Science.gov

Sample records for myocardial delayed contrast

  1. Cardiac Amyloidosis: Typical Imaging Findings and Diffuse Myocardial Damage Demonstrated by Delayed Contrast-Enhanced MRI

    SciTech Connect

    Sueyoshi, Eijun Sakamoto, Ichiro; Okimoto, Tomoaki; Hayashi, Kuniaki; Tanaka, Kyouei; Toda, Genji

    2006-08-15

    Amyloidosis is a rare systemic disease. However, involvement of the heart is a common finding and is the most frequent cause of death in amyloidosis. We report the sonographic, scintigraphic, and MRI features of a pathologically proven case of cardiac amyloidosis. Delayed contrast-enhanced MR images, using an inversion recovery prepped gradient-echo sequence, revealed diffuse enhancement in the wall of both left and right ventricles. This enhancement suggested expansion of the extracellular space of the myocardium caused by diffuse myocardial necrosis secondary to deposition of amyloid.

  2. Imaging of myocardial infarction using carbon nanotube micro-computed tomography and delayed contrast enhancement

    NASA Astrophysics Data System (ADS)

    Burk, Laurel M.; Wang, Kohan; Kang, Eunice; Rojas, Mauricio; Willis, Monte; Lee, Yueh Z.; Lu, Jianping; Zhou, Otto

    2011-03-01

    We demonstrate the application of our cardiac- and respiratory-gated carbon nanotube (CNT) micro-CT system by evaluating murine myocardial infarction models with a delayed contrast enhancement technique. Myocardial infarction was induced in 8 wild-type male mice. The ischemia reperfusion model was achieved by surgical occlusion of the LAD artery for 30 minutes followed by 24 hours of reperfusion. Free-breathing subjects were anesthetized with isoflurane during imaging. Respiratory and cardiac signals were monitored externally to gate the scan. Micro-CT data was obtained at 50kV, 3mA cathode current for 15ms per projection. All images were acquired during end exhalation at either 0msec or 55msec after the R-wave (diastole or systole, respectively). Following administration of Omnipaque 300mgI/mL at 0.1ml/5g, images were obtained at 0msec after the R-wave. Fenestra VC was then administered at a 0.1ml/5g dose, followed by images 0 and 55msec after the R-wave. Hearts were then harvested, sliced 1mm thick and stained with TTC. All animals survived surgery and imaging; all demonstrated obvious delayed contrast enhancement in the left ventricular wall in Omnipaque images. Fenestra VC revealed cardiac functional changes quantified by low ejection fractions. All subjects demonstrated areas of myocardial infarct in the LAD distribution on both TTC staining and micro-CT imaging. CNT enabled gated cardiac micro-CT imaging demonstrates the ability to consistently identify areas of myocardial infarct in mice, providing a powerful tool for the study of cardiovascular biology. Further work is ongoing to streamline the imaging protocol and perform more quantitative analysis of the images.

  3. Percent Infarct Mapping for Delayed Contrast Enhancement MR Imaging to Quantify Myocardial Viability by Gd(DTPA)

    PubMed Central

    Simor, Tamás; Surányi, Pál; Ruzsics, Balázs; Tóth, Attila; Tóth, Levente; Kiss, Pál; Brott, Brigitta C.; Varga-Szemes, Ákos; Elgavish, Ada; Elgavish, Gabriel A.

    2010-01-01

    Purpose To demonstrate the advantages of Signal Intensity Percent-Infarct-Mapping (SI-PIM) using the standard delayed enhancement (DE) acquisition in assessing viability following myocardial infarction (MI). SI-PIM quantifies MI density with a voxel-by-voxel resolution in clinically used DE images. Materials and Methods In canines (n=6), 96h after reperfused MI and administration of 0.2mmol/kg Gd(DTPA), ex-vivo DE images were acquired and SI-PIMs calculated. SI-PIM data were compared with data from DE images analyzed with several thresholding levels using SIremote+2SD, SIremote+6SD, SI full width half maximum (SIFWHM), and with triphenyl-tetrazolium-chloride (TTC) staining. SI-PIM was also compared to R1 percent infarct mapping (R1-PIM). Results Left ventricular infarct volumes (IV) in DE images, IVSIremote+2SD and IVSIremote+6SD overestimated (p<0.05) TTC by medians of 13.21ml [10.2; 15.2] and 6.2ml [3.79; 8.23], respectively. SIFWHM, SI-PIM and R1-PIM, however, only non-significantly underestimated TTC, by medians of −0.10ml [−0.12, −0.06], −0.86ml [−1.04; 1.54] and −1.30ml [−4.99; −0.29], respectively. The Infarct-Involved Voxel Volume (IIVV) of SI-PIM, 32.4ml [21.2, 46.3] is higher (p<0.01) than IIVVs of SIFWHM 8.3ml [3.79, 19.0]. SI-PIMFWHM, however, underestimates TTC (−5.74ml [−11.89; −2.52] (p<0.01)). Thus SI-PIM outperforms SIFWHM because larger IIVVs are obtained, and thus PIs both in the rim and the core of the infarcted tissue are characterized, in contradistinction from DE-SIFWHM which shows mainly the infarct core. Conclusion We have shown here, ex vivo, that SI-PIM has the same advantages as R1-PIM, but it is based on the scanning sequences of DE imaging, and thus it is obtainable within the same short scanning time as DE. This makes it a practical method for clinical studies. PMID:20882616

  4. MultiContrast Delayed Enhancement (MCODE) improves detection of subendocardial myocardial infarction by late gadolinium enhancement cardiovascular magnetic resonance: a clinical validation study

    PubMed Central

    2012-01-01

    Background Myocardial infarction (MI) documented by late gadolinium enhancement (LGE) has clinical and prognostic importance, but its detection is sometimes compromised by poor contrast between blood and MI. MultiContrast Delayed Enhancement (MCODE) is a technique that helps discriminate subendocardial MI from blood pool by simultaneously providing a T2-weighted image with a PSIR (phase sensitive inversion recovery) LGE image. In this clinical validation study, our goal was to prospectively compare standard LGE imaging to MCODE in the detection of MI. Methods Imaging was performed on a 1.5 T scanner on patients referred for CMR including a LGE study. Prospective comparisons between MCODE and standard PSIR LGE imaging were done by targeted, repeat imaging of slice locations. Clinical data were used to determine MI status. Images at each of multiple time points were read on separate days and categorized as to whether or not MI was present and whether an infarction was transmural or subendocardial. The extent of infarction was scored on a sector-by-sector basis. Results Seventy-three patients were imaged with the specified protocol. The majority were referred for vasodilator perfusion exams and viability assessment (37 ischemia assessment, 12 acute MI, 10 chronic MI, 12 other diagnoses). Forty-six patients had a final diagnosis of MI (30 subendocardial and 16 transmural). MCODE had similar specificity compared to LGE at all time points but demonstrated better sensitivity compared to LGE performed early and immediately before and after the MCODE (p = 0.008 and 0.02 respectively). Conventional LGE only missed cases of subendocardial MI. Both LGE and MCODE identified all transmural MI. Based on clinical determination of MI, MCODE had three false positive MI’s; LGE had two false positive MI’s including two of the three MCODE false positives. On a per sector basis, MCODE identified more infarcted sectors compared to LGE performed immediately prior to MCODE (p < 0

  5. Myocardial perfusion imaging using contrast echocardiography.

    PubMed

    Pathan, Faraz; Marwick, Thomas H

    2015-01-01

    Microbubbles are an excellent intravascular tracer, and both the rate of myocardial opacification (analogous to coronary microvascular perfusion) and contrast intensity (analogous to myocardial blood volume) provide unique insights into myocardial perfusion. A strong evidence base has been accumulated to show comparability with nuclear perfusion imaging and incremental diagnostic and prognostic value relative to wall motion analysis. This technique also provides the possibility to measure myocardial perfusion at the bedside. Despite all of these advantages, the technique is complicated, technically challenging, and has failed to scale legislative and financial hurdles. The development of targeted imaging and therapeutic interventions will hopefully rekindle interest in this interesting modality. PMID:25817740

  6. Myocardial hypoperfusion on conventional contrast computed tomography.

    PubMed

    Ching, Shing; Chung, Tak Shun

    2015-10-01

    Non–electrocardiogram (ECG)–gated contrast computed tomography (CT) is commonly performed to exclude aortic dissection in chest pain patients. Besides evaluating the aorta for dissection flap, attention should be paid to the myocardium for areas of hypoenhancement that may suggest ischemia. Current models of multidetector CT enable assessment of myocardial perfusion with minimal motion artifact even without ECG gating. Transmural hypoenhancement with preserved wall thickness in a coronary distribution is highly specific for acute myocardial infarction. We report 2 cases of acute chest pain with initial nondiagnostic studies that underwent CT aortogram to exclude dissection. Instead, the CT showed myocardial hypoenhancement in left anterior descending artery territory. Myocardial hypoenhancement occurred before ST-segment elevation on ECG, suggesting that recognition of this important finding may lead to earlier revascularization decisions. PMID:26321167

  7. Delayed Myocardial Enhancement in Cardiac Magnetic Resonance Imaging

    PubMed Central

    Franco, Arie; Javidi, Saeed; Ruehm, Stefan G

    2015-01-01

    Delayed myocardial enhancement MRI is a highly valuable but non-specific imaging technique that is ancillary in the diagnosis of a variety of diseases including myocardial viability, cardiomyopathy, myocarditis and other infiltrative myocardial processes. The lack of specificity stems from the wide variety of differential diagnoses that may present with overlapping patterns of delayed enhancement. Many of these differential diagnoses have been presented and discussed in this article. PMID:26622933

  8. New imaging technology: measurement of myocardial perfusion by contrast echocardiography

    NASA Technical Reports Server (NTRS)

    Rubin, D. N.; Thomas, J. D.

    2000-01-01

    Myocardial perfusion imaging has long been a goal for the non-invasive echocardiographic assessment of the heart. However, many factors at play in perfusion imaging have made this goal elusive. Harmonic imaging and triggered imaging with newer contrast agents have made myocardial perfusion imaging potentially practical in the very near future. The application of indicator dilution theory to the coronary circulation and bubble contrast agents is fraught with complexities and sources of error. Therefore, quantification of myocardial perfusion by non-invasive echocardiographic imaging requires further investigation in order to make this technique clinically viable.

  9. Role of iodinated contrast material in the evaluation of myocardial infarction by computerized transmission tomography.

    PubMed

    Higgins, C B; Siemers, P T; Newell, J D; Schmidt, W

    1980-01-01

    In vivo and in vitro studies have shown that areas of myocardial infarctions can be delineated on CT scans after intravenous administration of iodinated contrast material to dogs with experimental myocardial infarctions. Within the first minute after intravenous administration of contrast material (initial myocardial perfusion phase), the infarct appears an as area of decreased x-ray attenuation (cold spot image). Studies using radiolabeled microspheres indicate that the relative attenuation numbers throughout the myocardium in this phase reflect myocardial perfusion (Hessel et al, 1978). Delayed scans obtained at 5 minutes and later showed a reversal in the attenuation values of normal and infarcted myocardium with the infarct appearing as an area of homogeneous or mottled increase in x-ray density compared to normal myocardium. (Siemers et al, 1978; Carlsson et al, 1977; Higgins et al, 1979). This phenomenon of delayed contrast enhancement of myocardial infarctions ensues as early as 8 hours after coronary occlusion (Higgins et al, 1979) and is present in evolved infarcts as old as 51 days (Newell et al, 1979). Direct measurements of iodine concentration in infarcts, normal myocardium, and organs surrounding the heart were performed in dogs with 48-hour-old myocardial infarctions using fluorescent excitation analysis (Higgins et al, 1978, 1979). These measurements of iodine concentration in tissue samples obtained at 10-180 minutes after intravenous administration of contrast material indicated that the highest iodine concentration in the infarct was at 10 minutes, but the highest ratio of iodine concentration of the infarct to normal myocardium was at 180 minutes. At all time intervals, the concentration of iodine within the infarct was fivefold greater than in the normal myocardium. PMID:7203920

  10. Cocaine use and delayed myocardial ischaemia and/or infarction

    PubMed Central

    Phang, Kee Wei; Wood, Alice

    2014-01-01

    A 37-year-old woman was admitted into the coronary care unit following chest pain after using cocaine. She was found to have significant myocardial ischaemia on blood and ECG investigations despite a recent coronary angiogram that had not demonstrated flow-limiting coronary disease. This case report summarises the risks of myocardial ischaemia and/or infarction for patients taking cocaine and the pathophysiology behind it, focusing in particular on the risks of delayed reaction some time after cocaine ingestion. PMID:25201873

  11. Understanding prehospital delay behavior in acute myocardial infarction in women.

    PubMed

    Waller, Cynthia G

    2006-12-01

    Studies demonstrate that acute myocardial infarction (AMI) mortality can be reduced if reperfusion therapy is initiated within 1 hour of AMI symptom onset. However, a considerable number of men and women arrive at the emergency department outside of the time frame for thrombolytic and angioplasty effectiveness. This is especially true for women who have been shown to delay longer than men due to their prehospital decision-making process utilized. With a mean total delay time greater than 4 hours, the time interval from symptom onset to transport activation to the hospital consumes the majority of the prehospital phase of emergency cardiac care. The health belief model, self-regulation model, theory of reasoned action, and theory of planned behavior have all been used to describe the prehospital decision-making process of both men and women with an AMI and the variables that impact that process. These models have identified the importance of symptom attribution to cardiac-related causes as a target variable for research and interventions related to care-seeking behavior. PMID:18340239

  12. Effect of trimetazidine on early and delayed doxorubicin myocardial toxicity.

    PubMed

    Perletti, G; Monti, E; Paracchini, L; Piccinini, F

    1989-01-01

    The influence of the administration of trimetazidine on the myocardial toxicity induced by doxorubicin was studied on an in vivo model in the rat. Trimetazidine was chosen due to its ability to act as a scavenger of oxygen-derived free radicals, which have been implicated in both early and delayed cardiotoxic manifestations after doxorubicin treatment. In the present study, doxorubicin was administered as 4 weekly i.v. injections of 3 mg/kg. The cardiotoxic effects were evaluated by measuring predictive ECG parameters (QT and ST intervals) as well as the contractile performance of atria isolated from treated animals. Heart preparations were also examined by light microscopy. Trimetazidine, 2.5 mg/kg/day i.p. for 3 days before doxorubicin administration plus 2.5 mg/kg/day p.o. for 10 weeks, was unable to prevent the development of doxorubicin-induced long-term cardiotoxicity. However, a significant improvement of the early cardiotoxic signs was observed in trimetazidine-treated rats, as reported in previous investigations. The present findings suggest that different target structures may be involved in the early and delayed free radical-mediated effects of doxorubicin. PMID:2636823

  13. Delayed clopidogrel transit during myocardial infarction evident on angiography.

    PubMed

    Ghobrial, Joanna; Gibson, C Michael; Pinto, Duane S

    2015-05-01

    We describe the case of a patient with non-ST segment elevation myocardial infarction (NSTEMI) where a limitation of oral clopidogrel loading prior to percutaneous coronary intervention (PCI) was directly visualized on angiography. Clopidogrel is a thienopyridine antiplatelet agent used in acute coronary syndromes. It reduces platelet aggregation via inhibition of the P2Y12 receptor. Clopidogrel is an inactive metabolite that is metabolized into the active metabolite by the cytochrome P450 isoenzymes located mostly in the liver and partly in the gastrointestinal system. As such, it requires at least 2 hours to reach maximal effect. A 63-year-old female went to an outside facility where she was diagnosed with NSTEMI and underwent angiography. She was administered 324 mg of aspirin and 600 mg of clopidogrel, and was transferred to our facility. Upon arrival, approximately 1.5 hours after the oral loading dose, the clopidogrel tablets were visualized intact in the stomach during angiography, implying a very low likelihood of adequate absorption or antiplatelet effect. This observation raises the concern that delayed gastrointestinal transit, apart from other metabolic derangements, may be a factor in achieving optimal platelet inhibition using oral agents. PMID:25929306

  14. Measurement of myocardial perfusion and infarction size using computer-aided diagnosis system for myocardial contrast echocardiography.

    PubMed

    Du, Guo-Qing; Xue, Jing-Yi; Guo, Yanhui; Chen, Shuang; Du, Pei; Wu, Yan; Wang, Yu-Hang; Zong, Li-Qiu; Tian, Jia-Wei

    2015-09-01

    Proper evaluation of myocardial microvascular perfusion and assessment of infarct size is critical for clinicians. We have developed a novel computer-aided diagnosis (CAD) approach for myocardial contrast echocardiography (MCE) to measure myocardial perfusion and infarct size. Rabbits underwent 15 min of coronary occlusion followed by reperfusion (group I, n = 15) or 60 min of coronary occlusion followed by reperfusion (group II, n = 15). Myocardial contrast echocardiography was performed before and 7 d after ischemia/reperfusion, and images were analyzed with the CAD system on the basis of eliminating particle swarm optimization clustering analysis. The myocardium was quickly and accurately detected using contrast-enhanced images, myocardial perfusion was quantitatively calibrated and a color-coded map calibrated by contrast intensity and automatically produced by the CAD system was used to outline the infarction region. Calibrated contrast intensity was significantly lower in infarct regions than in non-infarct regions, allowing differentiation of abnormal and normal myocardial perfusion. Receiver operating characteristic curve analysis documented that -54-pixel contrast intensity was an optimal cutoff point for the identification of infarcted myocardium with a sensitivity of 95.45% and specificity of 87.50%. Infarct sizes obtained using myocardial perfusion defect analysis of original contrast images and the contrast intensity-based color-coded map in computerized images were compared with infarct sizes measured using triphenyltetrazolium chloride staining. Use of the proposed CAD approach provided observers with more information. The infarct sizes obtained with myocardial perfusion defect analysis, the contrast intensity-based color-coded map and triphenyltetrazolium chloride staining were 23.72 ± 8.41%, 21.77 ± 7.8% and 18.21 ± 4.40% (% left ventricle) respectively (p > 0.05), indicating that computerized myocardial contrast echocardiography can

  15. Changes in transmural distribution of myocardial perfusion assessed by quantitative intravenous myocardial contrast echocardiography in humans

    PubMed Central

    Fukuda, S; Muro, T; Hozumi, T; Watanabe, H; Shimada, K; Yoshiyama, M; Takeuchi, K; Yoshikawa, J

    2002-01-01

    Objective: To clarify whether changes in transmural distribution of myocardial perfusion under significant coronary artery stenosis can be assessed by quantitative intravenous myocardial contrast echocardiography (MCE) in humans. Methods: 31 patients underwent dipyridamole stress MCE and quantitative coronary angiography. Intravenous MCE was performed by continuous infusion of Levovist. Images were obtained from the apical four chamber view with alternating pulsing intervals both at rest and after dipyridamole infusion. Images were analysed offline by placing regions of interest over both endocardial and epicardial sides of the mid-septum. The background subtracted intensity versus pulsing interval plots were fitted to an exponential function, y = A (1 − e−βt), where A is plateau level and β is rate of rise. Results: Of the 31 patients, 16 had significant stenosis (> 70%) in the left anterior descending artery (group A) and 15 did not (group B). At rest, there were no differences in the A endocardial to epicardial ratio (A-EER) and β-EER between the two groups (mean (SD) 1.2 (0.6) v 1.2 (0.8) and 1.2 (0.7) v 1.1 (0.6), respectively, NS). During hyperaemia, β-EER in group A was significantly lower than that in group B (1.0 (0.5) v 1.4 (0.5), p < 0.05) and A-EER did not differ between the two groups (1.0 (0.5) v 1.2 (0.4), NS). Conclusions: Changes in transmural distribution of myocardial perfusion under significant coronary artery stenosis can be assessed by quantitative intravenous MCE in humans. PMID:12231594

  16. Delayed contrast enhancement imaging of a murine model for ischemia reperfusion with carbon nanotube micro-CT.

    PubMed

    Burk, Laurel M; Wang, Ko-Han; Wait, John Matthew; Kang, Eunice; Willis, Monte; Lu, Jianping; Zhou, Otto; Lee, Yueh Z

    2015-01-01

    We aim to demonstrate the application of free-breathing prospectively gated carbon nanotube (CNT) micro-CT by evaluating a myocardial infarction model with a delayed contrast enhancement technique. Evaluation of murine cardiac models using micro-CT imaging has historically been limited by extreme imaging requirements. Newly-developed CNT-based x-ray sources offer precise temporal resolution, allowing elimination of physiological motion through prospective gating. Using free-breathing, cardiac-gated CNT micro-CT, a myocardial infarction model can be studied non-invasively and with high resolution. Myocardial infarction was induced in eight male C57BL/6 mice aged 8-12 weeks. The ischemia reperfusion model was achieved by surgically occluding the LAD artery for 30 minutes followed by 24 hours of reperfusion. Tail vein catheters were placed for contrast administration. Iohexol 300 mgI/mL was administered followed by images obtained in diastole. Iodinated lipid blood pool contrast agent was then administered, followed with images at systole and diastole. Respiratory and cardiac signals were monitored externally and used to gate the scans of free-breathing subjects. Seven control animals were scanned using the same imaging protocol. After imaging, the heart was harvested, cut into 1mm slices and stained with TTC. Post-processing analysis was performed using ITK-Snap and MATLAB. All animals demonstrated obvious delayed contrast enhancement in the left ventricular wall following the Iohexol injection. The blood pool contrast agent revealed significant changes in cardiac function quantified by 3-D volume ejection fractions. All subjects demonstrated areas of myocardial infarct in the LAD distribution on both TTC staining and micro-CT imaging. The CNT micro-CT system aids straightforward, free-breathing, prospectively-gated 3-D murine cardiac imaging. Delayed contrast enhancement allows identification of infarcted myocardium after a myocardial ischemic event. We demonstrate

  17. Delayed Contrast Enhancement Imaging of a Murine Model for Ischemia Reperfusion with Carbon Nanotube Micro-CT

    PubMed Central

    Burk, Laurel M.; Wang, Ko-Han; Wait, John Matthew; Kang, Eunice; Willis, Monte; Lu, Jianping; Zhou, Otto; Lee, Yueh Z.

    2015-01-01

    We aim to demonstrate the application of free-breathing prospectively gated carbon nanotube (CNT) micro-CT by evaluating a myocardial infarction model with a delayed contrast enhancement technique. Evaluation of murine cardiac models using micro-CT imaging has historically been limited by extreme imaging requirements. Newly-developed CNT-based x-ray sources offer precise temporal resolution, allowing elimination of physiological motion through prospective gating. Using free-breathing, cardiac-gated CNT micro-CT, a myocardial infarction model can be studied non-invasively and with high resolution. Myocardial infarction was induced in eight male C57BL/6 mice aged 8–12 weeks. The ischemia reperfusion model was achieved by surgically occluding the LAD artery for 30 minutes followed by 24 hours of reperfusion. Tail vein catheters were placed for contrast administration. Iohexol 300mgI/mL was administered followed by images obtained in diastole. Iodinated lipid blood pool contrast agent was then administered, followed with images at systole and diastole. Respiratory and cardiac signals were monitored externally and used to gate the scans of free-breathing subjects. Seven control animals were scanned using the same imaging protocol. After imaging, the heart was harvested, cut into 1mm slices and stained with TTC. Post-processing analysis was performed using ITK-Snap and MATLAB. All animals demonstrated obvious delayed contrast enhancement in the left ventricular wall following the Iohexol injection. The blood pool contrast agent revealed significant changes in cardiac function quantified by 3-D volume ejection fractions. All subjects demonstrated areas of myocardial infarct in the LAD distribution on both TTC staining and micro-CT imaging. The CNT micro-CT system aids straightforward, free-breathing, prospectively-gated 3-D murine cardiac imaging. Delayed contrast enhancement allows identification of infarcted myocardium after a myocardial ischemic event. We demonstrate

  18. Comparison of myocardial contrast echocardiography with NC100100 and 99mTc sestamibi SPECT for detection of resting myocardial perfusion abnormalities in patients with previous myocardial infarction

    PubMed Central

    Jucquois, I; Nihoyannopoulos, P; D'Hondt, A; Roelants, V; Robert, A; Melin, J; Glass, D; Vanoverschelde, J

    2000-01-01

    OBJECTIVE—To determine whether myocardial contrast echocardiography (MCE) following intravenous injection of perfluorocarbon microbubbles permits identification of resting myocardial perfusion abnormalities in patients who have had a previous myocardial infarction.
PATIENTS AND INTERVENTIONS—22 patients (mean (SD) age 66 (11) years) underwent MCE after intravenous injection of NC100100, a novel perfluorocarbon containing contrast agent, and resting 99mTc sestamibi single photon emission computed tomography (SPECT). With both methods, myocardial perfusion was graded semiquantitatively as 1 = normal, 0.5 = mild defect, and 0 = severe defect.
RESULTS—Among the 203 normally contracting segments, 151 (74%) were normally perfused by SPECT and 145 (71%) by MCE. With SPECT, abnormal tracer uptake was mainly found among normally contracting segments from the inferior wall. By contrast, with MCE poor myocardial opacification was noted essentially among the normally contracting segments from the anterior and lateral walls. Of the 142 dysfunctional segments, 87 (61%) showed perfusion defects by SPECT, and 94 (66%) by MCE. With both methods, perfusion abnormalities were seen more frequently among akinetic than hypokinetic segments. MCE correctly identified 81/139 segments that exhibited a perfusion defect by SPECT (58%), and 135/206 segments that were normally perfused by SPECT (66%). Exclusion of segments with attenuation artefacts (defined as abnormal myocardial opacification or sestamibi uptake but normal contraction) by either MCE or SPECT improved both the sensitivity (76%) and the specificity (83%) of the detection of SPECT perfusion defects by MCE.
CONCLUSIONS—The data suggest that MCE allows identification of myocardial perfusion abnormalities in patients who have had a previous myocardial infarction, provided that regional wall motion is simultaneously taken into account.


Keywords: myocardial contrast echocardiography; NC100100

  19. Rapid quantitative assessment of myocardial perfusion: spectral analysis of myocardial contrast echocardiographic images.

    PubMed

    Bae, Richard Y; Belohlavek, Marek; Greenleaf, James F; Seward, James B

    2002-01-01

    We described a novel rapid spectral analysis technique performed on raw digital in-phase quadrature (IQ) data that quantitatively differentiated perfused from nonperfused myocardium based on the simultaneous comparison of local fundamental and harmonic frequency band intensity levels. In open-chest pigs after ligation of the left anterior descending coronary artery (LAD) and continuous venous contrast infusion, the fundamental-to-harmonic intensity ratio (FHIR) for samples placed within the left ventricular (LV) cavity (10.8 +/- 1.7 dB) and perfused myocardium (13.7 +/- 1.6 dB) were significantly (P <.001) lower than for nonperfused myocardium (27.1 +/- 2.9 dB). In attenuated images, the FHIR for the LV cavity and perfused myocardium were also significantly (P <.05) lower than for the nonperfused myocardium (21.4 +/- 3.0 dB, 34.4 +/- 3.2 dB, and 40.2 +/- 4.4 dB, respectively). Spectral properties of contrast microbubbles, as characterized by the FHIR, allow for rapid quantitative assessment of myocardial perfusion from data contained in a single-image frame, without requiring background image subtraction and image averaging. PMID:11781556

  20. Cumulative phase delay imaging for contrast-enhanced ultrasound tomography.

    PubMed

    Demi, Libertario; van Sloun, Ruud J G; Wijkstra, Hessel; Mischi, Massimo

    2015-11-01

    Standard dynamic-contrast enhanced ultrasound (DCE-US) imaging detects and estimates ultrasound-contrast-agent (UCA) concentration based on the amplitude of the nonlinear (harmonic) components generated during ultrasound (US) propagation through UCAs. However, harmonic components generation is not specific to UCAs, as it also occurs for US propagating through tissue. Moreover, nonlinear artifacts affect standard DCE-US imaging, causing contrast to tissue ratio reduction, and resulting in possible misclassification of tissue and misinterpretation of UCA concentration. Furthermore, no contrast-specific modality exists for DCE-US tomography; in particular speed-of-sound changes due to UCAs are well within those caused by different tissue types. Recently, a new marker for UCAs has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental component is in fact observable for US propagating through UCAs, and is absent in tissue. In this paper, tomographic US images based on CPD are for the first time presented and compared to speed-of-sound US tomography. Results show the applicability of this marker for contrast specific US imaging, with cumulative phase delay imaging (CPDI) showing superior capabilities in detecting and localizing UCA, as compared to speed-of-sound US tomography. Cavities (filled with UCA) which were down to 1 mm in diameter were clearly detectable. Moreover, CPDI is free of the above mentioned nonlinear artifacts. These results open important possibilities to DCE-US tomography, with potential applications to breast imaging for cancer localization. PMID:26459771

  1. Cumulative phase delay imaging for contrast-enhanced ultrasound tomography

    NASA Astrophysics Data System (ADS)

    Demi, Libertario; van Sloun, Ruud J. G.; Wijkstra, Hessel; Mischi, Massimo

    2015-11-01

    Standard dynamic-contrast enhanced ultrasound (DCE-US) imaging detects and estimates ultrasound-contrast-agent (UCA) concentration based on the amplitude of the nonlinear (harmonic) components generated during ultrasound (US) propagation through UCAs. However, harmonic components generation is not specific to UCAs, as it also occurs for US propagating through tissue. Moreover, nonlinear artifacts affect standard DCE-US imaging, causing contrast to tissue ratio reduction, and resulting in possible misclassification of tissue and misinterpretation of UCA concentration. Furthermore, no contrast-specific modality exists for DCE-US tomography; in particular speed-of-sound changes due to UCAs are well within those caused by different tissue types. Recently, a new marker for UCAs has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental component is in fact observable for US propagating through UCAs, and is absent in tissue. In this paper, tomographic US images based on CPD are for the first time presented and compared to speed-of-sound US tomography. Results show the applicability of this marker for contrast specific US imaging, with cumulative phase delay imaging (CPDI) showing superior capabilities in detecting and localizing UCA, as compared to speed-of-sound US tomography. Cavities (filled with UCA) which were down to 1 mm in diameter were clearly detectable. Moreover, CPDI is free of the above mentioned nonlinear artifacts. These results open important possibilities to DCE-US tomography, with potential applications to breast imaging for cancer localization.

  2. Correlation between myocardial dysfunction and perfusion impairment in diabetic rats with velocity vector imaging and myocardial contrast echocardiography.

    PubMed

    Wei, Zhangrui; Zhang, Haibin; Su, Haili; Zhu, Ting; Zhu, Yongsheng; Zhang, Jun

    2012-11-01

    The purpose of this study was to investigate whether myocardial systolic dysfunction and perfusion impairment occur in diabetic rats, and to assess their relationship using velocity vector imaging (VVI) and myocardial contrast echocardiography (MCE). Forty-six rats were randomly divided into either control or the diabetes mellitus (DM) groups. DM was induced by intraperitoneal administration of streptozotocin. Twelve weeks later, 39 survival rats underwent VVI and MCE in short-axis view at the middle level of the left ventricle, both at rest and after dipyridamole stress. VVI-derived contractile parameters included peak systolic velocity (Vs ), circumferential strain (εc ), strain rate (SRc ), and their reserves. MCE-derived perfusion parameters consisted of myocardial blood flow (MBF) and myocardial flow reserve (MFR). At rest, SRc in the DM group was significantly lower than in the control group, Vs , εc , and MBF did not differ significantly between groups. After dipyridamole stress, all VVI parameters and their reserves in the DM group were significantly lower than those in the control group, MBF and MFR were substantially lower than those in the control group, too. Meanwhile, significant correlations between VVI parameter reserves and MFR were observed in the DM group. Both myocardial systolic function and perfusion were impaired in DM rats. Decreased MFR could be an important contributor to the reduction in myocardial contractile reserve. PMID:22931118

  3. Effect of streptozotocin-induced diabetes on myocardial blood flow reserve assessed by myocardial contrast echocardiography in rats

    PubMed Central

    Cosyns, Bernard; Droogmans, Steven; Hernot, Sophie; Degaillier, Céline; Garbar, Christian; Weytjens, Caroline; Roosens, Bram; Schoors, Danny; Lahoutte, Tony; Franken, Philippe R; Van Camp, Guy

    2008-01-01

    The role of structural and functional abnormalities of small vessels in diabetes cardiomyopathy remains unclear. Myocardial contrast echocardiography allows the quantification of myocardial blood flow at rest and during dipyridamole infusion. The aim of the study was to determine the myocardial blood flow reserve in normal rats compared with Streptozotocin-induced diabetic rats using contrast echocardiography. We prospectively studied 40 Wistar rats. Diabetes was induced by intravenous streptozotocin in 20 rats. All rats underwent baseline and stress (dipyridamole: 20 mg/kg) high power intermittent imaging in short axis view under anaesthesia baseline and after six months. Myocardial blood flow was determined and compared at rest and after dipyridamole in both populations. The myocardial blood flow reserve was calculated and compared in the 2 groups. Parameters of left ventricular function were determined from the M-mode tracings and histological examination was performed in all rats at the end of the study. At six months, myocardial blood flow reserve was significantly lower in diabetic rats compared to controls (3.09 ± 0.98 vs. 1.28 ± 0.67 ml min-1 g-1; p < 0.05). There were also a significant decrease in left ventricular function and a decreased capillary surface area and diameter at histology in the diabetic group. In this animal study, diabetes induced a functional alteration of the coronary microcirculation, as demonstrated by contrast echocardiography, a decrease in capillary density and of the cardiac systolic function. These findings may offer new insights into the underlying mechanisms of diabetes cardiomyopathy. PMID:18764943

  4. Novel ways to noninvasively detect inflammation of the myocardium: contrast-enhanced MRI and myocardial contrast echocardiography

    PubMed Central

    van den Brink, M.R.; Geluk, C.A.; Lindner, J.R.; Velthuis, B.K.; Vonken, E.J.; Cramer, M.J.M.

    2003-01-01

    Both contrast-enhanced magnetic resonance imaging (CE-MRI) and myocardial contrast echocardiography (MCE) are promising tools to detect cardiac inflammation. CE-MRI can be used to characterise the location and extent of myocardial inflammation, since areas of abnormal signal enhancement associated with regional wall motion abnormalities reliably indicate areas of active myocarditis. In MCE, chemically composed microbubbles can be visualised by ultrasound and used to determine the status of the cardiac microvasculature. If there is any inflammation the microbubbles will be phagocytosed by neutrophils and monocytes, thus enabling the degree of inflammation to be assessed. These noninvasive techniques may allow early diagnosis and accurate evaluation of myocardial inflammation. ImagesFigure 1Figure 2Figure 3Figure 4 PMID:25696203

  5. Imitation of contrastive lexical stress in children with speech delay

    NASA Astrophysics Data System (ADS)

    Vick, Jennell C.; Moore, Christopher A.

    2005-09-01

    This study examined the relationship between acoustic correlates of stress in trochaic (strong-weak), spondaic (strong-strong), and iambic (weak-strong) nonword bisyllables produced by children (30-50) with normal speech acquisition and children with speech delay. Ratios comparing the acoustic measures (vowel duration, rms, and f0) of the first syllable to the second syllable were calculated to evaluate the extent to which each phonetic parameter was used to mark stress. In addition, a calculation of the variability of jaw movement in each bisyllable was made. Finally, perceptual judgments of accuracy of stress production were made. Analysis of perceptual judgments indicated a robust difference between groups: While both groups of children produced errors in imitating the contrastive lexical stress models (~40%), the children with normal speech acquisition tended to produce trochaic forms in substitution for other stress types, whereas children with speech delay showed no preference for trochees. The relationship between segmental acoustic parameters, kinematic variability, and the ratings of stress by trained listeners will be presented.

  6. Cocaine-Induced Delayed Myocardial Infarction Complicated by Apical Thrombus.

    PubMed

    Khan, Rafay; Arshed, Sabrina; Jehangir, Waqas; Sen, Shuvendu; Yousif, Abdalla

    2016-01-01

    It is well demonstrated in the literature that cocaine use has been well linked to the formation of various forms of acute and chronic cardiovascular problems including but not limited to acute coronary syndromes. However, cocaine has been commonly associated with coronary vasospasms and less commonly with myocardial infarction and the formation of atrial thrombus. Through this case presentation, we illustrate the findings of a 35-year-old gentleman with history of cocaine use presenting with acute coronary syndrome and complicated by thrombus formation. Furthermore, through this report, we illustrate in a patient with no other risk factors and at a young age, how chronic cocaine use or even a history of usage may result in complications even weeks after its consumption. PMID:26668686

  7. Cocaine-Induced Delayed Myocardial Infarction Complicated by Apical Thrombus

    PubMed Central

    Khan, Rafay; Arshed, Sabrina; Jehangir, Waqas; Sen, Shuvendu; Yousif, Abdalla

    2016-01-01

    It is well demonstrated in the literature that cocaine use has been well linked to the formation of various forms of acute and chronic cardiovascular problems including but not limited to acute coronary syndromes. However, cocaine has been commonly associated with coronary vasospasms and less commonly with myocardial infarction and the formation of atrial thrombus. Through this case presentation, we illustrate the findings of a 35-year-old gentleman with history of cocaine use presenting with acute coronary syndrome and complicated by thrombus formation. Furthermore, through this report, we illustrate in a patient with no other risk factors and at a young age, how chronic cocaine use or even a history of usage may result in complications even weeks after its consumption. PMID:26668686

  8. Cumulative phase delay imaging - A new contrast enhanced ultrasound modality

    SciTech Connect

    Demi, Libertario Sloun, Ruud J. G. van; Mischi, Massimo; Wijkstra, Hessel

    2015-10-28

    Recently, a new acoustic marker for ultrasound contrast agents (UCAs) has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental pressure wave field components is in fact observable for ultrasound propagating through UCAs. This phenomenon is absent in the case of tissue nonlinearity and is dependent on insonating pressure and frequency, UCA concentration, and propagation path length through UCAs. In this paper, ultrasound images based on this marker are presented. The ULA-OP research platform, in combination with a LA332 linear array probe (Esaote, Firenze Italy), were used to image a gelatin phantom containing a PVC plate (used as a reflector) and a cylindrical cavity measuring 7 mm in diameter (placed in between the observation point and the PVC plate). The cavity contained a 240 µL/L SonoVueO{sup ®} UCA concentration. Two insonating frequencies (3 MHz and 2.5 MHz) were used to scan the gelatine phantom. A mechanical index MI = 0.07, measured in water at the cavity location with a HGL-0400 hydrophone (Onda, Sunnyvale, CA), was utilized. Processing the ultrasound signals backscattered from the plate, ultrasound images were generated in a tomographic fashion using the filtered back-projection method. As already observed in previous studies, significantly higher CPD values are measured when imaging at a frequency of 2.5 MHz, as compared to imaging at 3 MHz. In conclusion, these results confirm the applicability of the discussed CPD as a marker for contrast imaging. Comparison with standard contrast-enhanced ultrasound imaging modalities will be the focus of future work.

