants viz. total thiols, carbonyl content and plasma ascorbic acid levels in the patients has been evaluated. We have observed that L-arginine administration (three grams per day for 15 days) resulted in increased activity of free radical scavenging enzyme superoxide dismutase (SOD) and increase in the levels of total thiols (T-SH) and ascorbic acid with concomitant decrease in lipid per-oxidation, carbonyl content, serum cholesterol and the activity of proxidant enzyme, xanthine oxidase (XO). These findings suggest that the supplementation of L-arginine along with regular therapy may be beneficial to the patients of ischemic myocardial syndromes. PMID:20716909

Metabolic and cardiovascular adjustments during psychological stress and carotid artery intima-media thickness in youth

USDA-ARS?s Scientific Manuscript database

Objective: Absolute systolic blood pressure during exercise and a greater increase above baseline, or reactivity, in systolic blood pressure during psychological stress are correlated with an increased risk for cardiovascular disease. Most studies hypothesize that increased cardiovascular responses...

Myocardial and lung injuries induced by hydrogen sulfide and the effectiveness of oxygen therapy in rats.

PubMed

Wu, Na; Du, Xuqin; Wang, Dixin; Hao, Fengtong

2011-03-01

To study myocardial and lung injuries initiated by hydrogen sulfide, and evaluate the role and effectiveness of normobaric and hyperbaric oxygen (HBO) treatment in rats. One hundred healthy male Wistar rats were randomly divided into five groups: A: Normal control group (no H2S); B: H2S-exposed group; C: H2S+33% oxygen treatment group; D: H2S+50% oxygen treatment group; E: H2S+HBO group. The rats in groups C, D and E were exposed to H2S in an exposure chamber (1 m3) and were made to inhale 300 ppm hydrogen sulfide for 60 min, and then they were subjected to normobaric or HBO therapy. Normobaric oxygen was at concentrations of 33% or 50%, HBO was for 100 min including compression and decompression; the rats in group A inhaled air under the same conditions. Blood was sampled immediately after the experiment for analysis of arterial blood gases, myocardial enzymes and cardiac troponin I. Lung was rapidly removed to be made into tissue homogenates and then cytochrome c oxidase activity was measured; myocardial and lung ultrastructural changes were observed by electron microscopy. Arterial blood gases: partial pressure of O2 (mmHg) (Group A, 97.6 ± 8.38; B, 76.5 ± 6.95*; C, 83.2 ± 2.66*; D, 86.20 ± 10.75*; E, 93.50 ± 4.97: *p < 0.01 compared to group A) was significantly lower than that in group in all but HBO rats. For myocardial enzymes and cardiac troponin I every parameter in groups B and C was significantly higher than that in group A (p<0.01),with no difference in D and E. Cytochrome c oxidase activity (u/mg) of lung tissue was reduced compared to group A after all treatments (A, 1.76 ± 0.02; B, 0.36 ± 0.04; C, 0.50 ± 0.12; D, 0.56 ± 0.07; E, 0.68 ± 0.05 (A vs. B p < 0.01; B vs. C,D,E p < 0.05 or p < 0.01), with a graded effect of oxygen dose in C, D and E. Pathological changes: (1) Myocardium - Mitochondrial swelling and autolysis with blurred or broken cristae was observed in the myocardium of H2S-exposed group; in group E, mitochondrial structure was basically normal, and clear cristae were found. (2) Lung tissue - In H2S-exposed group, alveolar epithelial cells disappeared, vacuolization of the organelle occurred, nuclear membrane was irregular and marginal condensation of heterochromatin was present; nucleus showed relatively normal morphology in group E, although some vacuoles still persisted within them. HBO therapy can effectively improve arterial oxygen partial pressure, and significantly reduce myocardial damage, as well as potentially relieve lung injury in this model. Further work in humans appears warranted.

Long term effects of cocaine on the heart assessed by cardiovascular magnetic resonance at 3T

PubMed Central

2014-01-01

Background Cocaine is an addictive, sympathomimetic drug with potentially lethal effects. The prevalence and features of cocaine cardiotoxicity are not well known. We aimed to assess these effects using a comprehensive cardiovascular magnetic resonance (CMR) protocol in a large group of asymptomatic cocaine users. Methods Consecutive (n = 94, 81 males, 36.6 ±7 years), non-selected, cocaine abusers were recruited and had a medical history, examination, ECG, blood test and CMR. The CMR study included measurement of left and right ventricular (LV, RV) dimensions and ejection fraction (EF), sequences for detection of myocardial oedema and late gadolinium enhancement (LGE). Images were compared to a cohort of healthy controls. Results Years of regular cocaine use were 13.9 ± 9. When compared to the age-matched healthy cohort, the cocaine abusers had increased LV end-systolic volume, LV mass index and RV end-systolic volume, with decreased LVEF and RVEF. No subject had myocardial oedema, but 30% had myocardial LGE indicating myocardial damage. Conclusions CMR detected cardiovascular disease in 71% of this cohort of consecutive asymptomatic cocaine abusers and mean duration of abuse was related to probability of LV systolic dysfunction. PMID:24758161

An unusual case of infective endocarditis presenting as acute myocardial infarction.