  9. Cumulative phase delay imaging - A new contrast enhanced ultrasound modality

    NASA Astrophysics Data System (ADS)

    Demi, Libertario; van Sloun, Ruud J. G.; Wijkstra, Hessel; Mischi, Massimo

    2015-10-01

    Recently, a new acoustic marker for ultrasound contrast agents (UCAs) has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental pressure wave field components is in fact observable for ultrasound propagating through UCAs. This phenomenon is absent in the case of tissue nonlinearity and is dependent on insonating pressure and frequency, UCA concentration, and propagation path length through UCAs. In this paper, ultrasound images based on this marker are presented. The ULA-OP research platform, in combination with a LA332 linear array probe (Esaote, Firenze Italy), were used to image a gelatin phantom containing a PVC plate (used as a reflector) and a cylindrical cavity measuring 7 mm in diameter (placed in between the observation point and the PVC plate). The cavity contained a 240 µL/L SonoVueO® UCA concentration. Two insonating frequencies (3 MHz and 2.5 MHz) were used to scan the gelatine phantom. A mechanical index MI = 0.07, measured in water at the cavity location with a HGL-0400 hydrophone (Onda, Sunnyvale, CA), was utilized. Processing the ultrasound signals backscattered from the plate, ultrasound images were generated in a tomographic fashion using the filtered back-projection method. As already observed in previous studies, significantly higher CPD values are measured when imaging at a frequency of 2.5 MHz, as compared to imaging at 3 MHz. In conclusion, these results confirm the applicability of the discussed CPD as a marker for contrast imaging. Comparison with standard contrast-enhanced ultrasound imaging modalities will be the focus of future work.

  10. Acute effects of delayed reperfusion following myocardial infarction: a 3D x-ray imaging analysis

    NASA Astrophysics Data System (ADS)

    Simari, Robert D.; Bell, M. R.; Pao, Y. C.; Gersh, B. J.; Ritman, Erik L.

    1996-04-01

    Clinical and experimental data suggest that delayed reperfusion of the infarct related artery may limit infarct expansion without increasing myocardial salvage. In order to assess the potential mechanisms involved, an acute closed chest canine model of myocardial infarction and delayed reperfusion was studied. Nineteen dogs underwent 3D computed tomography in the Dynamic Spatial Reconstructor (a fast, volume imaging, CT scanner) at baseline and three and four hours later to estimate left ventricular chamber volumes, global distensibility and regional myocardial stiffness. A control group was scanned without intervention. An occlusion group underwent four hours of coronary artery occlusion. A reperfusion group underwent three hours of coronary artery occlusion followed by one hour of reperfusion. Similar infarct sizes were seen in the occlusion and reperfusion groups. Globally reperfusion was associated with increased left ventricular end diastolic pressure and prolongation of global relaxation. Regionally reperfusion was associated with increased myocardial stiffness, intramyocardial blood volume and wall thickness within the infarct zone relative to the not reperfused myocardium.

  11. Prehospital delay in patients presenting with acute ST-elevation myocardial infarction.

    PubMed

    Hong, Choon Chiet; Sultana, Papia; Wong, Aaron Sung Lung; Chan, Kim Poh; Pek, Pin Pin; Ong, Marcus Eng Hock

    2011-10-01

    To characterize prehospital delays in patients presenting with acute ST-elevation myocardial infarction to the emergency department of a tertiary hospital in Asia. A retrospective review of 273 patients with diagnosis of ST-elevation myocardial infarction; symptom to door (S2D) time was described in two ways, time from first onset of symptoms; and time from the onset of the worst episode to presentation at emergency department. The median first onset S2D time was 173 min (interquartile range 80-350 min); and median worst episode S2D time was 131 min (interquartile range 70-261 min). Patients with prehospital delay tended to use their own transport compared with the no delay group (P=0.026, 95% confidence interval=0.02-0.24). There was no difference in S2D times for typical compared with atypical symptoms. A large proportion of patients experienced delay in seeking medical care after the onset of acute coronary symptoms. Self-transport was associated with delay. PMID:21317785

  12. Delayed uptake and washout of contrast in non-viable infarcted myocardium shown with dynamic computed tomography

    PubMed Central

    Laugesen, Sofie; Agger, Peter; Hønge, Jesper; Smerup, Morten; Udholm, Nichlas; Bøtker, Hans Erik; Bøttcher, Morten

    2014-01-01

    Background Assessment of ischemic but potentially viable myocardium plays an important role in the planning of coronary revascularization. Until now SPECT, PET, and MRI have been used to identify viable myocardium. Computed tomography (CT) is increasingly used to diagnose coronary atherosclerosis. Objective To evaluate the feasibility of CT enhancement as a viability marker by investigating myocardial contrast distribution over time in pigs with experimentally induced antero-septal myocardial infarctions. Methods Twelve pigs were subjected to 60 min of balloon occlusion of the left anterior descending artery, followed by removal of the balloon and reperfusion. Four pigs died due to refractory ventricular fibrillation. After 6 weeks, dynamic cardiac CT was performed assessing both wall motion and contrast attenuation. Measurements of attenuation values in Hounsfield units (HU) in the infarct zone and the normal lateral wall were performed at 20 s, and 1, 3, 5, 8 and 12 min after contrast injection. Results We found highly significant differences in attenuation values between the two zones at all-time points except t =1 min (ANOVA P=0.85). The normal myocardium showed higher uptake- and washout-rates of contrast than the infarct zone (84±15 vs. 58±8 at 20 s, P=0.0001 and 27±12 vs. 81±13 at 12 min, P=0.0001). Specifically, the ratio between early (20 s) and late (12 min) uptake is a valid marker of viable myocardium. In all animals this ration was above one in the normal zone and below one in the infarct zone. Conclusions Delayed infarct related uptake and washout of contrast shows promise for future clinical application of CT in a combined assessment of coronary atherosclerosis and myocardial viability. PMID:25414821

  13. Advanced Echocardiography in Adult Zebrafish Reveals Delayed Recovery of Heart Function after Myocardial Cryoinjury

    PubMed Central

    Kossack, Mandy; Juergensen, Lonny; Fuchs, Dieter; Katus, Hugo A.; Hassel, David

    2015-01-01

    Translucent zebrafish larvae represent an established model to analyze genetics of cardiac development and human cardiac disease. More recently adult zebrafish are utilized to evaluate mechanisms of cardiac regeneration and by benefiting from recent genome editing technologies, including TALEN and CRISPR, adult zebrafish are emerging as a valuable in vivo model to evaluate novel disease genes and specifically validate disease causing mutations and their underlying pathomechanisms. However, methods to sensitively and non-invasively assess cardiac morphology and performance in adult zebrafish are still limited. We here present a standardized examination protocol to broadly assess cardiac performance in adult zebrafish by advancing conventional echocardiography with modern speckle-tracking analyses. This allows accurate detection of changes in cardiac performance and further enables highly sensitive assessment of regional myocardial motion and deformation in high spatio-temporal resolution. Combining conventional echocardiography measurements with radial and longitudinal velocity, displacement, strain, strain rate and myocardial wall delay rates after myocardial cryoinjury permitted to non-invasively determine injury dimensions and to longitudinally follow functional recovery during cardiac regeneration. We show that functional recovery of cryoinjured hearts occurs in three distinct phases. Importantly, the regeneration process after cryoinjury extends far beyond the proposed 45 days described for ventricular resection with reconstitution of myocardial performance up to 180 days post-injury (dpi). The imaging modalities evaluated here allow sensitive cardiac phenotyping and contribute to further establish adult zebrafish as valuable cardiac disease model beyond the larval developmental stage. PMID:25853735

  14. Neural Mechanisms and Delayed Gastric Emptying of Liquid Induced Through Acute Myocardial Infarction in Rats

    PubMed Central

    Nunez, Wilson Ranu Ramirez; Ozaki, Michiko Regina; Vinagre, Adriana Mendes; Collares, Edgard Ferro; de Almeida, Eros Antonio

    2015-01-01

    Background In pathological situations, such as acute myocardial infarction, disorders of motility of the proximal gut can trigger symptoms like nausea and vomiting. Acute myocardial infarction delays gastric emptying (GE) of liquid in rats. Objective Investigate the involvement of the vagus nerve, α 1-adrenoceptors, central nervous system GABAB receptors and also participation of paraventricular nucleus (PVN) of the hypothalamus in GE and gastric compliance (GC) in infarcted rats. Methods Wistar rats, N = 8-15 in each group, were divided as INF group and sham (SH) group and subdivided. The infarction was performed through ligation of the left anterior descending coronary artery. GC was estimated with pressure-volume curves. Vagotomy was performed by sectioning the dorsal and ventral branches. To verify the action of GABAB receptors, baclofen was injected via icv (intracerebroventricular). Intravenous prazosin was used to produce chemical sympathectomy. The lesion in the PVN of the hypothalamus was performed using a 1mA/10s electrical current and GE was determined by measuring the percentage of gastric retention (% GR) of a saline meal. Results No significant differences were observed regarding GC between groups; vagotomy significantly reduced % GR in INF group; icv treatment with baclofen significantly reduced %GR. GABAB receptors were not conclusively involved in delaying GE; intravenous treatment with prazosin significantly reduced GR% in INF group. PVN lesion abolished the effect of myocardial infarction on GE. Conclusion Gastric emptying of liquids induced through acute myocardial infarction in rats showed the involvement of the vagus nerve, alpha1- adrenergic receptors and PVN. PMID:25494017

  15. Predictors of Prehospital Delay in Patients With Acute Myocardial Infarction in Kashan City

    PubMed Central

    Saberi, Farzaneh; Adib-Hajbaghery, Mohsen; Zohrehea, Javad

    2014-01-01

    Background: The prehospital delay might result in death in patients with acute myocardial infarction (AMI). Objectives: This study aimed to investigate the prehospital delay and its related factors in patients with AMI admitted to Kashan’s Shahid Beheshti Hospital. Patients and Methods: This cross-sectional study was conducted on 117 patients with AMI in the second half of 2013. The interval between the onset of symptoms and arrival at the hospital was noted and in cases of delay, the factors leading to the delay were investigated using a questionnaire. The content validity of the questionnaire was confirmed through content validity method and its internal consistency was confirmed using Cronbach's alpha coefficient. Chi-square test, odds ratio, and logistic regression analysis were used in data analysis. Results: The median delay was 129 minutes (mean ± SD, 240.44 ± 295.30). Overall, 32.5% of patients were admitted within 90 minutes of symptom onset. The long distance between living locations to the hospital was the most common cause of delay to hospital admission (31.7%). Significant associations were observed between the delay time and location of residency (P = 0.00) and type of transportation vehicle (P = 0.003). Multivariate logistic regression analysis showed that the location of residency and type of transportation vehicle could significantly predict the delay time in patients with AMI (P = 0.039 and 0.036, respectively). Conclusions: The delay time from symptom onset to hospital admission was high in patients with AMI. It is necessary to create emergency medical system (EMS) stations in suburbs and train the public on the importance of quick contact with the EMS when the symptoms of an AMI are observed. PMID:25741517

  16. Effect of genetic disruption of poly (ADP-ribose) synthetase on delayed production of inflammatory mediators and delayed necrosis during myocardial ischemia-reperfusion injury.

    PubMed

    Yang, Z; Zingarelli, B; Szabó, C

    2000-01-01

    The nuclear enzyme poly (ADP ribose) synthetase (PARS) has been shown to play an important role in the pathogenesis of various forms of ischemia or reperfusion injury and circulatory shock. Recent studies demonstrated that inhibition or genetic inactivation of PARS is beneficial in the early phase of myocardial reperfusion injury. The aim of the present study was to investigate whether inactivation of PARS influences the delayed myocardial necrosis and the production of the proinflammatory cytokine tumor necrosis factor alpha (TNFalpha), the anti-inflammatory cytokine interleukin-10 (IL-10), and the free radical nitric oxide in the late stage of myocardial reperfusion injury. The results demonstrate that genetic disruption of PARS provides marked protection against the delayed myocardial ischemia and reperfusion injury. In addition, in the absence of functional PARS, a suppression of TNFalpha, IL-10, and nitric oxide production was found. These findings provide direct evidence that PARS activation participates in the development of delayed cell injury and delayed mediator production in myocardial reperfusion injury. PMID:10638671

  17. Computerized measurement of myocardial infarct size on contrast-enhanced magnetic resonance images

    NASA Astrophysics Data System (ADS)

    Hsu, Li-Yueh; Kellman, Peter; Natanzon, Alex; Hirsch, Glenn A.; Aletras, Anthony H.; Arai, Andrew E.

    2005-04-01

    Purpose: To validate a computer algorithm for measuring myocardial infarct size on gadolinium enhanced MR images. The results of computer infarct sizing are studied on phase-sensitive and magnitude imaging against a histopathology reference. Materials and Methods: Validations were performed in 9 canine myocardial infarctions determined by triphenyltetrazolium chloride (TTC). The algorithm analyzed the pixel intensity distribution within manually traced myocardial regions. Pixels darker than an automatically determined threshold were first excluded from further analysis. Selected image features were used to remove false positive regions. A threshold 50% between bright and dark regions was then used to minimize partial volume errors. Post-processing steps were applied to identify microvascular obstruction. Both phase sensitive and magnitude reconstructed MR images were measured by the computer algorithm in units of % of the left ventricle (LV) infarction and compared to TTC. Results: Correlations of MR and TTC infarct size were 0.96 for both phase sensitive and magnitude imaging. Bland Altman analysis showed no consistent bias as a function of infarct size. The average error of computer infarct sizing was less than 2% of the LV for both reconstructions. Fixed intensity thresholding was less accurate compared to the computer algorithm. Conclusions: MR can accurately depict myocardial infarction. The proposed computer algorithm accurately measures infarct size on contrast-enhanced MR images against the histopathology reference. It is effective for both phase-sensitive and magnitude imaging.

  18. Prehospital system delay in patients with ST-segment elevation myocardial infarction in Singapore

    PubMed Central

    Ho, Andrew Fu Wah; Pek, Pin Pin; Fook-Chong, Stephanie; Wong, Ting Hway; Ng, Yih Yng; Wong, Aaron Sung Lung; Ong, Marcus Eng Hock

    2015-01-01

    BACKGROUND: Timely reperfusion in ST-segment elevation myocardial infarction (STEMI) improves outcomes. System delay is that between first medical contact and reperfusion therapy, comprising prehospital and hospital components. This study aimed to characterize prehospital system delay in Singapore. METHODS: A retrospective chart review was performed for 462 consecutive STEMI patients presenting to a tertiary hospital from December 2006 to April 2008. Patients with cardiac arrest secondarily presented were excluded. For those who received emergency medical services (EMS), ambulance records were reviewed. Time intervals in the hospital were collected prospectively. The patients were divided into two equal groups of high/low prehospital system delay using visual binning technique. RESULTS: Of 462 patients, 76 received EMS and 52 of the 76 patients were analyzed. The median system delay was 125.5 minutes and the median prehospital system delay was 33.5 minutes (interquartile range [IQR]=27.0, 42.0). Delay between call-received-by-ambulance and ambulance-dispatched was 2.48 minutes (IQR=1.47, 16.55); between ambulance-dispatch and arrival-at-patient-location was 8.07 minutes (IQR=1.30, 22.13); between arrival-at- and departure-from-patient-location was 13.12 minutes (IQR=3.12, 32.2); and between leaving-patient-location to ED-registration was 9.90 minutes (IQR=1.62, 32.92). Comparing patients with prehospital system delay of less than 35.5 minutes versus more showed that the median delay between ambulance-dispatch and arrival-at-patient-location was shorter (5.75 vs. 9.37 minutes, P<0.01). The median delay between arrival-at-patient-location and leaving-patient-location was also shorter (10.78 vs. 14.37 minutes, P<0.01). CONCLUSION: Prehospital system delay in our patients was suboptimal. This is the first attempt at characterizing prehospital system delay in Singapore and forms the basis for improving efficiency of STEMI care. PMID:26693262

  19. Comparison of mortality benefit of immediate thrombolytic therapy versus delayed primary angioplasty for acute myocardial infarction.

    PubMed

    Kent, David M; Ruthazer, Robin; Griffith, John L; Beshansky, Joni R; Grines, Cindy L; Aversano, Thomas; Concannon, Thomas W; Zalenski, Robert J; Selker, Harry P

    2007-05-15

    Primary percutaneous coronary intervention (PPCI) yields superior mortality outcomes compared with thrombolysis in ST-elevation acute myocardial infarction (STEMI) but takes longer to administer. Previous meta-regressions have estimated that a procedure-related delay of 60 minutes would nullify the benefits of PPCI on mortality. Using a combined database from randomized clinical trials and registries (n = 2,781) and an independently developed model of mortality risk in STEMI, we developed logistic regression models predicting 30-day mortality for PPCI and thrombolysis by examining the influence of baseline risk on the treatment effect of PPCI and on the hazard of treatment delay. We used these models to solve mathematically for "time interval to mortality equivalence," defined as the PPCI-related delay that would nullify its expected mortality benefit over thrombolysis, and to explore the influence of baseline risk on this value. As baseline risk increases, the relative benefit of PPCI compared with thrombolytic therapy significantly increases (p = 0.002); patients with STEMI at relatively low risk of mortality accrue little or no incremental mortality benefit from PPCI, but high-risk patients benefit greatly. However, as baseline risk increases, the hazard associated with longer treatment-related delay also increases (p = 0.007). These 2 effects are compensatory and yield a roughly uniform time interval to mortality equivalence of approximately 100 minutes in patients who have at least a moderate degree of mortality risk (> approximately 4%). In conclusion, the mortality benefits of PPCI and the hazard of PPCI-related delay depend on baseline risk. Previous meta-regressions appear to have underestimated the PPCI-related delay that would nullify the incremental benefits of PPCI. PMID:17493465

  20. Comparison of delay times to hospital presentation for physicians and nonphysicians with acute myocardial infarction.

    PubMed

    Ridker, P M; Manson, J E; Goldhaber, S Z; Hennekens, C H; Buring, J E

    1992-07-01

    To evaluate whether patients who recognize the symptoms of myocardial ischemia and have easy access to medical care have shortened time delays between onset of symptoms and hospital presentation, the total time interval between symptom onset and hospital arrival for 258 U.S. male physicians experiencing a first acute myocardial infarction (AMI) in the Physicians' Health Study (PHS) was compared with that of a comparable group of 240 men enrolled in the U.S. component of the Second International Study of Infarct Survival (ISIS-2), as well as with those of previously published series of patients with AMI. For patients presenting for medical care within 24 hours of symptom onset, the median time delay from onset of symptoms to presentation for medical care was 1.8 hours in the PHS, and 4.9 hours in the U.S. component of ISIS-2 (p less than 0.001). Furthermore, 56% of participants in the PHS presented for medical care within 2 hours and 72% within 4 hours of symptom onset compared with 20% (p less than 0.001) and 44% (p less than 0.001), respectively, for ISIS-2 participants. In previously published series, the average time to presentation was comparable to that in the ISIS-2 trial, with variation depending on country of origin and on local population density. The median time to medical presentation in any previous series was not shorter than that in the PHS. Thus, physicians in the PHS had significantly shorter time delays between onset of symptoms and presentation for medical care. This difference may help explain the far lower than expected cardiovascular mortality rates among physician participants in the PHS.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1615847

  1. Paramagnetic pyrophosphate. Preliminary studies on magnetic resonance contrast enhancement of acute myocardial infarction.

    PubMed

    Maurer, A H; Knight, L C; Siegel, J A; Elfenbein, I B; Adler, L P

    1990-02-01

    Ferric pyrophosphate (Fe-PyP) was investigated in an animal model of acute myocardial infarction for its potential to provide contrast enhancement of the peri-infarct zone using magnetic resonance (MR) imaging. Radiotracer studies compared the biodistribution of soluble 59Fe-PyP with 99mTc-PyP in excised tissue samples. Preferential localization of 59Fe-PyP in the peri-infarct zone was found to be similar to 99mTc-PyP. The ratio (percent dose/gram of tissue) at the edge of the infarct to normal tissue was 1.30 +/- 0.16 and 1.44 +/- 0.33 for 99mTc-PyP and 59Fe-PyP, respectively. In initial studies with high doses of the contrast agent, gated T1-weighted MR images of animals with 48-hour-old infarcts were obtained at 15-minute intervals after injection of Fe-PyP at a dose of 350 mg/kg. Contrast enhancement of the infarct zone was observed in all studies and was maximal 15-30 minutes after injection. Signal intensity ratios (infarct/normal) increased from a baseline 1.31 +/- 0.22 to a peak 1.90 +/- 0.57. Studies were then performed with smaller amounts of Fe-PyP. Images obtained with 50 mg/kg Fe-PyP showed contrast enhancement beginning at 60 minutes. Toxicology studies showed primarily respiratory effects, which became significant at doses of 190 mg/kg. These preliminary studies suggest that Fe-PyP potentially could serve as an MR contrast agent to localize and size acute myocardial infarcts; however, its clinical use may be limited by potential toxicity and dose limitations. PMID:2155882

  2. Acrolein inhalation causes myocardial strain delay and decreased cardiac performance as detected by high-frequency echocardiography in mice

    EPA Science Inventory

    Acrolein, an unsaturated aldehyde found in air pollution, impairs Ca2+ flux and contraction in cardiomyocytes in vitro. To better define direct and delayed functional cardiac effects, we hypothesized that a single exposure to acrolein would modify myocardial strain and performanc...

  3. Myofilament calcium sensitization delays decompensated hypertrophy differently between the sexes following myocardial infarction

    PubMed Central

    Shioura, Krystyna M.; Farjah, Mariam; Geenen, David L.; Solaro, R. John

    2011-01-01

    Contractile dysfunction is common to many forms of cardiovascular disease. Approaches directed at enhancing cardiac contractility at the level of the myofilaments during heart failure (HF) may provide a means to improve overall cardiovascular function. We are interested in gender-based differences in cardiac function and the effect of sarcomere activation agents that increase contractility. Thus, we studied the effect of gender and time on integrated arterial-ventricular function (A-V relationship) following myocardial infarction (MI). In addition, transgenic mice that overexpress the slow skeletal troponin I isoform were used to determine the impact of increased myofilament Ca2+ sensitivity following MI. Based on pressure-volume (P-V) loop measurements, we used derived parameters of cardiovascular function to reveal the effects of sex, time, and increased myofilament Ca2+ sensitivity among groups of post-MI mice. Analysis of the A-V relationship revealed that the initial increase was similar between the sexes, but the vascular unloading of the heart served to delay the decompensated stage in females. Conversely, the vascular response at 6 and 10 wk post-MI in males contributed to the continuous decline in cardiovascular function. Increasing the myofilament Ca2+ sensitivity appeared to provide sufficient contractile support to improve contractile function in both male and female transgenic mice. However, the improved contractile function was more beneficial in males as the concurrent vascular response contributed to a delayed decompensated stage in female transgenic mice post-MI. This study represents a quantitative approach to integrating the vascular-ventricular relationship to provide meaningful and diagnostic value following MI. Consequently, the data provide a basis for understanding how the A-V relationship is coupled between males and females and the enhanced ability of the cardiovascular system to tolerate pathophysiological stresses associated with HF in

  4. Obesity superimposed on aging magnifies inflammation and delays the resolving response after myocardial infarction.

    PubMed

    Lopez, Elizabeth F; Kabarowski, Janusz H; Ingle, Kevin A; Kain, Vasundhara; Barnes, Stephen; Crossman, David K; Lindsey, Merry L; Halade, Ganesh V

    2015-02-15

    Polyunsaturated fatty acid (PUFA) intake has increased over the last 100 yr, contributing to the current obesogenic environment. Obesity and aging are prominent risk factors for myocardial infarction (MI). How obesity interacts with aging to alter the post-MI response, however, is unclear. We tested the hypothesis that obesity in aging mice would impair the resolution of post-MI inflammation. PUFA diet (PUFA aging group) feeding to 12-mo-old C57BL/6J mice for 5 mo showed higher fat mass compared with standard lab chow (LC)-fed young (LC young group; 3-5 mo old) or aging alone control mice (LC aging group). LC young, LC aging, and PUFA aging mice were subjected to coronary artery ligation to induce MI. Despite similar infarct areas post-MI, plasma proteomic profiling revealed higher VCAM-1 in the PUFA aging group compared with LC young and LC aging groups, leading to increased neutrophil infiltration in the PUFA aging group (P<0.05). Macrophage inflammatory protein-1γ and CD40 were also increased at day 1, and myeloperoxidase remained elevated at day 5, an observation consistent with delayed wound healing in the PUFA aging group. Lipidomic analysis showed higher levels of arachidonic acid and 12(S)-hydroxyeicosatetraenoic acid at day 1 post-MI in the PUFA aging group compared with the LC aging group (all P<0.05), thereby mediating neutrophil extravasation in the PUFA aging group. The inflammation-resolving enzymes 5-lipoxygenase, cyclooxygenase-2, and heme oxyegnase-1 were altered to delay wound healing post-MI in the PUFA aging group compared with LC young and LC aging groups. PUFA aging magnifies the post-MI inflammatory response and impairs the healing response by stimulating prolonged neutrophil trafficking and proinflammatory lipid mediators. PMID:25485899

  5. Obesity superimposed on aging magnifies inflammation and delays the resolving response after myocardial infarction

    PubMed Central

    Lopez, Elizabeth F.; Kabarowski, Janusz H.; Ingle, Kevin A.; Kain, Vasundhara; Barnes, Stephen; Crossman, David K.; Lindsey, Merry L.

    2014-01-01

    Polyunsaturated fatty acid (PUFA) intake has increased over the last 100 yr, contributing to the current obesogenic environment. Obesity and aging are prominent risk factors for myocardial infarction (MI). How obesity interacts with aging to alter the post-MI response, however, is unclear. We tested the hypothesis that obesity in aging mice would impair the resolution of post-MI inflammation. PUFA diet (PUFA aging group) feeding to 12-mo-old C57BL/6J mice for 5 mo showed higher fat mass compared with standard lab chow (LC)-fed young (LC young group; 3–5 mo old) or aging alone control mice (LC aging group). LC young, LC aging, and PUFA aging mice were subjected to coronary artery ligation to induce MI. Despite similar infarct areas post-MI, plasma proteomic profiling revealed higher VCAM-1 in the PUFA aging group compared with LC young and LC aging groups, leading to increased neutrophil infiltration in the PUFA aging group (P < 0.05). Macrophage inflammatory protein-1γ and CD40 were also increased at day 1, and myeloperoxidase remained elevated at day 5, an observation consistent with delayed wound healing in the PUFA aging group. Lipidomic analysis showed higher levels of arachidonic acid and 12(S)-hydroxyeicosatetraenoic acid at day 1 post-MI in the PUFA aging group compared with the LC aging group (all P < 0.05), thereby mediating neutrophil extravasation in the PUFA aging group. The inflammation-resolving enzymes 5-lipoxygenase, cyclooxygenase-2, and heme oxyegnase-1 were altered to delay wound healing post-MI in the PUFA aging group compared with LC young and LC aging groups. PUFA aging magnifies the post-MI inflammatory response and impairs the healing response by stimulating prolonged neutrophil trafficking and proinflammatory lipid mediators. PMID:25485899

  6. Feasibility Study of Myocardial Perfusion and Oxygenation by Non-Contrast MRI: Comparison with PET Study in a Canine Model

    PubMed Central

    McCommis, Kyle S.; Zhang, Haosen; Herrero, Pilar; Gropler, Robert J.; Zheng, Jie

    2008-01-01

    The purpose of this study was to examine the feasibility of quantifying myocardial blood flow (MBF) and rate of myocardial oxygen consumption (MVO2) during pharmacologically induced stress without using a contrast agent. The former was measured by the arterial spin labeling (ASL) method and the later was obtained by measuring the oxygen extraction fraction (OEF) with the magnetic resonance imaging (MRI) blood oxygenation level-dependent (BOLD) effect and Fick's law. The MRI results were compared with the established positron emission tomography (PET) methods. Six mongrel dogs with induced acute moderate left coronary artery stenosis were scanned using a clinical PET and a 1.5T MRI system, in the same day. Regional MBF, myocardial OEF, and MVO2 were measured with both imaging modalities. Correlation coefficients (R2) of the three myocardial indexes (MBF, OEF, and MVO2) between MRI and PET methods ranged from 0.70 to 0.93. Bland-Altman statistics demonstrated that the estimated precision of the limits of agreement between MRI and PET measurements varied from 18% (OEF), to 37% (MBF), and 45% (MVO2). The detected changes in these indexes, at rest and during dobutamine stress, were similar between two image modalities. The proposed non-contrast MRI technique is a promising method to quantitatively assess myocardial perfusion and oxygenation. PMID:17566684

  7. CT of multiple sclerosis: reassessment of delayed scanning with high doses of contrast material

    SciTech Connect

    Spiegel, S.M.; Vinuela, F.; Fox, A.J.; Pelz, D.M.

    1985-09-01

    A prospective study involving 87 patients was carried out to evaluate the necessity for a high dose of contrast material in addition to delayed computed tomographic (CT) scanning for optimal detection of the lesions of multiple sclerosis in the brain. In patients with either clinically definite multiple sclerosis or laboratory-supported definite multiple sclerosis, CT scans were obtained with a uniform protocol. Lesions consistent with multiple sclerosis were demonstrated on the second scan in 54 patients. In 36 of these 54 patients, the high-dose delayed scan added information. These results are quite similar to those of a previous study from this institution using different patients, in whom the second scan was obtained immediately after the bolus injection of contrast material containing 40 g of organically bound iodine. The lack of real difference in the results of the two studies indicate that the increased dose, not just the delay in scanning, is necessary for a proper study.

  8. Predictors of delayed pre-hospital presentation among patients with ST-segment elevation myocardial infarction

    PubMed Central

    Albrahim, Mohammed; Ahmed, Amjad M.; Alwakeel, Abdulrahman; Hijji, Faisal; Al-Mallah, Mouaz H.

    2016-01-01

    Background: Early treatment of ST elevation myocardial infarction (STEMI) is essential to improve survival of these patients. However, not all patients present early enough to receive optimal treatment especially in third world countries. Social factors affecting early vs. late treatment have not been studied, particularly in the Middle East. Thus, the aim of this study was to determine the social factors associated with delayed presentation of STEMI patients. Methods: All patients with STEMI presenting to King Abdulaziz Cardiac Center (KACC) between October 2013 and July 2014 were approached. After obtaining consent, patients were interviewed regarding their psychosocial circumstances using a standardized questionnaire. Their medical charts were also reviewed for further clinical data. Patients were divided according to their symptom-to-door time into early ( ≤ 6h) and late (>6h) presentation and group comparisons were conducted. Results: A total of 79 patients were enrolled, of which 24 patients (30%) presented late. Patients with increased symptom-to-door time had higher prevalence of diabetes (40% vs. 79.2%, p = 0.001), hypertension (43.6% vs. 70.8%, p = 0.023), and dyslipidemia (23.6% vs. 54.2%, p = 0.009). Most of the late presenters did not undergo primary coronary intervention (72.7% vs. 47.8%, P = 0.034) and had less prior information about myocardial infarction (43.6% vs. 25%, P = 0.023). Late presenters were more often illiterates and lived most often far away from the hospital. Using multivariate logistic regression; dyslipidemia was the only independent predictor for the late hospital presentation for STEMI patients. Conclusion: One third of patients with STEMI present more than six hours after symptom onset; these patients have a higher prevalence of coronary risk factors and less information about STEMI. Programs should be designed to educate patients and the general public about the symptoms of STEMI and the necessary action to be

  9. Follow-up of a 1-year media campaign on delay times and ambulance use in suspected acute myocardial infarction.

    PubMed

    Herlitz, J; Blohm, M; Hartford, M; Karlson, B W; Luepker, R; Holmberg, S; Risenfors, M; Wennerblom, B

    1992-02-01

    In order to reduce the delay times from onset of symptoms to arrival in hospital, and increase the use of ambulance in patients with suspected acute myocardial infarction (AMI), a media campaign was initiated in an urban area. An initial 3-week intense campaign was followed by a maintenance phase of 1 year. Delay times and ambulance use during the campaign were compared with the previous 21 months. Among patients admitted to a coronary care unit (CCU) due to suspected AMI, the median delay time was reduced from 3 h to 2 h 40 min and the mean delay time was reduced from 11 h 33 min to 7 h 42 min (P less than 0.001). Among patients with confirmed AMI the median delay time was reduced from 3 h to 2 h 20 min and the mean delay time from 10 h to 6 h 27 min (P less than 0.001). We conclude that a 1-year media campaign can reduce delay times in suspected AMI, and that this effect appears to continue at 1 year, but ambulance use seems to be more difficult to influence. PMID:1555612

  10. Frequency Dependence of Petechial Hemorrhage and Cardiomyocyte Injury Induced during Myocardial Contrast Echocardiography.

    PubMed

    Miller, Douglas L; Lu, Xiaofang; Fabiilli, Mario; Fields, Kristina; Dou, Chunyan

    2016-08-01

    Myocardial contrast echocardiography (MCE) for perfusion imaging can induce microscale bio-effects during intermittent high-Mechanical Index scans. The dependence of MCE-induced bio-effects on the ultrasonic frequency was examined in rats at 1.6, 2.5 and 3.5 MHz. Premature complexes were counted in the electrocardiogram, petechial hemorrhages with microvascular leakage on the heart surface were observed at the time of exposure, plasma troponin elevation was measured after 4 h and cardiomyocyte injury was detected at 24 h. Increasing response to exposure above an apparent threshold was observed for all endpoints at each frequency. The effects decreased with increasing ultrasonic frequency, and the thresholds increased. Linear regressions for frequency-dependent thresholds indicated coefficients and exponents of 0.6 and 1.07 for petechial hemorrhages, respectively, and 1.02 and 0.8 for cardiomyocyte death, compared with 1.9 and 0.5 (square root) for the guideline limit of the mechanical index. The results clarify the dependence of cardiac bio-effects on frequency, and should allow development of theoretical descriptions of the phenomena and improved safety guidance for MCE. PMID:27126240

  11. [Immediate and delayed hypersensitivity reactions to iodinated radiographic contrast agents: an update].

    PubMed

    Khachman, Dalia; Gandia, Peggy; Sallerin, François; Mailly, Nicolas

    2009-01-01

    Diagnostic and interventional radiology of patients is nowadays crucial with increasing requirement for iodinated contrast agents infusion. Besides adverse reactions after administration of the iodinated contrast agents due to their toxicity, immediate hypersensitivity reactions and reactions resembling delayed hypersensitivity appearing from 1 hour to several days later, have been reported. Patients at high risk to develop such adverse events have to be detected on the basis of their risk factors in order to prevent or limit serious outcomes. Previous reactions to contrast media, asthma, atopy and cardiovascular disorders are risk factors for anaphylactic or anaphylactoid reactions. Female gender, age and beta-blockers increase the severity. This article aims to summarize the risk of allergic reactions related to the use of iodinated contrast agents and to suggest a way for diagnosis, treatment and prevention according to each clinical situation. PMID:19863909

  12. Intravenous myocardial contrast echocardiography predicts regional and global left ventricular remodelling after acute myocardial infarction: comparison with low dose dobutamine stress echocardiography

    PubMed Central

    Abe, Y; Muro, T; Sakanoue, Y; Komatsu, R; Otsuka, M; Naruko, T; Itoh, A; Yoshiyama, M; Haze, K; Yoshikawa, J

    2005-01-01

    Objective: To assess the role of intravenous myocardial contrast echocardiography (MCE) in predicting functional recovery and regional or global left ventricular (LV) remodelling after acute myocardial infarction (AMI) compared with low dose dobutamine stress echocardiography (LDSE). Methods: 21 patients with anterior AMI and successful primary angioplasty underwent MCE and LDSE during the subacute stage (2–4 weeks after AMI). Myocardial perfusion and contractile reserve were assessed in each segment (12 segment model) with MCE and LDSE. The 118 dyssynergic segments in the subacute stage were classified as recovered, unchanged, or remodelled according to wall motion at six months’ follow up. Percentage increase in LV end diastolic volume (%ΔEDV) was also calculated. Results: The presence of perfusion was less accurate than the presence of contractile reserve in predicting regional recovery (55% v 81%, p < 0.0001). However, the absence of perfusion was more accurate than the absence of contractile reserve in predicting regional remodelling (83% v 48%, p < 0.0001). The number of segments without perfusion was an independent predictor of %ΔEDV, whereas the number of segments without contractile reserve was not. The area under the receiver operating characteristic curve showed that the number of segments without perfusion predicted substantial LV dilatation (%ΔEDV > 20%) more accurately than did the number of segments without contractile reserve (0.88 v 0.72). Conclusion: In successfully revascularised patients with AMI, myocardial perfusion assessed by MCE is predictive of regional and global LV remodelling rather than of functional recovery, whereas contractile reserve assessed by LDSE is predictive of functional recovery rather than of LV remodelling. PMID:15797931

  13. Delayed Transcranial Echo-Contrast Bolus Arrival in Unilateral Internal Carotid Artery Stenosis and Occlusion.

    PubMed

    Gómez-Choco, Manuel; Schreiber, Stephan J; Weih, Markus; Doepp, Florian; Valdueza, José M

    2015-07-01

    Some patients with internal carotid artery (ICA) occlusion or stenosis are at risk of developing a hemodynamic stroke. Transcranial ultrasonography using an echo-contrast bolus technique might be able to assess the extent of hemodynamic compromise. We describe a transcranial Doppler sonographic method that analyzes the differences in echo-contrast bolus arrival between both middle cerebral arteries after intravenous echo-contrast application. Ten patients with 50%-79% ICA stenosis, 10 patients with 80%-99% ICA stenosis and 22 patients with ICA occlusion were studied and compared with 15 age-matched controls. There were significant increases in delayed filling of the middle cerebral artery in both 80%-99% stenoses and occlusions compared with controls. The extent of the observed delays did not correlate with vasomotor reactivity. Echo-contrast bolus arrival time can be used to gain additional information on the intracranial hemodynamic effects of extracranial carotid artery disease that seems to be independent of the established ultrasound indices. PMID:25890887

  14. Delayed rectifier K channels contribute to contrast adaptation in mammalian retinal ganglion cells

    PubMed Central

    Weick, Michael; Demb, Jonathan B.

    2011-01-01

    SUMMARY Retinal ganglion cells adapt by reducing their sensitivity during periods of high contrast. Contrast adaptation in the firing response depends on both presynaptic and intrinsic mechanisms. Here, we investigated intrinsic mechanisms for contrast adaptation in OFF Alpha ganglion cells in the in vitro guinea pig retina. Using either visual stimulation or current injection, we show that brief depolarization evoked spiking and suppressed firing during subsequent depolarization. The suppression could be explained by Na channel inactivation, as shown in salamander cells. However, brief hyperpolarization in the physiological range (5–10 mV) also suppressed firing during subsequent depolarization. This suppression was sensitive selectively to blockers of delayed-rectifier K channels (KDR). Somatic membrane patches showed TEA-sensitive KDR currents with activation near −25 mV and removal of inactivation at voltages negative to Vrest. Brief periods of hyperpolarization apparently remove KDR inactivation and thereby increase the channel pool available to suppress excitability during subsequent depolarization. PMID:21745646

  15. Prognostic significance of infarct core pathology revealed by quantitative non-contrast in comparison with contrast cardiac magnetic resonance imaging in reperfused ST-elevation myocardial infarction survivors

    PubMed Central

    Carrick, David; Haig, Caroline; Rauhalammi, Sam; Ahmed, Nadeem; Mordi, Ify; McEntegart, Margaret; Petrie, Mark C.; Eteiba, Hany; Hood, Stuart; Watkins, Stuart; Lindsay, Mitchell; Mahrous, Ahmed; Ford, Ian; Tzemos, Niko; Sattar, Naveed; Welsh, Paul; Radjenovic, Aleksandra; Oldroyd, Keith G.; Berry, Colin

    2016-01-01

    Aims To assess the prognostic significance of infarct core tissue characteristics using cardiac magnetic resonance (CMR) imaging in survivors of acute ST-elevation myocardial infarction (STEMI). Methods and results We performed an observational prospective single centre cohort study in 300 reperfused STEMI patients (mean ± SD age 59 ± 12 years, 74% male) who underwent CMR 2 days and 6 months post-myocardial infarction (n = 267). Native T1 was measured in myocardial regions of interest (n = 288). Adverse remodelling was defined as an increase in left ventricular (LV) end-diastolic volume ≥20% at 6 months. All-cause death or first heart failure hospitalization was a pre-specified outcome that was assessed during follow-up (median duration 845 days). One hundred and sixty (56%) patients had a hypo-intense infarct core disclosed by native T1. In multivariable regression, infarct core native T1 was inversely associated with adverse remodelling [odds ratio (95% confidence interval (CI)] per 10 ms reduction in native T1: 0.91 (0.82, 0.00); P = 0.061). Thirty (10.4%) of 288 patients died or experienced a heart failure event and 13 of these events occurred post-discharge. Native T1 values (ms) within the hypo-intense infarct core (n = 160 STEMI patients) were inversely associated with the risk of all-cause death or first hospitalization for heart failure post-discharge (for a 10 ms increase in native T1: hazard ratio 0.730, 95% CI 0.617, 0.863; P < 0.001) including after adjustment for left ventricular ejection fraction, infarct core T2 and myocardial haemorrhage. The prognostic results for microvascular obstruction were similar. Conclusion Infarct core native T1 represents a novel non-contrast CMR biomarker with potential for infarct characterization and prognostication in STEMI survivors. Confirmatory studies are warranted. ClinicalTrials.gov identifier NCT02072850. PMID:26261290

  16. Cardiovascular magnetic resonance by non contrast T1-mapping allows assessment of severity of injury in acute myocardial infarction

    PubMed Central

    2012-01-01

    Background Current cardiovascular magnetic resonance (CMR) methods, such as late gadolinium enhancement (LGE) and oedema imaging (T2W) used to depict myocardial ischemia, have limitations. Novel quantitative T1-mapping techniques have the potential to further characterize the components of ischemic injury. In patients with myocardial infarction (MI) we sought to investigate whether state-of the art pre-contrast T1-mapping (1) detects acute myocardial injury, (2) allows for quantification of the severity of damage when compared to standard techniques such as LGE and T2W, and (3) has the ability to predict long term functional recovery. Methods 3T CMR including T2W, T1-mapping and LGE was performed in 41 patients [of these, 78% were ST elevation MI (STEMI)] with acute MI at 12-48 hour after chest pain onset and at 6 months (6M). Patients with STEMI underwent primary PCI prior to CMR. Assessment of acute regional wall motion abnormalities, acute segmental damaged fraction by T2W and LGE and mean segmental T1 values was performed on matching short axis slices. LGE and improvement in regional wall motion at 6M were also obtained. Results We found that the variability of T1 measurements was significantly lower compared to T2W and that, while the diagnostic performance of acute T1-mapping for detecting myocardial injury was at least as good as that of T2W-CMR in STEMI patients, it was superior to T2W imaging in NSTEMI. There was a significant relationship between the segmental damaged fraction assessed by either by LGE or T2W, and mean segmental T1 values (P < 0.01). The index of salvaged myocardium derived by acute T1-mapping and 6M LGE was not different to the one derived from T2W (P = 0.88). Furthermore, the likelihood of improvement of segmental function at 6M decreased progressively as acute T1 values increased (P < 0.0004). Conclusions In acute MI, pre-contrast T1-mapping allows assessment of the extent of myocardial damage. T1-mapping might become an important

  17. Contrast enhanced electron beam computed tomography to analyse the coronary arteries in patients after acute myocardial infarction

    PubMed Central

    Achenbach, S; Ropers, D; Regenfus, M; Muschiol, G; Daniel, W; Moshage, W

    2000-01-01

    OBJECTIVE—To evaluate the accuracy of contrast enhanced electron beam computed tomography (EBCT) after acute myocardial infarction in determining patency of the infarct related artery and detecting high grade stenoses and occlusions in the coronary vessels.
DESIGN—Case study using blinded comparison with invasive coronary angiography.
PATIENTS—36 patients (mean age 53 years) 4-70 days after acute myocardial infarction.
INTERVENTIONS—The patients were studied by EBCT and invasive coronary angiography. For EBCT, 50 axial images of the heart (3 mm slice thickness) were acquired. They were triggered by the ECG during breath holding, after intravenous injection of contrast agent. The original images, surface reconstructions, and maximum intensity projections were evaluated for the presence of high grade stenoses and occlusions of the coronary arteries.
MAIN OUTCOME MEASURES—EBCT results were compared with invasive coronary angiography.
RESULTS—Of a total of 144 coronary arteries (left main, left anterior descending, left circumflex, and right coronary artery in 36 patients), 29 (20%) were unevaluable by EBCT. In the remaining arteries, 33 of 36 high grade lesions were correctly detected (92% sensitivity). Specificity was also 92% (73/79). Patency of the infarct related artery was correctly detected in 15 of 16 cases (94%). Five of the 14 occluded infarct related arteries (35%) were mistaken as stenotic but patent, and six could not be assessed.
CONCLUSIONS—EBCT is very accurate in detecting significant coronary artery lesions in patients after acute myocardial infarction, but differentiation between occluded and patent infarct related arteries is currently unreliable.


Keywords: electron beam CT; coronary angiography; myocardial infarction; computed tomography PMID:11040005

  18. Alexithymia Affects Pre-Hospital Delay of Patients with Acute Myocardial Infarction: Meta-Analysis of Existing Studies

    PubMed Central

    Preti, Antonio; Sancassiani, Federica; Cadoni, Federica; Carta, Mauro Giovanni

    2013-01-01

    Background: The time between the onset of symptoms and reperfusion is a critical determinant of the clinical course of patients with acute myocardial infarction (AMI). Any delay in seeking help will affect patient’s outcome. Alexithymia can influence the information processing but also the skills to detect the signal of an ongoing AMI. Method: Systematic review and meta-analysis of studies investigating the role of alexithymia in pre-hospital delay after AMI. Pubmed/Medline and PsychINFO/Ovid search from 1990 until 2012. Results: Out of 29 studies investigating the role of psychological factors in pre-hospital delay after AMI, 3 studies specifically assessed alexithymia, involving 258 patients. All studies used the Toronto Alexithymia Scale to group patients into clusters by time to presentation after AMI. Meta-analysis of data showed that the patients with higher emotional awareness (i.e., low alexithymia) had shorter time to presentation after AMI. Conclusions: Preliminary evidence indicates that alexithymia may have a role in seeking help delay after AMI. Further studies are necessary to better appreciate how alexithymia influence help-seeking in patients with an evolving AMI and in what extent their ineffective behavior can be changed. PMID:23878612

  19. Morphine delays the onset of action of prasugrel in patients with prior history of ST-elevation myocardial infarction.

    PubMed

    Thomas, Mark R; Morton, Allison C; Hossain, Rashed; Chen, Beining; Luo, Lei; Shahari, Nur Nazihah B Md; Hua, Peng; Beniston, Richard G; Judge, Heather M; Storey, Robert F

    2016-07-01

    Delays in the onset of action of prasugrel during primary percutaneous coronary intervention (PPCI) have been reported and could be related to the effects of morphine on gastric emptying and subsequent intestinal absorption. The study objective was to determine whether morphine delays the onset of action of prasugrel in patients with a prior history of ST-elevation myocardial infarction (STEMI) treated with PPCI. This was a crossover study of 11 aspirin-treated patients with prior history of STEMI treated with PPCI, for which prasugrel and morphine had been previously administered. Patients were randomised to receive either morphine (5 mg) or saline intravenously followed by 60 mg prasugrel. Blood samples were collected before randomised treatment and over 24 hours after prasugrel administration. The inhibitory effects of prasugrel on platelets were determined using the VerifyNow P2Y12 assay and light transmission aggregometry. Plasma levels of prasugrel and prasugrel active metabolite were measured. Platelet reactivity determined by VerifyNow PRU, VerifyNow % Inhibition and LTA was significantly higher at 30-120 minutes (min) when morphine had been co-administered compared to when saline had been co-administered. Morphine, compared to saline, significantly delayed adequate platelet inhibition after prasugrel administration (158 vs 68 min; p = 0.006). Patients with delayed onset of platelet inhibition also had evidence of delayed absorption of prasugrel. In conclusion, prior administration of intravenous morphine significantly delays the onset of action of prasugrel. Intravenous drugs may be necessary to reduce the risk of acute stent thrombosis in morphine-treated STEMI patients undergoing PPCI. PMID:27099137

  20. Delayed Luminance and Chromatic Contrast Sensitivity in Infants with Spontaneously Regressed Retinopathy of Prematurity

    PubMed Central

    Bosworth, Rain; Robbins, Shira L.; Granet, David B.; Dobkins, Karen

    2013-01-01

    Background The current study assessed whether contrast sensitivity is affected in preterm infants with a history of spontaneously regressed retinopathy of prematurity (ROP, Stages 1–3). Specifically, we employed luminance (light/dark) and chromatic (red/green) stimuli, which are mediated by the magnocellular (M) and parvocellular (P) subcortical pathways, respectively. Methods Contrast sensitivity (CS) was measured using forced choice preferential looking testing in 21 infants with a history of ROP and 41 control preterm infants who were born prematurely but did not develop ROP, tested between 8 and 47 weeks (2–11 months) postterm age. Infants were presented with chromatic and luminance drifting sinusoidal gratings, which appeared randomly on the left or right side of the monitor on each trial. The contrast of the stimuli varied across trials and was defined in terms of root mean squared cone contrast for long- and medium-wavelength cones. Results Between 8 and 25 weeks postterm, ROP infants had significantly worse CS, and there was a trend for greater impairment for Luminance than Chromatic CS. This delay was not seen at older ages between 26 and 47 weeks postterm. Conclusions These findings are consistent with the concept that early maturation of the M pathway is vulnerable to biological insult, as in the case of ROP, to a greater extent than is the P pathway. PMID:23744448

  1. Anatomical and functional imaging of myocardial infarction in mice using micro-CT and eXIA 160 contrast agent

    PubMed Central

    Ashton, Jeffrey R.; Befera, Nicholas; Clark, Darin; Qi, Yi; Mao, Lan; Rockman, Howard A.; Johnson, G. Allan; Badea, Cristian T.

    2014-01-01

    Non-invasive small animal imaging techniques are essential for evaluation of cardiac disease and potential therapeutics. A novel preclinical iodinated contrast agent called eXIA 160 has recently been developed, which has been evaluated for micro-CT cardiac imaging. eXIA 160 creates strong contrast between blood and tissue immediately after its injection and is subsequently taken up by the myocardium and other metabolically active tissues over time. We focus on these properties of eXIA and show its use in imaging myocardial infarction in mice. Five C57BL/6 mice were imaged ~ 2 weeks after LAD coronary artery ligation. Six C57BL/6 mice were used as controls. Immediately after injection of eXIA 160, an enhancement difference between blood and myocardium of ~340 HU enabled cardiac function estimation via 4D micro-CT scanning with retrospective gating. Four hours post-injection, the healthy perfused myocardium had a contrast difference of ~140 HU relative to blood while the infarcted myocardium showed no enhancement. These differences allowed quantification of infarct size via dual energy micro-CT. In vivo micro-SPECT imaging and ex vivo TTC staining provided validation for the micro-CT findings. Root mean squared error of infarct measurements was 2.7% between micro-CT and SPECT, and 4.7% between micro-CT and TTC. Thus, micro-CT with eXIA 160 can be used to provide both morphological and functional data for preclinical studies evaluating myocardial infarction and potential therapies. Further studies are warranted to study the potential use of eXIA 160 as a CT molecular imaging tool for other metabolically active tissues in the mouse. PMID:24523061

  2. Preference for a Stimulus that Follows a Relatively Aversive Event: Contrast or Delay Reduction?

    ERIC Educational Resources Information Center

    Singer, Rebecca A.; Berry, Laura M.; Zentall, Thomas R.

    2007-01-01

    Several types of contrast effects have been identified including incentive contrast, anticipatory contrast, and behavioral contrast. Clement, Feltus, Kaiser, and Zentall (2000) proposed a type of contrast that appears to be different from these others and called it within-trial contrast. In this form of contrast the relative value of a reinforcer…

  3. Timely reperfusion for ST-segment elevation myocardial infarction: Effect of direct transfer to primary angioplasty on time delays and clinical outcomes

    PubMed Central

    Estévez-Loureiro, Rodrigo; López-Sainz, Ángela; Pérez de Prado, Armando; Cuellas, Carlos; Calviño Santos, Ramón; Alonso-Orcajo, Norberto; Salgado Fernández, Jorge; Vázquez-Rodríguez, Jose Manuel; López-Benito, Maria; Fernández-Vázquez, Felipe

    2014-01-01

    Primary percutaneous coronary intervention (PPCI) is the preferred reperfusion therapy for patients presenting with ST-segment elevation myocardial infarction (STEMI) when it can be performed expeditiously and by experienced operators. In spite of excellent clinical results this technique is associated with longer delays than thrombolysis and this fact may nullify the benefit of selecting this therapeutic option. Several strategies have been proposed to decrease the temporal delays to deliver PPCI. Among them, prehospital diagnosis and direct transfer to the cath lab, by-passing the emergency department of hospitals, has emerged as an attractive way of diminishing delays. The purpose of this review is to address the effect of direct transfer on time delays and clinical events of patients with STEMI treated by PPCI. PMID:24976914

  4. Preference for the Outcome that Follows a Relatively Aversive Event: Contrast or Delay Reduction?

    ERIC Educational Resources Information Center

    Singer, Rebecca A.; Zentall, Thomas R.

    2011-01-01

    Pigeons prefer a positive discriminative (S+) stimulus that follows a less preferred event (a large number of required responses, a longer delay, or the absence of food) over a different S+ with a similar history of reinforcement that follows a more preferred event (a single required response, no delay, or food). We proposed that this phenomenon…

  5. Computational Fluid Dynamics Simulations of Contrast Agent Bolus Dispersion in a Coronary Bifurcation: Impact on MRI-Based Quantification of Myocardial Perfusion

    PubMed Central

    Schmidt, Regine; Graafen, Dirk; Weber, Stefan; Schreiber, Laura M.

    2013-01-01

    Contrast-enhanced first-pass magnetic resonance imaging (MRI) in combination with a tracer kinetic model, for example, MMID4, can be used to determine myocardial blood flow (MBF) and myocardial perfusion reserve (MPR). Typically, the arterial input function (AIF) required for this methodology is estimated from the left ventricle (LV). Dispersion of the contrast agent bolus might occur between the LV and the myocardial tissue. Negligence of bolus dispersion could cause an error in MBF determination. The aim of this study was to investigate the influence of bolus dispersion in a simplified coronary bifurcation geometry including one healthy and one stenotic branch on the quantification of MBF and MPR. Computational fluid dynamics (CFD) simulations were combined with MMID4. Different inlet boundary conditions describing pulsatile and constant flows for rest and hyperemia and differing outflow conditions have been investigated. In the bifurcation region, the increase of the dispersion was smaller than inside the straight vessels. A systematic underestimation of MBF values up to −16.1% for pulsatile flow and an overestimation of MPR up to 7.5% were found. It was shown that, under the conditions considered in this study, bolus dispersion can significantly influence the results of quantitative myocardial MR-perfusion measurements. PMID:23533541

  6. Impact of health care system delay in patients with ST-elevation myocardial infarction on return to labor market and work retirement.

    PubMed

    Laut, Kristina Grønborg; Hjort, Jacob; Engstrøm, Thomas; Jensen, Lisette Okkels; Tilsted Hansen, Hans-Henrik; Jensen, Jan Skov; Pedersen, Frants; Jørgensen, Erik; Holmvang, Lene; Pedersen, Alma Becic; Christensen, Erika Frischknecht; Lippert, Freddy; Lang-Jensen, Torsten; Jans, Henning; Hansen, Poul Anders; Trautner, Sven; Kristensen, Steen Dalby; Lassen, Jens Flensted; Lash, Timothy L; Clemmensen, Peter; Terkelsen, Christian Juhl

    2014-12-15

    System delay (delay from emergency medical service call to reperfusion with primary percutaneous coronary intervention [PPCI]) is acknowledged as a performance measure in ST-elevation myocardial infarction (STEMI), as shorter system delay is associated with lower mortality. It is unknown whether system delay also impacts ability to stay in the labor market. Therefore, the aim of the study was to evaluate whether system delay is associated with duration of absence from work or time to retirement from work among patients with STEMI treated with PPCI. We conducted a population-based cohort study including patients ≤67 years of age who were admitted with STEMI from January 1, 1999, to December 1, 2011 and treated with PPCI. Data were derived from Danish population-based registries. Only patients who were full- or part-time employed before their STEMI admission were included. Association between system delay and time to return to the labor market was analyzed using a competing-risk regression analysis. Association between system delay and time to retirement from work was analyzed using a Cox regression model. A total of 4,061 patients were included. Ninety-three percent returned to the labor market during 4 years of follow-up, and 41% retired during 8 years of follow-up. After adjustment, system delay >120 minutes was associated with reduced resumption of work (subhazard ratio 0.86, 95% confidence interval 0.81 to 0.92) and earlier retirement from work (hazard ratio 1.21, 95% confidence interval 1.08 to 1.36). In conclusion, system delay was associated with reduced work resumption and earlier retirement. This highlights the value of system delay as a performance measure in treating patients with STEMI. PMID:25438906

  7. A Novel Method for Quantifying Smooth Regional Variations in Myocardial Contractility Within an Infarcted Human Left Ventricle Based on Delay-Enhanced Magnetic Resonance Imaging.

    PubMed

    Genet, Martin; Chuan Lee, Lik; Ge, Liang; Acevedo-Bolton, Gabriel; Jeung, Nick; Martin, Alastair; Cambronero, Neil; Boyle, Andrew; Yeghiazarians, Yerem; Kozerke, Sebastian; Guccione, Julius M

    2015-08-01

    Heart failure is increasing at an alarming rate, making it a worldwide epidemic. As the population ages and life expectancy increases, this trend is not likely to change. Myocardial infarction (MI)-induced adverse left ventricular (LV) remodeling is responsible for nearly 70% of heart failure cases. The adverse remodeling process involves an extension of the border zone (BZ) adjacent to an MI, which is normally perfused but shows myofiber contractile dysfunction. To improve patient-specific modeling of cardiac mechanics, we sought to create a finite element model of the human LV with BZ and MI morphologies integrated directly from delayed-enhancement magnetic resonance (DE-MR) images. Instead of separating the LV into discrete regions (e.g., the MI, BZ, and remote regions) with each having a homogeneous myocardial material property, we assumed a functional relation between the DE-MR image pixel intensity and myocardial stiffness and contractility--we considered a linear variation of material properties as a function of DE-MR image pixel intensity, which is known to improve the accuracy of the model's response. The finite element model was then calibrated using measurements obtained from the same patient--namely, 3D strain measurements-using complementary spatial modulation of magnetization magnetic resonance (CSPAMM-MR) images. This led to an average circumferential strain error of 8.9% across all American Heart Association (AHA) segments. We demonstrate the utility of our method for quantifying smooth regional variations in myocardial contractility using cardiac DE-MR and CSPAMM-MR images acquired from a 78-yr-old woman who experienced an MI approximately 1 yr prior. We found a remote myocardial diastolic stiffness of C(0) = 0.102 kPa, and a remote myocardial contractility of T(max) = 146.9 kPa, which are both in the range of previously published normal human values. Moreover, we found a normalized pixel intensity range of 30% for the BZ, which is consistent with

  8. Ramipril-induced delayed myocardial protection against free radical injury involves bradykinin B2 receptor-NO pathway and protein synthesis

    PubMed Central

    Jin, Zhu-Qiu; Chen, Xiu

    1998-01-01

    The aim of the present study was to examine whether ramipril induces delayed myocardial protection against free radical injuries ex vivo and to determine the possible role of the bradykinin B2–nitric oxide (NO) pathway, prostaglandins(PGs) and protein synthesis in this delayed adaptive response.Rats were pretreated with ramipril (10 or 50 μg kg−1, i.v.) and hearts were isolated after 24, 48 and 72 h. Langendorff hearts were subjected to 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical-induced injury.Left ventricular developed pressure (LVDP) and its maximal increase velocity (+dP/dtmax), coronary flow (CF), heart rate (HR), lactate dehydrogenase (LDH) in coronary effluent and thiobarbituric acid reactive substances (TBARS) in the myocardium were measured.The results showed that in the DPPH control group, 20 min after free radical-induced injury, LVDP, +dP/dtmax, CF, HR declined, whereas TBARS and LDH increased significantly. The above cardiac function parameters were significantly improved in RAM-pretreated rats after 24 and 48 h.Pretreatment with HOE 140, the selective bradykinin B2 receptor antagonist, NG-nitro-L-arginine, the NO synthase inhibitor, and actinomycin D, the RNA transcription inhibitor, prior to ramipril injection abolished the beneficial effects of ramipril at 24 h while indomethacin, a cyclooxygenase inhibitor, pretreatment had no effect on ramipril-induced delayed protection.In conclusion, ramipril induces delayed myocardial protection against free radical injury in the rat heart. This delayed protection was sustained for 48 h, is associated with the bradykinin B2 receptor–NO pathway and depends on protein but not prostaglandin synthesis. PMID:9806340

  9. Impact of iodinated contrast injections on percent diameter coronary arterial stenosis and implications for trials of intracoronary pharmacotherapies in patients with ST-elevation myocardial infarction.

    PubMed

    Gibson, C Michael; Buros, Jacqueline; Ciaglo, Lauren N; Southard, Matthew C; Takao, Shaun; Harrigan, Caitlin; Filopei, Jason; Lew, Michelle; Marble, Susan J; Murphy, Sabina A; Cohen, Mauricio G

    2007-07-01

    Administration of fibrinolytic, antiplatelet, and antithrombotic agents by the intracoronary route may disaggregate clot, but the potential role of the mechanical force of the injection itself in decreasing clot burden has not been studied. Patients with ST-segment elevation myocardial infarction who were pretreated in the emergency room (ER) with unfractionated heparin and aspirin in the TITAN-TIMI 34 study were randomized to treatment with eptifibatide in the ER (n = 131) versus after diagnostic catheterization (n = 150). Quantitative coronary angiography was used to assess change in diameter stenosis from time of first contrast injection to injection before percutaneous coronary intervention (PCI) immediately preceding wire placement down the culprit artery in a matching view. Successful perfusion of the myocardium was assessed after PCI by the presence of Thrombolysis In Myocardial Infarction myocardial perfusion grade of 2 or 3. In patients treated with eptifibatide in the ER, there was a 1.3% absolute improvement in diameter stenosis from the first injection to the injection before PCI (p = 0.02), whereas there was no change in diameter stenosis in patients not treated with eptifibatide in the ER (0.0%, p = NS). Each 1% improvement in percent diameter stenosis during diagnostic injections before PCI was strongly correlated with an open muscle after PCI (adjusted odds ratio 1.09, 95% confidence interval 1.02 to 1.16, p = 0.012). In conclusion, the mechanical force of a contrast injection decreases thrombotic burden in patients with ST-segment elevation myocardial infarction pretreated with eptifibatide but not with placebo. Future trials of intracoronary pharmacotherapies should include a control arm in which saline is injected to account for the potential clot disaggregation that occurs as a result of iodinated contrast injections, particularly if the patient has been pretreated with aggressive pharmacotherapy. PMID:17599433

  10. System Dynamics Modeling in the Evaluation of Delays of Care in ST-Segment Elevation Myocardial Infarction Patients within a Tiered Health System

    PubMed Central

    de Andrade, Luciano; Lynch, Catherine; Carvalho, Elias; Rodrigues, Clarissa Garcia; Vissoci, João Ricardo Nickenig; Passos, Guttenberg Ferreira; Pietrobon, Ricardo; Nihei, Oscar Kenji; de Barros Carvalho, Maria Dalva

    2014-01-01

    Background Mortality rates amongst ST segment elevation myocardial infarction (STEMI) patients remain high, especially in developing countries. The aim of this study was to evaluate the factors related with delays in the treatment of STEMI patients to support a strategic plan toward structural and personnel modifications in a primary hospital aligning its process with international guidelines. Methods and Findings The study was conducted in a primary hospital localized in Foz do Iguaçu, Brazil. We utilized a qualitative and quantitative integrated analysis including on-site observations, interviews, medical records analysis, Qualitative Comparative Analysis (QCA) and System Dynamics Modeling (SD). Main cause of delays were categorized into three themes: a) professional, b) equipment and c) transportation logistics. QCA analysis confirmed four main stages of delay to STEMI patient’s care in relation to the ‘Door-in-Door-out’ time at the primary hospital. These stages and their average delays in minutes were: a) First Medical Contact (From Door-In to the first contact with the nurse and/or physician): 7 minutes; b) Electrocardiogram acquisition and review by a physician: 28 minutes; c) ECG transmission and Percutaneous Coronary Intervention Center team feedback time: 76 minutes; and d) Patient’s Transfer Waiting Time: 78 minutes. SD baseline model confirmed the system’s behavior with all occurring delays and the need of improvements. Moreover, after model validation and sensitivity analysis, results suggested that an overall improvement of 40% to 50% in each of these identified stages would reduce the delay. Conclusions This evaluation suggests that investment in health personnel training, diminution of bureaucracy, and management of guidelines might lead to important improvements decreasing the delay of STEMI patients’ care. In addition, this work provides evidence that SD modeling may highlight areas where health system managers can implement and

  11. Morphine delays and attenuates ticagrelor exposure and action in patients with myocardial infarction: the randomized, double-blind, placebo-controlled IMPRESSION trial

    PubMed Central

    Kubica, Jacek; Adamski, Piotr; Ostrowska, Małgorzata; Sikora, Joanna; Kubica, Julia Maria; Sroka, Wiktor Dariusz; Stankowska, Katarzyna; Buszko, Katarzyna; Navarese, Eliano Pio; Jilma, Bernd; Siller-Matula, Jolanta Maria; Marszałł, Michał Piotr; Rość, Danuta; Koziński, Marek

    2016-01-01

    Aims The currently available data indicate a drug–drug interaction between morphine and oral P2Y12 receptor inhibitors, when administered together. The aim of this trial was to assess the influence of infused morphine on pharmacokinetics and pharmacodynamics of ticagrelor and its active metabolite (AR-C124910XX) in patients with acute myocardial infarction. Methods and results In a single-centre, randomized, double-blind trial, patients were assigned in a 1:1 ratio to receive intravenously either morphine (5 mg) or placebo, followed by a 180 mg loading dose of ticagrelor. Pharmacokinetics was determined with liquid chromatography tandem mass spectrometry and ticagrelor antiplatelet effects were measured with up to three different platelet function tests: vasodilator-stimulated phosphoprotein phosphorylation assay, multiple electrode aggregometry and VerifyNow. The pharmacokinetic and pharmacodynamic assessment was performed in 70 patients (35 in each study group). Morphine lowered the total exposure to ticagrelor and its active metabolite by 36% (AUC(0–12): 6307 vs. 9791 ng h/mL; P = 0.003), and 37% (AUC(0–12): 1503 vs. 2388 ng h/mL; P = 0.008), respectively, with a concomitant delay in maximal plasma concentration of ticagrelor (4 vs. 2 h; P = 0.004). Multiple regression analysis showed that lower AUC(0–12) values for ticagrelor were independently associated with the administration of morphine (P = 0.004) and the presence of ST-segment elevation myocardial infarction (P = 0.014). All three methods of platelet reactivity assessment showed a stronger antiplatelet effect in the placebo group and a greater prevalence of high platelet reactivity in patients receiving morphine. Conclusions Morphine delays and attenuates ticagrelor exposure and action in patients with myocardial infarction. ClinicalTrials.gov Identifier: NCT02217878. PMID:26491112

  12. The delayed onset of subharmonic and ultraharmonic emissions from a phospholipid-shelled microbubble contrast agent

    PubMed Central

    Shekhar, Himanshu; Awuor, Ivy; Thomas, Keri; Rychak, Joshua J.; Doyley, Marvin M.

    2014-01-01

    Characterizing the nonlinear response of microbubble contrast agents is important for their efficacious use in imaging and therapy. In this paper, we report that the subharmonic and ultraharmonic response of lipid-shelled microbubble contrast agents exhibits a strong temporal dependence. We characterized nonlinear emissions from Targestar-P® microbubbles (Targeson Inc., San Diego, CA, USA) periodically for 60 minutes, at 10 MHz excitation frequency. The results revealed a considerable increase in the subharmonic and ultraharmonic response (nearly 12–15 and 5–8 dB) after 5–10 minutes of agent preparation. However, the fundamental and the harmonic response remained almost unchanged in this period. During the next 50 minutes, the subharmonic, fundamental, ultraharmonic, and harmonic responses decreased steadily by 2–5 dB. The temporal changes in the nonlinear behavior of the agent appeared to be primarily mediated by gas-exchange through the microbubble shell; temperature and prior acoustic excitation based mechanisms were ruled out. Further, there was no measurable change in the agent size distribution by static diffusion. We envisage that these findings will help obtain reproducible measurements from agent characterization, nonlinear imaging, and fluid-pressure sensing. These findings also suggest the possibility for improving nonlinear imaging by careful design of ultrasound contrast agents. PMID:24582298

  13. A case of delayed onset nephrogenic systemic fibrosis after gadolinium based contrast injection.

    PubMed

    Do, Jong Geol; Kim, Young Bum; Lee, Dae Gu; Hwang, Ji Hye

    2012-12-01

    Nephrogenic systemic fibrosis (NSF) is a rare fibrosing disorder of the skin and joints that occurs in patients with advanced renal insufficiency. This condition is progressive and can be seriously disabling. Gadolinium based contrast agent (GBCA) has been identified as a potential cause of this condition. A 56-years-old man in hemodialysis developed stiffness and contracture of the whole limbs eight years after frequent GBCA exposure for cervical magnetic resonance imaging. For the first time in Korea, we report late-onset nephrogenic systemic fibrosis after GBCA exposure and performed an electrophysiologic study of this condition. PMID:23342325

  14. Comparison of dynamic susceptibility contrast-MRI perfusion quantification methods in the presence of delay and dispersion

    NASA Astrophysics Data System (ADS)

    Maan, Bianca; Simões, Rita Lopes; Meijer, Frederick J. A.; Klaas Jan Renema, W.; Slump, Cornelis H.

    2011-03-01

    The perfusion of the brain is essential to maintain brain function. Stroke is an example of a decrease in blood flow and reduced perfusion. During ischemic stroke the blood flow to tissue is hampered due to a clot inside a vessel. To investigate the recovery of stroke patients, follow up studies are necessary. MRI is the preferred imaging modality for follow up because of the absence of radiation dose concerns, contrary to CT. Dynamic Susceptibility Contrast (DSC) MRI is an imaging technique used for measuring perfusion of the brain, however, is not standard applied in the clinical routine due to lack of immediate patient benefit. Several post processing algorithms are described in the literature to obtain cerebral blood flow (CBF). The quantification of CBF relies on the deconvolution of a tracer concentration-time curve in an arterial and a tissue voxel. There are several methods to obtain this deconvolution based on singular-value decomposition (SVD). This contribution describes a comparison between the different approaches as currently there is no best practice for (all) clinical relevant situations. We investigate the influence of tracer delay, dispersion and recirculation on the performance of the methods. In the presence of negative delays, the truncated SVD approach overestimates the CBF. Block-circulant and reformulated SVD are delay-independent. Due to its delay dependent behavior, the truncated SVD approach performs worse in the presence of dispersion as well. However all SVD approaches are dependent on the amount of dispersion. Moreover, we observe that the optimal truncation parameter varies when recirculation is added to noisy data, suggesting that, in practice, these methods are not immune to tracer recirculation. Finally, applying the methods to clinical data resulted in a large variability of the CBF estimates. Block-circulant SVD will work in all situations and is the method with the highest potential.

  15. Non-Ischemic Perfusion Defects due to Delayed Arrival of Contrast Material on Stress Perfusion Cardiac Magnetic Resonance Imaging after Coronary Artery Bypass Graft Surgery

    PubMed Central

    Kim, Yeo Koon; Park, Sang Joon; Cheon, Gi Jeong; Lee, Whal; Chung, Jin Wook; Park, Jae Hyung

    2014-01-01

    Herein we report about the adenosine stress perfusion MR imaging findings of a 50-year-old man who exhibited two different perfusion defects resulting from two different mechanisms after a coronary artery bypass surgery. An invasive coronary angiography confirmed that one perfusion defect at the mid-anterior wall resulted from an ischemia due to graft stenosis. However, no stenosis was detected on the graft responsible for the mid-inferior wall showing the other perfusion defect. It was assumed that the perfusion defect at the mid-inferior wall resulted from delayed perfusion owing to the long pathway of the bypass graft. The semiquantitative analysis of corrected signal-time curves supported our speculation, demonstrating that the rest-to-stress ratio index of the maximal slope of the myocardial territory in question was similar to those of normal myocardium, whereas that of myocardium with the stenotic graft showed a typical ischemic pattern. A delayed perfusion during long graft pathway in a post-bypass graft patient can mimick a true perfusion defect on myocardial stress MR imaging. Radiologists should be aware of this knowledge to avoid misinterpretation of graft and myocardial status in post bypass surgery patients. PMID:24644408

  16. Quantitative Myocardial Perfusion with Dynamic Contrast-Enhanced Imaging in MRI and CT: Theoretical Models and Current Implementation

    PubMed Central

    Handayani, A.; Dijkstra, H.; Prakken, N. H. J.; Slart, R. H. J. A.; Oudkerk, M.; Van Ooijen, P. M. A.; Vliegenthart, R.; Sijens, P. E.

    2016-01-01

    Technological advances in magnetic resonance imaging (MRI) and computed tomography (CT), including higher spatial and temporal resolution, have made the prospect of performing absolute myocardial perfusion quantification possible, previously only achievable with positron emission tomography (PET). This could facilitate integration of myocardial perfusion biomarkers into the current workup for coronary artery disease (CAD), as MRI and CT systems are more widely available than PET scanners. Cardiac PET scanning remains expensive and is restricted by the requirement of a nearby cyclotron. Clinical evidence is needed to demonstrate that MRI and CT have similar accuracy for myocardial perfusion quantification as PET. However, lack of standardization of acquisition protocols and tracer kinetic model selection complicates comparison between different studies and modalities. The aim of this overview is to provide insight into the different tracer kinetic models for quantitative myocardial perfusion analysis and to address typical implementation issues in MRI and CT. We compare different models based on their theoretical derivations and present the respective consequences for MRI and CT acquisition parameters, highlighting the interplay between tracer kinetic modeling and acquisition settings. PMID:27088083

  17. Quantitative Myocardial Perfusion with Dynamic Contrast-Enhanced Imaging in MRI and CT: Theoretical Models and Current Implementation.

    PubMed

    Pelgrim, G J; Handayani, A; Dijkstra, H; Prakken, N H J; Slart, R H J A; Oudkerk, M; Van Ooijen, P M A; Vliegenthart, R; Sijens, P E

    2016-01-01

    Technological advances in magnetic resonance imaging (MRI) and computed tomography (CT), including higher spatial and temporal resolution, have made the prospect of performing absolute myocardial perfusion quantification possible, previously only achievable with positron emission tomography (PET). This could facilitate integration of myocardial perfusion biomarkers into the current workup for coronary artery disease (CAD), as MRI and CT systems are more widely available than PET scanners. Cardiac PET scanning remains expensive and is restricted by the requirement of a nearby cyclotron. Clinical evidence is needed to demonstrate that MRI and CT have similar accuracy for myocardial perfusion quantification as PET. However, lack of standardization of acquisition protocols and tracer kinetic model selection complicates comparison between different studies and modalities. The aim of this overview is to provide insight into the different tracer kinetic models for quantitative myocardial perfusion analysis and to address typical implementation issues in MRI and CT. We compare different models based on their theoretical derivations and present the respective consequences for MRI and CT acquisition parameters, highlighting the interplay between tracer kinetic modeling and acquisition settings. PMID:27088083

  18. Myocardial Extracellular Volume Fraction with Dual-Energy Equilibrium Contrast-enhanced Cardiac CT in Nonischemic Cardiomyopathy: A Prospective Comparison with Cardiac MR Imaging.

    PubMed

    Lee, Hye-Jeong; Im, Dong Jin; Youn, Jong-Chan; Chang, Suyon; Suh, Young Joo; Hong, Yoo Jin; Kim, Young Jin; Hur, Jin; Choi, Byoung Wook

    2016-07-01

    Purpose To evaluate the feasibility of equilibrium contrast material-enhanced dual-energy cardiac computed tomography (CT) to determine extracellular volume fraction (ECV) in nonischemic cardiomyopathy (CMP) compared with magnetic resonance (MR) imaging. Materials and Methods This study was approved by the institutional review board; informed consent was obtained. Seven healthy subjects and 23 patients (six with hypertrophic CMP, nine with dilated CMP, four with amyloidosis, and four with sarcoidosis) (mean age ± standard deviation, 57.33 years ± 14.82; 19 male participants [63.3%]) were prospectively enrolled. Twelve minutes after contrast material injection (1.8 mL/kg at 3 mL/sec), dual-energy cardiac CT was performed. ECV was measured by two observers independently. Hematocrit levels were compared between healthy subjects and patients with the Mann-Whitney U test. In per-subject analysis, interobserver agreement for CT was assessed with the intraclass correlation coefficient (ICC), and intertest agreement between MR imaging and CT was assessed with Bland-Altman analysis. In per-segment analysis, Student t tests in the linear mixed model were used to compare ECV on CT images between healthy subjects and patients. Results Hematocrit level was 43.44% ± 1.80 for healthy subjects and 41.23% ± 5.61 for patients with MR imaging (P = .16) and 43.50% ± 1.92 for healthy subjects and 41.35% ± 5.92 for patients with CT (P = .15). For observer 1 in per-subject analysis, ECV was 34.18% ± 8.98 for MR imaging and 34.48% ± 8.97 for CT. For observer 2, myocardial ECV was 34.42% ± 9.03 for MR imaging and 33.98% ± 9.05 for CT. Interobserver agreement for ECV at CT was excellent (ICC = 0.987). Bland-Altman analysis between MR imaging and CT showed a small bias (-0.06%), with 95% limits of agreement of -1.19 and 1.79. Compared with healthy subjects, patients with hypertrophic CMP, dilated CMP, amyloidosis, and sarcoidosis had significantly higher myocardial ECV at dual

  19. Geometric feature-based multimodal image registration of contrast-enhanced cardiac CT with gated myocardial perfusion SPECT

    PubMed Central

    Woo, Jonghye; Slomka, Piotr J.; Dey, Damini; Cheng, Victor Y.; Hong, Byung-Woo; Ramesh, Amit; Berman, Daniel S.; Karlsberg, Ronald P.; Kuo, C.-C. Jay; Germano, Guido

    2009-01-01

    Purpose: Cardiac computed tomography (CT) and single photon emission computed tomography (SPECT) provide clinically complementary information in the diagnosis of coronary artery disease (CAD). Fused anatomical and physiological data acquired sequentially on separate scanners can be coregistered to accurately diagnose CAD in specific coronary vessels. Methods: A fully automated registration method is presented utilizing geometric features from a reliable segmentation of gated myocardial perfusion SPECT (MPS) volumes, where regions of myocardium and blood pools are extracted and used as an anatomical mask to de-emphasize the inhomogeneities of intensity distribution caused by perfusion defects and physiological variations. A multiresolution approach is employed to represent coarse-to-fine details of both volumes. The extracted voxels from each level are aligned using a similarity measure with a piecewise constant image model and minimized using a gradient descent method. The authors then perform limited nonlinear registration of gated MPS to adjust for phase differences by automatic cardiac phase matching between CT and MPS. For phase matching, they incorporate nonlinear registration using thin-plate-spline-based warping. Rigid registration has been compared with manual alignment (n=45) on 20 stress/rest MPS and coronary CTA data sets acquired from two different sites and five stress CT perfusion data sets. Phase matching was also compared to expert visual assessment. Results: As compared with manual alignment obtained from two expert observers, the mean and standard deviation of absolute registration errors of the proposed method for MPS were4.3±3.5, 3.6±2.6, and 3.6±2.1mm for translation and 2.1±3.2°, 0.3±0.8°, and 0.7±1.2° for rotation at site A and 3.8±2.7, 4.0±2.9, and 2.2±1.8mm for translation and 1.1±2.0°, 1.6±3.1°, and 1.9±3.8° for rotation at site B. The results for CT perfusion were 3.0±2.9, 3.5±2.4, and 2.8±1.0mm for translation and 3

  20. Future changes in the African monsoon analysed with 8 CMIP5 models: contrasted rainfall dipole and delayed withdrawal

    NASA Astrophysics Data System (ADS)

    Monerie, P.