PubMed

Chen, Zhong; Ng, Francesca; Nageh, Thuraia

2007-06-01

A 39-year-old Zimbabwean man presented with a 1 week history of fever, general malaise and acute-onset chest pain. He had a urethral stricture, which had been managed with an indwelling supra-pubic catheter. The electrocardiography on admission showed inferior ST-T segments elevation. His chest pain and electrocardiography changes resolved subsequent to thrombolysis, and he remained haemodynamically stable. The 12-h troponin I was increased at 10.5 microg/l (NR <0.04 microg/l). Echocardiography confirmed severe mitral regurgitation and a flail anterior mitral valve leaflet with an independently oscillating mobile vegetation. Enterococci faecalis were grown on blood cultures. A diagnosis of enterococci infective endocarditis with concomitant acute myocardial infarction due to possible septic emboli was made. Despite the successful outcome from thrombolysis in the setting of acute myocardial infarction with infective endocarditis, the case highlights the current lack of definitive data on the optimal acute management of such an unusual clinical scenario. Although there is serious concern that thrombolytic treatment for myocardial infarction in the setting of infective endocarditis may be associated with higher risk of cerebral haemorrhage, there is little documented evidence supporting the safety of primary percutaneous coronary intervention with these patients.

Emerging drugs for the treatment of angina pectoris.

PubMed

Chong, Cher-Rin; Ong, Gao J; Horowitz, John D

2016-12-01

Angina pectoris, or symptomatic myocardial ischaemia, reflects an impairment of coronary blood flow, and usually a deficiency of available myocardial energetics. Treatment options vary with the precise cause, which may vary with regards to the roles of increased myocardial oxygen demand versus reduced supply. Traditionally, organic nitrates, β-adrenoceptor antagonists, and non-dihydropyridine calcium antagonists were the only commonly used prophylactic anti-anginal agents. However, many patients failed to respond adequately to such therapy, and/or were unsuitable for their use. Areas covered: A number of 'new' agents have been shown to represent ancillary forms of prophylactic anti-anginal therapy and are particularly useful in patients who are relatively unsuitable for either percutaneous or surgical revascularisation. These include modulators of myocardial metabolic efficiency, such as perhexiline, trimetazidine and ranolazine, as well as high dose allopurinol, nicorandil and ivabradine. The advantages and disadvantages of these various agents are summarized. Expert opinion: 'Optimal' medical treatment of angina pectoris now includes use of agents primarily intended to reduce risk of infarction (e.g. statins, aspirin, ACE inhibitors). In patients whose angina persists despite the use of 'standard' anti-anginal therapy, and who are not ideal for invasive revascularization options, a number of emerging drugs offer prospects of symptomatic relief.

CK-MB mass test in ischemic myocardial injury. Comparison of two tests: BioMerieux Vidas and sanofi access immunoassays.

PubMed

Poirey, S; Polge, A; Bertinchant, J P; Bancel, E; Boyer, J C; Fabbro-Peray, P; de Bornier, B M; Ledermann, B; Bonnier, M; Bali, J P

2000-01-01

The analytical and clinical performances of the new fluorescent immunoassay (CK-MB mass Vidas-BioMerieux) were examined and compared to the chemiluminescent test (CK-MB mass Access-Sanofi-Pasteur). Assay precisions of the CK-MB Vidas test within-assay or between-assay were less than 5.4 and 5.3%, respectively. Linearity was tested up to 214 microg/L. The CK-MB Vidas test was free of interference with CK-BB, CK-MM, and macro-CK. One hundred nineteen blood samples from patients with ischemic myocardial injury (IMI): acute myocardial infarction (AMI), suspected myocardial contusion (SMC), and unstable angina pectoris (UA), were tested using both immunoassays. In AMI, a good correlation was found (Y [CK-MB Access] = 1.1372 x [CK-MB Vidas] - 6.3902; r(2) = 0.96). In UA and SMC, low values were observed and both methods were well correlated (Y [CK-MB Access] = 1.3662 x [CK-MB Vidas] + 0.0671; r(2) = 0.97). Clinical data were in good agreement with both immunoassays. ROC analysis performed in AMI demonstrated that the clinical performances of the two assays were similar. Copyright 2000 Wiley-Liss, Inc.

Protection by Ethanolic Extract from Ulva lactuca L. against Acute Myocardial Infarction: Antioxidant and Antiapoptotic Activities.

PubMed

Widyaningsih, Wahyu; Pramono, Suwidjiyo; Zulaela; Sugiyanto; Widyarini, Sitarina

2017-12-01

Reactive oxygen species (ROS) play a major role in myocardial damage during acute myocardial infarction (AMI). This study aimed to determine the antioxidant and antiapoptotic activities of an ethanolic extract from Ulva lactuca L. (EEUL) against AMI. Thirty-six male Wistar rats were divided into six groups: one control group and five treatment groups. Treatment group II was given 85 mg/kg body weight (BW) of isoproterenol (ISO). Group III, IV and V were given ISO and EEUL at 250, 500 and 750 mg/kg BW, respectively. Group VI were given 10 mg/kg BW of ISO and melatonin. EEUL and melatonin were orally administered for 28 days. ISO was injected subcutaneously on day 29 and 30 to chemically induce AMI. On day 31, blood was collected for antioxidant assay and heart tissues were collected for histological examination. The activity of catalase (CAT), an endogenous antioxidant, in the EEUL-treatment groups was significantly increased compared to the ISO-treatment group ( P < 0.001). The EEUL-treatment groups showed significantly decreased expression of caspase-3 ( P < 0.001) and better myocardial tissue morphology. EEUL possibly protects against AMI because of its antioxidant and antiapoptotic properties.

Effect of free fatty acids on myocardial function and metabolism in the ischemic dog heart

PubMed Central

Kjekshus, John K.; Mjøs, Ole D.