    2013-12-01

    Based on the approach of Fontaine et al. (2011) and Monerie et al. (2013) we study the African Monsoon (AM) future changes. We used 8 available CMIP5/AR5 AOGCMs from 8 different climate centres and the RCP4.5 emission scenario. Data are analysed with the 'one model one vote' concept and a multi-model approach. The results refer to the difference of a ';future horizon' (2031-2070) minus the ';present' period (1960-1999) and are discussed in terms of monsoon dynamics and climate change. CMIP5 AOGCMs produces a warmer world in the future, especially over land. The sea-band thermal gradient is enhanced and create therefore the basic energy conditions for a reinforced monsoon in the future. The future changes show a contrasted response with less (more) rainfall expected over the western (central-eastern) Sahel. The deficits are chiefly linked to subsidence anomalies in mid-troposphere preventing deep moist convection and precipitation due to modifications in the zonal circulation. The surplus are associated with a more intense monsoon circulation, an increasing of the mean moisture flux convergence over the continental Sahel favoured by the greater surface warming over the continent. An African Rainfall Pattern Index (ARPI), based on the standardized rainfall differences between these regions is defined for capturing the rainfall contrast over years 1900 to 2100. It has been compared to the thermal evolution on both the present and future periods. This allowed us to document the effect of the global warming on Sahelian rainfall patterns by extracting low-frequency signals (20-year-cut-off). The contrasted rainfall pattern change at Sahelian latitudes is therefore expected to occur more frequently in the future. These results are according to Fontaine et al. (2011) and Monerie et al. (2013) who shown through 12 CMIP3 models an increasing (decreasing) of rainfall amounts above the central part (western part) of the Sahel in a future period. In addition to these results we

  1. [The diagnostic value of Tc-99m PYP, Tl-201 dual isotope SPECT to predict the viability of damaged myocardium in the acute phase of myocardial infarction--comparison with stress, delayed, and reinjected Tl-201 SPECT].

    PubMed

    Matsuo, H; Watanabe, S; Arai, M; Kotoo, Y; Oohashi, H; Oda, H; Ueno, K; Matsubara, T; Ohno, M; Mori, S

    1991-05-01

    To assess the diagnostic value of Tc-99m PYP, Tl-201 dual isotope SPECT for the evaluation of myocardial viability, segmental comparison between dual isotope SPECT and exercise, delayed, and reinjected Tl study were performed with 18 AMI patients. Among 72 damaged myocardial segments, 48 segments (67%) were judged as viable by chronic phase Tl studies. The segments with severely reduced Tl uptake by dual SPECT showed significantly lower prevalence of viable myocardium than the segments with reduced and normal Tl uptake (p less than 0.001). The segments with PYP accumulation localized to the subendocardium represented the favorable outcome compared with the transmural accumulation (p less than 0.001). And overlap segments show better prognosis than the segments without overlap (p less than 0.05). Most importantly, we can get better predictive accuracy of myocardial scar by dual isotope SPECT than the judgement by Tl or PYP SPECT alone (83.3% vs 77.8%, 68.1%). Thus, we conclude that Tc-99m PYP, Tl-201 dual isotope SPECT is useful to assess the severity of myocardial damage in the acute phase of myocardial infarction. PMID:1653372

  2. Reducing time delay in the thrombolysis of myocardial infarction: an internal quality improvement project. ARIAM Project Group. Analisis del Retraso en Infarto Agudo de Miocardio.

    PubMed

    Saturno, P J; Felices, F; Segura, J; Vera, A; Rodriguez, J J

    2000-01-01

    The objectives of this study were to improve thrombolytic therapy in acute myocardial infarction by reducing the "door-to-needle" time in a 285-bed university hospital in Spain. A quality management approach was used involving all the relevant staff. Target standard was set at 35 minutes. Baseline data, intervention effect, and continuous monitoring were analyzed using x control charts. Analysis of baseline data showed a wide out-of-control variation and 72 minutes' average delay. Cause analysis revealed organizational and clinical problems that were subjected to intervention. Postintervention data showed a stable process, with an average of 30 minutes. Continuous monitoring showed further improvement in average time and predictable variation. The template of the current control chart has an average of 26 minutes. Quality management methods, particularly staff involvement in problem analysis and intervention design, and the use of control charts were useful to understand, solve, and continuously monitor an important clinical problem whose existence was evident only after it was measured. PMID:10872258

  3. Multi-vendor, multicentre comparison of contrast-enhanced SSFP and T2-STIR CMR for determining myocardium at risk in ST-elevation myocardial infarction

    PubMed Central

    Nordlund, David; Klug, Gert; Heiberg, Einar; Koul, Sasha; Larsen, Terje H.; Hoffmann, Pavel; Metzler, Bernhard; Erlinge, David; Atar, Dan; Aletras, Anthony H.; Carlsson, Marcus; Engblom, Henrik; Arheden, Håkan

    2016-01-01

    Aims Myocardial salvage, determined by cardiac magnetic resonance imaging (CMR), is used as end point in cardioprotection trials. To calculate myocardial salvage, infarct size is related to myocardium at risk (MaR), which can be assessed by T2-short tau inversion recovery (T2-STIR) and contrast-enhanced steady-state free precession magnetic resonance imaging (CE-SSFP). We aimed to determine how T2-STIR and CE-SSFP perform in determining MaR when applied in multicentre, multi-vendor settings. Methods and results A total of 215 patients from 17 centres were included after percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction. CMR was performed within 1–8 days. These patients participated in the MITOCARE or CHILL-MI cardioprotection trials. Additionally, 8 patients from a previous study, imaged 1 day post-CMR, were included. Late gadolinium enhancement, T2-STIR, and CE-SSFP images were acquired on 1.5T MR scanners (Philips, Siemens, or GE). In 65% of the patients, T2-STIR was of diagnostic quality compared with 97% for CE-SSFP. In diagnostic quality images, there was no difference in MaR by T2-STIR and CE-SSFP (bias: 0.02 ± 6%, P = 0.96, r2 = 0.71, P < 0.001), or between treatment and control arms. No change in size or quality of MaR nor ability to identify culprit artery was seen over the first week after the acute event (P = 0.44). Conclusion In diagnostic quality images, T2-STIR and CE-SSFP provide similar estimates of MaR, were constant over the first week, and were not affected by treatment. CE-SSFP had a higher degree of diagnostic quality images compared with T2 imaging for sequences from two out of three vendors. Therefore, CE-SSFP is currently more suitable for implementation in multicentre, multi-vendor clinical trials. PMID:27002140

  4. Impact of trimetazidine on incidence of myocardial injury and contrast-induced nephropathy in diabetic patients with renal dysfunction undergoing elective percutaneous coronary intervention.

    PubMed

    Shehata, Mohamed

    2014-08-01

    Trimetazidine is an anti-ischemic agent with antioxidant activity. This study evaluated the effect of periprocedural administration of trimetazidine on the incidence of percutaneous coronary intervention (PCI)-induced myocardial injury and contrast-induced nephropathy (CIN) in diabetic patients with mild-to-moderate renal dysfunction. One hundred patients with a mean glomerular filtration rate of 48 ± 16 (ml/min/1.73 m(2)) were prospectively enrolled, then randomly assigned to receive (50 patients; trimetazidine group) or not receive (50 patients; control group) periprocedural trimetazidine (70 mg/day) for 72 hours. The serum creatinine level was measured pre-PCI, 72 hours, and 10 days thereafter. An increase in the serum creatinine level by >0.5 mg/dl or 0.25% of the baseline value is considered as CIN. Cardiac troponin I levels were measured before and 6, 12, and 24 hours after PCI. Mean age of the study cohort was 59 ± 6 years (men 68%). The serum creatinine level in the control group increased significantly 3 days after PCI and decreased on the tenth day. However, it showed no significant change in the trimetazidine group. Incidence of CIN was 12% in the trimetazidine group and 28% in the control group (p <0.05). Cardiac troponin I levels were significantly reduced in the trimetazidine group (6 hours: 8 ± 0.3 vs 16 ± 0.2 pg/ml, 12 hours: 13 ± 0.9 vs 24 ± 0.8 pg/ml, 24 hours: 7 ± 0.7 vs 14 ± 0.3 pg/ml, p <0.001). In conclusion, trimetazidine intake before elective PCI in diabetic patients with mild-to-moderate renal dysfunction is associated with decreased incidence of CIN and myocardial injury. PMID:24927970

  5. Contrast echocardiography in acute myocardial ischemia. III. An in vivo comparison of the extent of abnormal wall motion with the area at risk for necrosis.

    PubMed

    Kaul, S; Pandian, N G; Gillam, L D; Newell, J B; Okada, R D; Weyman, A E

    1986-02-01

    To define the in vivo relation between abnormal wall motion and the area at risk for necrosis after acute coronary occlusion, 11 open chest dogs were studied. Five dogs underwent left anterior descending coronary artery occlusion and six underwent left circumflex artery occlusion. Area at risk was defined at five short-axis levels (mitral valve, chordal, high and low papillary muscle and apex) using myocardial contrast echocardiography. Wall motion was measured in the cycles preceding injection of contrast medium. Two observers used two different methods to measure wall motion. In method A, end-diastolic to end-systolic fractional radial change for each of 32 endocardial targets was determined. The extent of abnormal wall motion was then calculated using three definitions of wall motion abnormality: akinesia/dyskinesia, fractional inward endocardial excursion of less than 10%, and fractional inward endocardial excursion of less than 20%. In method B, the information from the entire systolic contraction sequence was analyzed and correlated with a normal contraction pattern. The best linear correlation between area at risk (AR) and abnormal wall motion (AWM) was achieved using method B and expressed by the following linear regression: AWM = 0.92 AR + 3.0 (r = 0.92, p less than 0.0001, SEE = 1.7%). Of the three definitions of abnormality used in method A, the best correlation was achieved between area at risk and less than 10% inward endocardial excursion and was expressed by the following polynomial regression: AWM = -0.01 AR2 + 1.5 AR -0.14 (r = 0.92, p less than 0.001, SEE = 1.7%). These data demonstrate that there is a definite relation between area at risk and abnormal wall motion but that this relation varies depending on the method used to analyze wall motion. However, wall motion during acute ischemia is also influenced by the loading conditions of the heart. Because these may vary in a manner that is independent of the ischemic process, measurement of both

  6. Cardiac Mr For The Assessment Of Myocardial Viability

    PubMed Central

    Kim, Han W.; Kim, Raymond J.

    2013-01-01

    This article focuses on delayed contrast enhanced MRI (DE-MRI) to assess myocardial viability. We start by discussing previous literature that evaluated the potential importance of myocardial viability testing and follow up with the more recent Surgical Treatment for Heart Disease Trial (STICH) trial results. We then provide an overview of the basic concepts and technical aspects of the current DE-MRI technique and review the initial studies demonstrating that DE-MRI before coronary revascularization can predict functional improvement. Finally, we use DE-MRI as a paradigm to discuss physiological insights into viability assessment and examine common assumptions in the metrics used to evaluate viability techniques. PMID:24066200

  7. Relative importance of emergency medical system transport and the prehospital electrocardiogram on reducing hospital time delay to therapy for acute myocardial infarction: a preliminary report from the Cincinnati Heart Project.

    PubMed

    Kereiakes, D J; Gibler, W B; Martin, L H; Pieper, K S; Anderson, L C

    1992-04-01

    Substantial time delays from symptom onset to diagnosis and treatment of patients with acute myocardial infarction have been demonstrated. To determine the relative importance of prehospital mode of patient transport and the relative impact of emergency medical system transport with or without a prehospital cellular electrocardiogram (ECG) on hospital time delays to initiation of thrombolytic therapy, four prospective parallel groups of patients with acute myocardial infarction were evaluated. The median hospital time delay to treatment median (twenty-fifth and seventy-fifth percentiles) was 64 minutes (46 and 87 minutes, respectively, for twenty-fifth and seventy-fifth percentiles) for patients transported by private automobile ("walk-in"); 55 minutes (45 and 68 minutes, respectively) for patients transported by local ambulance; 50 minutes (38 and 81 minutes, respectively) for patients transported by the emergency medical system without a prehospital ECG; and 30 minutes (27 and 35 minutes, respectively) for patients transported by the emergency medical system who had a 12-lead ECG transmitted from the field. Patients transported by the emergency medical system were randomized to receive cellular telephone transmission of a prehospital 12-lead ECG. Specialized emergency medical system transport alone did not facilitate in-hospital initiation of thrombolytic therapy in patients with acute myocardial infarction when compared with those brought by local ambulance or by private automobile. A significant reduction in hospital time delay to treatment was observed only in patients transported by the emergency medical system who had cellular transmission of a prehospital 12-lead ECG from the field. PMID:1549989

  8. Effectiveness of Contrasting Approaches to Response-Contingent Learning among Children with Significant Developmental Delays and Disabilities

    ERIC Educational Resources Information Center

    Raab, Melinda; Dunst, Carl J.; Hamby, Deborah W.

    2016-01-01

    Findings from a randomized controlled design study of an ability-based versus needs-based approach to response-contingent learning among children with significant developmental delays and disabilities who did not use instrumental behavior to produce reinforcing consequences are reported. The ability-based intervention and needs-based intervention…

  9. Comparison of Different Risk Scores for Predicting Contrast Induced Nephropathy and Outcomes After Primary Percutaneous Coronary Intervention in Patients With ST Elevation Myocardial Infarction.

    PubMed

    Liu, Yuan-Hui; Liu, Yong; Zhou, Ying-Ling; He, Peng-Cheng; Yu, Dan-Qing; Li, Li-Wen; Xie, Nian-Jin; Guo, Wei; Tan, Ning; Chen, Ji-Yan

    2016-06-15

    Accurate risk stratification for contrast-induced nephropathy (CIN) is important for patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We aimed to compare the prognostic value of validated risk scores for CIN. We prospectively enrolled 422 consecutive patients with STEMI undergoing PPCI. Mehran; Gao; Chen; age, serum creatinine (SCr), or glomerular filtration rate, and ejection fraction (ACEF or AGEF); and Global Registry for Acute Coronary Events risk scores were calculated for each patient. The prognostic accuracy of the 6 scores for CIN, and in-hospital and 3-year all-cause mortality and major adverse clinical events (MACEs), was assessed using the c-statistic for discrimination and the Hosmer-Lemeshow test for calibration. CIN was defined as either CIN-narrow (increase in SCr ≥0.5 mg/dl) or CIN broad (≥0.5 mg/dl and/or a ≥25% increase in baseline SCr). All risk scores had relatively high predictive values for CIN-narrow (c-statistic: 0.746 to 0.873) and performed well for prediction of in-hospital death (0.784 to 0.936), MACEs (0.685 to 0.763), and 3-year all-cause mortality (0.655 to 0.871). The ACEF and AGEF risk scores had better discrimination and calibration for CIN-narrow and in-hospital outcomes. However, all risk score exhibited low predictive accuracy for CIN-broad (0.555 to 0.643) and 3-year MACEs (0.541 to 0.619). In conclusion, risk scores for predicting CIN perform well in stratifying the risk of CIN-narrow, in-hospital death or MACEs, and 3-year all-cause mortality in patients with STEMI undergoing PPCI. The ACEF and AGEF risk scores appear to have greater prognostic value. PMID:27161818

  10. Delayed application of the anesthetic propofol contrasts the neurotoxic effects of kainate on rat organotypic spinal slice cultures.

    PubMed

    Bajrektarevic, Dzejla; Nistri, Andrea

    2016-05-01

    Excitotoxicity due to hyperactivation of glutamate receptors is thought to underlie acute spinal injury with subsequent strong deficit in spinal network function. Devising an efficacious protocol of neuroprotection to arrest excitotoxicity might, therefore, spare a substantial number of neurons and allow later recovery. In vitro preparations of the spinal cord enable detailed measurement of spinal damage evoked by the potent glutamate analogue kainate. Any clinically-relevant neuroprotective treatment should start after the initial lesion and spare networks for at least 24h when cell damage plateaus. Using this strategy, we have observed that the gas anesthetic methoxyflurane provided strong, delayed neuroprotection. It is unclear if this beneficial effect was due to the mechanism of action by methoxyflurane, or it was the consequence of anesthetic depression. To test this hypothesis, we investigated the effect by propofol (commonly injected i.v. for general anesthesia) after kainate excitotoxicity induced on organotypic spinal slices. At 5μM concentration, propofol significantly attenuated cell death, including neuronal losses and, especially, damage to the highly vulnerable motoneurons. The action by propofol was fully prevented when co-applied with the GABAA antagonist bicuculline, indicating that neuroprotection required intact GABAA receptor function. Although bicuculline per se was not neurotoxic, it largely enhanced the lesional effects of kainate, suggesting that GABAA receptor activity could limit excitotoxicity. Our data might offer an explanation for the beneficial clinical outcome of neurosurgery performed as soon as possible after spinal lesion: we posit that general anesthesia contributes to this outcome, regardless of the type of anesthetic used. PMID:26947011

  11. [Hypertrophic cardiomyopathy with mid-ventricular obstruction complicated by apical aneurysm appearing as delayed contrast hyperenhancement on magnetic resonance imaging: two case reports].

    PubMed

    Teraoka, Kunihiko; Hirano, Masaharu; Ogawa, Takashi; Sasame, Atsuko; Yanagisawa, Hidefumi; Namatame, Yasuhide; Shindo, Naohisa; Takei, Yasuyoshi; Sasaki, Kazuyoshi; Katsuyama, Hiroaki; Abe, Kimihiko; Yamashina, Akira

    2003-08-01

    Case 1: A 52-year-old man presented with a chief complaint of palpitation. Diabetes mellitus was pointed out in 1992. Electrocardiography (ECG) revealed left ventricular hypertrophy in 1997. He visited our department in October 1997. Echocardiography showed increased wall thickness at the interventricular septum. The diagnosis was hypertrophic cardiomyopathy. Holter ECG revealed nonsustained ventricular tachycardia in December 1997. After this, he visited our outpatient clinic. Echocardiography indicated ventricular aneurysm in January 2002, so he was hospitalized in March 2002. Case 2: A 64-year-old woman was transferred to our hospital because of chest discomfort and tachycardial attack. She had been treated for hypertension and diabetes mellitus. She was taken to a hospital by ambulance. On admission, ECG showed wide QRS tachycardia. Cardiac magnetic resonance imaging in both patients disclosed almost complete obstruction of the mid-ventricle in the systolic phase on long- and short-axis cine images, and gadolinium delayed imaging revealed contrast hyperenhancement corresponding to an apical ventricular aneurysm on both long- and short-axis images. The final diagnosis was mid-ventricular obstructive hypertrophic cardiomyopathy with apical aneurysm characterized by delayed hyperenhancement on magnetic resonance imaging with gadolinium. PMID:12964519

  12. Positron emission tomography detects tissue metabolic activity in myocardial segments with persistent thallium perfusion defects

    SciTech Connect

    Brunken, R.; Schwaiger, M.; Grover-McKay, M.; Phelps, M.E.; Tillisch, J.; Schelbert, H.R.

    1987-09-01

    Positron emission tomography with /sup 13/N-ammonia and /sup 18/F-2-deoxyglucose was used to assess myocardial perfusion and glucose utilization in 51 myocardial segments with a stress thallium defect in 12 patients. Myocardial infarction was defined by a concordant reduction in segmental perfusion and glucose utilization, and myocardial ischemia was identified by preservation of glucose utilization in segments with rest hypoperfusion. Of the 51 segments studied, 36 had a fixed thallium defect, 11 had a partially reversible defect and 4 had a completely reversible defect. Only 15 (42%) of the 36 segments with a fixed defect and 4 (36%) of the 11 segments with a partially reversible defect exhibited myocardial infarction on study with positron tomography. In contrast, residual myocardial glucose utilization was identified in the majority of segments with a fixed (58%) or a partially reversible (64%) thallium defect. All of the segments with a completely reversible defect appeared normal on positron tomography. Apparent improvement in the thallium defect on delayed images did not distinguish segments with ischemia from infarction. Thus, positron emission tomography reveals evidence of persistent tissue metabolism in the majority of segments with a fixed or partially resolving stress thallium defect, implying that markers of perfusion alone may underestimate the extent of viable tissue in hypoperfused myocardial segments.

  13. A percutaneous coronary intervention-thrombolytic predictive instrument to assist choosing between immediate thrombolytic therapy versus delayed primary percutaneous coronary intervention for acute myocardial infarction.

    PubMed

    Kent, David M; Ruthazer, Robin; Griffith, John L; Beshansky, Joni R; Concannon, Thomas W; Aversano, Thomas; Grines, Cindy L; Zalenski, Robert J; Selker, Harry P

    2008-03-15

    Based on the thrombolytic predictive instrument (TPI), we sought to create electrocardiographically based, real-time decision support to immediate identification of patients with ST-segment elevation myocardial infarction (STEMI) likely to benefit from primary percutaneous coronary intervention (PCI) compared with thrombolysis. Using data from the Atlantic Cardiovascular Patient Outcomes Research Team (C-PORT) Trial, we tested a mathematical model predicting mortality in patients with STEMI if treated with PCI and if treated with thrombolytic therapy. We adapted the model for incorporation into computerized electrocardiograms as a PCI-TPI. For patients with STEMI in the C-PORT Trial, the model yielded unbiased mortality predictions: for those receiving thrombolysis, it predicted 6.3% mortality and actual mortality was 6.0% (95% confidence interval 3.0 to 10.6); for those receiving PCI, it predicted 4.5% mortality and actual mortality was 3.9% (95% confidence interval 1.4 to 8.2). Excellent discrimination was reflected by its receiver operating characteristic curve area of 0.86. According to the model, and validated by actual trial outcomes, 1/3 of subjects accounted for all the mortality benefit from PCI. In conclusion, for STEMI, the PCI-TPI accurately predicts mortality for treatment with PCI and with thrombolytic therapy. Incorporated into electrocardiogram, it may assist targeting PCI to those who benefit most and identifying patients before hospitalization for whom a receiving hospital should prepare for PCI. PMID:18328842

  14. Contrast echocardiography 1996. A review.

    PubMed Central

    Villarraga, H R; Foley, D A; Mulvagh, S L

    1996-01-01

    Remarkable advances in the field of contrast echocardiography have been made during the last decade. Interest in ultrasound contrast agents that strengthen the backscattered ultrasound signal and improve image display has stimulated further research. Echocardiographic contrast agents providing left ventricular cavity image enhancement after intravenous injection are now available. A role for contrast echocardiography in the assessment of myocardial perfusion has been established within the invasive clinical setting. With the development of newer contrast agents and new ultrasound technology, myocardial perfusion imaging using contrast echocardiography after venous injection is no longer the unattainable "holy grail," but is fast approaching clinical applicability. Images PMID:8792539

  15. Myocardial Galectin-3 Expression Is Associated with Remodeling of the Pressure-Overloaded Heart and May Delay the Hypertrophic Response without Affecting Survival, Dysfunction, and Cardiac Fibrosis.

    PubMed

    Frunza, Olga; Russo, Ilaria; Saxena, Amit; Shinde, Arti V; Humeres, Claudio; Hanif, Waqas; Rai, Vikrant; Su, Ya; Frangogiannis, Nikolaos G

    2016-05-01

    The β-galactoside-binding animal lectin galectin-3 is predominantly expressed by activated macrophages and is a promising biomarker for patients with heart failure. Galectin-3 regulates inflammatory and fibrotic responses; however, its role in cardiac remodeling remains unclear. We hypothesized that galectin-3 may be up-regulated in the pressure-overloaded myocardium and regulate hypertrophy and fibrosis. In normal mouse myocardium, galectin-3 was constitutively expressed in macrophages and was localized in atrial but not ventricular cardiomyocytes. In a mouse model of transverse aortic constriction, galectin-3 expression was markedly up-regulated in the pressure-overloaded myocardium. Early up-regulation of galectin-3 was localized in subpopulations of macrophages and myofibroblasts; however, after 7 to 28 days of transverse aortic constriction, a subset of cardiomyocytes in fibrotic areas contained large amounts of galectin-3. In vitro, cytokine stimulation suppressed galectin-3 synthesis by macrophages and cardiac fibroblasts. Correlation studies revealed that cardiomyocyte- but not macrophage-specific galectin-3 localization was associated with adverse remodeling and dysfunction. Galectin-3 knockout mice exhibited accelerated cardiac hypertrophy after 7 days of pressure overload, whereas female galectin-3 knockouts had delayed dilation after 28 days of transverse aortic constriction. However, galectin-3 loss did not affect survival, systolic and diastolic dysfunction, cardiac fibrosis, and cardiomyocyte hypertrophy in the pressure-overloaded heart. Despite its potential role as a prognostic biomarker, galectin-3 is not a critical modulator of cardiac fibrosis but may delay the hypertrophic response. PMID:26948424

  16. Myocardial Bridge

    MedlinePlus

    ... artery. See also on this site: Ask a Texas Heart Institute Doctor: Search "myocardial bridge" Updated August ... comments. Terms of Use and Privacy Policy © Copyright Texas Heart Institute All rights reserved.

  17. Abnormal Myocardial Blood Flow Reserve Observed in Cardiac Amyloidosis

    PubMed Central

    Nel, Karen; Senior, Roxy; Greaves, Kim

    2016-01-01

    We performed real-time myocardial contrast echocardiography on a patient with cardiac amyloidosis and previous normal coronary angiography presenting with atypical chest pain to assess myocardial blood flow reserve (MBFR). Myocardial contrast echocardiography was performed and flash microbubble destruction and replenishment analysis was used to calculate myocardial blood flow. Dipyridamole was used to achieve hyperemia. MBFR was derived from the ratio of peak myocardial blood flow at hyperemia and rest. The results show a marked reduction in MBFR in our patient. Previous reports of luminal obstruction of intramyocardial rather than epicardial vessels by amyloid deposition may be causing microvascular dysfunction. PMID:27081447

  18. Myocardial diseases of animals.

    PubMed Central

    Van Vleet, J. F.; Ferrans, V. J.

    1986-01-01

    seen less frequently; and, in contrast to man, coronary artery disease and myocardial ischemia are rather infrequent in animals. The present review shows clearly that the spectrum of myocardial diseases in animals is enlarging and that many newly recognized diseases are emerging and assuming considerable importance. For example, various heritable cardiomyopathies have recently been described in the KK mouse, cattle, and rats. Increasingly recognized myocardial diseases include cardiomyopathies in cats, dogs, and birds; anthracycline cardiotoxicity; furazolidone cardiotoxicity; ionophore cardiotoxicity; myocardial damage associated with central nervous system injuries; myocardial hypertrophy in Images Figure 1 Figure 2 Figure 45 Figure 46 Figure 47 Figure 48 Figure 61 Figure 62 Figure 63 Figure 64 Figure 79 Figure 75 Figure 76 Figure 77 Figure 78 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 & 30 Figure 31 Figure 32 Figure 33 Figure 34 Figure 35 Figure 36 Figure 37 Figure 38 Figure 39 Figure 40 Figure 41 Figure 42 Figure 43 Figure 44 Figure 49 Figure 50 Figure 51 Figure 52 Figure 53 Figure 54 Figure 55 Figure 56 Figure 57 Figure 58 Figure 59 Figure 60 Figure 65 Figure 66 Figure 67 Figure 68 Figure 69 Figure 70 Figure 71 & 72 Figure 73 & 74 PMID:3524254

  19. Low-loss, high-index-contrast Si₃N₄/SiO₂ optical waveguides for optical delay lines in microwave photonics signal processing.

    PubMed

    Zhuang, Leimeng; Marpaung, David; Burla, Maurizio; Beeker, Willem; Leinse, Arne; Roeloffzen, Chris

    2011-11-01

    We report the design and characterization of Si₃N₄/SiO₂ optical waveguides which are specifically developed for optical delay lines in microwave photonics (MWP) signal processing applications. The waveguide structure consists of a stack of two Si₃N₄ stripes and SiO₂ as an intermediate layer. Characterization of the waveguide propagation loss was performed in race track-shaped optical ring resonators (ORRs) with a free-spectral range of 20 GHz and a bending radius varied from 50 μm to 125 μm. A waveguide propagation loss as low as 0.095 dB/cm was measured in the ORRs with bend radii ≥ 70 μm. Using the waveguide technology two types of RF-modulated optical sideband filters with high sideband suppression and small transition band consisting of an Mach-Zehnder interferometer and ORRs are also demonstrated. These results demonstrate the potential of the waveguide technology to be applied to construct compact on-chip MWP signal processors. PMID:22109196

  20. Cardiac magnetic resonance detection and typical appearance of microvascular obstruction following myocardial infarction.

    PubMed

    Karatzis, Emmanouil N; Pipilis, Athanassios G; Malios, Konstantinos; Andreou, John; Roussakis, Arkadios; Tsertos, Fotios; Danias, Peter G

    2009-01-01

    We report the case of a 58-year-old man with a recent anterior myocardial infarction, for which he did not receive prompt reperfusion therapy. The patient underwent cardiac magnetic resonance (CMR) imaging, for the assessment of left ventricular function and myocardial viability, and coronary angiography, two weeks after the acute cardiac event. The CMR study demonstrated a moderately dilated left ventricle, with impaired systolic function and wall motion abnormalities in the anterior, apical and inferior left ventricular walls. The T1-weighted images obtained early after contrast administration demonstrated a dark rim in the endocardial region of the interventricular septum and apex. The delayed-enhanced images demonstrated complete absence of signal at the same rim, adjacent to a hyper-enhanced region that corresponded to the wall motion abnormalities. These findings are suggestive of microvascular obstruction in the distribution of the left anterior descending coronary artery. Microvascular obstruction has been reported to correlate positively with the size of the infarction and the left ventricular end-diastolic volume, and inversely with the left ventricular ejection fraction. Furthermore, it has been reported as an independent predictor of future major cardiovascular events. Microvascular obstruction should be routinely checked for in patients presenting in the peri-myocardial infarction period for CMR assessment of myocardial viability. PMID:19329419

  1. Prognostic Impact of Combined Contrast-Induced Acute Kidney Injury and Hypoxic Liver Injury in Patients with ST Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention: Results from INTERSTELLAR Registry

    PubMed Central

    Suh, Young Ju; Kim, Tae-Hoon; Jang, Ho-Jun; Suh, Jon; Park, Hyun Woo; Oh, Pyung Chun; Shin, Sung-Hee; Woo, Seong-Il; Kim, Dae-Hyeok; Kwan, Jun; Kang, WoongChol

    2016-01-01

    Background Besides contrast-induced acute kidney injury(CI-AKI), adscititious vital organ damage such as hypoxic liver injury(HLI) may affect the survival in patients with ST-elevation myocardial infarction (STEMI). We sought to evaluate the prognostic impact of CI-AKI and HLI in STEMI patients who underwent primary percutaneous coronary intervention (PCI). Methods A total of 668 consecutive patients (77.2% male, mean age 61.3±13.3 years) from the INTERSTELLAR STEMI registry who underwent primary PCI were analyzed. CI-AKI was defined as an increase of ≥0.5 mg/dL in serum creatinine level or 25% relative increase, within 48h after the index procedure. HLI was defined as ≥2-fold increase in serum aspartate transaminase above the upper normal limit on admission. Patients were divided into four groups according to their CI-AKI and HLI states. Major adverse cardiovascular and cerebrovascular events (MACCE) defined as a composite of all-cause mortality, non-fatal MI, non-fatal stroke, ischemia-driven target lesion revascularization and target vessel revascularization were recorded. Results Over a mean follow-up period of 2.2±1.6 years, 94 MACCEs occurred with an event rate of 14.1%. The rates of MACCE and all-cause mortality were 9.7% and 5.2%, respectively, in the no organ damage group; 21.3% and 21.3% in CI-AKI group; 18.5% and 14.6% in HLI group; and 57.7% and 50.0% in combined CI-AKI and HLI group. Survival probability plots of composite MACCE and all-cause mortality revealed that the combined CI-AKI and HLI group was associated with the worst prognosis (p<0.0001 for both). Conclusion Combined CI-AKI after index procedure and HLI on admission is associated with poor clinical outcomes in patients with STEMI who underwent primary PCI. (INTERSTELLAR ClinicalTrials.gov number, NCT02800421.) PMID:27415006

  2. Thallium-201 myocardial scintigraphy in acute myocardial infarction and ischemia

    SciTech Connect

    Wackers, F.J.

    1982-04-01

    Thallium-201 scintigraphy provides a sensitive and reliable method of detecting acute myocardial infarction and ischemia when imaging is performed with understanding of the temporal characteristics and accuracy of the technique. The results of scintigraphy are related to the time interval between onset of symptoms and time of imaging. During the first 6 hr after chest pain almost all patients with acute myocardial infarction and approximately 50% of the patients with unstable angina will demonstrate /sup 201/TI pefusion defects. Delayed imaging at 2-4 hr will permit distinction between ischemia and infarction. In patients with acute myocardial infarction, the size of the perfusion defect accurately reflects the extent of the infarcted and/or jeopardized myocardium, which may be used for prognostic stratification. In view of the characteristics of /sup 201/TI scintigraphy, the most practical application of this technique is in patients in whom myocardial infarction has to be ruled out, and for early recognition of patients at high risk for complications.

  3. Correlation of CT-based regional cardiac function (SQUEEZ) with myocardial strain calculated from tagged MRI: an experimental study.

    PubMed

    Pourmorteza, Amir; Chen, Marcus Y; van der Pals, Jesper; Arai, Andrew E; McVeigh, Elliot R

    2016-05-01

    The objective of this study was to investigate the correlation between local myocardial function estimates from CT and myocardial strain from tagged MRI in the same heart. Accurate detection of regional myocardial dysfunction can be an important finding in the diagnosis of functionally significant coronary artery disease. Tagged MRI is currently a reference standard for noninvasive regional myocardial function analysis; however, it has practical drawbacks. We have developed a CT imaging protocol and automated image analysis algorithm for estimating regional cardiac function from a few heartbeats. This method tracks the motion of the left ventricular (LV) endocardial surface to produce local function maps: we call the method Stretch Quantification of Endocardial Engraved Zones (SQUEEZ). Myocardial infarction was created by ligation of the left anterior descending coronary artery for 2 h followed by reperfusion in canine models. Tagged and cine MRI scans were performed during the reperfusion phase and first-pass contrast enhanced CT scans were acquired. The average delay between the CT and MRI scans was <1 h. Circumferential myocardial strain (Ecc) was calculated from the tagged MRI data. The agreement between peak systolic Ecc and SQUEEZ was investigated in 162 segments in the 9 hearts. Linear regression and Bland-Altman analysis was used to assess the correlation between the two metrics of local LV function. The results show good agreement between SQUEEZ and Ecc: (r = 0.71, slope = 0.78, p < 0.001). Furthermore, Bland-Altman showed a small bias of -0.02 with 95 % confidence interval of 0.1, and standard deviation of 0.05 representing ~6.5 % of the dynamic range of LV function. The good agreement between the estimates of local myocardial function obtained from CT SQUEEZ and tagged MRI provides encouragement to investigate the use of SQUEEZ for measuring regional cardiac function at a low clinical dose in humans. PMID:26706935

  4. Delayed ejaculation

    MedlinePlus

    Ejaculatory incompetence; Sex - delayed ejaculation; Retarded ejaculation; Anejaculation; Infertility - delayed ejaculation ... include: Religious background that makes the person view sex as sinful Lack of attraction for a partner ...

  5. Uncommon and dynamic changes detected by 123I-15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid myocardial single photon emission computed tomography in a stunned myocardium induced by coronary microvascular spasm.

    PubMed

    Zen, K; Ito, K; Hikosaka, T; Adachi, Y; Yoneyama, S; Katoh, S; Azuma, A; Sugihara, H; Nakagawa, M

    2000-08-01

    A 55-yr-old man underwent surgery. Soon after the procedure was finished, the patient complained of chest pain, and the electrocardiogram showed increase in the ST-segment in some leads. Emergency angiography showed normal coronary arteries, but there was asynergy in the left ventricle, and delayed filling of contrast medium was observed in the LCA. An intracoronary infusion of isosorbide dinitrate did not improve the delayed filling of contrast medium or ST segment increase in the electrocardiogram. Soon after nicorandil was injected into the LCA, the patient's symptoms, electrocardiogram, and delayed filling of contrast medium dramatically improved. On the second day, initial imaging by 123I-BMIPP myocardial SPECT showed a moderate increase in tracer uptake in the apico-anteroseptal region and a moderate decrease in tracer uptake in the lateral region, in which the first left ventriculography showed akinesis, and delayed imaging revealed a moderate increase in tracer uptake in the apical region and a high washout of 123I-BMIPP in the anteroseptal and lateral regions. On the sixth day, initial imaging by 123I-BMIPP myocardial SPECT showed a moderate decrease in tracer uptake in the apical and lateral regions and a mild decrease in tracer uptake in the anteroseptal region, and delayed imaging revealed a moderate increase in tracer uptake in the apical region and a high washout of 123I-BMIPP in the anteroseptal and lateral regions. By the 30th day, 123I-BMIPP myocardial SPECT had normalized. We consider that these dynamic changes in 123I-BMIPP myocardial SPECT imaging may reflect metabolic changes in fatty acids in the ischemic state, the size of the triacylglycerol pool, and the degree of turnover in the triacylglycerol pool. PMID:11023032

  6. Magnetic resonance imaging and multi-detector computed tomography assessment of extracellular compartment in ischemic and non-ischemic myocardial pathologies

    PubMed Central

    Saeed, Maythem; Hetts, Steven W; Jablonowski, Robert; Wilson, Mark W

    2014-01-01

    Myocardial pathologies are major causes of morbidity and mortality worldwide. Early detection of loss of cellular integrity and expansion in extracellular volume (ECV) in myocardium is critical to initiate effective treatment. The three compartments in healthy myocardium are: intravascular (approximately 10% of tissue volume), interstitium (approximately 15%) and intracellular (approximately 75%). Myocardial cells, fibroblasts and vascular endothelial/smooth muscle cells represent intracellular compartment and the main proteins in the interstitium are types I/III collagens. Microscopic studies have shown that expansion of ECV is an important feature of diffuse physiologic fibrosis (e.g., aging and obesity) and pathologic fibrosis [heart failure, aortic valve disease, hypertrophic cardiomyopathy, myocarditis, dilated cardiomyopathy, amyloidosis, congenital heart disease, aortic stenosis, restrictive cardiomyopathy (hypereosinophilic and idiopathic types), arrythmogenic right ventricular dysplasia and hypertension]. This review addresses recent advances in measuring of ECV in ischemic and non-ischemic myocardial pathologies. Magnetic resonance imaging (MRI) has the ability to characterize tissue proton relaxation times (T1, T2, and T2*). Proton relaxation times reflect the physical and chemical environments of water protons in myocardium. Delayed contrast enhanced-MRI (DE-MRI) and multi-detector computed tomography (DE-MDCT) demonstrated hyper-enhanced infarct, hypo-enhanced microvascular obstruction zone and moderately enhanced peri-infarct zone, but are limited for visualizing diffuse fibrosis and patchy microinfarct despite the increase in ECV. ECV can be measured on equilibrium contrast enhanced MRI/MDCT and MRI longitudinal relaxation time mapping. Equilibrium contrast enhanced MRI/MDCT and MRI T1 mapping is currently used, but at a lower scale, as an alternative to invasive sub-endomyocardial biopsies to eliminate the need for anesthesia, coronary

  7. Myocardial imaging. Coxsackie myocarditis

    SciTech Connect

    Wells, R.G.; Ruskin, J.A.; Sty, J.R.