1972-01-01

Since elevation of plasma concentrations of free fatty acids (FFA) increases myocardial oxygen consumption without influencing mechanical performance in normal hearts, it was the purpose of this study to determine whether FFA would modify mechanical performance at limited oxygen supply. Left coronary blood flow was reduced by gradual clamping of a shunt from the left carotid artery until moderate ventricular dilatation supervened. Left ventricular systolic pressure (LVSP), its maximal rate of rise (dP/dt) and stroke volume (SV) were unchanged or slightly reduced. The ischemia resulted in a decrease in myocardial oxygen consumption (MVO2) from 9.7±1.1 ml/min to 7.9±0.8 ml/min, and myocardial lactate uptake was reduced or reversed to excretion. Increasing the plasma concentrations of FFA from 359±47 μEq/1 to 3688±520 μEq/1 by intravenous infusion of a triglyceride emulsion and heparin resulted in further ventricular dilatation, accompanied by increased excretion of lactate. The ventricular decompensation and enhancement of anaerobic myocardial metabolism associated with increased uptake of FFA was not related to changes in coronary flow, MVO2, or LVSP. dP/dt and SV were virtually unchanged. Intravenous infusion of glucose/insulin, which lowered plasma concentrations of FFA, reversed ventricular dilatation and lactate excretion. The data support the hypothesis that high concentrations of FFA play a significant role in increasing myocardial oxygen requirement and thereby promote depression of contractility of the hypoxic heart in experimental animals. Images PMID:5032525

In vivo visualization method by absolute blood flow velocity based on speckle and fringe pattern using two-beam multipoint laser Doppler velocimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kyoden, Tomoaki, E-mail: kyouden@nc-toyama.ac.jp; Naruki, Shoji; Akiguchi, Shunsuke

Two-beam multipoint laser Doppler velocimetry (two-beam MLDV) is a non-invasive imaging technique able to provide an image of two-dimensional blood flow and has potential for observing cancer as previously demonstrated in a mouse model. In two-beam MLDV, the blood flow velocity can be estimated from red blood cells passing through a fringe pattern generated in the skin. The fringe pattern is created at the intersection of two beams in conventional LDV and two-beam MLDV. Being able to choose the depth position is an advantage of two-beam MLDV, and the position of a blood vessel can be identified in a three-dimensionalmore » space using this technique. Initially, we observed the fringe pattern in the skin, and the undeveloped or developed speckle pattern generated in a deeper position of the skin. The validity of the absolute velocity value detected by two-beam MLDV was verified while changing the number of layers of skin around a transparent flow channel. The absolute velocity value independent of direction was detected using the developed speckle pattern, which is created by the skin construct and two beams in the flow channel. Finally, we showed the relationship between the signal intensity and the fringe pattern, undeveloped speckle, or developed speckle pattern based on the skin depth. The Doppler signals were not detected at deeper positions in the skin, which qualitatively indicates the depth limit for two-beam MLDV.« less

Effects of short-term continuous positive airway pressure on myocardial sympathetic nerve function and energetics in patients with heart failure and obstructive sleep apnea: a randomized study.

PubMed

Hall, Allison B; Ziadi, Maria C; Leech, Judith A; Chen, Shin-Yee; Burwash, Ian G; Renaud, Jennifer; deKemp, Robert A; Haddad, Haissam; Mielniczuk, Lisa M; Yoshinaga, Keiichiro; Guo, Ann; Chen, Li; Walter, Olga; Garrard, Linda; DaSilva, Jean N; Floras, John S; Beanlands, Rob S B

2014-09-09

Heart failure with reduced ejection fraction and obstructive sleep apnea (OSA), 2 states of increased metabolic demand and sympathetic nervous system activation, often coexist. Continuous positive airway pressure (CPAP), which alleviates OSA, can improve ventricular function. It is unknown whether this is due to altered oxidative metabolism or presynaptic sympathetic nerve function. We hypothesized that short-term (6-8 weeks) CPAP in patients with OSA and heart failure with reduced ejection fraction would improve myocardial sympathetic nerve function and energetics. Forty-five patients with OSA and heart failure with reduced ejection fraction (left ventricular ejection fraction 35.8±9.7% [mean±SD]) were evaluated with the use of echocardiography and 11C-acetate and 11C-hydroxyephedrine positron emission tomography before and ≈6 to 8 weeks after randomization to receive short-term CPAP (n=22) or no CPAP (n=23). Work metabolic index, an estimate of myocardial efficiency, was calculated as follows: (stroke volume index×heart rate×systolic blood pressure÷Kmono), where Kmono is the monoexponential function fit to the myocardial 11C-acetate time-activity data, reflecting oxidative metabolism. Presynaptic sympathetic nerve function was measured with the use of the 11C-hydroxyephedrine retention index. CPAP significantly increased hydroxyephedrine retention versus no CPAP (Δretention: +0.012 [0.002, 0.021] versus -0.006 [-0.013, 0.005] min(-1); P=0.003). There was no significant change in work metabolic index between groups. However, in those with more severe OSA (apnea-hypopnea index>20 events per hour), CPAP significantly increased both work metabolic index and systolic blood pressure (P<0.05). In patients with heart failure with reduced ejection fraction and OSA, short-term CPAP increased hydroxyephedrine retention, indicating improved myocardial sympathetic nerve function, but overall did not affect energetics. In those with more severe OSA, CPAP may improve cardiac efficiency. Further outcome-based investigation of the consequences of CPAP is warranted. http://www.clinicaltrials.gov. Unique identifier: NCT00756366. © 2014 American Heart Association, Inc.