    1986-09-01

    A 3-week-old male neonate with heart failure associated with Coxsackie virus infection was imaged with Tc-99m PYP and TI-201. The abnormal imaging pattern suggested myocardial infarction. Autopsy findings indicated that the cause was myocardial necrosis secondary to an acute inflammatory process. Causes of abnormal myocardial uptake of Tc-99m PYP in pediatrics include infarction, myocarditis, cardiomyopathy, bacterial endocarditis, and trauma. Myocardial imaging cannot provide a specific cause diagnosis. Causes of myocardial infarction in pediatrics are listed in Table 1.

  8. Myocardial infarction--fusion or confusion?

    PubMed

    Ardhanari, Sivakumar; Shah, Ashok J; Thakur, Ranjan K

    2009-09-01

    A patient with a dualchamber pacemaker with dynamic atrioventricular delay (AVD) experienced acute substernal chest pain. The rhythm strip in the ambulance showed intermittent ST elevation in the inferior leads. An emergent cardiac catheterization revealed nonobstructive coronary artery disease. Rate-responsive dual-chamber pacing with dynamic AVD was responsible for varying devvgrees of ventricular fusion due to competition with the patient's normal conduction. Intermittent ST elevation, evident only during ventricular fusion should have suggested secondary ventricular repolarization and not myocardial injury, but concomitant chest pain and inconspicuous bipolar pacing artifacts added to the confusion. Ventricular pacing may not only mask acute ST-T changes due to myocardial injury, but can also mimic acute myocardial infarction. PMID:19726827

  9. Contrast studies.

    PubMed

    Anderson, Susan M

    2006-01-01

    Contrast media plays an important role in imaging soft tissues and organs. Though contrast imaging is considered safe, radiologic technologists can improve the safety of contrast examinations by reviewing institutional safety procedures, safe practices for different methods of contrast administration and possible complications. The need for efficient communication and attention to detail during contrast procedures is essential for patient safety. PMID:16998193

  10. Contrast stress echocardiography in hypertensive heart disease

    PubMed Central

    2011-01-01

    Hypertension is associated with atherosclerosis and cardiac and vascular structural and functional changes. Myocardial ischemia may arise in hypertension independent of coronary artery disease through an interaction between several pathophysiological mechanisms, including left ventricular hypertrophy, increased arterial stiffness and reduced coronary flow reserve associated with microvascular disease and endothelial dysfunction. The present case report demonstrates how contrast stress echocardiography can be used to diagnose myocardial ischemia in a hypertensive patient with angina pectoris but without significant obstructive coronary artery disease. The myocardial ischemia was due to severe resistant hypertension complicated with concentric left ventricular hypertrophy and increased arterial stiffness. PMID:22093163

  11. Magnetic Resonance Imaging of Acute Reperfused Myocardial Infarction: Intraindividual Comparison of ECIII-60 and Gd-DTPA in a Swine Model

    SciTech Connect

    Jin Jiyang; Teng Gaojun; Feng Yi; Wu Yanping; Jin Qindi; Wang Yu; Wang Zhen; Lu Qin; Jiang Yibo; Wang Shengqi; Chen Feng; Marchal, Guy; Ni Yicheng

    2007-04-15

    Purpose. To compare a necrosis-avid contrast agent (NACA) bis-Gd-DTPA-pamoic acid derivative (ECIII-60) after intracoronary delivery with an extracellular agent Gd-DTPA after intravenous injection on magnetic resonance imaging (MRI) in a swine model of acute reperfused myocardial infarction (MI). Methods. Eight pigs underwent 90 min of transcatheter coronary balloon occlusion and 60 min of reperfusion. After intravenous injection of Gd-DTPA at a dose of 0.2 mmol/kg, all pigs were scanned with T1-weighted MRI until the delayed enhancement of MI disappeared. Then they were intracoronarily infused with ECIII-60 at 0.0025 mmol/kg and imaged for 5 hr. Signal intensity, infarct-over-normal contrast ratio and relative infarct size were quantified, compared, and correlated with the results of postmortem MRI and triphenyltetrazolium chloride (TTC) histochemical staining. Results. A contrast ratio over 3.0 was induced by both Gd-DTPA and ECIII-60. However, while the delayed enhancement with Gd-DTPA virtually vanished in 1 hr, ECIII-60 at an 80x smaller dose depicted the MI accurately over 5 hr as proven by ex vivo MRI and TTC staining. Conclusion. Both Gd-DTPA and ECIII-60 strongly enhanced acute MI. Comparing with fading contrast in a narrow time window with intravenous Gd-DTPA, intracoronary ECIII-60 persistently demarcated the acute MI, indicating a potential method for postprocedural assessment of myocardial viability after coronary interventions.

  12. Delayed ejaculation

    MedlinePlus

    Ejaculatory incompetence; Sex - delayed ejaculation; Retarded ejaculation; Anejaculation ... include: Religious background that makes the person view sex as sinful Lack of attraction for a partner ...

  13. Idiopathic calcified myocardial mass

    PubMed Central

    Patterson, David; Gibson, Derek; Gomes, Ricardo; McDonald, Lawson; Olsen, Eckhardt; Parker, John; Ross, Donald

    1974-01-01

    Patterson, D., Gibson, D., Gomes, R., McDonald, L., Olsen, E., Parker, J., and Ross, D. (1974).Thorax,29, 589-594. Idiopathic calcified myocardial mass. Myocardial calcification can be subdivided into three groups—metastatic, dystrophic or an extension inwards from the pericardium. This case in which the calcified myocardial mass was initially delineated by radiography and by echocardiography and subsequently removed does not fit into any subdivision and has been termed idiopathic. Images PMID:4279467

  14. [Myocardial responses to ischemia].

    PubMed

    Borisenko, V G; Gubareva, E A; Kade, A Kh

    2010-01-01

    The paper details the types of a myocardial response to impaired blood flow, such as myocardial stunning, hibernation, ischemic preconditioning, warm-up phenomenon, ischemic postconditioning, remodeling, and infarction. According to the pathogenesis, the authors identify several types of myocardial dysfunction in transient ischemic attack--uptake, delivery; and a mixed one. It is concluded the myocardial response to damage depends on a combination of influencing factors, a number of pathophysiological processes starting in the acute phase of ischemia achieve its peak in the late period. PMID:20564927

  15. CAD of myocardial perfusion

    NASA Astrophysics Data System (ADS)

    Storm, Corstiaan J.; Slump, Cornelis H.

    2007-03-01

    Our purpose is in the automated evaluation of the physiological relevance of lesions in coronary angiograms. We aim to extract as much as possible quantitative information about the physiological condition of the heart from standard angiographic image sequences. Coronary angiography is still the gold standard for evaluating and diagnosing coronary abnormalities as it is able to locate precisely the coronary artery lesions. The dimensions of the stenosis can be assessed nowadays successfully with image processing based Quantitative Coronary Angiography (QCA) techniques. Our purpose is to assess the clinical relevance of the pertinent stenosis. We therefore analyze the myocardial perfusion as revealed in standard angiographic image sequences. In a Region-of-Interest (ROI) on the angiogram (without an overlaying major blood vessel) the contrast is measured as a function of time (the so-called time-density curve). The required hyperemic state of exercise is induced artificially by the injection of a vasodilator drug e.g. papaverine. In order to minimize motion artifacts we select based on the recorded ECG signal end-diastolic images in both a basal and a hyperemic run in the same projection to position the ROI. We present the development of the algorithms together with results of a small study of 20 patients which have been catheterized following the standard protocol.

  16. Delayed discharge.

    PubMed

    Allen, Daniel

    2016-07-01

    Essential facts Delays in discharging older peo ple from hospital cost the NHS £820 million a year, according to a report from the National Audit Office (NAO). Last year in acute hospitals, 1.15 million bed days were lost to delayed transfers of care, an increase of 31% since 2013. The NAO says rising demand for NHS services is compounded by reduced local authority spending on adult social care - down by 10% since 2009-10. PMID:27380673

  17. Patient and System-Related Delays of Emergency Medical Services Use in Acute ST-Elevation Myocardial Infarction: Results from the Third Gulf Registry of Acute Coronary Events (Gulf RACE-3Ps)

    PubMed Central

    AlHabib, Khalid F.; Sulaiman, Kadhim; Al Suwaidi, Jassim; Almahmeed, Wael; Alsheikh-Ali, Alawi A.; Amin, Haitham; Al Jarallah, Mohammed; Alfaleh, Hussam F.; Panduranga, Prashanth; Hersi, Ahmad; Kashour, Tarek; Al Aseri, Zohair; Ullah, Anhar; Altaradi, Hani B.; Nur Asfina, Kazi; Welsh, Robert C.; Yusuf, Salim

    2016-01-01

    Background Little is known about Emergency Medical Services (EMS) use and pre-hospital triage of patients with acute ST-elevation myocardial infarction (STEMI) in Arabian Gulf countries. Methods Clinical arrival and acute care within 24 h of STEMI symptom onset were compared between patients transferred by EMS (Red Crescent and Inter-Hospital) and those transferred by non-EMS means. Data were retrieved from a prospective registry of 36 hospitals in 6 Arabian Gulf countries, from January 2014 to January 2015. Results We enrolled 2,928 patients; mean age, 52.7 (SD ±11.8) years; 90% men; and 61.7% non-Arabian Gulf citizens. Only 753 patients (25.7%) used EMS; which was mostly via Inter-Hospital EMS (22%) rather than direct transfer from the scene to the hospital by the Red Crescent (3.7%). Compared to the non-EMS group, the EMS group was more likely to arrive initially at a primary or secondary health care facility; thus, they had longer median symptom-onset-to-emergency department arrival times (218 vs. 158 min; p˂.001); they were more likely to receive primary percutaneous coronary interventions (62% vs. 40.5%, p = 0.02); they had shorter door-to-needle times (38 vs. 42 min; p = .04); and shorter door-to-balloon times (47 vs. 83 min; p˂.001). High EMS use was independently predicted mostly by primary/secondary school educational levels and low or moderate socioeconomic status. Low EMS use was predicted by a history of angina and history of percutaneous coronary intervention. The groups had similar in-hospital deaths and outcomes. Conclusion Most acute STEMI patients in the Arabian Gulf region did not use EMS services. Improving Red Crescent infrastructure, establishing integrated STEMI networks, and launching educational public campaigns are top health care system priorities. PMID:26807577

  18. Salutary effect of adjunctive intracoronary nicorandil administration on restoration of myocardial blood flow and functional improvement in patients with acute myocardial infarction.

    PubMed

    Sakata, Y; Kodama, K; Komamura, K; Lim, Y J; Ishikura, F; Hirayama, A; Kitakaze, M; Masuyama, T; Hori, M

    1997-06-01

    Salutary effect of nicorandil, a K+ adenosine triphosphate channel opener, on restoration of myocardial blood flow and functional improvement after coronary revascularization was investigated in 20 patients with first anterior acute myocardial infarction. Ten patients received intracoronary administration of nicorandil (2 mg) after coronary revascularization; the other 10 patients received coronary revascularization only and served as control subjects. Myocardial contrast echocardiography and two-dimensional echocardiography were performed to assess microvascular integrity and regional function in the infarcted area. Nicorandil improved peak contrast intensity ratio (p < 0.001), calculated as the ratio of peak contrast intensity in the infarcted and noninfarcted areas, indicating the restoration of myocardial blood flow to the infarcted myocardium. Regional wall motion improved more significantly in 1 month in patients who received nicorandil (p < 0.01). Thus our results suggested the usefulness of intracoronary nicorandil administration after coronary revascularization for restoring blood flow and functional improvement in patients with acute myocardial infarction. PMID:9200388

  19. ST-segment elevation myocardial infarction management in Europe.

    PubMed

    Tubaro, Marco; Sonia Petronio, Anna

    2009-10-01

    The rate of percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction varies between European countries, as does total mortality as a result of acute myocardial infarction. These differences arise partly because of differences between countries in the time delay from symptom onset to first medical contact, and from first medical contact to reperfusion with thrombolysis or PCI. The European Society of Cardiology guidelines emphasize the importance of early reperfusion therapy. There are, however, often logistical delays in transport of the patient, in diagnosis of myocardial infarction and in preparation of medical teams to be available to perform PCI. Studies have shown that door-to-balloon time may improve with an integrated approach coordinating systems, procedures and institutions, and steps such as including prehospital triage and prehospital electrocardiogram transmission can dramatically reduce door-to-balloon time. Early transfer to PCI is associated with fewer ischaemic complications. PMID:19851218

  20. Thrombolytic therapy in acute myocardial infarction.

    PubMed

    Woo, K S; White, H D

    1994-07-01

    Thrombolytic therapy has revolutionized the treatment of acute myocardial infarction by reducing mortality and preserving left ventricular function. It is relatively safe and cost-effective. However, it is currently underused in most countries. Patients in whom thrombolysis is indicated include those with ST elevation on the electrocardiogram or bundle branch block pattern who present within 12 hours of myocardial infarction; the indications should be widened to include the elderly, patients who have undergone nontraumatic cardiopulmonary resuscitation, and women during menstruation. The risk-benefit ratio should be assessed for the individual patient. Prehospital thrombolytic treatment has been shown to be feasible with the support of well-trained staff and resuscitation equipment, and may be cost-effective in communities with time delays before hospitalization greater than 1 hour. The most important strategy is to shorten the "door to needle" time in hospital. The importance of full infarct-related artery flow (Thrombolysis in Myocardial Infarction [TIMI] grade 3 flow) for preservation of ventricular function and survival has been documented in the second Thrombolysis Trial of Eminase in Acute Myocardial Infarction (TEAM 2) and the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO) studies. Aspirin and heparin are beneficial adjunctive regimens to thrombolytic therapy but optimal epicardial reperfusion is achieved in only about half of patients. Improved thrombolytic, adjunctive antiplatelet, and antithrombotic regimens are required to achieve early full reperfusion, which is crucial to improve survival and quality of life. PMID:7919592

  1. Molecular and cellular mechanisms of myocardial stunning.

    PubMed

    Bolli, R; Marbán, E

    1999-04-01

    The past two decades have witnessed an explosive growth of knowledge regarding postischemic myocardial dysfunction or myocardial "stunning." The purpose of this review is to summarize current information regarding the pathophysiology and pathogenesis of this phenomenon. Myocardial stunning should not be regarded as a single entity but rather as a "syndrome" that has been observed in a wide variety of experimental settings, which include the following: 1) stunning after a single, completely reversible episode of regional ischemia in vivo; 2) stunning after multiple, completely reversible episodes of regional ischemia in vivo; 3) stunning after a partly reversible episode of regional ischemia in vivo (subendocardial infarction); 4) stunning after global ischemia in vitro; 5) stunning after global ischemia in vivo; and 6) stunning after exercise-induced ischemia (high-flow ischemia). Whether these settings share a common mechanism is unknown. Although the pathogenesis of myocardial stunning has not been definitively established, the two major hypotheses are that it is caused by the generation of oxygen-derived free radicals (oxyradical hypothesis) and by a transient calcium overload (calcium hypothesis) on reperfusion. The final lesion responsible for the contractile depression appears to be a decreased responsiveness of contractile filaments to calcium. Recent evidence suggests that calcium overload may activate calpains, resulting in selective proteolysis of myofibrils; the time required for resynthesis of damaged proteins would explain in part the delayed recovery of function in stunned myocardium. The oxyradical and calcium hypotheses are not mutually exclusive and are likely to represent different facets of the same pathophysiological cascade. For example, increased free radical formation could cause cellular calcium overload, which would damage the contractile apparatus of the myocytes. Free radical generation could also directly alter contractile filaments in a

  2. Transient myocardial ischaemia after acute myocardial infarction.

    PubMed Central

    Currie, P; Saltissi, S

    1990-01-01

    The prevalence and characteristics of transient myocardial ischaemia were studied in 203 patients with recent acute myocardial infarction by both early (6.4 days) and late (38 days) ambulatory monitoring of the ST segment. Transient ST segment depression was much commoner during late (32% patients) than early (14%) monitoring. Most transient ischaemia (greater than 85% episodes) was silent and 80% of patients had only silent episodes. During late monitoring painful ST depression was accompanied by greater ST depression and tended to occur at a higher heart rate. Late transient ischaemia showed a diurnal distribution, occurred at a higher initial heart rate, and was more often accompanied by a further increase in heart rate than early ischaemia. Thus in the first 2 months after myocardial infarction transient ischaemia became increasingly common and more closely associated with increased myocardial oxygen demand. Because transient ischaemic episodes during early and late ambulatory monitoring have dissimilar characteristics they may also have different pathophysiologies and prognostic implications. PMID:2245108

  3. Developmental delay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nutrition support is essential for the care of the child with developmental delay. After a thorough evaluation, an individualized intervention plan that accounts for the child’s nutrition status, feeding ability, and medical condition may be determined. Nutrition assessments may be performed at leas...

  4. Asymptomatic myocardial ischemia following cold provocation

    SciTech Connect

    Shea, M.J.; Deanfield, J.E.; deLandsheere, C.M.; Wilson, R.A.; Kensett, M.; Selwyn, A.P.

    1987-09-01

    Cold is thought to provoke angina in patients with coronary disease either by an increase in myocardial demand or an increase in coronary vascular resistance. We investigated and compared the effects of cold pressor stimulation and symptom-limited supine bicycle exercise on regional myocardial perfusion in 35 patients with stable angina and coronary disease and in 10 normal subjects. Regional myocardial perfusion was assessed with positron emission tomography and rubidium-82. Following cold pressor stimulation 24 of 35 patients demonstrated significant abnormalities of regional myocardial perfusion with reduced cation uptake in affected regions of myocardium: 52 +/- 9 to 43 +/- 9 (p less than 0.001 vs normal subjects). Among these 24 patients only nine developed ST depression and only seven had angina. In contrast, 29 of 35 patients underwent supine exercise, and abnormal regional myocardial perfusion occurred in all 29, with a reduction in cation intake from 48 +/- 10 to 43 +/- 14 (p less than 0.001 vs normal subjects). Angina was present in 27 of 29 and ST depression in 25 of 29. Although the absolute decrease in cation uptake was somewhat greater following cold as opposed to exercise, the peak heart rate after cold was significantly lower than that after exercise (82 +/- 12 vs 108 +/- 16 bpm, p less than 0.05). Peak systolic blood pressures after cold and exercise were similar (159 +/- 24 vs 158 +/- 28). Thus, cold produces much more frequent asymptomatic disturbances of regional myocardial perfusion in patients with stable angina and coronary disease than is suggested by pain or ECG changes.

  5. Myocardial infarction and marijuana.

    PubMed

    Charles, R; Holt, S; Kirkham, N

    1979-04-01

    Myocardial infarction in the virtual absence of risk factors occurred in a 25-year old man shortly after smoking a cigarette containing marijuana. Subsequent coronary arteriography was normal. PMID:466984

  6. Contrastive Lexicology.

    ERIC Educational Resources Information Center

    Hartmann, R. R. K.

    This paper deals with the relation between etymologically related words in different languages. A survey is made of seven stages in the development of contrastive lexicology. These are: prelinguistic word studies, semantics, lexicography, translation, foreign language learning, bilingualism, and finally contrastive analysis. Concerning contrastive…

  7. Experimental myocardial infarction

    PubMed Central

    Kumar, Raj; Joison, Julio; Gilmour, David P.; Molokhia, Farouk A.; Pegg, C. A. S.; Hood, William B.

    1971-01-01

    The hemodynamic effects of tachycardia induced by atrial pacing were investigated in left ventricular failure of acute and healing experimental myocardial infarction in 20 intact, conscious dogs. Myocardial infarction was produced by gradual inflation of a balloon cuff device implanted around the left anterior descending coronary artery 10-15 days prior to the study. 1 hr after acute myocardial infarction, atrial pacing at a rate of 180 beats/min decreased left ventricular end-diastolic pressure from 19 to 8 mm Hg and left atrial pressure from 17 to 12 mm Hg, without change in cardiac output. In the healing phase of myocardial infarction 1 wk later, atrial pacing decreased left ventricular end-diastolic pressure from 17 to 9 mm Hg and increased the cardiac output by 37%. This was accompanied by evidence of peripheral vasodilation. In two dogs with healing anterior wall myocardial infarction, left ventricular failure was enhanced by partial occlusion of the circumflex coronary artery. Both the dogs developed pulmonary edema. Pacing improved left ventricular performance and relieved pulmonary edema in both animals. In six animals propranolol was given after acute infarction, and left ventricular function deteriorated further. However the pacing-induced augmentation of cardiac function was unaltered and, hence, is not mediated by sympathetics. The results show that the spontaneous heart rate in left ventricular failure of experimental canine myocardial infarction may be less than optimal and that maximal cardiac function may be achieved at higher heart rates. Images PMID:4395910

  8. Characterization of Benign Myocarditis Using Quantitative Delayed-Enhancement Imaging Based on Molli T1 Mapping.

    PubMed

    Toussaint, Marcel; Gilles, Raymond J; Azzabou, Noura; Marty, Benjamin; Vignaud, Alexandre; Greiser, Andreas; Carlier, Pierre G

    2015-10-01

    Delayed contrast enhancement after injection of a gadolinium-chelate (Gd-chelate) is a reference imaging method to detect myocardial tissue changes. Its localization within the thickness of the myocardial wall allows differentiating various pathological processes such as myocardial infarction (MI), inflammatory myocarditis, and cardiomyopathies. The aim of the study was first to characterize benign myocarditis using quantitative delayed-enhancement imaging and then to investigate whether the measure of the extracellular volume fraction (ECV) can be used to discriminate between MI and myocarditis.In 6 patients with acute benign myocarditis (32.2 ± 13.8 year-old, subepicardial late gadolinium enhancement [LGE]) and 18 patients with MI (52.3 ± 10.9 year-old, subendocardial/transmural LGE), myocardial T1 was determined using the Modified Look-Locker Imaging (MOLLI) sequence at 3 Tesla before and after Gd-chelate injection. T1 values were compared in LGE and normal regions of the myocardium. The myocardial T1 values were normalized to the T1 of blood, and the ECV was calculated from T1 values of myocardium and blood pre- and post-Gd injection.In both myocarditis and MI, the T1 was lower in LGE regions than in normal regions of the left ventricle. T1 of LGE areas was significantly higher in myocarditis than in MI (446.8 ± 45.8 vs 360.5 ± 66.9 ms, P = 0.003) and ECV was lower in myocarditis than in MI (34.5 ± 3.3 vs 53.8 ± 13.0 %, P = 0.004).Both inflammatory process and chronic fibrosis induce LGE (subepicardial in myocarditis and subendocardial in MI). The present study demonstrates that the determination of T1 and ECV is able to differentiate the 2 histological patterns.Further investigation will indicate whether the severity of ECV changes might help refine the predictive risk of LGE in myocarditis. PMID:26512599

  9. Myocardial Noncompaction Presenting With Myocardial Bridge

    PubMed Central

    Shen, Yuechun; Li, Xinchun; Lu, Dongfeng; Xiao, Aiyi; Li, Jun

    2015-01-01

    Abstract Myocardial noncompaction, namly isolated noncompaction of the left ventricular myocardium (NVM), is a rare congenital disease. It can be either seen in the absence of other cardiac anomalies, or associated with other congenital cardiac defects, mostly stenotic lesions of the left ventricular outflow tract. A myocardial bridge (MB) is thought being associated with coronary heart disease, such as coronary spasm, arrhythmia, and so on. The significance of MB in association with other congenital cardiac conditions is unknown. We report a novel case who was presented NVM and MB. A 34-year-old man complained of chest prickling-like pain and dizzy for 1 year. His blood pressure was 110/70 mm Hg. Echocardiograph revealed increased trabeculations below the level of papillary muscle of left ventricle (LV); deep intertrabecular recesses in the endocardial wall of LV particularly in apex free wall; and LV ejection fraction of 57%. A coronary computerized tomography scan showed that part, 38.9 cm, of left descending artery tunnel was surrounding by cardiac muscles rather than resting on top of the myocardium. The therapeutics interventions included lifestyle cares, agents of anti-ischemia and improvement myocardial cell metabolism. The patient was followed up for 2.6 years, and his general condition was stable. This case indicates that NVM can be developed with MB, and the complete diagnosis of NVM and MB should be made by different image studies. PMID:26356695

  10. Contrast Materials

    MedlinePlus

    ... or other reactions to contrast materials are rare, radiology departments are well-equipped to deal with them. ... is given. However, both the American College of Radiology (ACR) and the European Society of Urogenital Radiology ...

  11. Decreased selenium levels in acute myocardial infarction

    SciTech Connect

    Kok, F.J.; Hofman, A.; Witteman, J.C.M.; de Bruijn, A.M.; Kruyssen, D.H.C.M.; de Bruin, M.; Valkenburg, H.A. )

    1989-02-24

    To study the association between selenium status and the risk of myocardial infarction, the authors compared plasma, erythrocyte, and toenail selenium levels and the activity of erythrocyte glutathione peroxidase among 84 patients with acute myocardial infarction and 84 population controls. Mean concentrations of all selenium measurements were lower in cases than controls. The differences were statistically significant, except for the plasma selenium level. A positive trend in the risk of acute myocardial infarction from high to low toenail selenium levels was observed, which persisted after adjustment for other risk factors for myocardial infarction. In contrast, erythrocyte glutathione peroxidase activity was significantly higher in cases than controls. Because toenail selenium level reflects blood levels up to one year before sampling, these findings suggest that a low selenium status was present before the infarction and, thus, may be of etiologic relevance. The higher glutathione peroxidase activity in the cases may be interpreted as a defense against increased oxidant stress either preceding or following the acute event.

  12. Multi-modality imaging for the assessment of myocardial perfusion with emphasis on stress perfusion CT and MR imaging.

    PubMed

    Ko, Sung Min; Hwang, Hweung Kon; Kim, Sung Mok; Cho, Ihn Ho

    2015-06-01

    High-quality and non-invasive diagnostic tools for assessing myocardial ischemia are necessary for therapeutic decisions regarding coronary artery disease. Myocardial perfusion has been studied using myocardial contrast echo perfusion, single-photon emission computed tomography, positron emission tomography, cardiovascular magnetic resonance, and, more recently, computed tomography. The addition of coronary computed tomography angiography to myocardial perfusion imaging improves the specificity and overall diagnostic accuracy of detecting the hemodynamic significance of coronary artery stenosis. This study reviews the benefits, limitations, and imaging findings of various imaging modalities for assessing myocardial perfusion, with particular emphasis on stress perfusion computed tomography and cardiovascular magnetic resonance imaging. PMID:25809387

  13. Tomographic myocardial perfusion scintigraphy in children with Kawasaki disease

    SciTech Connect

    Spielmann, R.P.; Nienaber, C.A.; Hausdorf, G.; Montz, R.

    1987-12-01

    Myocardial infarction and stenotic coronary lesions are serious late complications in children with Kawasaki disease. For the noninvasive assessment of myocardial perfusion, dipyridamole-redistribution /sup 201/Tl emission computed tomography (ECT) was performed in seven children (age 2 8/12-8 7/12 yr) 3-20 mo after the acute stage of the disease. In all patients, coronary aneurysms had been demonstrated by cross-sectional echocardiography. The scintigrams of six children showed no significant regional reduction of myocardial thallium uptake. These children had remained asymptomatic since the acute stage of Kawasaki disease. Persistent and transient thallium defects were present in one child with documented myocardial infarction. For this patient, obstruction of corresponding coronary vessels was confirmed by contrast angiography. It is suggested, that /sup 201/Tl ECT after dipyridamole-induced vasodilation may be used as a safe alternative to invasive coronary angiography for follow-up investigations in patients with Kawasaki disease.

  14. New perspectives on the role of cardiac magnetic resonance imaging to evaluate myocardial salvage and myocardial hemorrhage after acute reperfused ST-elevation myocardial infarction.

    PubMed

    Mangion, Kenneth; Corcoran, David; Carrick, David; Berry, Colin

    2016-07-01

    Cardiac magnetic resonance (CMR) imaging enables the assessment of left ventricular function and pathology. In addition to established contrast-enhanced methods for the assessment of infarct size and microvascular obstruction, other infarct pathologies, such as myocardial edema and myocardial hemorrhage, can be identified using innovative CMR techniques. The initial extent of myocardial edema revealed by T2-weighted CMR has to be stable for edema to be taken as a retrospective marker of the area-at-risk, which is used to calculate myocardial salvage. The timing of edema assessment is important and should be focused within 2 - 7 days post-reperfusion. Some recent investigations have called into question the diagnostic validity of edema imaging after acute STEMI. Considering the results of these studies, as well as results from our own laboratory, we conclude that the time-course of edema post-STEMI is unimodal, not bimodal. Myocardial hemorrhage is the final consequence of severe vascular injury and a progressive and prognostically important complication early post-MI. Myocardial hemorrhage is a therapeutic target to limit reperfusion injury and infarct size post-STEMI. PMID:27043975

  15. Contrast lipocryolysis

    PubMed Central

    Pinto, Hernán; Melamed, Graciela

    2014-01-01

    Alternative crystal structures are possible for all lipids and each different crystal structure is called a polymorphic form. Inter-conversion between polymorphisms would imply the possibility of leaning crystal formation toward the most effective polymorphism for adipocyte destruction. Food industry has been tempering lipids for decades. Tempering technology applied to lipocryolysis gave birth to “contrast lipocryolysis”, which involves pre- and post-lipocryolysis fat layer heating as part of a specific tempering protocol. In this study, we evaluated the skinfold thickness of 10 subjects after a single contrast lipocryolysis session and witnessed important and fast reductions. PMID:25068088

  16. [Transition of myocardial ischemia to heart failure].

    PubMed

    Ertl, G; Fraccarollo, D; Gaudron, P; Hu, K; Laser, A; Neubauer, S; Schorb, W

    1998-09-01

    Myocardial ischemia results in myocardial dysfunction. Recovery may be delayed ("stunning"), or persistent if perfusion remains reduced ("hibernation") and ischemia may go on to necrosis, thus, contributing to chronic heart failure. In addition, myocardium not directly affected by ischemia may undergo adaptive processes like hypertrophy and dilatation, which may result in chronic left heart failure. This process is characterized by hemodynamic, neurohumoral, and progressive morphologic changes of the heart which are closely interrelated. Hemodynamic changes basically consist of an increase in left ventricular filling pressure and a decrease in global ejection fraction, and, in most cases years after myocardial infarction, in an increase in systemic vascular resistance and right atrial pressure. Neurohumoral changes consist of an increase in plasma catecholamines, atrial natriuretic factor and vasopressin, and in an activation of the renin-angiotensin-system. Plasma endothelin-1 was recently reported to be increased in patients with heart failure, and prognosis was related to endothelin levels. Diminished response of vessels to endothelium (EDRF/NO) dependent vasodilatation suggests impairment of vascular endothelium in heart failure. Local changes of cardiac neurohumoral systems could contribute to structural changes of the heart, e.g., systemic activation to hemodynamic changes. Structural changes of the heart are characterized by an increase in volume and thickness of surviving myocardium and an expansion of ischemic and necrotic myocardium. Molecular control of these processes which include various cell types, such as cardiomyocytes and cardiofibroblasts, are currently an issue of intense research and could result in specific therapeutic importance. PMID:9816648

  17. Use of ultrafast computed tomography to quantitate regional myocardial perfusion: a preliminary report

    SciTech Connect

    Rumberger, J.A.; Feiring, A.J.; Lipton, M.J.; Higgins, C.B.; Ell, S.R.; Marcus, M.L.

    1987-01-01

    The purpose of this study was to assess the potential for rapid acquisition computed axial tomography (Imatron C-100) to quantify regional myocardial perfusion. Myocardial and left ventricular cavity contrast clearance curves were constructed after injecting nonionic contrast (1 ml/kg over 2 to 3 seconds) into the inferior vena cava of six anesthetized, closed chest dogs (n = 14). Independent myocardial perfusion measurements were obtained by coincident injection of radiolabeled microspheres into the left atrium during control, intermediate and maximal myocardial vasodilation with adenosine (0.5 to 1.0 mg/kg per min, intravenously, respectively). At each flow state, 40 serial short-axis scans of the left ventricle were taken near end-diastole at the midpapillary muscle level. Contrast clearance curves were generated and analyzed from the left ventricular cavity and posterior papillary muscle regions after excluding contrast recirculation and minimizing partial volume effects. The area under the curve (gamma variate function) was determined for a region of interest placed within the left ventricular cavity. Characteristics of contrast clearance data from the posterior papillary muscle region that were evaluated included the peak myocardial opacification, area under the contrast clearance curve and a contrast clearance time defined by the full width/half maximal extent of the clearance curve. Myocardial perfusion (microspheres) ranged from 35 to 450 ml/100 g per min (mean 167 +/- 125).

  18. Delaying obsolescence.

    PubMed

    Lawlor, Rob

    2015-04-01

    This paper argues that those who emphasise that designers and engineers need to plan for obsolescence are too conservative. Rather, in addition to planning for obsolescence, designers and engineers should also think carefully about what they could do in order delay obsolescence. They should so this by thinking about the design itself, thinking of ways in which products could be useful and appealing for longer before becoming obsolete, as well thinking about the wider context in terms of the marketing of products, and also the social and legal. The paper also considers objections that these suggestions are unrealistically idealistic, failing to recognise the economic realities. I respond to these objections appealing to research in advertising, psychology, cognitive linguistics, philosophy, history, and economics, as well as drawing on the Statement of Ethical Principles developed by the Royal Academy of Engineering and the Engineering Council. PMID:24792878

  19. Bovine myocardial epithelial inclusions.

    PubMed

    Baker, D C; Schmidt, S P; Langheinrich, K A; Cannon, L; Smart, R A

    1993-01-01

    Light microscopic, histochemical, immunohistochemical, and ultrastructural methods were used to examine myocardial epithelial masses in the hearts of ten cattle. The tissues consisted of paraffin-embedded or formalin-fixed samples from eight hearts that were being inspected in slaughter houses and from two hearts from calves that died of septicemia. The ages of the cattle ranged from 4 days to 12 years; the breeds were unspecified for all but one Hereford female and the two Holstein calves; and there were three males, four females, and three steers. The masses in these cases were compared with similar appearing lesions found in other animal species. The lesions in the bovine hearts were single to multiple, well circumscribed, found in the left ventricle wall, and composed of squamous to cuboidal epithelial cells that formed tubular, ductular, and acinar structures with lumens that were void or filled with amorphous protein globules. Electron microscopic examination revealed epithelial cells that had sparse apical microvilli, tight apical intercellular junctions, perinuclear bundles of filaments, and rare cilia. Almost half of the bovine epithelial masses (4/9) had occasional diastase-resistant periodic acid-Schiff-positive granules in their cytoplasm, and few had hyaluronidase-resistant alcian blue-positive granules (2/9) or colloidal iron-positive granules (1/9). All myocardial masses had abundant collagen surrounding the tubular and acinar structures, and 2/9 had elastin fibers as well. None of the myocardial masses had Churukian-Schenk or Fontana Masson's silver staining granules in epithelial cells. Immunohistochemically, all bovine myocardial tumors stained positively for cytokeratin (8/8), and occasional masses stained positively for vimentin (3/8) or carcinoembryonic antigen (3/8). None of the masses stained positively for desmin. The myocardial epithelial tumors most likely represent endodermal rests of tissue misplaced during organogenesis. PMID:7680178

  20. Significance of 99mTc-Sestamibi myocardial scintigraphy after percutaneous coronary intervention in patients with acute myocardial infarction

    PubMed Central

    Akashi, Yoshihiro J.; Ashikaga, Kohei; Takano, Makoto; Izumo, Masaki; Ishibashi, Yuki; Kida, Keisuke; Yoneyama, Kihei; Suzuki, Kengo; Miyake, Fumihiko; Banach, Maciej

    2011-01-01

    Summary Background This study was designed to clarify the significance of washout rate (WR) determined from 99mTc-sestamibi myocardial scintigraphic images and the levels of cardiac enzymes in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI). Material/Methods A total of 56 consecutive patients with AMI (mean age 65.8±8.5 years), who underwent PCI on admission, were included. Cardiac enzyme, the MB isoenzyme of creatinine kinase (CK-MB), was measured every 3 h after admission. Two weeks after the onset of AMI, 99mTc-sestamibi myocardial scintigraphy was performed at early (30 min) and delayed (4 h) phases after tracer injection. The heart-to-mediastinum ratio (H/M) and WR were calculated from the planar images. Results PCI was performed at 9.4±6.0 h after the onset of AMI. In 26 patients the culprit lesion was located in the right coronary artery and in 24 patients it was located in the left anterior descending coronary artery. The peak CK-MB was 274.1±169.4 IU/L (13.5±3.9 h). The early and delayed H/Ms and WR of 99mTc-sestamibi were 2.74±0.58, 3.00±0.70, and 58.8±10.0%, respectively. The delayed H/M was significantly correlated with the peak CK-MB (r=−0.37, p=0.005). The WR of 99mTc-sestamibi was also significantly correlated with the peak CK-MB (r=−0.34, p=0.012). Conclusions These results suggest that the WR determined from 99mTc-sestamibi myocardial scintigraphic images reflects the extent of myocardial damage in AMI patients. PMID:21358600

  1. Perioperative Assessment of Myocardial Deformation

    PubMed Central

    Duncan, Andra E.; Alfirevic, Andrej; Sessler, Daniel I.; Popovic, Zoran B.; Thomas, James D.