ECG strain pattern in hypertension is associated with myocardial cellular expansion and diffuse interstitial fibrosis: a multi-parametric cardiac magnetic resonance study

PubMed Central

Rodrigues, Jonathan C.L.; Amadu, Antonio Matteo; Ghosh Dastidar, Amardeep; McIntyre, Bethannie; Szantho, Gergley V.; Lyen, Stephen; Godsave, Cattleya; Ratcliffe, Laura E.K.; Burchell, Amy E.; Hart, Emma C.; Hamilton, Mark C.K.; Nightingale, Angus K.; Paton, Julian F.R.; Manghat, Nathan E.; Bucciarelli-Ducci, Chiara

2017-01-01

Aims In hypertension, the presence of left ventricular (LV) strain pattern on 12-lead electrocardiogram (ECG) carries adverse cardiovascular prognosis. The underlying mechanisms are poorly understood. We investigated whether hypertensive ECG strain is associated with myocardial interstitial fibrosis and impaired myocardial strain, assessed by multi-parametric cardiac magnetic resonance (CMR). Methods and results A total of 100 hypertensive patients [50 ± 14 years, male: 58%, office systolic blood pressure (SBP): 170 ± 30 mmHg, office diastolic blood pressure (DBP): 97 ± 14 mmHg) underwent ECG and 1.5T CMR and were compared with 25 normotensive controls (46 ± 14 years, 60% male, SBP: 124 ± 8 mmHg, DBP: 76 ± 7 mmHg). Native T1 and extracellular volume fraction (ECV) were calculated with the modified look-locker inversion-recovery sequence. Myocardial strain values were estimated with voxel-tracking software. ECG strain (n = 20) was associated with significantly higher indexed LV mass (LVM) (119 ± 32 vs. 80 ± 17 g/m2, P < 0.05) and ECV (30 ± 4 vs. 27 ± 3%, P < 0.05) compared with hypertensive subjects without ECG strain (n = 80). ECG strain subjects had significantly impaired circumferential strain compared with hypertensive subjects without ECG strain and controls (−15.2 ± 4.7 vs. −17.0 ± 3.3 vs. −17.3 ± 2.4%, P < 0.05, respectively). In subgroup analysis, comparing ECG strain subjects to hypertensive subjects with elevated LVM but no ECG strain, a significantly higher ECV (30 ± 4 vs. 28 ± 3%, P < 0.05) was still observed. Indexed LVM was the only variable independently associated with ECG strain in multivariate logistic regression analysis [odds ratio (95th confidence interval): 1.07 (1.02–1.12), P < 0.05). Conclusion In hypertension, ECG strain is a marker of advanced LVH associated with increased interstitial fibrosis and associated with significant myocardial circumferential strain impairment. PMID:27334442

ECG strain pattern in hypertension is associated with myocardial cellular expansion and diffuse interstitial fibrosis: a multi-parametric cardiac magnetic resonance study.

PubMed

Rodrigues, Jonathan C L; Amadu, Antonio Matteo; Ghosh Dastidar, Amardeep; McIntyre, Bethannie; Szantho, Gergley V; Lyen, Stephen; Godsave, Cattleya; Ratcliffe, Laura E K; Burchell, Amy E; Hart, Emma C; Hamilton, Mark C K; Nightingale, Angus K; Paton, Julian F R; Manghat, Nathan E; Bucciarelli-Ducci, Chiara

2017-04-01

In hypertension, the presence of left ventricular (LV) strain pattern on 12-lead electrocardiogram (ECG) carries adverse cardiovascular prognosis. The underlying mechanisms are poorly understood. We investigated whether hypertensive ECG strain is associated with myocardial interstitial fibrosis and impaired myocardial strain, assessed by multi-parametric cardiac magnetic resonance (CMR). A total of 100 hypertensive patients [50 ± 14 years, male: 58%, office systolic blood pressure (SBP): 170 ± 30 mmHg, office diastolic blood pressure (DBP): 97 ± 14 mmHg) underwent ECG and 1.5T CMR and were compared with 25 normotensive controls (46 ± 14 years, 60% male, SBP: 124 ± 8 mmHg, DBP: 76 ± 7 mmHg). Native T1 and extracellular volume fraction (ECV) were calculated with the modified look-locker inversion-recovery sequence. Myocardial strain values were estimated with voxel-tracking software. ECG strain (n = 20) was associated with significantly higher indexed LV mass (LVM) (119 ± 32 vs. 80 ± 17 g/m2, P < 0.05) and ECV (30 ± 4 vs. 27 ± 3%, P < 0.05) compared with hypertensive subjects without ECG strain (n = 80). ECG strain subjects had significantly impaired circumferential strain compared with hypertensive subjects without ECG strain and controls (-15.2 ± 4.7 vs. -17.0 ± 3.3 vs. -17.3 ± 2.4%, P < 0.05, respectively). In subgroup analysis, comparing ECG strain subjects to hypertensive subjects with elevated LVM but no ECG strain, a significantly higher ECV (30 ± 4 vs. 28 ± 3%, P < 0.05) was still observed. Indexed LVM was the only variable independently associated with ECG strain in multivariate logistic regression analysis [odds ratio (95th confidence interval): 1.07 (1.02-1.12), P < 0.05). In hypertension, ECG strain is a marker of advanced LVH associated with increased interstitial fibrosis and associated with significant myocardial circumferential strain impairment. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Cardiology.

Cold crystalloid versus warm blood cardioplegia in patients undergoing aortic valve replacement.

PubMed

Nardi, Paolo; Vacirca, Sara R; Russo, Marco; Colella, Dionisio F; Bassano, Carlo; Scafuri, Antonio; Pellegrino, Antonio; Melino, Gerry; Ruvolo, Giovanni

2018-03-01

Myocardial protection techniques during cardiac arrest have been extensively investigated in the clinical setting of coronary revascularization. Fewer studies have been carried out of patients affected by left ventricular hypertrophy, where the choice of type and temperature of cardioplegia remain controversial. We have retrospectively investigated myocardial injury and short-term outcome in patients undergoing aortic valve replacement plus or minus coronary artery bypass grafting with using cold crystalloid cardioplegia (CCC) or warm blood cardioplegia (WBC). From January 2015 to October 2016, 191 consecutive patients underwent aortic valve replacement plus or minus coronary artery bypass grafting in normothermic cardiopulmonary bypass. Cardiac arrest was obtained with use of intermittent antegrade CCC group (n=32) or WBC group (n=159), according with the choice of the surgeon. As compared with WBC group, in CCC group creatine-kinase-MB (CK-MB), cardiac troponin I (cTnI), aspartate aminotransferase (AST) release, and their peak levels, were lower during each time points of evaluation, with the greater statistically significant difference at time 0 (P<0.05, for all comparisons). A time 0, CK-MB/CK ratio >10% was 5.9% in CCC group versus 7.8% in WBC group (P<0.0001). At time 0 CK-MB/CK ratio >10% in patients undergoing isolated aortic valve replacement was 6.0% in CCC group versus 8.0% in WBC group (P<0.01). No any difference was found in perioperative myocardial infarction (0% versus 3.8%), postoperative (PO) major complications (15.6% versus 16.4%), in-hospital mortality (3.1% versus 1.3%). In aortic valve surgery a significant decrease of myocardial enzymes release is observed in favor of CCC, but this difference does not translate into different clinical outcome. However, this study suggests that in presence of cardiac surgical conditions associated with significant left ventricular hypertrophy, i.e., the aortic valve disease, a better myocardial protection can be achieved with the use of a cold rather than a warm cardioplegia. Therefore, CCC can be still safely used.

Effects of benefits and harms on older persons' willingness to take medication for primary cardiovascular prevention.

PubMed

Fried, Terri R; Tinetti, Mary E; Towle, Virginia; O'Leary, John R; Iannone, Lynne

2011-05-23

Quality-assurance initiatives encourage adherence to evidenced-based guidelines based on a consideration of treatment benefit. We examined older persons' willingness to take medication for primary cardiovascular disease prevention according to benefits and harms. In-person interviews were performed with 356 community-living older persons. Participants were asked about their willingness to take medication for primary prevention of myocardial infarction (MI) with varying benefits in terms of absolute 5-year risk reduction and varying harms in terms of type and severity of adverse effects. Most (88%) would take medication, providing an absolute benefit of 6 fewer persons with MI out of 100, approximating the average risk reduction of currently available medications. Of participants who would not take it, 17% changed their preference if the absolute benefit was increased to 10 fewer persons with MI, and, of participants who would take it, 82% remained willing if the absolute benefit was decreased to 3 fewer persons with MI. In contrast, large proportions (48%-69%) were unwilling or uncertain about taking medication with average benefit causing mild fatigue, nausea, or fuzzy thinking, and only 3% would take medication with adverse effects severe enough to affect functioning. Older persons' willingness to take medication for primary cardiovascular disease prevention is relatively insensitive to its benefit but highly sensitive to its adverse effects. These results suggest that clinical guidelines and decisions about prescribing these medications to older persons need to place emphasis on both benefits and harms.

Benefit and harm of intensive blood pressure treatment: Derivation and validation of risk models using data from the SPRINT and ACCORD trials

PubMed Central

Denton, Brian T.; Hayward, Rodney A.