    2014-01-01

    Evaluation of left ventricular performance improves risk assessment and guides anesthetic decisions. However, the most common echocardiographic measure of myocardial function, the left ventricular ejection fraction (LVEF), has important limitations. LVEF is limited by subjective interpretation which reduces accuracy and reproducibility, and LVEF assesses global function without characterizing regional myocardial abnormalities. An alternative objective echocardiographic measure of myocardial function is thus needed. Myocardial deformation analysis, which performs quantitative assessment of global and regional myocardial function, may be useful for perioperative care of surgical patients. Myocardial deformation analysis evaluates left ventricular mechanics by quantifying strain and strain rate. Strain describes percent change in myocardial length in the longitudinal (from base to apex) and circumferential (encircling the short-axis of the ventricle) direction and change in thickness in the radial direction. Segmental strain describes regional myocardial function. Strain is a negative number when the ventricle shortens longitudinally or circumferentially and is positive with radial thickening. Reference values for normal longitudinal strain from a recent meta-analysis using transthoracic echocardiography are (mean ± SD) −19.7 ± 0.4%, while radial and circumferential strain are 47.3 ± 1.9 and −23.3 ± 0.7%, respectively. The speed of myocardial deformation is also important and is characterized by strain rate. Longitudinal systolic strain rate in healthy subjects averages −1.10 ± 0.16 sec−1. Assessment of myocardial deformation requires consideration of both strain (change in deformation), which correlates with LVEF, and strain rate (speed of deformation), which correlates with rate of rise of left ventricular pressure (dP/dt). Myocardial deformation analysis also evaluates ventricular relaxation, twist, and untwist, providing new and noninvasive methods to

  2. T1 Mapping in Characterizing Myocardial Disease: A Comprehensive Review.

    PubMed

    Puntmann, Valentina O; Peker, Elif; Chandrashekhar, Y; Nagel, Eike

    2016-07-01

    Cardiovascular magnetic resonance provides insights into myocardial structure and function noninvasively, with high diagnostic accuracy and without ionizing radiation. Myocardial tissue characterization in particular gives cardiovascular magnetic resonance a prime role among all the noninvasive cardiovascular investigations. Late gadolinium enhancement imaging is an established method for visualizing replacement scar, providing diagnostic and prognostic information in a variety of cardiac conditions. Late gadolinium enhancement, however, relies on the regional segregation of tissue characteristics to generate the imaging contrast. Thus, myocardial pathology that is diffuse in nature and affecting the myocardium in a rather uniform and global distribution is not well visualized with late gadolinium enhancement. Examples include diffuse myocardial inflammation, fibrosis, hypertrophy, and infiltration. T1 mapping is a novel technique allowing to diagnose these diffuse conditions by measurement of T1 values, which directly correspond to variation in intrinsic myocardial tissue properties. In addition to providing clinically meaningful indices, T1-mapping measurements also allow for an estimation of extracellular space by calculation of extracellular volume fraction. Multiple lines of evidence suggest a central role for T1 mapping in detection of diffuse myocardial disease in early disease stages and complements late gadolinium enhancement in visualization of the regional changes in common advanced myocardial disease. As a quantifiable measure, it may allow grading of disease activity, monitoring progress, and guiding treatment, potentially as a fast contrast-free clinical application. We present an overview of clinically relevant technical aspects of acquisition and processing, and the current state of art and evidence, supporting its clinical use. PMID:27390332

  3. Simultaneous technetium-99m MIBI angiography and myocardial perfusion imaging

    SciTech Connect

    Baillet, G.Y.; Mena, I.G.; Kuperus, J.H.; Robertson, J.M.; French, W.J.

    1989-01-01

    Resting first-pass radionuclide angiography (FPRNA) was performed with the myocardial perfusion agent technetium-99m MIBI. In 27 patients, it was compared with technetium-99m diethylenetriamine pentaacetic acid FPRNA. A significant correlation was present in left (r = 0.93, p less than 0.001) as well as right (r = 0.92, p less than 0.001) ventricular ejection fraction measured with both radiopharmaceuticals. In 13 patients, MIBI derived segmental wall motion was compared with contrast ventriculography. A high correlation was present (p less than 0.001), and qualitative agreement was found in 38/52 segments. In 19 patients with myocardial infarction a significant correlation was present between MIBI segmental wall motion and perfusion scores (p less than 0.001). In ten patients with a history of myocardial infarction, 18 myocardial segments demonstrated diseased coronary vessels and impaired wall motion at contrast angiography. These segments were all identified by the MIBI wall motion and perfusion study. We conclude that MIBI is a promising agent for simultaneous evaluation of cardiac function and myocardial perfusion at rest.

  4. Severe coronary tortuosity or myocardial bridging in patients with chest pain, normal coronary arteries, and reversible myocardial perfusion defects.

    PubMed

    Gaibazzi, Nicola; Rigo, Fausto; Reverberi, Claudio

    2011-10-01

    We reviewed patients with normal or near-normal coronary angiograms enrolled in the SPAM contrast stress echocardiographic diagnostic study in which 400 patients with chest pain syndrome of suspected cardiac origin with a clinical indication to coronary angiography were enrolled. Patients underwent dipyridamole contrast stress echocardiography (cSE) with sequential analysis of wall motion, myocardial perfusion, and Doppler coronary flow reserve before elective coronary angiography. Ninety-six patients with normal or near-normal epicardial coronary arteries were screened for the presence of 2 prespecified findings: severely tortuous coronary arteries and myocardial bridging. Patients were divided in 2 groups based on the presence (false-positive results, n = 37) or absence (true-negative results, n = 59) of reversible myocardial perfusion defects during cSE and compared for history and clinical and angiographic characteristics. Prevalence of severely tortuous coronary arteries (35% vs 5%, p <0.001) or myocardial bridging (13% vs 2%, p <0.05) was 7 times higher in patients who demonstrated reversible perfusion defects at cSE compared to those without reversible perfusion defects. No significant differences were found between the 2 groups for the main demographic variables and risk factors. Patients in the false-positive group more frequently had a history of effort angina (p <0.001) and ST-segment depression at treadmill electrocardiography (p <0.001). In conclusion, we hypothesize that patients with a positive myocardial perfusion finding at cSE but without obstructive epicardial coronary artery disease have a decreased myocardial blood flow reserve, which may be caused by a spectrum of causes other than obstructive coronary artery disease, among which severely tortuous coronary arteries/myocardial bridging may play a significant role. PMID:21784382

  5. Myocardial perfusion echocardiography and coronary microvascular dysfunction

    PubMed Central

    Barletta, Giuseppe; Del Bene, Maria Riccarda

    2015-01-01

    Our understanding of coronary syndromes has evolved in the last two decades out of the obstructive atherosclerosis of epicardial coronary arteries paradigm to include anatomo-functional abnormalities of coronary microcirculation. No current diagnostic technique allows direct visualization of coronary microcirculation, but functional assessments of this circulation are possible. This represents a challenge in cardiology. Myocardial contrast echocardiography (MCE) was a breakthrough in echocardiography several years ago that claimed the capability to detect myocardial perfusion abnormalities and quantify coronary blood flow. Research demonstrated that the integration of quantitative MCE and fractional flow reserve improved the definition of ischemic burden and the relative contribution of collaterals in non-critical coronary stenosis. MCE identified no-reflow and low-flow within and around myocardial infarction, respectively, and predicted the potential functional recovery of stunned myocardium using appropriate interventions. MCE exhibited diagnostic performances that were comparable to positron emission tomography in microvascular reserve and microvascular dysfunction in angina patients. Overall, MCE improved echocardiographic evaluations of ischemic heart disease in daily clinical practice, but the approval of regulatory authorities is lacking. PMID:26730291

  6. Multispectral optoacoustic tomography of myocardial infarction

    PubMed Central

    Taruttis, Adrian; Wildgruber, Moritz; Kosanke, Katja; Beziere, Nicolas; Licha, Kai; Haag, Rainer; Aichler, Michaela; Walch, Axel; Rummeny, Ernst; Ntziachristos, Vasilis

    2012-01-01

    Objectives To investigate the feasibility of a high resolution optical imaging strategy for myocardial infarction. Background Near-infrared approaches to imaging cardiovascular disease enable visualization of disease-associated biological processes in vivo. However, even at the scale of small animals, the strong scattering of light prevents high resolution imaging after the first 1–2 mm of tissue, leading to degraded signal localization. Methods Multispectral optoacoustic tomography (MSOT) was used to non-invasively image myocardial infarction (MI) in a murine model of coronary artery ligation at resolutions not possible with current deep-tissue optical imaging methods. Post-MI imaging was based on resolving the spectral absorption signature of a dendritic polyglycerol sulfate-based (dPGS) near-infrared imaging agent targeted to P- and L-selectin. Results In vivo imaging succeeded in detection of the agent in the injured myocardium after intravenous injection. The high anatomic resolution (<200 μm) achieved by the described method allowed signals originating in the infarcted heart to be distinguished from uptake in adjacent regions. Histological analysis found dPGS signal in infarcted areas, originating from leukocytes and endothelial cells. Conclusions MSOT imaging of myocardial infarction provides non-invasive visualization of optical contrast with a high spatial resolution that is not degraded by the scattering of light. PMID:25327410

  7. Myocardial perfusion echocardiography and coronary microvascular dysfunction.

    PubMed

    Barletta, Giuseppe; Del Bene, Maria Riccarda

    2015-12-26

    Our understanding of coronary syndromes has evolved in the last two decades out of the obstructive atherosclerosis of epicardial coronary arteries paradigm to include anatomo-functional abnormalities of coronary microcirculation. No current diagnostic technique allows direct visualization of coronary microcirculation, but functional assessments of this circulation are possible. This represents a challenge in cardiology. Myocardial contrast echocardiography (MCE) was a breakthrough in echocardiography several years ago that claimed the capability to detect myocardial perfusion abnormalities and quantify coronary blood flow. Research demonstrated that the integration of quantitative MCE and fractional flow reserve improved the definition of ischemic burden and the relative contribution of collaterals in non-critical coronary stenosis. MCE identified no-reflow and low-flow within and around myocardial infarction, respectively, and predicted the potential functional recovery of stunned myocardium using appropriate interventions. MCE exhibited diagnostic performances that were comparable to positron emission tomography in microvascular reserve and microvascular dysfunction in angina patients. Overall, MCE improved echocardiographic evaluations of ischemic heart disease in daily clinical practice, but the approval of regulatory authorities is lacking. PMID:26730291

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

    PubMed Central

    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. PMID:26824042

  9. 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. PMID:26824042

  10. Acute myocardial infarction.

    PubMed

    Rischpler, Christoph

    2016-09-01

    Inflammatory processes after myocardial infarction have gained major interest in recent cardiovascular research. It is believed that not only the degree of cell recruitment to the heart plays a pivotal role in the quality of wound healing after myocardial infarction, but also the balance between different types or even subtypes of cells. It is also this balance which is thought to control key processes in tissue repair, such as apoptosis and neoangiogenesis. In this paper, we aim to review imaging strategies (with a special focus on nuclear molecular imaging strategies) that target cells and processes involved in postischemic inflammation and that have a high potential to be translated into clinic or that are already being used and evaluated in humans. PMID:27225319

  11. Automated quantification of myocardial infarction from MR images by accounting for partial volume effects: animal, phantom, and human study.

    PubMed

    Heiberg, Einar; Ugander, Martin; Engblom, Henrik; Götberg, Matthias; Olivecrona, Göran K; Erlinge, David; Arheden, Håkan

    2008-02-01

    Ethics committees approved human and animal study components; informed written consent was provided (prospective human study [20 men; mean age, 62 years]) or waived (retrospective human study [16 men, four women; mean age, 59 years]). The purpose of this study was to prospectively evaluate a clinically applicable method, accounting for the partial volume effect, to automatically quantify myocardial infarction from delayed contrast material-enhanced magnetic resonance images. Pixels were weighted according to signal intensity to calculate infarct fraction for each pixel. Mean bias +/- variability (or standard deviation), expressed as percentage left ventricular myocardium (%LVM), were -0.3 +/- 1.3 (animals), -1.2 +/- 1.7 (phantoms), and 0.3 +/- 2.7 (patients), respectively. Algorithm had lower variability than dichotomous approach (2.7 vs 7.7 %LVM, P < .01) and did not differ from interobserver variability for bias (P = .31) or variability (P = .38). The weighted approach provides automatic quantification of myocardial infarction with higher accuracy and lower variability than a dichotomous algorithm. PMID:18055873

  12. [Mortality of myocardial infarction].

    PubMed

    Bonnefoy, E; Kirkorian, G

    2011-12-01

    Coronary disease is a major cause of death and disability. From 1975 to 2000, coronary mortality was reduced by half. Better treatments and reduction of risk factors are the main causes. This phenomenon is observed in most developed countries, but mortality from coronary heart disease continues to increase in developing countries. In-hospital mortality of ST elevation myocardial infarction (STEMI) is in the range of 7 to 10% in registries. In infarction without ST segment elevation (NSTEMI), in-hospital mortality is around 5%. More recent studies found a similar in-hospital mortality for STEMI and NSTEMI. Because of patient selection and monitoring, mortality in clinical trials is much lower. After adjustment for the extent of coronary disease, age, risk factors, history of myocardial infarction, the excess mortality observed in women is fading. Many clinical, biological and laboratory parameters are associated with mortality in myocardial infarction. They refer to the immediate risk of death (ventricular rhythm disturbances, shock…), the extent of infarction (number of leads with ST elevation on the ECG, release of biomarkers, ejection fraction…), the presence of heart failure, the failure of reperfusion and the patient's baseline risk (age, renal function…). Risk scores, and more specifically the GRACE risk score, synthesize these different markers to predict the risk of death in a given patient. However, their use for the treatment of myocardial only concerns NSTEMI. Only a limited number of mechanical or pharmacological interventions reduces mortality of heart attack. The main benefits are observed with reperfusion by thrombolysis or primary angioplasty in STEMI, aspirin, heparin, beta-blockers, angiotensin converting enzyme inhibitors. Some medications such as bivalirudin and fondaparinux reduce mortality by decreasing the incidence of hemorrhagic complications. The guidelines classify interventions according to their benefit and especially their ability

  13. Myocardial perfusion as assessed by thallium-201 scintigraphy during the discontinuation of mechanical ventilation in ventilator-dependent patients

    SciTech Connect

    Hurford, W.E.; Lynch, K.E.; Strauss, H.W.; Lowenstein, E.; Zapol, W.M. )

    1991-06-01

    Patients who cannot be separated from mechanical ventilation (MV) after an episode of acute respiratory failure often have coexisting coronary artery disease. The authors hypothesized that increased left ventricular (LV) wall stress during periods of spontaneous ventilation (SV) could alter myocardial perfusion in these patients. Using thallium-201 (201TI) myocardial scintigraphy, the authors studied the occurrence of myocardial perfusion abnormalities during periods of SV in 15 MV-dependent patients (nine women, six men; aged 71 {plus minus} 7 yr, mean {plus minus} SD). Fourteen of these patients were studied once with 201TI myocardial scintigraphy during intermittent mechanical ventilation (IMV) and again on another day, after at least 10 min of SV through a T-piece. One patient was studied during SV only. Thirteen of 14 of the patients (93%) studied during MV had abnormal patterns of initial myocardial 201TI uptake, but only 1 patient demonstrated redistribution of 201TI on delayed images. The remainder of the abnormalities observed during MV were fixed defects. SV produced significant alterations of myocardial 201TI distribution or transient LV dilation, or both, in 7 of the 15 patients (47%). Four patients demonstrated new regional decreases of LV myocardial thallium concentration with redistribution of the isotope on delayed images. The patient studied only during SV also had myocardial 201TI defects with redistribution. Five patients (3 also having areas of 201TI redistribution) had transient LV dilation during SV.

  14. Could contrast-enhanced CT detect STEMI prior to electrocardiogram?

    PubMed

    Sabbagh, Chadi; Rahi, Mayda; Baz, Maria; Haddad, Fadi; Helwe, Omar; Aoun, Noel; Ibrahim, Tony; Abdo, Lynn

    2015-01-01

    We present here a case in which contrast-enhanced computed tomography (CT) was the first diagnostic tool to detect myocardial hypoperfusion in a patient with atypical symptoms and normal electrocardiogram (ECG) on admission. An ST-segment elevation was detected thereafter on a second ECG realized several minutes after CT with raised troponin levels. Percutaneous coronary intervention was performed after failure of thrombolysis and confirmed occlusion of the left anterior descending artery. Further studies are needed to evaluate the role of high-resolution contrast-enhanced CT with or without coronary angiography in the workup of suspected myocardial infarction in the setting of a normal ECG. PMID:25085282

  15. Stochastic switching in delay-coupled oscillators.

    PubMed

    D'Huys, Otti; Jüngling, Thomas; Kinzel, Wolfgang

    2014-09-01

    A delay is known to induce multistability in periodic systems. Under influence of noise, coupled oscillators can switch between coexistent orbits with different frequencies and different oscillation patterns. For coupled phase oscillators we reduce the delay system to a nondelayed Langevin equation, which allows us to analytically compute the distribution of frequencies and their corresponding residence times. The number of stable periodic orbits scales with the roundtrip delay time and coupling strength, but the noisy system visits only a fraction of the orbits, which scales with the square root of the delay time and is independent of the coupling strength. In contrast, the residence time in the different orbits is mainly determined by the coupling strength and the number of oscillators, and only weakly dependent on the coupling delay. Finally we investigate the effect of a detuning between the oscillators. We demonstrate the generality of our results with delay-coupled FitzHugh-Nagumo oscillators. PMID:25314515

  16. Echocardiographic assessment of myocardial ischemia.

    PubMed

    Leischik, Roman; Dworrak, Birgit; Sanchis-Gomar, Fabian; Lucia, Alejandro; Buck, Thomas; Erbel, Raimund

    2016-07-01

    Over the last 60 years, echocardiography has emerged as a dominant and indispensable technique for the detection and assessment of coronary heart disease (CHD). In this review, we will describe and discuss this powerful tool of cardiology, especially in the hands of an experienced user, with a focus on myocardial ischemia. Technical development is still on-going, and various new ultrasound techniques have been established in the field of echocardiography in the last several years, including tissue Doppler imaging (TDI), contrast echocardiography, three-dimensional echocardiography (3DE), and speckle tracking echocardiography (i.e., strain/strain rate-echocardiography). High-end equipment with harmonic imaging, high frame rates and the opportunity to adjust mechanical indices has improved imaging quality. Like all new techniques, these techniques must first be subjected to comprehensive scientific assessment, and appropriate training that accounts for physical and physiological limits should be provided. These limits will constantly be redefined as echocardiographic techniques continue to change, which will present new challenges for the further development of ultrasound technology. PMID:27500160

  17. Echocardiographic assessment of myocardial ischemia

    PubMed Central

    Dworrak, Birgit; Sanchis-Gomar, Fabian; Lucia, Alejandro; Buck, Thomas; Erbel, Raimund

    2016-01-01

    Over the last 60 years, echocardiography has emerged as a dominant and indispensable technique for the detection and assessment of coronary heart disease (CHD). In this review, we will describe and discuss this powerful tool of cardiology, especially in the hands of an experienced user, with a focus on myocardial ischemia. Technical development is still on-going, and various new ultrasound techniques have been established in the field of echocardiography in the last several years, including tissue Doppler imaging (TDI), contrast echocardiography, three-dimensional echocardiography (3DE), and speckle tracking echocardiography (i.e., strain/strain rate-echocardiography). High-end equipment with harmonic imaging, high frame rates and the opportunity to adjust mechanical indices has improved imaging quality. Like all new techniques, these techniques must first be subjected to comprehensive scientific assessment, and appropriate training that accounts for physical and physiological limits should be provided. These limits will constantly be redefined as echocardiographic techniques continue to change, which will present new challenges for the further development of ultrasound technology. PMID:27500160

  18. Myocardial Defect Detection Using PET-CT: Phantom Studies

    PubMed Central

    Mananga, Eugene S.; El Fakhri, Georges; Schaefferkoetter, Joshua; Bonab, Ali A.; Ouyang, Jinsong

    2014-01-01

    It is expected that both noise and activity distribution can have impact on the detectability of a myocardial defect in a cardiac PET study. In this work, we performed phantom studies to investigate the detectability of a defect in the myocardium for different noise levels and activity distributions. We evaluated the performance of three reconstruction schemes: Filtered Back-Projection (FBP), Ordinary Poisson Ordered Subset Expectation Maximization (OP–OSEM), and Point Spread Function corrected OSEM (PSF–OSEM). We used the Channelized Hotelling Observer (CHO) for the task of myocardial defect detection. We found that the detectability of a myocardial defect is almost entirely dependent on the noise level and the contrast between the defect and its surroundings. PMID:24505429

  19. Assessing Myocardial Disease Using T1ρ MRI.

    PubMed

    Han, Yuchi; Liimatainen, Timo; Gorman, Robert C; Witschey, Walter R T

    2014-02-01

    There is great interest to use magnetic resonance imaging (MRI) for non-invasive assessment of myocardial disease in ischemic and non-ischemic cardiomyopathies. Recently, there has been a renewed interest to use a magnetic resonance imaging (MRI) technique utilizing spin locking radiofrequency (RF) pulses, called T1ρ MRI. The spin locking RF pulse creates sensitivity to some mechanisms of nuclear relaxation such as (1)H exchange between water and amide, amine and hydroxyl functional groups in molecules; consequently, there is the potential to non-invasively, and without exogenous contrast agents, obtain important molecular information from diseased myocardial tissue. The purpose of this article is to review and critically examine the recent published literature in the field related to T1ρ MRI of myocardial disease. PMID:24688628

  20. Assessing Myocardial Disease Using T1ρ MRI

    PubMed Central

    Han, Yuchi; Liimatainen, Timo; Gorman, Robert C.

    2014-01-01

    There is great interest to use magnetic resonance imaging (MRI) for non-invasive assessment of myocardial disease in ischemic and non-ischemic cardiomyopathies. Recently, there has been a renewed interest to use a magnetic resonance imaging (MRI) technique utilizing spin locking radiofrequency (RF) pulses, called T1ρ MRI. The spin locking RF pulse creates sensitivity to some mechanisms of nuclear relaxation such as 1H exchange between water and amide, amine and hydroxyl functional groups in molecules; consequently, there is the potential to non-invasively, and without exogenous contrast agents, obtain important molecular information from diseased myocardial tissue. The purpose of this article is to review and critically examine the recent published literature in the field related to T1ρ MRI of myocardial disease. PMID:24688628

  1. Dipyridamole thallium-201 myocardial scintigraphy

    SciTech Connect

    Not Available

    1988-09-01

    Thallium-201 (/sup 201/Tl) myocardial scintigraphy is a sensitive technique for detecting coronary artery disease. Standardized exercise testing is the most common method for inducing myocardial stress for /sup 201/Tl imaging. Unfortunately, a significant number of patients are unable to undergo adequate treadmill or bicycle exercise. In these patients, pharmacologic stress with dipyridamole provides a safe, efficacious, and reliable alternative.

  2. Diurnal variations in myocardial metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The heart is challenged by a plethora of extracellular stimuli over the course of a normal day, each of which distinctly influences myocardial contractile function. It is therefore not surprising that myocardial metabolism also oscillates in a time-of-day dependent manner. What is becoming increasin...

  3. Primary coronary angioplasty in patients with acute myocardial infarction.

    PubMed Central

    Popma, J J; Chuang, Y C; Satler, L F; Kleiber, B; Leon, M B

    1994-01-01

    In some patients with acute myocardial infarction, thrombolytic therapy may be limited by its failure to reperfuse the occluded artery, by recurrent ischemia (despite initially successful reperfusion), and by major hemorrhagic complications. Primary coronary angioplasty may circumvent these limitations. This article reviews the results of primary angioplasty reported in patients with myocardial infarction and makes recommendations for its use. The review includes pertinent articles found in the English language literature from July 1987 to July 1993 on MEDLINE. Nonrandomized series of primary angioplasty in acute myocardial infarction have demonstrated high procedural success rates (86% to 99%) and infrequent recurrent ischemia (4%). Two randomized trials comparing primary angioplasty and thrombolytic therapy have shown that primary angioplasty results in lower mortality, less recurrent ischemia, shorter length of hospital stay, and improved left ventricular function. Two other randomized studies have shown little benefit from primary angioplasty on myocardial salvage, recurrent ischemia, or ventricular function. One major limitation of primary angioplasty is that it requires 24-hour availability of a catheterization laboratory and experienced surgical personnel. Primary angioplasty may be the preferred approach in patients with extensive myocardial infarction who have immediate (< 120 min) access to a cardiac catheterization laboratory with experienced personnel. Patients having 1) contraindications to thrombolytic therapy, 2) cardiogenic shock, 3) prior coronary bypass surgery, or 4) "stuttering" onset of pain may also benefit from primary angioplasty. Poor candidates for this procedure are those with a small myocardial infarction, those in whom undue delays in access to a cardiac catheterization facility would be expected, or those with complex coronary anatomy, including left main coronary artery disease. PMID:8061539

  4. Impact of myocardial ischemia on myocardial revascularization in stable ischemic heart disease. Lessons from the COURAGE and FAME 2 trials.

    PubMed

    Torosoff, M T; Sidhu, M S; Boden, W E

    2013-06-01

    In patients with stable ischemic heart disease (SIHD), myocardial revascularization should be performed to either improve survival or improve symptoms and functional status among patients who are not well controlled with optimal medical therapy (OMT). A general consensus exists on the core elements of OMT, which include both lifestyle intervention and intensive secondary prevention with proven pharmacotherapies. By contrast, however, there is less general agreement as to what constitutes the optimal approach to revascularization in SIHD patients. The COURAGE and FAME 2 randomized trials form the foundation of the current clinical evidence base and raise the important question: "What is the impact of myocardial ischemia on myocardial revascularization in stable ischemic heart disease?" PMID:23695652

  5. Preoperative prediction of reversible myocardial asynergy by postexercise radionuclide ventriculography

    SciTech Connect

    Rozanski, A.; Berman, D.; Gray, R.; Diamond, G.; Raymond, M.; Prause, J.; Maddahi, J.; Swan, H.J.; Matloff, J.

    1982-07-22

    Myocardial asynergy is sometimes reversed by coronary bypass, and a noninvasive method of predicting which assess are reversible would be desirable. To assess whether changes in myocardial wall motion observed immediately after exercise can differentiate reversible from nonreversible myocardial asynergy, we evaluated 53 patients by radionuclide ventriculography before and after exercise and again at rest after coronary bypass surgery. Preoperative improvement in wall motion immediately after exercise was highly predictive of the surgical outcome (average chance-corrected agreement, 91 per cent). At surgery the asynergic segments that had improved after exercise were free of grossly apparent epicardial scarring. The accuracy of these predictions for postoperative improvement was significantly greater (P less than 0.01) than that of analysis of Q waves on resting electrocardiography (average chance-corrected agreement, 40 per cent). In contrast, preoperative changes in left ventricular ejection fraction after exercise were not predictive of postoperative resting ejection fraction. We conclude that postexercise radionuclide ventriculography can be used to identify reversible resting myocardial asynergy. This test should prove effective in predicting which patients with myocardial asynergy are most likely to benefit from aortocoronary revascularization.

  6. Cortical laminar necrosis following myocardial infarction.

    PubMed

    Lattanzi, Simona; Silvestrini, Mauro; Provinciali, Leandro

    2016-01-01

    The cortical laminar necrosis (CLN) is a permanent injury characterized by the selective delayed necrosis of the cerebral cortex, mainly of the third layer, and usually greater in the depths and sides of the sulci than over the crest of the gyri. The damage involves all cellular components - either neurons, glia cells and blood vessels - and results in a focal cortical band of pan-necrosis detectable in late sub-acute or chronic stages of reduced energy supply to the brain. The CLN has been described in different conditions as hypoxia, hypoglycemia and status epilepticus. At brain CT or MR scans it appears with pathognomonic highly hyperdense or T1-hyperintense lesions following the gyral anatomy of the cerebral cortex. We reported a case of CLN associated to myocardial infarct and discussed the underlying mechanisms. PMID:27375142

  7. Spiral MR myocardial tagging.

    PubMed

    Ryf, Salome; Kissinger, Kraig V; Spiegel, Marcus A; Börnert, Peter; Manning, Warren J; Boesiger, Peter; Stuber, Matthias

    2004-02-01

    In the present study, complementary spatial modulation of magnetization (CSPAMM) myocardial tagging was extended with an interleaved spiral imaging sequence. The use of a spiral sequence enables the acquisition of grid-tagged images with a tagline distance as low as 4 mm in a single breath-hold. Alternatively, a high temporal resolution of 77 frames per second was obtained with 8-mm grid spacing. Ten healthy adult subjects were studied. With this new approach, high-quality images can be obtained and the tags persist throughout the entire cardiac cycle. PMID:14755646

  8. Assessment of myocardial viability.

    PubMed

    Travin, Mark I; Bergmann, Steven R

    2005-01-01

    The prevalence of left ventricular (LV) dysfunction and resultant congestive heart failure is increasing. Patients with this condition are at high risk for cardiac death and usually have significant limitations in their lifestyles. Although there have been advances in medical therapy resulting in improved survival and well being, the best and most definitive therapy, when appropriate, is revascularization. In the setting of coronary artery disease, accounting for approximately two thirds of cases of congestive heart failure, LV dysfunction often is not the result of irreversible scar but rather caused by impairment in function and energy use of still viable-myocytes, with the opportunity for improved function if coronary blood flow is restored. Patients with LV dysfunction who have viable myocardium are the patients at highest risk because of the potential for ischemia but at the same time benefit most from revascularization. It is important to identify viable myocardium in these patients, and radionuclide myocardial scintigraphy is an excellent tool for this. Single-photon emission computed tomography perfusion scintigraphy, whether using thallium-201, Tc-99m sestamibi, or Tc-99m tetrofosmin, in stress and/or rest protocols, has consistently been shown to be an effective modality for identifying myocardial viability and guiding appropriate management. Metabolic imaging with positron emission tomography radiotracers frequently adds additional information and is a powerful tool for predicting which patients will have an improved outcome from revascularization, including some patients referred instead for cardiac transplantation. Other noninvasive modalities, such as stress echocardiography, also facilitate the assessment of myocardial viability, but there are advantages and disadvantages compared with the nuclear techniques. Nuclear imaging appears to require fewer viable cells for detection, resulting in a higher sensitivity but a lower specificity than stress

  9. Relation of coronary microvascular dysfunction in hypertrophic cardiomyopathy to contractile dysfunction independent from myocardial injury.

    PubMed

    Timmer, Stefan A J; Germans, Tjeerd; Götte, Marco J W; Rüssel, Iris K; Lubberink, Mark; Ten Berg, Jurrien M; Ten Cate, Folkert J; Lammertsma, Adriaan A; Knaapen, Paul; van Rossum, Albert C

    2011-05-15

    We studied the spatial relations among hyperemic myocardial blood flow (hMBF), contractile function, and morphologic tissue alterations in 19 patients with hypertrophic cardiomyopathy (HC). All patients were studied with oxygen-15 water positron emission tomography during rest and adenosine administration to assess myocardial perfusion. Cardiovascular magnetic resonance was performed to derive delayed contrast-enhanced images and to calculate contractile function (E(cc)) with tissue tagging. Eleven healthy subjects underwent similar positron emission tomographic and cardiovascular magnetic resonance scanning protocols and served as a control group. In the HC group, hMBF averaged 2.46 ± 0.91 ml/min/g and mean E(cc) was -14.7 ± 3.4%, which were decreased compared to the control group (3.97 ± 1.48 ml/min/g and -17.7 ± 3.2%, respectively, p <0.001 for the 2 comparisons). Delayed contrast enhancement (DCE) was present only in patients with HC, averaging 6.2 ± 10.3% of left ventricular mass. In the HC group, E(cc) and DCE in the septum (-13.7 ± 3.6% and 10.2 ± 13.6%) significantly differed from the lateral wall (-16.0 ± 2.8% and 2.4 ± 5.9%, p <0.001 for the 2 comparisons). In general, hMBF and E(cc) were decreased in segments displaying DCE compared to nonenhanced segments (p <0.001 for the comparisons). In the HC group, univariate analysis revealed relations of hMBF to E(cc) (r = -0.45, p <0.001) and DCE (r = -0.31, p <0.001). Multivariate analysis revealed that E(cc) was independently related to hMBF (beta -0.37, p <0.001) and DCE (beta 0.28, p <0.001). In conclusion, in HC hMBF is impaired and related to contractile function independent from presence of DCE. When present, DCE reflected a progressed disease state as characterized by an increased perfusion deficit and contractile dysfunction. PMID:21377644

  10. Evaluation of the effect of myocardial segmentation errors on myocardial blood flow estimates from DCE-MRI

    NASA Astrophysics Data System (ADS)

    Biglands, J.; Magee, D.; Boyle, R.; Larghat, A.; Plein, S.; Radjenović, A.

    2011-04-01

    Quantitative analysis of cardiac dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) perfusion datasets is dependent on the drawing (manually or automatically) of myocardial contours. The required accuracy of these contours for myocardial blood flow (MBF) estimation is not well understood. This study investigates the relationship between myocardial contour errors and MBF errors. Myocardial contours were manually drawn on DCE-MRI perfusion datasets of healthy volunteers imaged in systole. Systematic and random contour errors were simulated using spline curves and the resulting errors in MBF were calculated. The degree of contour error was also evaluated by two recognized segmentation metrics. We derived contour error tolerances in terms of the maximum deviation (MD) a contour could deviate radially from the 'true' contour expressed as a fraction of each volunteer's mean myocardial width (MW). Significant MBF errors were avoided by setting tolerances of MD <= 0.4 MW, when considering the whole myocardium, MD <= 0.3 MW, when considering six radial segments, and MD <= 0.2 MW for further subdivision into endo- and epicardial regions, with the exception of the anteroseptal region, which required greater accuracy. None of the considered segmentation metrics correlated with MBF error; thus, both segmentation metrics and MBF errors should be used to evaluate contouring algorithms.

  11. Noninvasive estimation of regional myocardial oxygen consumption by positron emission tomography with carbon-11 acetate in patients with myocardial infarction

    SciTech Connect

    Walsh, M.N.; Geltman, E.M.; Brown, M.A.; Henes, C.G.; Weinheimer, C.J.; Sobel, B.E.; Bergmann, S.R. )

    1989-11-01

    We previously demonstrated in experimental studies that myocardial oxygen consumption (MVO2) can be estimated noninvasively with positron emission tomography (PET) from analysis of the myocardial turnover rate constant (k) after administration of carbon-11 (11C) acetate. To determine regional k in healthy human subjects and to estimate alterations in MVO2 accompanying myocardial ischemia, we administered (11C)acetate to five healthy human volunteers and to six patients with myocardial infarction. Extraction of (11C)acetate by the myocardium was avid and clearance from the blood-pool rapid yielding myocardial images of excellent quality. Regional k was homogeneous in myocardium of healthy volunteers (coefficient variation = 11%). In patients, k in regions remote from the area of infarction was not different from values in myocardium of healthy human volunteers (0.061 +/- 0.025 compared with 0.057 +/- 0.008 min-1). In contrast, MVO2 in the center of the infarct region was only 6% of that in remote regions (p less than 0.01). In four patients studied within 48 hr of infarction and again more than seven days after the acute event, regional k and MVO2 did not change. The approach developed should facilitate evaluation of the efficacy of interventions designed to enhance recovery of jeopardized myocardium and permit estimation of regional MVO2 and metabolic reserve underlying cardiac disease of diverse etiologies.

  12. Assessment, significance and mechanism of ventricular electrical instability after myocardial infarction.

    PubMed

    Richards, David A B; Denniss, A Robert

    2007-06-01

    The mechanism of reentrant tachycardia was established nearly a century ago, but the relationships between myocardial infarction and predisposition to sudden death were not unravelled until much later. In the latter half of the twentieth century many studies sought to ascertain what variables were predictive of death following myocardial infarction. Approximately one half of all deaths during the year following myocardial infarction are sudden and due to ventricular tachycardia (VT) or ventricular fibrillation (VF). We aimed to utilise non-invasive signal-averaging, along with programmed electrical stimulation of the heart, to determine whether one could predict spontaneous ventricular tachycardia and sudden death late after myocardial infarction. The sensitivity of ventricular electrical instablility (inducible ventricular tachycardia or fibrillation) as a predictor of instantaneous death or spontaneous VT was 86%, and the specificity was 83%. When other variables (delayed ventricular activation at signal-averaging, ejection fraction at gated heart pool scan, ventricular ectopic activity at ambulatory monitoring and exercise testing) were taken into account, inducible VT at electrophysiological study was the single best predictor of spontaneous VT and sudden cardiac death after myocardial infarction. The Westmead studies of Uther et al. in the decade or so from 1980 established programmed stimulation as the best predictor of sudden death after myocardial infarction. Subsequent studies by others have demonstrated a survival advantage of defibrillator implantation in patients with low ejection fraction (and inducible ventricular tachycardia) after myocardial infarction. PMID:17446130

  13. Trauma Induced Myocardial Infarction

    PubMed Central

    Lolay, Georges A.; Abdel-Latef, Ahmed K.

    2016-01-01

    Chest Trauma in athletes is a common health problem. However, myocardial infarction secondary to coronary dissection in the setting of blunt chest trauma is extremely rare. We report a case of acute inferior wall myocardial infarction following blunt chest trauma. A 32-year-old male with no relevant medical problems was transferred to our medical center for retrosternal chest pain after being elbowed in the chest during a soccer game. Few seconds later, he started experiencing sharp retrosternal chest pain that was severe to that point where he called the emergency medical service. Upon arrival to the Trauma department patient was still complaining of chest pain. ECG demonstrated ST segment elevation in the inferior leads with reciprocal changes in the lateral leads all consistent with active ischemia. After rolling out Aortic dissection, patient was loaded with ASA, ticagerlor, heparin and was emergently taken to the cardiac catheterization lab. Coronary angiography demonstrated 100% thrombotic occlusion in the distal right coronary artery with TIMI 0 flow distally. After thrombus aspiration, a focal dissection was noted on the angiogram that was successfully stented. Two days after admission patient was discharged home. Echocardiography prior to discharge showed inferior wall akinesis, normal right ventricular systolic function and normal overall ejection fraction. PMID:26490501

  14. Valsartan after myocardial infarction.

    PubMed

    Güleç, Sadi

    2014-12-01

    One of the important problems of the patients undergoing acute myocardial infarction (MI) is early development of heart failure. It has been revealed in various studies that renin-angiotensin-aldosterone system (RAAS) has a significant role in this process. The studies conducted with angiotensin converting enzyme (ACE) inhibitors have resulted in decreased mortality rate. Another RAAS blocker which was discovered about ten years later than other ACE inhibitors in historical process is angiotensin receptor blockers (ARB) inhibiting the efficiency of angiotensin 2 by binding to angiotensin 1 receptor. Valsartan is one of the molecules of this group, which has higher number of large-scale randomized clinical studies. In this review, following presentation of a general overview on heart failure after acute MI, the efficiency of ARBs in this patient group will be discussed. This discussion will mostly emphasize the construction, outcomes and clinical importance of VALIANT (VALsartan In Acute myocardial iNfarcTion), which is the study on valsartan after acute MI heart failure. PMID:25604205

  15. Bronchogenic Carcinoma with Cardiac Invasion Simulating Acute Myocardial Infarction

    PubMed Central

    Das, Anirban; Das, Sibes K.; Pandit, Sudipta; Karmakar, Rathindra Nath

    2016-01-01

    Cardiac metastases in bronchogenic carcinoma may occur due to retrograde lymphatic spread or by hematogenous dissemination of tumour cells, but direct invasion of heart by adjacent malignant lung mass is very uncommon. Pericardium is frequently involved in direct cardiac invasion by adjacent lung cancer. Pericardial effusion, pericarditis, and tamponade are common and life threatening presentation in such cases. But direct invasion of myocardium and endocardium is very uncommon. Left atrial endocardium is most commonly involved in such cases due to anatomical contiguity with pulmonary hilum through pulmonary veins, and in most cases left atrial involvement is asymptomatic. But myocardial compression and invasion by adjacent lung mass may result in myocardial ischemia and may present with retrosternal, oppressive chest pain which clinically may simulate with the acute myocardial infarction (AMI). As a result, it leads to misdiagnosis and delayed diagnosis of lung cancer. Here we report a case of non-small-cell carcinoma of right lung which was presented with asymptomatic invasion in left atrium and retrosternal chest pain simulating AMI due to myocardial compression by adjacent lung mass, in a seventy-four-year-old male smoker. PMID:27042370

  16. How we perform delayed enhancement imaging.

    PubMed

    Kim, Raymond J; Shah, Dipan J; Judd, Robert M

    2003-07-01

    Recently, numerous studies have demonstrated the effectiveness of a segmented inversion recovery fast gradient echo (seg IR-FGE) sequence for differentiating injured from normal myocardium. This technique for delayed enhancement imaging has been shown to be effective in identifying the presence and extent of myocardial infarction, as well as predicting improvement in contractile function after coronary revascularization. In this article we outline the procedure of delayed enhancement imaging performed at our center, describe the seg IR-FGE sequence in more detail, including our process for choosing sequence settings, review our process of image interpretation, and highlight potential pitfalls (and techniques to overcome them) that we have encountered in our experience with performing the technique in over 1500 patients. PMID:12882082

  17. Lay Public's Knowledge and Decisions in Response to Symptoms of Acute Myocardial Infarction

    ERIC Educational Resources Information Center

    Cytryn, Kayla N.; Yoskowitz, Nicole A.; Cimino, James J.; Patel, Vimla L.