2017-01-01

Background Intensive blood pressure (BP) treatment can avert cardiovascular disease (CVD) events but can cause some serious adverse events. We sought to develop and validate risk models for predicting absolute risk difference (increased risk or decreased risk) for CVD events and serious adverse events from intensive BP therapy. A secondary aim was to test if the statistical method of elastic net regularization would improve the estimation of risk models for predicting absolute risk difference, as compared to a traditional backwards variable selection approach. Methods and findings Cox models were derived from SPRINT trial data and validated on ACCORD-BP trial data to estimate risk of CVD events and serious adverse events; the models included terms for intensive BP treatment and heterogeneous response to intensive treatment. The Cox models were then used to estimate the absolute reduction in probability of CVD events (benefit) and absolute increase in probability of serious adverse events (harm) for each individual from intensive treatment. We compared the method of elastic net regularization, which uses repeated internal cross-validation to select variables and estimate coefficients in the presence of collinearity, to a traditional backwards variable selection approach. Data from 9,069 SPRINT participants with complete data on covariates were utilized for model development, and data from 4,498 ACCORD-BP participants with complete data were utilized for model validation. Participants were exposed to intensive (goal systolic pressure < 120 mm Hg) versus standard (<140 mm Hg) treatment. Two composite primary outcome measures were evaluated: (i) CVD events/deaths (myocardial infarction, acute coronary syndrome, stroke, congestive heart failure, or CVD death), and (ii) serious adverse events (hypotension, syncope, electrolyte abnormalities, bradycardia, or acute kidney injury/failure). The model for CVD chosen through elastic net regularization included interaction terms suggesting that older age, black race, higher diastolic BP, and higher lipids were associated with greater CVD risk reduction benefits from intensive treatment, while current smoking was associated with fewer benefits. The model for serious adverse events chosen through elastic net regularization suggested that male sex, current smoking, statin use, elevated creatinine, and higher lipids were associated with greater risk of serious adverse events from intensive treatment. SPRINT participants in the highest predicted benefit subgroup had a number needed to treat (NNT) of 24 to prevent 1 CVD event/death over 5 years (absolute risk reduction [ARR] = 0.042, 95% CI: 0.018, 0.066; P = 0.001), those in the middle predicted benefit subgroup had a NNT of 76 (ARR = 0.013, 95% CI: −0.0001, 0.026; P = 0.053), and those in the lowest subgroup had no significant risk reduction (ARR = 0.006, 95% CI: −0.007, 0.018; P = 0.71). Those in the highest predicted harm subgroup had a number needed to harm (NNH) of 27 to induce 1 serious adverse event (absolute risk increase [ARI] = 0.038, 95% CI: 0.014, 0.061; P = 0.002), those in the middle predicted harm subgroup had a NNH of 41 (ARI = 0.025, 95% CI: 0.012, 0.038; P < 0.001), and those in the lowest subgroup had no significant risk increase (ARI = −0.007, 95% CI: −0.043, 0.030; P = 0.72). In ACCORD-BP, participants in the highest subgroup of predicted benefit had significant absolute CVD risk reduction, but the overall ACCORD-BP participant sample was skewed towards participants with less predicted benefit and more predicted risk than in SPRINT. The models chosen through traditional backwards selection had similar ability to identify absolute risk difference for CVD as the elastic net models, but poorer ability to correctly identify absolute risk difference for serious adverse events. A key limitation of the analysis is the limited sample size of the ACCORD-BP trial, which expanded confidence intervals for ARI among persons with type 2 diabetes. Additionally, it is not possible to mechanistically explain the physiological relationships explaining the heterogeneous treatment effects captured by the models, since the study was an observational secondary data analysis. Conclusions We found that predictive models could help identify subgroups of participants in both SPRINT and ACCORD-BP who had lower versus higher ARRs in CVD events/deaths with intensive BP treatment, and participants who had lower versus higher ARIs in serious adverse events. PMID:29040268

ABO blood group and vascular disease: an update.

PubMed

Dentali, Francesco; Sironi, Anna Paola; Ageno, Walter; Crestani, Silvia; Franchini, Massimo

2014-02-01

It has been well known for many years that the ABO blood group has a major influence on hemostasis, through its influence on von Willebrand factor and, consequently, factor VIII plasma levels. Although the relationship between non-O blood type and the risk of venous thromboembolism is nowadays also well established, the association with arterial thrombotic events (i.e., myocardial infarction [MI] and ischemic stroke) is less well characterized. To elucidate the latter issue, we have conducted a systematic review and meta-analysis of the existing literature. After an electronic search strategy using MEDLINE and EMBASE and a manual review of abstract books of the International Society on Thrombosis and Haemostasis and of reference lists of all retrieved articles, 28 studies were finally included in our systematic review. The prevalence of non-O blood group was significantly higher in patients with MI (pooled odds ratio [OR]: 1.28, 95% confidence interval [CI]: 1.17-1.40; p < 0.001) and ischemic stroke (pooled OR: 1.17, 95% CI: 1.01-1.35; p = 0.03) than in controls. The restriction of the analysis to high quality studies only confirmed the association with MI (pooled OR: 1.17, 95% CI: 1.03-1.32) but not with ischemic stroke (pooled OR: 1.28, 95% CI: 0.94-1.74). In conclusion, the results of our meta-analysis confirm the existing literature evidence of a weak association between non-O blood group and vascular arterial thrombosis, in particular myocardial ischemia. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Blood cardioplegia with N-acetylcysteine may reduce coronary endothelial activation and myocardial oxidative stress.

PubMed

Rodrigues, Alfredo J; Evora, Paulo R B; Bassetto, Solange; Alves, Lafaiete; Scorzoni Filho, Adilson; Origuela, Eliana A; Vicente, Walter V A

2009-01-01

The aim of this prospective study was to compare the efficacy of intermittent antegrade blood cardioplegia with or without n-acetylcysteine (NAC) in reducing myocardial oxidative stress and coronary endothelial activation. Twenty patients undergoing elective isolated coronary artery bypass graft surgery were randomly assigned to receive intermittent antegrade blood cardioplegia (32 degrees C-34 degrees C) with (NAC group) or without (control group) 300 mg of NAC. For these 2 groups we compared clinical outcome, hemodynamic evolution, systemic plasmatic levels of troponin I, and plasma concentrations of malondialdehyde (MDA) and soluble vascular adhesion molecule 1 (sVCAM-1) from coronary sinus blood samples. Patient demographic characteristics and operative and postoperative data findings in both groups were similar. There was no hospital mortality. Comparing the plasma levels of MDA 10 min after the aortic cross-clamping and of sVCAM-1 30 min after the aortic cross-clamping period with the levels obtained before the aortic clamping period, we observed increases of both markers, but the increase was significant only in the control group (P= .039 and P= .064 for MDA; P= .004 and P= .064 for sVCAM-1). In both groups there was a significant increase of the systemic serum levels of troponin I compared with the levels observed before cardiopulmonary bypass (P< .001), but the differences between the groups were not significant (P= .570). Our investigation showed that NAC as an additive to blood cardioplegia in patients undergoing on-pump coronary artery bypass graft surgery may reduce oxidative stress and the resultant coronary endothelial activation.

Feasibility of using high-speed electron beam x-ray CT (EBCT) to follow the time course of the pulmonary response to pneumonectomy in rabbits

NASA Astrophysics Data System (ADS)

Olson, L. E.; Wright, V. P.; Hoffman, Eric A.

1994-05-01

This report focuses on preliminary experiments designed to determine regional blood flows and air, blood, and tissue contents at end expiratory lung volume in anesthetized, paralyzed, normal, sham-operated, and pneumonectomized (left lung removed) rabbits with and without wax plombage. High temporal resolution measurements were made with an EBCT scanner during the mechanical injection of a bolus of radiopaque contrast material into the pulmonary vasculature. The time-intensity curves of selected lung regions were analyzed with VIDAR using a modification of the myocardial blood flow model proposed by Wolfkiel et al. The resulting data provided an estimate of regional blood flow and total and regional air, blood and `tissue' contents, where `tissue' represents intracellular and interstitial water, i.e., lung water exclusive of blood. The estimates of mean lung air, blood and tissue contents were similar across groups and consistent with anticipated results.

Blood pressure-lowering treatment based on cardiovascular risk: a meta-analysis of individual patient data.

PubMed

2014-08-16

We aimed to investigate whether the benefits of blood pressure-lowering drugs are proportional to baseline cardiovascular risk, to establish whether absolute risk could be used to inform treatment decisions for blood pressure-lowering therapy, as is recommended for lipid-lowering therapy. This meta-analysis included individual participant data from trials that randomly assigned patients to either blood pressure-lowering drugs or placebo, or to more intensive or less intensive blood pressure-lowering regimens. The primary outcome was total major cardiovascular events, consisting of stroke, heart attack, heart failure, or cardiovascular death. Participants were separated into four categories of baseline 5-year major cardiovascular risk using a risk prediction equation developed from the placebo groups of the included trials (<11%, 11-15%, 15-21%, >21%). 11 trials and 26 randomised groups met the inclusion criteria, and included 67,475 individuals, of whom 51,917 had available data for the calculation of the risk equations. 4167 (8%) had a cardiovascular event during a median of 4·0 years (IQR 3·4-4·4) of follow-up. The mean estimated baseline levels of 5-year cardiovascular risk for each of the four risk groups were 6·0% (SD 2·0), 12·1% (1·5), 17·7% (1·7), and 26·8% (5·4). In each consecutive higher risk group, blood pressure-lowering treatment reduced the risk of cardiovascular events relatively by 18% (95% CI 7-27), 15% (4-25), 13% (2-22), and 15% (5-24), respectively (p=0·30 for trend). However, in absolute terms, treating 1000 patients in each group with blood pressure-lowering treatment for 5 years would prevent 14 (95% CI 8-21), 20 (8-31), 24 (8-40), and 38 (16-61) cardiovascular events, respectively (p=0·04 for trend). Lowering blood pressure provides similar relative protection at all levels of baseline cardiovascular risk, but progressively greater absolute risk reductions as baseline risk increases. These results support the use of predicted baseline cardiovascular disease risk equations to inform blood pressure-lowering treatment decisions. None. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of intraaortic balloon counterpulsation (IABP) on myocardial infarct size and collateral flow in an experimental dog model.

PubMed

Müller, K D; Lübbecke, F; Schaper, W; Walter, P

1982-01-01

To determine the influence of IABP on infarct size and collateral blood flow in each of 12 openchest anaesthetised mongrel dogs two small branches of the left coronary artery were occluded consecutively. The perfusion areas of both branches were comparable in size. IABP was started immediately before ligation of the first branch for a 90-min period followed by a reperfusion period of 90 min. Subsequently the second vessel was also occluded for 90 min as a control without IABP while myocardial oxygen consumption remained constant and was then reperfused. Infarct size was expressed as a percentage of the perfusion area. A difference in infarct size with and without IABP (18 +/- 17, 18 +/- 10% respectively) could not be observed. However a significant increase of collateral blood flow due to IABP in the subendocardial layer from 8.9 +/- 4.8 to 14.9 +/- 4.6 ml/100 g/min (p less than 0.05) was prevalent. In the subepicardial layer the augmentation from 23.7 +/- 19.9 to 26.9 +/- 15.2 was not significant. Thus, in spite of a small increase of collateral blood flow in the subendocardial layer of the ischemic myocardium the infarct size was not reduced by IABP in our dog model.

Comparative cardiac effects of three hepatobiliary radiopharmacologicals in the dog: concise communication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shani, J.; Sarel, O.; Rogel, S.

1982-04-01

Three hepatobiliary agents with an acetanilide-imidoacetic-acid moiety resembling that in lidocaine were investigated for their possible effects on contractility and conductivity in the heart and on arterial pressure and aortic blood flow. This was done in the light of lidocaine's numerous cardiac side effects. HIDA, BIDA, and DIPA, each with traces of decayed /sup 99m/Tc, were injected i.v. into anesthetized dogs with an A-V block, and their effects on the above parameters were followed until control levels were reestablished. Whereas lidocaine raises the diastolic threshold and prolongs the refractory period, the three agents tested do not prolong myocardial conductivity. Bothmore » HIDA and BIDA have an effect similar to that of lidocaine, but DIPA has no effect on the latter two parameters. Moreover, whereas lidocaine depressed myocardial contractility, blood pressure, and blood flow, HIDA has a less prominent effect on these parameters, and neither BIDA nor DIPA has any such effect. It is concluded that even though the effect of HIDA on the heart is milder than that of lidocaine, the effects of both BIDA and DIPA are even less pronounced, and they are less likely to cause cardiac side effects when similar doses are administered during nuclear medicine procedures.« less

Comparative cardiac effects of three hepatobiliary radiopharmacologicals in the dog: concise communication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shani, J.; Rogel, S.; Weininger, J.