    2009-01-01

    Despite public health initiatives targeting rapid action in response to symptoms of myocardial infarction (MI), people continue to delay in going to a hospital when experiencing these symptoms due to lack of recognition as cardiac-related. The objective of this research was to characterize lay individuals' knowledge of symptoms of acute myocardial…

  18. Quality of Care for Acute Myocardial Infarction in Rural and Urban US Hospitals

    ERIC Educational Resources Information Center

    Baldwin, Laura-Mae; MacLehose, Richard F.; Hart, L. Gary; Beaver, Shelli K.; Every,Nathan; Chan,Leighton

    2004-01-01

    Context: Acute myocardial infarction (AMI) is a common and important cause of admission to US rural hospitals, as transport of patients with AMI to urban settings can result in unacceptable delays in care. Purpose: To examine the quality of care for patients with AMI in rural hospitals with differing degrees of remoteness from urban centers.…

  19. Contrast media in cardiovascular magnetic resonance.

    PubMed

    Lombardi, Massimo; Aquaro, Giovanni; Favilli, Brunella

    2005-01-01

    Among the available imaging techniques, Magnetic Resonance Imaging (MRI) is gaining an increasing role in the cardiologic setting because its specific properties such as the use of non ionising energies, the natural strong contrast between different tissues, the absence of spatial limitations, the good spatial and temporal resolution, the reduced operator dependency. To further improve the images quality and the histopathologic characterisation of tissues the use of contrast media (molecules containing gadolinium, manganese, iron, dysprosium ions) has been proposed both in the experimental and in the clinical settings. Among these ions gadolinium, which having 7 odd electrons in the external orbit has a strong magnetic momentum, is the most used. Gadolinium by itself is extremely toxic but once it is linked with a chelanting agent such as DTPA (Dietilen-Triamin-Penta-Acetic acid) the resulting complex shows a very low toxicity. The number of Gadolinium based compound is growing together with the use of contrast agents in MRI. These contrast agents are routinely used to perform Magnetic Resonance Angiography (MRA) and to a better definition of several cardiac diseases such as the presence of a intra- or paracardiac mass, the evaluation of myocardial perfusion and the evaluation of viability. Both the latter applications have relevant clinical implications. In fact the assessment of myocardial perfusion is one of the most used approach for detecting inducible myocardial ischemia due to major coronary artery disease or to assess the presence of a microvascular disease. The presence and the extent of viable myocardium is deeply modifying the clinical decision making as this viable tissue can recruit a normal function spontaneously or after revascularisation. Furthermore, the extent of viable myocardium has a strong correlation with negative prognosis. Clinical events are also time related to the detection of viable tissue. These evidences imply that the diagnostic

  20. [Study of post-myocardial infarction ventricular aneurysms with equilibrium radionuclide angiography. Significance of Fourier analysis].

    PubMed

    de Sá, M E; Ferreira, R; Rebelo, J R; Nogueira, A; Baptista, A M; Ribeiro, C

    2001-05-01

    The concept of left ventricular aneurysm has been a subject of controversy and it's not yet completely settled. This has some implications on the patients selection for surgery and explains the various non-invasive methods so far developed for the clinical assessment of patients with ventricular aneurysms. Seventy-one patients with ischemic heart disease, 65 with recent myocardial infarction, were studied by equilibrium radionuclide angiography (ERNA) in order to define left ventricular wall motion abnormalities. One hundred ERNA were undertaken, through the usual erytrocites in vivo labelling technic, employing a GE 400 T Gama-Camera GP. Image acquisition was through 400 cardiac cycles, on LAO (30 and 60 degrees) and left lateral. PAGE protocol was employed. Fourier transform was used in the present work to obtain phase and amplitude images, which actually became the main criteria to define aneurysmatic areas. Global ejection fraction, regional wall motion and regional ejection fraction were other parameters investigated. Wall motion abnormalities have been identified in all the 65 patients having suffered a myocardial infarction. Extensive areas of akinesia or localized dyskinesia were present in 40 patients (16.5%), while remainder 25 had just localized hypoakinesia. Phase image enabled the selection of LV areas of contraction delay in 19 of the 40 patients with extensive wall motion abnormalities (Group I). In such Group I we could identify an LV area with contrasting colour, defining the aneurysmatic LV portion. In the order 21 patients with extensive akinesia, no significant changes of colour were present on ventricular phase image (Group II) meaning absence of aneurysm. No phase disturbances were seen in the remainder 25 patients with MI (Group III) and the 6 patients with CAD without MI had normal phase images (Group IV). The percentage of akinetic segments was 39.1 and 35.4 in Group I and II, respectively (p = .53) while it was significantly lower in Group

  1. Myocardial infarction after dipyridamole-assisted thallium-201 imaging

    SciTech Connect

    Biddle, P.; Lanspa, T.J.; Mohiuddin, S.M.; Malesker, M.A.; Hilleman, D.E. )

    1989-09-01

    A 77-year-old woman with suspected coronary artery disease underwent an oral dipyridamole/thallium-201 myocardial imaging study. Approximately 75 minutes after ingestion of dipyridamole 300 mg suspension, the patient developed chest pain, hypotension, nausea, and diaphoresis. An electrocardiogram revealed ST-T wave changes suggestive of inferior ischemia. Appropriate therapeutic measures, including aminophylline and nitroglycerin, were instituted. Delayed thallium images revealed reversible ischemia in the anteroseptal and posterobasal regions with a fixed defect in the inferobasal region. Cardiac enzyme studies were also indicative of acute myocardial injury. The patient subsequently underwent coronary arteriography and four-vessel coronary artery bypass grafting and was discharged without further complication. This report raises concerns about the potential danger of dipyridamole in patients with severe coronary artery stenosis and collateral circulation. Prophylactic aminophylline should be considered in these patients.

  2. A Case of Post Myocardial Infarction Papillary Muscle Rupture.

    PubMed

    Anuwatworn, Amornpol; Milnes, Christopher; Kumar, Vishesh; Raizada, Amol; Nykamp, Verlyn; Stys, Adam

    2016-06-01

    Papillary muscle rupture is a rare, life-threatening post myocardial infarction mechanical complication. Without surgical intervention, prognosis is very poor. Clinicians need to recognize this complication early, as prompt therapy is crucial. We present a case of inferior ST elevation myocardial infarction complicated by posteromedial papillary muscle rupture resulting in severe acute mitral regurgitation (flail anterior mitral leaflet), acute pulmonary edema and cardiogenic shock. In our patient, a new mitral regurgitation murmur suggested this mechanical complication. Complete disruption of papillary muscle was visualized by transesophageal echocardiography. This case illustrates the importance of good physical examination for early diagnosis of papillary muscle rupture, so that life-saving treatment can be administered without delay. PMID:27443107

  3. An unusual myocardial infarction

    PubMed Central

    Di Michele, Sara; Mirabelli, Francesca; Mankad, Sunil

    2014-01-01

    Summary We present a 74-year-old male with a chondrosarcoma, who presented with chest pain. The history, electrocardiogram (ECG), and biomarkers established the diagnosis of myocardial infarction (MI); angiography did not show coronary atherosclerosis and, both initial transthoracic echocardiogram and chest computed tomography (CT), did not demonstrate any cardiac abnormalities. A second echocardiogram following a routine ECG showed presence of a mass involving the right ventricle and the cardiac apex that was confirmed by chest CT scan. We underline the importance of considering cardiac tumors in the clinical arena of MI management. Learning points Cardiac tumors cause ECG changes similar to ischemic heart diseases.Keep in mind cardiac tumors when performing transthoracic echocardiogram (TTE) in the setting of suspected MI.TTE is the technique of choice in detecting cardiac tumors. PMID:26693309

  4. Masquerades of myocardial infarction.

    PubMed Central

    Bean, W. B.

    1976-01-01

    I summarize these observations in Figure 1. It represents every person in a hypothetical population who has myocardial infarction. A large but unknown number, some believe almost half, never get help. Mobile coronary care units are reducing this group, but so far only a little. When the diagnosis is not understood the disease is not recognized. Then come discovery and popularization. Hereafter masquerades hide some cases and the diagnosis is missed. Somewhere fairly early the diagnostic fad leads to false positive diagnosis. As new techniques are discovered, perfected and mastered, false positive errors and masquerades leading to oversights diminish but still exist. All the skill and technical virtuosity in the world will not be applied if we do not think of the disease. When we think of it, even obscure cases may be resolved easily. PMID:960416

  5. Delayed orgasm and anorgasmia.

    PubMed

    Jenkins, Lawrence C; Mulhall, John P

    2015-11-01

    Delayed orgasm/anorgasmia defined as the persistent or recurrent difficulty, delay in, or absence of attaining orgasm after sufficient sexual stimulation, which causes personal distress. Delayed orgasm and anorgasmia are associated with significant sexual dissatisfaction. A focused medical history can shed light on the potential etiologies, which include medications, penile sensation loss, endocrinopathies, penile hyperstimulation, and psychological etiologies. Unfortunately, there are no excellent pharmacotherapies for delayed orgasm/anorgasmia, and treatment revolves largely around addressing potential causative factors and psychotherapy. PMID:26439762

  6. Current trend of acute myocardial infarction in Korea (from the Korea Acute Myocardial Infarction Registry from 2006 to 2013).

    PubMed

    Kook, Hyun Yi; Jeong, Myung Ho; Oh, Sangeun; Yoo, Sung-Hee; Kim, Eun Jung; Ahn, Youngkeun; Kim, Ju Han; Chai, Leem Soon; Kim, Young Jo; Kim, Chong Jin; Chan Cho, Myeong

    2014-12-15

    Although the incidence of acute myocardial infarction (AMI) in Korea has been rapidly changed because of westernization of diet, lifestyle, and aging of the population, the recent trend of the myocardial infarction have not been reported by classification. We investigated recent trends in the incidence and mortality associated with the 2 major types of AMI. We reviewed 39,978 patients registered in the Korea Acute Myocardial Infarction Registry for either ST-segment elevation acute myocardial infarction (STEMI) or non-ST-segment elevation acute myocardial infarction (NSTEMI) from 2006 to 2013. When the rate for AMI were investigated according to each year, the incidence rates of STEMI decreased markedly from 60.5% in 2006 to 48.1% in 2013 (p <0.001). In contrast, a gradual increase in the incidence rates of NSTEMI was observed from 39.5% in 2006 to 51.9% in 2013 (p <0.001). As risk factors, hypertension, diabetes mellitus, and dyslipidemia were much more common in patients with NSTEMI than STEMI. Among medical treatments, the use of β blockers, angiotensin receptor blocker, and statin were increased from 2006 to 2013 in patients with STEMI and NSTEMI. Patients with STEMI and NSTEMI were more inclined to be increasingly treated by invasive treatments with percutaneous coronary intervention. In conclusion, this study demonstrated that the trend of myocardial infarction has been changed rapidly in the aspect of risk factors, ratio of STEMI versus NSTEMI, and therapeutic strategies during the recent 8 years in Korea. PMID:25438907

  7. Speech and Language Delay

    MedlinePlus

    MENU Return to Web version Speech and Language Delay Overview How do I know if my child has speech delay? Every child develops at his or her ... of the same age, the problem may be speech delay. Your doctor may think your child has ...

  8. Delay Discounting and Gambling

    PubMed Central

    Madden, Gregory J.; Francisco, Monica T.; Brewer, Adam T.; Stein, Jeffrey S.

    2011-01-01

    Delay discounting describes the decline in the value of a reinforcer as the delay to that reinforcer increases. A review of the available studies revealed that steep delay discounting is positively correlated with problem or pathological gambling. One hypothesis regarding this correlation derives from the discounting equation proposed by Mazur (1989). According to the equation, steeper discounting renders the difference between fixed-delayed rewards and gambling-like variable-delayed rewards larger; with the latter being more valuable. The present study was designed to test this prediction by first assessing rats’ impulsive choices across four delays to a larger-later reinforcer. A second condition quantified strength of preference for mixed- over fixed-delays, with the duration of the latter adjusted between sessions to achieve indifference. Strength of preference for the mixed-delay alternative is given by the fixed delay at indifference (lower fixed-delay values reflect stronger preferences). Percent impulsive choice was not correlated with the value of the fixed delay at indifference and, therefore, the prediction of the hyperbolic model of gambling was not supported. A follow-up assessment revealed a significant decrease in impulsive choice after the second condition. This shift in impulsive choice could underlie the failure to observe the predicted correlation between impulsive choice and degree of preference for mixed- over fixed delays. PMID:21352902

  9. Wave Propagation of Myocardial Stretch: Correlation with Myocardial Stiffness

    PubMed Central

    Pislaru, Cristina; Pellikka, Patricia A.; Pislaru, Sorin V.

    2015-01-01

    The mechanism of flow propagation during diastole in the left ventricle (LV) has been well described. Little is known about the associated waves propagating along the heart wall s. These waves may have a mechanism similar to pulse wave propagation in arteries. The major goal of the study was to evaluate the effect of myocardial stiffness and preload on this wave transmission. Methods Longitudinal late diastolic deformation and wave speed (Vp) of myocardial stretch in the anterior LV wall were measured using sonomicrometry in sixteen pigs. Animals with normal and altered myocardial stiffness (acute myocardial infarction) were studied with and without preload alterations. Elastic modulus estimated from Vp (EVP; Moens-Korteweg equation) was compared to incremental elastic modulus obtained from exponential end -diastolic stress-strain relation (ESS). Myocardial distensibility and α-and β-coefficients of stress-strain relations were calculated. Results Vp was higher at reperfusion compared to baseline (2.6±1.3 m/s vs. 1.3±0.4 m/s; p=0.005) and best correlated with ESS (r 2=0.80, p<0.0001), β-coefficient (r2=0.78, p<0.0001), distensibility (r2=0.47, p=0.005), and wall thickness/diameter ratio (r2=0.42, p=0.009). Elastic moduli (EVP and ESS) were strongly correlated (r2=0.83, p<0.0001). Increasing preload increased Vp and EVP and decreased distensibility. At multivariate analysis, ESS, wall thickness, and end-diastolic and systolic LV pressures were independent predictors of Vp (r2model=0.83, p<0.0001). Conclusions The main determinants of wave propagation of longitudinal myocardial stretch were myocardial stiffness and LV geometry and pressure. This local wave speed could potentially be measured noninvasively by echocardiography. PMID:25193091

  10. ADAMTS13 deficiency exacerbates VWF-dependent acute myocardial ischemia/reperfusion injury in mice

    PubMed Central

    Gandhi, Chintan; Motto, David G.; Jensen, Melissa; Lentz, Steven R.

    2012-01-01

    Epidemiologic studies suggest that elevated VWF levels and reduced ADAMTS13 activity in the plasma are risk factors for myocardial infarction. However, it remains unknown whether the ADAMTS13-VWF axis plays a causal role in the pathophysiology of myocardial infarction. In the present study, we tested the hypothesis that ADAMTS13 reduces VWF-mediated acute myocardial ischemia/reperfusion (I/R) injury in mice. Infarct size, neutrophil infiltration, and myocyte apoptosis in the left ventricular area were quantified after 30 minutes of ischemia and 23.5 hours of reperfusion injury. Adamts13−/− mice exhibited significantly larger infarcts concordant with increased neutrophil infiltration and myocyte apoptosis compared with wild-type (WT) mice. In contrast, Vwf−/− mice exhibited significantly reduced infarct size, neutrophil infiltration, and myocyte apoptosis compared with WT mice, suggesting a detrimental role for VWF in myocardial I/R injury. Treating WT or Adamts13−/− mice with neutralizing Abs to VWF significantly reduced infarct size compared with control Ig–treated mice. Finally, myocardial I/R injury in Adamts13−/−/Vwf−/− mice was similar to that in Vwf−/− mice, suggesting that the exacerbated myocardial I/R injury observed in the setting of ADAMTS13 deficiency is VWF dependent. These findings reveal that ADAMTS13 and VWF are causally involved in myocardial I/R injury. PMID:22983446

  11. Myocardial edema imaging by cardiovascular magnetic resonance: current status and future potential.

    PubMed

    Carbone, Iacopo; Friedrich, Matthias G

    2012-02-01

    Cardiovascular magnetic resonance (CMR) imaging is widely established, free of radioactive material or ionizing radiation, and the accepted noninvasive gold standard for numerous noninvasive cardiac markers. Using a technique called T2-weighted imaging, CMR can be used to assess myocardial edema as a reliable marker for acute, potentially reversible myocardial injury. Contrast agents are not required as the myocardial free water content affects the magnetic properties of the tissue, thus providing inherent image contrast. In this review, we illustrate the utility of T2-weighted techniques in the assessment of myocardial edema in a range of clinical scenarios. The detection of myocardial edema is clinically relevant in many acute settings and may be further helpful to better understand the pathophysiology of many non-acute clinical diseases. Currently, T2-weighted CMR represents the only imaging modality that can accurately depict and quantify the presence of myocardial edema in a noninvasive fashion. Thus, T2-weighted imaging should be included in a comprehensive CMR imaging protocol, especially if an acute injury is suspected. PMID:22139527

  12. Management of ventricular septal rupture in acute myocardial infarction.

    PubMed Central

    Khan, M M; Patterson, G C; O'Kane, H O; Adgey, A A

    1980-01-01

    Four patients with rupture of the interventricular septum after myocardial infarction are described. This condition carries a grave prognosis. Surgical repair of the septum is almost always urgently required if the left-to-right shunt is large (QP/WS > 3). Results are better if surgery can be deferred for six weeks to allow the infarcted area to heal and the tissues to be come firmer. This delay may be achieved by using a combination of agents to reduce afterload and to exert a positive inotropic effect. The timing of surgical intervention was an important factor in the survival of three of the four patients. PMID:7437199

  13. Experimental myocardial infarction

    PubMed Central

    Hood, William B.; Bianco, Jesus A.; Kumar, Raj; Whiting, Richard B.

    1970-01-01

    Compliance of the infarcted left ventricle was studied in dogs 3-5 days after occlusion of the left anterior descending coronary artery. Compliance was assessed from postmortem pressure-volume curves and from pressure-length measurements (mercury-in-silastic segment length gauges) made both in vivo and postmortem. Postmortem pressure-volume curves showed reduced compliance compared to sham-operated animals. Postmortem pressure-length curves of infarcted and adjacent normal myocardium indicated that the diminished total compliance could be attributed to an increase in stiffness of the infarcted area. This was confirmed by in vivo end-diastolic pressure-length changes produced by transient aortic occlusion. The infarcted area was akinetic, showing neither contraction nor aneurysmal bulging. In addition, anesthetized dogs with infarcts, when compared with sham-operated animals, had similar left ventricular end-diastolic volumes (indicator dilution method), but higher left ventricular end-diastolic pressures. Taken with previous observations, which show that systolic aneurysmal bulging is uniformly present at the onset of ischemia, these results indicate that stiffening of the ischemic myocardium occurs during the first 5 days after infarction, and show that elevation of left ventricular filling pressure does not necessarily signify ventricular dilatation. The results also suggest a mechanism whereby ventricular performance may improve during recovery from acute myocardial infarction. Images PMID:4914678

  14. Myocardial perfusion imaging for detection of silent myocardial ischemia

    SciTech Connect

    Beller, G.A.

    1988-04-21

    Despite the widespread use of the exercise stress test in diagnosing asymptomatic myocardial ischemia, exercise radionuclide imaging remains useful for detecting silent ischemia in numerous patient populations, including those who are totally asymptomatic, those who have chronic stable angina, those who have recovered from an episode of unstable angina or an uncomplicated myocardial infarction, and those who have undergone angioplasty or received thrombolytic therapy. Studies show that thallium scintigraphy is more sensitive than exercise electrocardiography in detecting ischemia, i.e., in part, because perfusion defects occur more frequently than ST depression and before angina in the ischemic cascade. Thallium-201 scintigraphy can be performed to differentiate a true- from a false-positive exercise electrocardiographic test in patients with exercise-induced ST depression and no angina. The development of technetium-labeled isonitriles may improve the accuracy of myocardial perfusion imaging. 11 references.

  15. MYOCARDIAL AKT: THE OMNIPRESENT NEXUS

    PubMed Central

    Sussman, Mark A.; Völkers, Mirko; Fischer, Kimberlee; Bailey, Brandi; Cottage, Christopher T.; Din, Shabana; Gude, Natalie; Avitabile, Daniele; Alvarez, Roberto; Sundararaman, Balaji; Quijada, Pearl; Mason, Matt; Konstandin, Mathias H.; Malhowski, Amy; Cheng, Zhaokang; Khan, Mohsin; McGregor, Michael

    2013-01-01

    One of the greatest examples of integrated signal transduction is revealed by examination of effects mediated by AKT kinase in myocardial biology. Positioned at the intersection of multiple afferent and efferent signals, AKT exemplifies a molecular sensing node that coordinates dynamic responses of the cell in literally every aspect of biological responses. The balanced and nuanced nature of homeostatic signaling is particularly essential within the myocardial context, where regulation of survival, energy production, contractility, and response to pathological stress all flow through the nexus of AKT activation or repression. Equally important, the loss of regulated AKT activity is primarily the cause or consequence of pathological conditions leading to remodeling of the heart and eventual decompensation. This review presents an overview compendium of the complex world of myocardial AKT biology gleaned from more than a decade of research. Summarization of the widespread influence that AKT exerts upon myocardial responses leaves no doubt that the participation of AKT in molecular signaling will need to be reckoned with as a seemingly omnipresent regulator of myocardial molecular biological responses. PMID:21742795

  16. How reliable is myocardial imaging in the diagnosis of acute myocardial infarction

    SciTech Connect

    Willerson, J.T.

    1983-01-01

    Myocardial scintigraphic techniques available presently allow a sensitive and relatively specific diagnosis of acute myocardial infarction when they are used correctly, although every technique has definite limitations. Small myocardial infarcts (less than 3 gm.) may be missed, and there are temporal limitations in the usefulness of the scintigraphic techniques. The development of tomographic methodology that may be used with single-photon radionuclide emitters (including technetium and /sup 201/Tl will allow the detection of relatively small abnormalities in myocardial perfusion and regions of myocardial infarction and will help to provide a more objective interpretation of the myocardial scintigrams. The use of overlay techniques allowing simultaneous assessment of myocardial perfusion, infarct-avid imaging, and radionuclide ventriculograms will provide insight into the relevant aspects of the extent of myocardial damage, the relationship of damage to myocardial perfusion, and the functional impact of myocardial infarction on ventricular performance.

  17. Resonance Effects in Photoemission Time Delays.

    PubMed

    Sabbar, M; Heuser, S; Boge, R; Lucchini, M; Carette, T; Lindroth, E; Gallmann, L; Cirelli, C; Keller, U

    2015-09-25

    We present measurements of single-photon ionization time delays between the outermost valence electrons of argon and neon using a coincidence detection technique that allows for the simultaneous measurement of both species under identical conditions. The analysis of the measured traces reveals energy-dependent time delays of a few tens of attoseconds with high energy resolution. In contrast to photoelectrons ejected through tunneling, single-photon ionization can be well described in the framework of Wigner time delays. Accordingly, the overall trend of our data is reproduced by recent Wigner time delay calculations. However, besides the general trend we observe resonance features occurring at specific photon energies. These features have been qualitatively reproduced and identified by a calculation using the multiconfigurational Hartree-Fock method, including the influence of doubly excited states and ionization thresholds. PMID:26451550

  18. CGI delay compensation

    NASA Technical Reports Server (NTRS)

    Mcfarland, Richard E.

    1986-01-01

    Computer-generated graphics in real-time helicopter simulation produces objectionable scene-presentation time delays. In the flight simulation laboratory at Ames Research Center, it has been determined that these delays have an adverse influence on pilot performance during aggressive tasks such as nap-of-the-earth (NOE) maneuvers. Using contemporary equipment, computer-generated image (CGI) time delays are an unavoidable consequence of the operations required for scene generation. However, providing that magnitide distortions at higher frequencies are tolerable, delay compensation is possible over a restricted frequency range. This range, assumed to have an upper limit of perhaps 10 or 15 rad/sec, conforms approximately to the bandwidth associated with helicopter handling qualities research. A compensation algorithm is introduced here and evaluated in terms of tradeoffs in frequency responses. The algorithm has a discrete basis and accommodates both a large, constant transport delay interval and a periodic delay interval, as associated with asynchronous operations.

  19. Maturation of Lesions Induced by Myocardial Cavitation-Enabled Therapy.

    PubMed

    Lu, Xiaofang; Miller, Douglas L; Dou, Chunyan; Zhu, Yiying I; Fabiilli, Mario L; Owens, Gabe E; Kripfgans, Oliver D

    2016-07-01

    Myocardial contrast echocardiography at enhanced therapeutic parameters may be a novel means of tissue reduction therapy, as for hypertrophic cardiomyopathy. Dahl/SS rats were anesthetized and treated with high-amplitude pulsed ultrasound guided by 10-MHz ultrasound images. Contrast microbubbles were infused via the tail vein during intermittent pulse-burst exposure at 4 MPa. A sham group, a low-impact group (group A, 5 cycle pulses with Gaussian modulation and 1:4 trigger for 5 min) and a high-impact group (group B, 10 cycle pulses with 4-ms square modulation and 1:8 trigger for 10 min) were tested. The higher exposure used in group B yielded more substantial injury than the lower exposure in group A. Treated rats in both groups A and B had significant increases in wall thickness measured by echocardiography the next day, which returned to normal by the end of 6 wk. Six weeks after ultrasound exposure, heart tissue samples exhibited tissue fibrosis in Masson's trichrome stained histology. Maturation of lesions involved fibrosis replacement, preserving structural tissue integrity. This study indicates that myocardial injury noted previously progresses into permanent loss of myocardial tissue that may be sufficient for possible hypertrophic cardiomyopathy therapy. More research is needed to define the treatment parameters required for symptomatic relief for hypertrophic cardiomyopathy. PMID:27087693

  20. Pbx acts with Hand2 in early myocardial differentiation

    PubMed Central

    Maves, Lisa; Tyler, Ashlee; Moens, Cecilia B.; Tapscott, Stephen J.

    2009-01-01

    Transcription factors of the basic helix-loop-helix (bHLH) family are critical regulators of muscle cell differentiation. For example, Myod drives skeletal muscle differentiation, and Hand2 potentiates cardiac muscle differentiation. Understanding how these bHLH factors regulate distinct transcriptional targets in a temporally and spatially controlled manner is critical for understanding their activity in cellular differentiation. We previously showed that Pbx homeodomain proteins modulate the activity of Myod to promote the differentiation of fast-twitch skeletal muscle. Here, we test the hypothesis that Pbx proteins are also necessary for cardiac muscle differentiation through interacting with Hand2. We show that Pbx proteins are required for the activation of cardiac muscle differentiation in zebrafish embryos. Loss of Pbx activity leads to delay of myocardial differentiation and subsequent defective cardiac morphogenesis, similar to reduced Hand2 activity. Genetic interaction experiments support the hypothesis that Pbx proteins modulate the activity of Hand2 in myocardial differentiation. Furthermore, we show that Pbx proteins directly bind the promoter of the myocardial differentiation gene myl7 in vitro, supporting a direct role for Pbx proteins in promoting cardiac muscle differentiation. Our findings demonstrate new roles for Pbx proteins in vertebrate cardiac development and also provide new insight into connections between the transcriptional regulation of skeletal and cardiac muscle differentiation programs. PMID:19607825

  1. VARIABLE TIME DELAY MEANS

    DOEpatents

    Clemensen, R.E.

    1959-11-01

    An electrically variable time delay line is described which may be readily controlled simuitaneously with variable impedance matching means coupied thereto such that reflections are prevented. Broadly, the delay line includes a signal winding about a magnetic core whose permeability is electrically variable. Inasmuch as the inductance of the line varies directly with the permeability, the time delay and characteristic impedance of the line both vary as the square root of the permeability. Consequently, impedance matching means may be varied similariy and simultaneously w:th the electrically variable permeability to match the line impedance over the entire range of time delay whereby reflections are prevented.

  2. Myocardial infarction following bee sting.

    PubMed

    Puvanalingam, A; Karpagam, P; Sundar, C; Venkatesan, S; Ragunanthanan

    2014-08-01

    Bee stings are commonly encountered worldwide. Various manifestations after bee sting have been described. Local reactions are common. Unusually, manifestations like vomiting, diarrhoea, dyspnoea, generalised oedema, acute renal failure, hypotension and collapse may occur. Rarely vasculitis, serum sickness, neuritis and encephalitis have been described which generally develop days to weeks after a sting. Acute coronary syndromes after hymenoptera stings and other environmental exposures are referred to as the Kounis syndrome or allergic myocardial ischaemia and infarction. We report a 60 year old male who developed myocardial infarction after multiple bee stings over his body. PMID:25856951

  3. Functional significance of predischarge exercise thallium-201 findings following intravenous streptokinase therapy during acute myocardial infarction

    SciTech Connect

    Touchstone, D.A.; Beller, G.A.; Nygaard, T.W.; Watson, D.D.; Tedesco, C.; Kaul, S.

    1988-12-01

    The purpose of this study was to determine which predischarge exercise thallium-201 imaging pattern(s) best correlate with myocardial salvage following intravenous streptokinase therapy (IVSK). Myocardial salvage was defined as improvement in regional left ventricular function determined by two-dimensional echocardiography between the time of admission and time of discharge in 21 prospectively studied patients receiving IVSK within 4 hours of chest pain. All patients had coronary angiography 2 hours following IVSK. Whereas 16 of the 21 patients (76%) had patent infarct-related vessels, only seven (33%) showed significant improvement in regional function at hospital discharge. Eleven patients demonstrated persistent defects (PD), and five each showed delayed and reverse redistribution. Patients with both delayed and reverse redistribution demonstrated significant improvement in regional left ventricular function score, while those with PD did not (+3.9 +/- 3.3 versus -0.5 +/- 2.9, p = 0.004). All other clinical, exercise, electrocardiographic, scintigraphic, and angiographic variables were similar between all patients, with the exception of the interval between chest pain and the institution of IVSK, which was longer in patients with reverse compared to delayed redistribution (3.5 +/- 0.4 versus 2.2 +/- 0.4 hours, p = 0.001). It is concluded that both delayed and reverse redistribution seen on predischarge exercise thallium-201 imaging are associated with myocardial salvage, defined as serial improvement in regional systolic function. Despite a high infarct vessel patency rate in patients with acute myocardial infarction receiving IVSK within 4 hours of onset of symptoms, only one third demonstrated improvement in regional function that was associated with either delayed or reverse redistribution seen on predischarge exercise thallium-201 imaging.

  4. Acute myocardial infarction due to left anterior descending coronary artery dissection after blunt chest trauma.

    PubMed

    Oghlakian, Gerard; Maldjian, Pierre; Kaluski, Edo; Saric, Muhamed

    2010-03-01

    Cardiac complications of chest trauma range from arrhythmias to valvular avulsions to myocardial contusion, rupture, and rarely myocardial infarction. We describe a case of a young patient with blunt chest trauma after a motor vehicle accident in whom the diagnosis of myocardial infarction was established a week later because no electrocardiogram or cardiac biomarkers were obtained on presentation. Retrospective review of contrast-enhanced computed tomography (CT) of the chest done on presentation demonstrated a perfusion defect in the distribution of the left anterior descending artery (LAD). Subsequent coronary angiography demonstrated dissection in the proximal LAD. Our case illustrates the importance of electrocardiography and contrast-enhanced chest CT in initial evaluation of patients with blunt chest trauma and suspected injury to the coronary arteries. PMID:19214607

  5. In vivo determination of acute myocardial ischemia based on photoacoustic imaging with a focused transducer

    NASA Astrophysics Data System (ADS)

    Li, Zhifang; Li, Hui; Chen, Haiyu; Xie, Wengming

    2011-07-01

    The location and ischemia extent are two important parameters for evaluating the acute myocardial ischemia (AMI). A focused-transducer-based photoacoustic imaging method was employed to assess time-dependent AMI. Our preliminary results show that the photoacoustic signal could identify the myocardium. The intensity and area of photoacoustic images of myocardium could be used for characterizing the ischemia extent and scope of myocardial ischemia. The results also imply that the intensity and area of photoacoustic images are the rapid fall of an exponential model with an increase of delaying time after the left anterior descending coronary artery (LAD) occlusion. These experimental results were consistent with the clinical characteristics. The findings suggest that the photoacoustic imaging be a potential tool for the real-time assessment of acute myocardial ischemia during surgical operation.

  6. Protective metabolic effects of propranolol during total myocardial ischemia.

    PubMed

    Veronee, C D; Lewis, W R; Takla, M W; Hull-Ryde, E A; Lowe, J E

    1986-09-01

    Clinical trials have shown an increase in survival in patients treated with beta blockers after infarction. In addition, the majority of patients undergoing myocardial revascularization are also treated preoperatively with beta blockers. It is commonly thought that beta blockers exert their protective effect primarily by decreasing heart rate and subsequent myocardial work. The present study was designed to determine whether beta blockade has any primary protective metabolic effects on globally ischemic myocardium. Thirty-four anesthetized dogs underwent total myocardial ischemia at 37 degrees C. High-energy nucleotide and lactate levels in left ventricular tissue samples were determined at control and at 15 minute intervals as well as at the onset of ischemic contracture in 24 dogs. Seventeen dogs were treated with propranolol before ischemia. The time to ischemic contracture in control dogs was 63.3 +/- 1.4 minutes compared with 75.9 +/- 2.2 minutes in the propranolol-treated group (p less than 0.01). In addition to significantly delaying the onset of ischemic contracture, propranolol also decreased the rate of anaerobic glycolysis during ischemia. Ischemic contracture occurred in the control group with an average adenosine triphosphate level of 1.26 +/- 0.08 mumol compared to 0.91 +/- 0.08 mumol/gm wet weight for the beta blocked group (p less than 0.0025). These are the first data suggesting that the protective effects of beta blockade may be related to a beneficial effect on ischemic myocardial metabolism allowing myocardium to survive with lower levels of adenosine triphosphate. PMID:3018382

  7. Acute myocardial infarction

    PubMed Central

    Domes, Trustin; Szafran, Olga; Bilous, Cheryl; Olson, Odell; Spooner, G. Richard

    2006-01-01

    OBJECTIVE To assess the quality of care of acute myocardial infarction (AMI) in a rural health region. DESIGN Clinical audit employing multiple explicit criteria of care elements for emergency department and in-hospital AMI management. The audit was conducted using retrospective chart review. SETTING Twelve acute care health centres and hospitals in the East Central Health Region, a rural health region in Alberta, where medical and surgical services are provided almost entirely by family physicians. PARTICIPANTS Hospital inpatients with a confirmed discharge diagnosis of AMI (ICD-9-CM codes 410.xx) during the period April 1, 2001, to March 31, 2002, were included (177 confirmed cases). MAIN OUTCOME MEASURES Quality of AMI care was assessed using guidelines from the American College of Cardiology and the American Heart Association and the Canadian Cardiovascular Outcomes Research Team and Canadian Cardiovascular Society. Quality of care indicators at three stages of patient care were assessed: at initial recognition and AMI management in the emergency department, during in-hospital AMI management, and at preparation for discharge from hospital. RESULTS In the emergency department, the quality of care was high for most procedural and therapeutic audit elements, with the exception of rapid electrocardiography, urinalysis, and provision of nitroglycerin and morphine. Average door-to-needle time for thrombolysis was 102.5 minutes. The quality of in-hospital care was high for most elements, but low for nitroglycerin and angiotensin-converting enzyme (ACE) inhibitors, daily electrocardiography, and counseling regarding smoking cessation and diet. Few patients received counseling for lifestyle changes at hospital discharge. Male and younger patients were treated more aggressively than female and older patients. Sites that used care protocols achieved better results in initial AMI management than sites that did not. Stress testing was not readily available in the rural

  8. Myocardial contusion following nonfatal blunt chest trauma

    SciTech Connect

    Kumar, S.A.; Puri, V.K.; Mittal, V.K.; Cortez, J.

    1983-04-01

    Currently available diagnostic techniques for myocardial contusion following blunt chest trauma were evaluated. We investigated 30 patients prospectively over a period of 1 year for the presence of myocardial contusion. Among the 30 patients, eight were found to have myocardial contusion on the basis of abnormal electrocardiograms, elevated creatine phosphokinase MB fraction (CPK-MB), and positive myocardial scan. Myocardial scan was positive in seven of eight patients (87.5%). CPK-MB fraction was elevated in four of eight patients (50%). Definitive electrocardiographic changes were seen in only two of eight patients (25%). It appears that myocardial scan using technetium pyrophosphate and CPK-MB fraction determinations are the most reliable aids in diagnosis of myocardial contusion following blunt chest trauma.

  9. Digital time delay

    DOEpatents

    Martin, A.D.

    1986-05-09

    Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay provides a first output signal at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits latch the high resolution data to form a first synchronizing data set. A selected time interval has been preset to internal counters and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses count down the counters to generate an internal pulse delayed by an internal which is functionally related to the preset time interval. A second LCD corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD to generate a second set of synchronizing data which is complementary with the first set of synchronizing data for presentation to logic circuits. The logic circuits further delay the internal output signal with the internal pulses. The final delayed output signal thereafter enables the output pulse generator to produce the desired output pulse at the preset time delay interval following input of the trigger pulse.

  10. Spousal Adjustment to Myocardial Infarction.

    ERIC Educational Resources Information Center

    Ziglar, Elisa J.

    This paper reviews the literature on the stresses and coping strategies of spouses of patients with myocardial infarction (MI). It attempts to identify specific problem areas of adjustment for the spouse and to explore the effects of spousal adjustment on patient recovery. Chapter one provides an overview of the importance in examining the…

  11. [Sewer gas induced myocardial toxicity].

    PubMed

    Antonelli, Dante; Sabanchiev, Avi; Rosner, Ehud; Turgeman, Yoav

    2014-07-01

    We report the case of a 19 year-old worker who collapsed after acute exposure to sewer gas. He rapidly developed cardiorespiratory failure with electrocardiographic, echocardiographic and laboratory findings of myocardial involvement. The mainstay of the therapy was mainly supportive treatment with a successful outcome. PMID:25189024

  12. Thrombolysis for Acute Myocardial Infarction

    PubMed Central

    Webb, John; Thompson, Christopher

    1992-01-01

    Thrombolysis has an important role in the management of acute myocardial infarction. Early treatment can markedly reduce mortality and morbidity. This new standard of care requires knowledge of accepted indications and contraindications for thrombolysis as well as familiarity with available agents and regimens. ImagesFigure 3 PMID:21221398

  13. Effects of heart rate on myocardial thallium-201 uptake and clearance

    SciTech Connect

    Nordrehaug, J.E.; Danielsen, R.; Vik-Mo, H. )

    1989-12-01

    The effects of heart rate on the myocardial uptake and clearance of {sup 201}Tl were studied prospectively in seven healthy men, mean age 43 +/- 7 (s.d.) yr. Initial and delayed (3 hr) thallium images were obtained in three views after three bicycle exercise tests: to maximal, 80% and 60% of predicted maximal heart rate. The mean of three views initial myocardial {sup 201}Tl uptake was higher at maximal than at both 80% and 60% of predicted maximal heart rate, being 81% (p less than 0.01) and 60% (p less than 0.01) of maximal activity, respectively. The myocardial activity in the delayed images was identical. There was a linear relationship between heart rate and the initial myocardial activity, r = 0.86 (p less than 0.001). The mean (range) {sup 201}Tl clearance was 58% (51-65), 47% (34-56), and 34% (22-49) (all differences p less than 0.01), respectively. Concordance among the three individual views in estimating clearance was best for the highest exercise level. There was a linear relationship between heart rate and clearance, r = 0.80 (p less than 0.001). Clearance was altered by only 1.67 x 10%/heart bpm (0.024 hr/heart beat). Clearance in the liver, spleen and lungs increased at submaximal exercise levels. Thus, a linear relationship between heart rate and clearance is the result of changes in the initial exercise myocardial {sup 201}Tl activity. Submaximal exercise may reduce reproducibility of clearance estimation, and the change of myocardial clearance with heart rate seems less than previously suggested.