1982-04-01

Three hepatobiliary agents with an acetanilide-imidoacetic-acid moiety resembling that in lidocaine were investigated for their possible effects on contractility and conductivity in the heart and on arterial pressure and aortic blood flow. This was done in the light of lidocaine's numerous cardiac side effects. HIDA, BIDA, and DIPA, each with traces of decayed Tc-99m, were injected i.v. into anesthetized dogs with an A-V block, and their effects on the above parameters were followed until control levels were reestablished. Wheras lidocaine raises the diastolic threshold and prolongs the refractory period, the three agents tested do not prolong myocardial conductivity. Both HIDAmore » and BIDA have an effect similar to that of lidocaine, but DIPA has no effect on the latter two parameters. Moreover, whereas lidocaine depresses myocardial contractility, blood pressure, and blood flow, HIDA has a less prominent effect on these parameters, and neither BIDA nor DIPA has any such effect. It is concluded that even though the effect of HIDA on the heart is milder than that of lidocaine, the effects of both BIDA and DIPA are even less pronounced, and they are less likely to cause cardiac side effects when similar doses are administered during nuclear medicine procedures.« less

Effects of CT-based attenuation correction of rat microSPECT images on relative myocardial perfusion and quantitative tracer uptake

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strydhorst, Jared H., E-mail: jared.strydhorst@gmail.com; Ruddy, Terrence D.; Wells, R. Glenn

2015-04-15

Purpose: Our goal in this work was to investigate the impact of CT-based attenuation correction on measurements of rat myocardial perfusion with {sup 99m}Tc and {sup 201}Tl single photon emission computed tomography (SPECT). Methods: Eight male Sprague-Dawley rats were injected with {sup 99m}Tc-tetrofosmin and scanned in a small animal pinhole SPECT/CT scanner. Scans were repeated weekly over a period of 5 weeks. Eight additional rats were injected with {sup 201}Tl and also scanned following a similar protocol. The images were reconstructed with and without attenuation correction, and the relative perfusion was analyzed with the commercial cardiac analysis software. The absolutemore » uptake of {sup 99m}Tc in the heart was also quantified with and without attenuation correction. Results: For {sup 99m}Tc imaging, relative segmental perfusion changed by up to +2.1%/−1.8% as a result of attenuation correction. Relative changes of +3.6%/−1.0% were observed for the {sup 201}Tl images. Interscan and inter-rat reproducibilities of relative segmental perfusion were 2.7% and 3.9%, respectively, for the uncorrected {sup 99m}Tc scans, and 3.6% and 4.3%, respectively, for the {sup 201}Tl scans, and were not significantly affected by attenuation correction for either tracer. Attenuation correction also significantly increased the measured absolute uptake of tetrofosmin and significantly altered the relationship between the rat weight and tracer uptake. Conclusions: Our results show that attenuation correction has a small but statistically significant impact on the relative perfusion measurements in some segments of the heart and does not adversely affect reproducibility. Attenuation correction had a small but statistically significant impact on measured absolute tracer uptake.« less

Change in serum lipids after acute coronary syndromes: secondary analysis of SPACE ROCKET study data and a comparative literature review.

PubMed

Barth, Julian H; Jackson, Beryl M; Farrin, Amanda J; Efthymiou, Maria; Worthy, Gillian; Copeland, Joanne; Bailey, Kristian M; Romaine, Simon P R; Balmforth, Anthony J; McCormack, Terry; Whitehead, Andrew; Flather, Marcus D; Nixon, Jane; Hall, Alistair S

2010-10-01

It has long been an accepted belief that serum cholesterol significantly falls after myocardial infarction and that a return to pre-event levels takes approximately 3 months. The magnitude and clinical significance of this fall has recently been challenged. In the Secondary Prevention of Acute Coronary Events-Reduction Of Cholesterol to Key European Targets (SPACE ROCKET) trial, we measured serum lipids of individuals on day 1 and between days 2 and 4 after acute myocardial infarction (AMI). Second, we performed a thorough literature review and compared all studies reporting data on absolute changes in lipids immediately after AMI, using weighted means. Of 1263 SPACE ROCKET participants, 128 had paired lipid measurements where both samples had been measured using identical methods at baseline and on days 2-4 after AMI. The mean lowering in total cholesterol between day 1 and day 2-4 was 0.71 mmol/L (95% CI 0.58-0.84; P < 0.0001) and in triglycerides was 0.10 mmol/L (-0.14-0.33; P = 0.405). A total of 25 papers showing absolute lipid changes post-AMI were identified. The combined data demonstrated a mean fall in total cholesterol of 9% to 11% from baseline over days 3-14 post-AMI, whereas for triglycerides, there was a rise of 18% from baseline to between day 9 and 12 weeks. After a secondary analysis of SPACE ROCKET data and a comparison of previously published data, we report a 10% fall in total cholesterol after AMI-a difference that is of high clinical significance. Consequently, measurement of serum lipids in patients with AMI should be performed within the first hours after presentation.