  14. A Simple Protocol for the Myocardial Differentiation of Human iPS Cells.

    PubMed

    Aikawa, Nobuo; Suzuki, Yui; Takaba, Katsumi

    2015-01-01

    We have developed a simple protocol for inducing the myocardial differentiation of human induced pluripotent stem (iPS) cells. Human iPS cell-derived embryonic bodies (EBs) were treated with a combination of activin-A, bone morphogenetic protein-4 and wnt-3a for one day in serum-free suspension culture, and were subsequently treated with noggin for three days. Thereafter, the EBs were subjected to adherent culture in media with 5% serum. All EBs were differentiated into spontaneously beating EBs, which were identified by the presence of striated muscles in transmission electron microscopy and the expression of the specific cardiomyocyte markers, NKX2-5 and TNNT2. The beating rate of the beating EBs was decreased by treatment with a rapidly activating delayed rectifier potassium current (Ikr) channel blocker, E-4031, an Ikr trafficking inhibitor, pentamidin, and a slowly activating delayed rectifier potassium current (Iks) channel blocker, chromanol 293B, and was increased by treatment with a beta-receptor agonist, isoproterenol. At a low concentration, verapamil, a calcium channel blocker, increased the beating rate of the beating EBs, while a high concentration decreased this rate. These findings suggest that the spontaneously beating EBs were myocardial cell clusters. This simple protocol for myocardial differentiation would be useful in providing a sufficient number of the beating myocardial cell clusters for studies requiring human myocardium. PMID:26133717

  15. Effects of dipyridamole-induced vasodilation on myocardial uptake and clearance kinetics of thallium-201

    SciTech Connect

    Beller, G.A.; Holzgrefe, H.H.; Watson, D.D.

    1983-12-01

    Myocardial thallium-201 (201Tl) uptake and clearance after intravenous administration of dipyridamole (150 micrograms/kg) were determined in 12 open-chest anesthetized dogs with a partial coronary artery stenosis. 201Tl (1.5 mCi) was injected intravenously and myocardial biopsy specimens were obtained 10 min, 60 min, and 2 hr after injection. Serial changes in 201Tl activity in the normal zone and in the zone of partial stenosis were correlated with microsphere-determined regional blood flow and distal coronary pressure. Another nine dogs with equivalent stenosis not given dipyridamole before 201Tl served as controls. Data indicate that dipyridamole-induced vasodilation in the presence of a partial stenosis results in diminished uptake and delayed clearance compared with increased uptake and more rapid clearance in normally perfused myocardium producing an initial 201Tl defect with delayed redistribution.

  16. Native Magnetic Resonance T1-Mapping Identifies Diffuse Myocardial Injury in Hypothyroidism

    PubMed Central

    Qu, Aijuan; Chen, Zhe; Jia, Yumei; Yang, Ning; Feng, Xiaomeng; Liu, Jia; Xu, Yuan; Yang, Xinchun; Wang, Guang

    2016-01-01

    Background and Aim Hypothyroidism (HT) is characterized by thyroid hormone deficiencies, which can lead to diffuse myocardial interstitium lesions in patients with HT. Myocardial longitudinal relaxation time (T1) mapping is a potential diagnostic tool for quantifying diffuse myocardial injury. This study aimed to assess the usefulness of T1 mapping in identifying myocardial involvement in HT, and determine the relationship between T1 values and myocardial function. Methods A cross-sectional study was conducted with 30 untreated HT patients alongside 23 age- and sex-matched healthy controls. All subjects underwent cardiac magnetic resonance (CMR) with non-contrast (native) T1 mapping using a modified Look-Locker inversion-recovery (MOLLI) sequence to assess the native T1 values of myocardium and cardiac function. Results Native myocardial T1 values were significantly increased in HT patients, especially those with pericardial effusion (p < 0.05), compared with healthy controls. In addition, significantly reduced peak filling rate (PFR) and prolonged peak filling time (PFT) were obtained (p < 0.05) in HT patients compared with controls. Furthermore, stroke volume (SV) and cardiac index (CI) were significantly lower in HT patients than controls (all p < 0.05). Interestingly, native T1 values were negatively correlated with free triiodothyronine (FT3), PFR, SV and CI (all p < 0.05). Conclusion Diffuse myocardial injuries are common in HT patients, and increased T1 values are correlated with FT3 and cardiac function impairment. These findings indicate that T1 mapping might be useful in evaluating myocardial injuries in HT patients. PMID:26964099

  17. Prompt Recognition of Left Ventricular Free-Wall Rupture Aided by the Use of Contrast Echocardiography.

    PubMed

    Okabe, Toshimasa; Julien, Howard M; Kaliyadan, Antony G; Siu, Henry; Marhefka, Gregary D

    2015-10-01

    In the modern period of reperfusion, left ventricular free-wall rupture occurs in less than 1% of myocardial infarctions. Typically, acute left ventricular free-wall rupture leads to sudden death from immediate cardiac tamponade. We present the case of a 59-year-old woman who sustained a posterior-wall myocardial infarction and subsequent cardiac arrest with pulseless electrical activity. A bedside transthoracic echocardiogram showed pericardial effusion with cardiac tamponade. Emergency pericardiocentesis yielded 500 mL of blood, and spontaneous circulation returned. Contrast-enhanced echocardiograms revealed inferolateral akinesis and a new, small myocardial slit with systolic extrusion of contrast medium, consistent with left ventricular free-wall rupture. During immediate open-heart surgery, a small hole in an area of necrotic tissue was discovered and repaired. This case highlights the usefulness of bedside contrast-enhanced echocardiography in confirming acute left ventricular free-wall rupture and enabling rapid surgical treatment. PMID:26504446

  18. Calpain inhibition preserves myocardial structure and function following myocardial infarction.

    PubMed

    Mani, Santhosh K; Balasubramanian, Sundaravadivel; Zavadzkas, Juozas A; Jeffords, Laura B; Rivers, William T; Zile, Michael R; Mukherjee, Rupak; Spinale, Francis G; Kuppuswamy, Dhandapani

    2009-11-01

    Cardiac pathology, such as myocardial infarction (MI), activates intracellular proteases that often trigger programmed cell death and contribute to maladaptive changes in myocardial structure and function. To test whether inhibition of calpain, a Ca(2+)-dependent cysteine protease, would prevent these changes, we used a mouse MI model. Calpeptin, an aldehydic inhibitor of calpain, was intravenously administered at 0.5 mg/kg body wt before MI induction and then at the same dose subcutaneously once per day. Both calpeptin-treated (n = 6) and untreated (n = 6) MI mice were used to study changes in myocardial structure and function after 4 days of MI, where end-diastolic volume (EDV) and left ventricular ejection fraction (EF) were measured by echocardiography. Calpain activation and programmed cell death were measured by immunohistochemistry, Western blotting, and TdT-mediated dUTP nick-end labeling (TUNEL). In MI mice, calpeptin treatment resulted in a significant improvement in EF [EF decreased from 67 + or - 2% pre-MI to 30 + or - 4% with MI only vs. 41 + or - 2% with MI + calpeptin] and attenuated the increase in EDV [EDV increased from 42 + or - 2 microl pre-MI to 73 + or - 4 microl with MI only vs. 55 + or - 4 microl with MI + calpeptin]. Furthermore, calpeptin treatment resulted in marked reduction in calpain- and caspase-3-associated changes and TUNEL staining. These studies indicate that calpain contributes to MI-induced alterations in myocardial structure and function and that it could be a potential therapeutic target in treating MI patients. PMID:19734364

  19. Delayed emergence after anesthesia.

    PubMed

    Tzabazis, Alexander; Miller, Christopher; Dobrow, Marc F; Zheng, Karl; Brock-Utne, John G

    2015-06-01

    In most instances, delayed emergence from anesthesia is attributed to residual anesthetic or analgesic medications. However, delayed emergence can be secondary to unusual causes and present diagnostic dilemmas. Data from clinical studies is scarce and most available published material is comprised of case reports. In this review, we summarize and discuss less common and difficult to diagnose reasons for delayed emergence and present cases from our own experience or reference published case reports/case series. The goal is to draw attention to less common reasons for delayed emergence, identify patient populations that are potentially at risk and to help anesthesiologists identifying a possible cause why their patient is slow to wake up. PMID:25912729

  20. Time delay spectrum conditioner

    DOEpatents

    Greiner, Norman R.

    1980-01-01

    A device for delaying specified frequencies of a multiple frequency laser beam. The device separates the multiple frequency beam into a series of spatially separated single frequency beams. The propagation distance of the single frequency beam is subsequently altered to provide the desired delay for each specific frequency. Focusing reflectors can be utilized to provide a simple but nonadjustable system or, flat reflectors with collimating and focusing optics can be utilized to provide an adjustable system.

  1. Quantification of regional myocardial wall motion by cardiovascular magnetic resonance

    PubMed Central

    Jiang, Kai

    2014-01-01

    Cardiovascular magnetic resonance (CMR) is a versatile tool that also allows comprehensive and accurate measurement of both global and regional myocardial contraction. Quantification of regional wall motion parameters, such as strain, strain rate, twist and torsion, has been shown to be more sensitive to early-stage functional alterations. Since the invention of CMR tagging by magnetization saturation in 1988, several CMR techniques have been developed to enable the measurement of regional myocardial wall motion, including myocardial tissue tagging, phase contrast mapping, displacement encoding with stimulated echoes (DENSE), and strain encoded (SENC) imaging. These techniques have been developed with their own advantages and limitations. In this review, two widely used and closely related CMR techniques, i.e., tissue tagging and DENSE, will be discussed from the perspective of pulse sequence development and image-processing techniques. The clinical and preclinical applications of tissue tagging and DENSE in assessing wall motion mechanics in both normal and diseased hearts, including coronary artery diseases, hypertrophic cardiomyopathy, aortic stenosis, and Duchenne muscular dystrophies, will be discussed. PMID:25392821

  2. Delayed voice communication

    NASA Astrophysics Data System (ADS)

    Love, Stanley G.; Reagan, Marcum L.

    2013-10-01

    We present results from simulated deep-space exploration missions that investigated voice communication with significant time delays. The simulations identified many challenges: confusion of sequence, blocked calls, wasted crew time, impaired ability to provide relevant information to the other party, losing track of which messages have reached the other party, weakened rapport between crew and ground, slow response to rapidly changing situations, and reduced situational awareness. These challenges were met in part with additional training; greater attention and foresight; longer, less frequent transmissions; meticulous recordkeeping and timekeeping; and specific alerting and acknowledging calls. Several simulations used both delayed voice and text messaging. Text messaging provided a valuable record of transmissions and allowed messages to be targeted to subsets of the flight and ground crew, but it was a poor choice for high-workload operators such as vehicle drivers and spacewalkers. Even with the foregoing countermeasures, delayed voice communication is difficult. Additional aids such as automatic delay timers and voice-to-text transcription would help. Tests comparing delays of 50 and 300 s unexpectedly revealed that communicating with the shorter delay was just as challenging as with the longer one.

  3. Imaging and Modeling of Myocardial Metabolism

    PubMed Central

    Jamshidi, Neema; Karimi, Afshin; Birgersdotter-Green, Ulrika; Hoh, Carl

    2010-01-01

    Current imaging methods have focused on evaluation of myocardial anatomy and function. However, since myocardial metabolism and function are interrelated, metabolic myocardial imaging techniques, such as positron emission tomography, single photon emission tomography, and magnetic resonance spectroscopy present novel opportunities for probing myocardial pathology and developing new therapeutic approaches. Potential clinical applications of metabolic imaging include hypertensive and ischemic heart disease, heart failure, cardiac transplantation, as well as cardiomyopathies. Furthermore, response to therapeutic intervention can be monitored using metabolic imaging. Analysis of metabolic data in the past has been limited, focusing primarily on isolated metabolites. Models of myocardial metabolism, however, such as the oxygen transport and cellular energetics model and constraint-based metabolic network modeling, offer opportunities for evaluation interactions between greater numbers of metabolites in the heart. In this review, the roles of metabolic myocardial imaging and analysis of metabolic data using modeling methods for expanding our understanding of cardiac pathology are discussed. PMID:20559785

  4. Radionuclide Tracers for Myocardial Perfusion Imaging and Blood Flow Quantification.

    PubMed

    deKemp, Robert A; Renaud, Jennifer M; Klein, Ran; Beanlands, Rob S B

    2016-02-01

    Myocardial perfusion imaging is performed most commonly using Tc-99m-sestamibi or tetrofosmin SPECT as well as Rb-82-rubidium or N-13-ammonia PET. Diseased-to-normal tissue contrast is determined by the tracer retention fraction, which decreases nonlinearly with flow. Reduced tissue perfusion results in reduced tracer retention, but the severity of perfusion defects is typically underestimated by 20% to 40%. Compared to SPECT, retention of the PET tracers is more linearly related to flow, and therefore, the perfusion defects are measured more accurately using N-13-ammonia or Rb-82. PMID:26590778

  5. Perioperative myocardial ischemia reperfusion injury.

    PubMed

    Shernan, Stanton K

    2003-09-01

    Myocardial I-R injury contributes to adverse cardiovascular outcomes after cardiac surgery. The pathogenesis of I-R injury is complex and involves the activation, coordination, and amplification of several systemic and local proinflammatory pathways (Fig. 4). Treatment and prevention of perioperative morbidity associated with myocardial I-R will ultimately require a multifocal approach. Combining preoperative risk stratification (co-morbidity and surgical complexity), minimizing initiating factors predisposing to SIRS, limiting ischemia duration, and administering appropriate immunotherapy directed toward systemic and local proinflammatory mediators of I-R injury, should all be considered. In addition, the role of the genetic-environmental interactions in the pathogenesis of cardiovascular disease is also being examined. Thus, in the near future, preoperative screening for polymorphisms of certain inflammatory and coagulation genes should inevitably help reduce morbidity by permitting the identification of high-risk cardiac surgical patients and introducing the opportunity for gene therapy or pharmacogenetic intervention [42,64]. PMID:14562561

  6. Myocardialization of the cardiac outflow tract

    NASA Technical Reports Server (NTRS)

    van den Hoff, M. J.; Moorman, A. F.; Ruijter, J. M.; Lamers, W. H.; Bennington, R. W.; Markwald, R. R.; Wessels, A.

    1999-01-01

    During development, the single-circuited cardiac tube transforms into a double-circuited four-chambered heart by a complex process of remodeling, differential growth, and septation. In this process the endocardial cushion tissues of the atrioventricular junction and outflow tract (OFT) play a crucial role as they contribute to the mesenchymal components of the developing septa and valves in the developing heart. After fusion, the endocardial ridges in the proximal portion of the OFT initially form a mesenchymal outlet septum. In the adult heart, however, this outlet septum is basically a muscular structure. Hence, the mesenchyme of the proximal outlet septum has to be replaced by cardiomyocytes. We have dubbed this process "myocardialization." Our immunohistochemical analysis of staged chicken hearts demonstrates that myocardialization takes place by ingrowth of existing myocardium into the mesenchymal outlet septum. Compared to other events in cardiac septation, it is a relatively late process, being initialized around stage H/H28 and being basically completed around stage H/H38. To unravel the molecular mechanisms that are responsible for the induction and regulation of myocardialization, an in vitro culture system in which myocardialization could be mimicked and manipulated was developed. Using this in vitro myocardialization assay it was observed that under the standard culture conditions (i) whole OFT explants from stage H/H20 and younger did not spontaneously myocardialize the collagen matrix, (ii) explants from stage H/H21 and older spontaneously formed extensive myocardial networks, (iii) the myocardium of the OFT could be induced to myocardialize and was therefore "myocardialization-competent" at all stages tested (H/H16-30), (iv) myocardialization was induced by factors produced by, most likely, the nonmyocardial component of the outflow tract, (v) at none of the embryonic stages analyzed was ventricular myocardium myocardialization-competent, and finally

  7. Acute care of myocardial infarction.

    PubMed Central

    Gutman, M. B.; Lee, T. F.; Gin, K.; Ho, K.

    1996-01-01

    Patients with acute myocardial infarct (AMI) need rapid diagnosis and prompt initiation of thrombolytic therapy. Patients with suspected cardiac ischemia must receive a coordinated team response by the emergency room staff including rapid electrocardiographic analysis and a quick but thorough history and physical examination to diagnose AMI. Thrombolysis and adjunct therapies should be administered promptly when indicated. The choice of thrombolytics is predicated by the location of the infarct. PMID:8754702

  8. Sensitivity to Auditory Velocity Contrast

    PubMed Central

    Locke, Shannon M.; Leung, Johahn; Carlile, Simon

    2016-01-01

    A natural auditory scene often contains sound moving at varying velocities. Using a velocity contrast paradigm, we compared sensitivity to velocity changes between continuous and discontinuous trajectories. Subjects compared the velocities of two stimulus intervals that moved along a single trajectory, with and without a 1 second inter stimulus interval (ISI). We found thresholds were threefold larger for velocity increases in the instantaneous velocity change condition, as compared to instantaneous velocity decreases or thresholds for the delayed velocity transition condition. This result cannot be explained by the current static “snapshot” model of auditory motion perception and suggest a continuous process where the percept of velocity is influenced by previous history of stimulation. PMID:27291488

  9. Sensitivity to Auditory Velocity Contrast.

    PubMed

    Locke, Shannon M; Leung, Johahn; Carlile, Simon

    2016-01-01

    A natural auditory scene often contains sound moving at varying velocities. Using a velocity contrast paradigm, we compared sensitivity to velocity changes between continuous and discontinuous trajectories. Subjects compared the velocities of two stimulus intervals that moved along a single trajectory, with and without a 1 second inter stimulus interval (ISI). We found thresholds were threefold larger for velocity increases in the instantaneous velocity change condition, as compared to instantaneous velocity decreases or thresholds for the delayed velocity transition condition. This result cannot be explained by the current static "snapshot" model of auditory motion perception and suggest a continuous process where the percept of velocity is influenced by previous history of stimulation. PMID:27291488

  10. Myocardial Infarction in the Elderly

    PubMed Central

    Carro, Amelia; Kaski, Juan Carlos

    2011-01-01

    Advances in pharmacological treatment and effective early myocardial revascularization have –in recent years- led to improved clinical outcomes in patients with acute myocardial infarction (AMI). However, it has been suggested that compared to younger subjects, elderly AMI patients are less likely to receive evidence-based treatment, including myocardial revascularization therapy. Several reasons have been postulated to explain this trend, including uncertainty regarding the true benefits of the interventions commonly used in this setting as well as increased risk mainly associated with comorbidities. The diagnosis, management, and post-hospitalization care of elderly patients presenting with an acute coronary syndrome pose many difficulties at present. A complex interplay of variables such as comorbidities, functional and socioeconomic status, side effects associated with multiple drug administration, and individual biologic variability, all contribute to creating a complex clinical scenario. In this complex setting, clinicians are often required to extrapolate evidence-based results obtained in cardiovascular trials from which older patients are often, implicitly or explicitly, excluded. This article reviews current recommendations regarding management of AMI in the elderly. PMID:22396870

  11. [Vectorcardiographic diagnosis of the myocardial inactivatable zone].

    PubMed

    de Micheli, A; Medrano, G A

    1989-01-01

    Clinical importance of the vectorcardiographic exploration (distant and spatial) of the myocardial electrical phenomenon is emphasized. This technique constitutes a useful integration of electrocardiographic exploration (near and analytical). The more characteristic morphological and chronological changes due to an inactivatable area are discussed in the light of ventricular myocardial depolarization. Some typical vectorcardiographic features corresponding to the presence of a myocardial inactivatable zone are presented. The utility of the complementary elements which vectorcardiography can bring to electrocardiography is emphasized. Both of these procedures integrate a rational exploration of electrical activity of the myocardium, the solid base of prognostic and therapeutic decisions in cases of myocardial infarction. PMID:2669657

  12. Myocardial ischaemia during tracheal intubation and extubation.

    PubMed

    Edwards, N D; Alford, A M; Dobson, P M; Peacock, J E; Reilly, C S

    1994-10-01

    The incidence of myocardial ischaemia during tracheal intubation and extubation was compared using ambulatory ECG monitoring in 60 patients undergoing a variety of different surgical operations. Seven patients had myocardial ischaemia after tracheal intubation and seven patients during tracheal extubation. The patients who developed myocardial ischaemia during tracheal extubation had significantly greater rate-pressure products immediately before tracheal extubation (P < 0.05) and 1 min after tracheal extubation (P < 0.01) compared with those patients who did not develop myocardial ischaemia during extubation. PMID:7999498

  13. Thrombus burden and myocardial damage during primary percutaneous coronary intervention.

    PubMed

    Napodano, Massimo; Dariol, Gilberto; Al Mamary, Ahmed H; Marra, Martina Perazzolo; Tarantini, Giuseppe; D'Amico, Gianpiero; Frigo, Anna Chiara; Buja, Paolo; Razzolini, Renato; Iliceto, Sabino

    2014-05-01

    Large thrombus burden (LTB) lesions in the context of primary percutaneous coronary intervention (p-PCI) have been related to unsuccessful angiographic reperfusion and unfavorable clinical outcomes. However, the hazard of LTB treatment on myocardial damage has not been evaluated. We investigated the impact of LTB on myocardial damage using contrast-enhanced cardiac magnetic resonance (CE-CMR) in the setting of p-PCI. In 327 patients, who underwent p-PCI without thrombus aspiration within 12 hours from symptom onset, we prospectively assessed the impact of LTB on infarct size and microvascular damage using CE-CMR. LTB was defined by the presence of Thrombolysis In Myocardial Infarction thrombus score ≥3 in patent infarct-related artery (IRA); or by "cut-off" occlusion pattern and/or large reference vessel diameter (≥3.5 mm) in occluded IRA. One hundred ninety-seven patients (60.2%) showed LTB and 130 (39.8%) did not. Distal embolization occurred in 18.8% patients with versus 6.9% without LTB (p = 0.003). At CE-CMR, patients with LTB had larger infarct size index (27.5 ± 11.1 vs 22.1 ± 17.5, p = 0.009) and more often transmural necrosis (70.5% vs 55.4%, p = 0.008) compared with patients without LTB. Excluding patients with distal embolization, patients with LTB still had larger necrosis. At multivariate analysis, occluded (IRA) at baseline, anterior infarction, and presence of LTB predicted transmural necrosis. In conclusion, LTB in the setting of p-PCI is related to larger myocardial damage as detected by CE-CMR, regardless of angiographic detectable distal embolization. PMID:24630783

  14. Assessment of myocardial fibrosis with T1 mapping MRI.

    PubMed

    Everett, R J; Stirrat, C G; Semple, S I R; Newby, D E; Dweck, M R; Mirsadraee, S

    2016-08-01

    Myocardial fibrosis can arise from a range of pathological processes and its presence correlates with adverse clinical outcomes. Cardiac magnetic resonance (CMR) can provide a non-invasive assessment of cardiac structure, function, and tissue characteristics, which includes late gadolinium enhancement (LGE) techniques to identify focal irreversible replacement fibrosis with a high degree of accuracy and reproducibility. Importantly the presence of LGE is consistently associated with adverse outcomes in a range of common cardiac conditions; however, LGE techniques are qualitative and unable to detect diffuse myocardial fibrosis, which is an earlier form of fibrosis preceding replacement fibrosis that may be reversible. Novel T1 mapping techniques allow quantitative CMR assessment of diffuse myocardial fibrosis with the two most common measures being native T1 and extracellular volume (ECV) fraction. Native T1 differentiates normal from infarcted myocardium, is abnormal in hypertrophic cardiomyopathy, and may be particularly useful in the diagnosis of Anderson-Fabry disease and amyloidosis. ECV is a surrogate measure of the extracellular space and is equivalent to the myocardial volume of distribution of the gadolinium-based contrast medium. It is reproducible and correlates well with fibrosis on histology. ECV is abnormal in patients with cardiac failure and aortic stenosis, and is associated with functional impairment in these groups. T1 mapping techniques promise to allow earlier detection of disease, monitor disease progression, and inform prognosis; however, limitations remain. In particular, reference ranges are lacking for T1 mapping values as these are influenced by specific CMR techniques and magnetic field strength. In addition, there is significant overlap between T1 mapping values in healthy controls and most disease states, particularly using native T1, limiting the clinical application of these techniques at present. PMID:27005015

  15. Angina and Mental Stress-Induced Myocardial Ischemia

    PubMed Central

    Pimple, Pratik; Shah, Amit J.; Rooks, Cherie; Bremner, J. Douglas; Nye, Jonathon; Ibeanu, Ijeoma; Raggi, Paolo; Vaccarino, Viola

    2015-01-01

    Objective Mental stress-induced myocardial ischemia is a common phenomenon in patients with coronary artery disease (CAD) and an emerging prognostic factor. Mental stress ischemia is correlated with ambulatory ischemia. However, whether it is related to angina symptoms during daily life has not been examined. Methods We assessed angina-frequency (past month) in 98 post-myocardial infarction (MI) subjects (age 18-60 years) using the Seattle Angina Questionnaire. Patients underwent [99mTc]sestamibi SPECT perfusion imaging at rest, after mental stress, and after exercise/pharmacological stress. Summed scores of perfusion abnormalities were obtained by observer-independent software. A summed-difference score (SDS), the difference between stress and rest scores, was used to quantify myocardial ischemia under both stress conditions. Results The mean age was 50 years, 50% were female and 60% were non-white. After adjustment for age, sex, smoking, CAD-severity, depressive, anger and anxiety symptoms, each 1-point increase in mental-stress SDS was associated with 1.73-unit increase in the angina-frequency score (95% CI: 0.09-3.37) and 17% higher odds of being in a higher angina-frequency category (OR: 1.17, 95% CI: 1.00-1.38). Depressive symptoms were associated with 12% higher odds of being in a higher angina-frequency category (OR: 1.12, 95% CI: 1.03-1.21). In contrast, exercise/pharmacological stress-induced SDS was not associated with angina-frequency. Conclusion Among young and middle-aged post-MI patients, myocardial ischemia induced by mental stress in the lab, but not by exercise/pharmacological stress, is associated with higher frequency of retrospectively reported angina during the day. Psychosocial stressors related to mental stress ischemia may be important contributory factor to daily angina. PMID:25727240

  16. [Contrast sensitivity in glaucoma].

    PubMed

    Bartos, D

    1989-05-01

    Author reports on results of the contrast sensitivity examinations using the Cambridge low-contrast lattice test supplied by Clement Clarke International LTD, in patients with open-angle glaucoma and ocular hypertension. In glaucoma patients there was observed statistically significant decrease of the contrast sensitivity. In patients with ocular hypertension decrease of the contrast sensitivity was in patients affected by corresponding changes of the visual field and of the optical disc. The main advantages of the Cambridge low-contrast lattice test were simplicity, rapidity and precision of its performance. PMID:2743444

  17. Electrocardiograms corresponding to the development of myocardial infarction in anesthetized WHHLMI rabbits (Oryctolagus cuniculus), an animal model for familial hypercholesterolemia.

    PubMed

    Kobayashi, Tsutomu; Ito, Takashi; Yamada, Satoshi; Kuniyoshi, Nobue; Shiomi, Masashi

    2012-10-01

    The aim of this study was to determine whether features indicative of myocardial ischemia occur in the electrocardiograms (ECG) in myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits, an animal model for human familial hypercholesterolemia. ECG were recorded in 110 anesthetized WHHLMI rabbits (age, 10 to 39 mo) by using unipolar and bipolar limb leads with or without chest leads. We noted the following electrocardiographic changes: T wave inversion (37.4%), ST segment depression (31.8%), deep Q wave (16.3%), reduced R wave amplitude (7.3%), ST segment elevation (2.7%), and high T wave (1.8%). These ECG changes resembled those in human patients with coronary heart disease. Histopathologic examination revealed that the left ventricular wall showed acute myocardial lesions, including loss of cross-striations, vacuolar degeneration, coagulation necrosis of cardiac myocytes, and edema between myofibrils, in addition to chronic myocardial lesions such as myocardial fibrosis. The coronary arteries that caused these ECG changes were severely stenosed due to atherosclerotic lesions. Ischemic ECG changes corresponded to the locations of the myocardial lesions. Normal ECG waveforms were similar between WHHLMI rabbits and humans, in contrast to the large differences between rabbits and mice or rats. In conclusion, ischemic ECG changes in WHHLMI rabbits reflect the location of myocardial lesions, making this model useful for studying coronary heart disease. PMID:23114045

  18. Myocardial perfusion scintigraphy: the evidence.

    PubMed

    Underwood, S R; Anagnostopoulos, C; Cerqueira, M; Ell, P J; Flint, E J; Harbinson, M; Kelion, A D; Al-Mohammad, A; Prvulovich, E M; Shaw, L J; Tweddel, A C

    2004-02-01

    This review summarises the evidence for the role of myocardial perfusion scintigraphy (MPS) in patients with known or suspected coronary artery disease. It is the product of a consensus conference organised by the British Cardiac Society, the British Nuclear Cardiology Society and the British Nuclear Medicine Society and is endorsed by the Royal College of Physicians of London and the Royal College of Radiologists. It was used to inform the UK National Institute of Clinical Excellence in their appraisal of MPS in patients with chest pain and myocardial infarction. MPS is a well-established, non-invasive imaging technique with a large body of evidence to support its effectiveness in the diagnosis and management of angina and myocardial infarction. It is more accurate than the exercise ECG in detecting myocardial ischaemia and it is the single most powerful technique for predicting future coronary events. The high diagnostic accuracy of MPS allows reliable risk stratification and guides the selection of patients for further interventions, such as revascularisation. This in turn allows more appropriate utilisation of resources, with the potential for both improved clinical outcomes and greater cost-effectiveness. Evidence from modelling and observational studies supports the enhanced cost-effectiveness associated with MPS use. In patients presenting with stable or acute chest pain, strategies of investigation involving MPS are more cost-effective than those not using the technique. MPS also has particular advantages over alternative techniques in the management of a number of patient subgroups, including women, the elderly and those with diabetes, and its use will have a favourable impact on cost-effectiveness in these groups. MPS is already an integral part of many clinical guidelines for the investigation and management of angina and myocardial infarction. However, the technique is underutilised in the UK, as judged by the inappropriately long waiting times and by

  19. [Myocardial infarction and thromboembolism during pregnancy].

    PubMed

    Härtel, Dirk; Sorges, Eckhard; Carlsson, Jörg; Römer, Volker; Tebbe, Ulrich

    2003-05-01

    Acute myocardial infarction is a very rare event during pregnancy and bears the problem of misdiagnosis. However, about 150 cases have been published worldwide with a preponderance of anterior wall infarcts. With more women delaying childbearing until an older age and increasing prevalence of smoking in young women, it can be expected that all forms of coronary artery disease--including acute myocardial infarction--will be seen more often in the future. Among the causes of coronary artery occlusion in pregnancy are (1) rupture of very small coronary artery plaques triggered by different events, e.g., hypertension; (2) plain coronary artery disease; (3) dissection of coronary arteries; (4) coronary artery spasms with/without arterial thrombosis. Prompt diagnosis and immediate therapy are necessary to lower the high mortality of mother and fetus. The gold standard in the therapy of acute myocardial infarction during pregnancy is immediate coronary angiography and percutaneous transluminal coronary angioplasty (PTCA) with or without stent implantation. Application of thrombolytics (recombinant tissue plasminogen activator [rt-PA], r-PA, streptokinase [SK], urokinase [UK]) has been reported in single patients but should be limited to cases where acute PTCA is not available and where the infarct occurs before the 14th week of pregnancy because of possible embryopathy. If the patient is in the last 10 weeks of pregnancy, anticipation of delivery should be part of the medical planning. Consultation with an obstetrician must be obtained as soon as the patient enters the hospital. Besides bleeding complications, venous thrombosis with pulmonary embolism is among the most common causes of death during pregnancy. Pregnancy-related changes in physiology - increase in the resistance to flow from the lower extremities to the heart - and congenital coagulation abnormalities are most important to be recognized. This leads to the fact that superficial and deep venous thromboses

  20. Effect of color coding and subtraction on the accuracy of contrast echocardiography

    NASA Technical Reports Server (NTRS)

    Pasquet, A.; Greenberg, N.; Brunken, R.; Thomas, J. D.; Marwick, T. H.

    1999-01-01

    BACKGROUND: Contrast echocardiography may be used to assess myocardial perfusion. However, gray scale assessment of myocardial contrast echocardiography (MCE) is difficult because of variations in regional backscatter intensity, difficulties in distinguishing varying shades of gray, and artifacts or attenuation. We sought to determine whether the assessment of rest myocardial perfusion by MCE could be improved with subtraction and color coding. METHODS AND RESULTS: MCE was performed in 31 patients with previous myocardial infarction with a 2nd generation agent (NC100100, Nycomed AS), using harmonic triggered or continuous imaging and gain settings were kept constant throughout the study. Digitized images were post processed by subtraction of baseline from contrast data and colorized to reflect the intensity of myocardial contrast. Gray scale MCE alone, MCE images combined with baseline and subtracted colorized images were scored independently using a 16 segment model. The presence and severity of myocardial contrast abnormalities were compared with perfusion defined by rest MIBI-SPECT. Segments that were not visualized by continuous (17%) or triggered imaging (14%) after color processing were excluded from further analysis. The specificity of gray scale MCE alone (56%) or MCE combined with baseline 2D (47%) was significantly enhanced by subtraction and color coding (76%, p<0.001) of triggered images. The accuracy of the gray scale approaches (respectively 52% and 47%) was increased to 70% (p<0.001). Similarly, for continuous images, the specificity of gray scale MCE with and without baseline comparison was 23% and 42% respectively, compared with 60% after post processing (p<0.001). The accuracy of colorized images (59%) was also significantly greater than gray scale MCE (43% and 29%, p<0.001). The sensitivity of MCE for both acquisitions was not altered by subtraction. CONCLUSION: Post-processing with subtraction and color coding significantly improves the accuracy

  1. Downhole delay assembly for blasting with series delay

    DOEpatents

    Ricketts, Thomas E.

    1982-01-01

    A downhole delay assembly is provided which can be placed into a blasthole for initiation of explosive in the blasthole. The downhole delay assembly includes at least two detonating time delay devices in series in order to effect a time delay of longer than about 200 milliseconds in a round of explosions. The downhole delay assembly provides a protective housing to prevent detonation of explosive in the blasthole in response to the detonation of the first detonating time delay device. There is further provided a connection between the first and second time delay devices. The connection is responsive to the detonation of the first detonating time delay device and initiates the second detonating time delay device. A plurality of such downhole delay assemblies are placed downhole in unfragmented formation and are initiated simultaneously for providing a round of explosive expansions. The explosive expansions can be used to form an in situ oil shale retort containing a fragmented permeable mass of formation particles.

  2. The Vernier delay unit

    SciTech Connect

    Pierce, W.B.

    1985-02-01

    One of the most critical timing specifications for the SLC machine occurs at the injector and ejector magnets for the Damping Ring. It has been determined that the trigger pulses to the magnets must be controlled to 0.1 ns. The primary source for all trigger pulses for the SLC machine is the Programmable Delay Unit (PDU). The PDU generates a 67.2 ns wide pulse with delay increments of 8.7 ns. The gap between the required accuracy and that available from the PDU requires the design of a new module that is called the Vernier Delay Unit (VDU). This module accepts the 67.2 ns pulse from the PDU and is capable of increasing the delay in steps of 0.1 ns from 0 to 10.7 ns plus the minimum 9 ns delay. The module has two totally independent channels. The pulse input to the module is software selectable from either the auxiliary backplane or a front panel Lemo connector. The auxiliary backplane pulses are to be the 67 ns differential ECL pulses from the PDU. The front panel input is to be a NIM level (-0.7 V 50 termination).

  3. Hypertension and acute myocardial infarction: an overview.

    PubMed

    Pedrinelli, Roberto; Ballo, Piercarlo; Fiorentini, Cesare; Denti, Silvia; Galderisi, Maurizio; Ganau, Antonello; Germanò, Giuseppe; Innelli, Pasquale; Paini, Anna; Perlini, Stefano; Salvetti, Massimo; Zacà, Valerio

    2012-03-01

    History of hypertension is a frequent finding in patients with acute myocardial infarction (AMI) and its recurring association with female sex, diabetes, older age, less frequent smoking and more frequent vascular comorbidities composes a risk profile quite distinctive from the normotensive ischemic counterpart.Antecedent hypertension associates with higher rates of death and morbid events both during the early and long-term course of AMI, particularly if complicated by left ventricular dysfunction and/or congestive heart failure. Renin-angiotensin-aldosterone system blockade, through either angiotensin-converting enzyme inhibition, angiotensin II receptor blockade or aldosterone antagonism, exerts particular benefits in that high-risk hypertensive subgroup.In contrast to the negative implications carried by antecedent hypertension, higher systolic pressure at the onset of chest pain associates with lower mortality within 1 year from coronary occlusion, whereas increased blood pressure recorded after hemodynamic stabilization from the acute ischemic event bears inconsistent relationships with recurring coronary events in the long-term follow-up.Whether antihypertensive treatment in post-AMI hypertensive patients prevents ischemic relapses is uncertain. As a matter of fact, excessive diastolic pressure drops may jeopardize coronary perfusion and predispose to new acute coronary events, although the precise cause-effect mechanisms underlying this phenomenon need further evaluation. PMID:22317927

  4. Motion and deformation tracking for short-axis echo-planar myocardial perfusion imaging.

    PubMed

    Yang, G Z; Burger, P; Panting, J; Gatehouse, P D; Rueckert, D; Pennell, D J; Firmin, D N

    1998-09-01

    The assessment of regional myocardial perfusion during the first-pass of a contrast agent bolus requires tracking of the signal time course for each myocardial segment so that a detailed perfusion map can be derived. To obtain such a map in practice, however, is not trivial because deformation of the shape of the myocardium and respiratory-induced motion render a major difficulty in this process. This study describes an automated approach for motion and deformation tracking of functional myocardial perfusion images. The effectiveness of the described method has been evaluated using a numerical phantom and results are compared with those from existing techniques which use deformable models. Preliminary results from applying our approach to 20 patients are discussed and compared with those from SPECT studies. PMID:9873904

  5. The Efficacy of Medical Stabilization Prior to Myocardial Revascularization in Early Refractory Postinfarction Angina

    PubMed Central

    Roberts, Arthur J.; Sanders, John H.; Moran, John H.; Spies, Stewart M.; Lesch, Michael L.; Michaelis, Lawrence L.

    1983-01-01

    operation. There was, however, no increase in EF in this subgroup of patients. On the basis of this study, the authors tentatively recommend a concerted effort at preoperative medical stabilization prior to CABG surgery in patients with persistent refractory myocardial ischemia soon after acute myocardial necrosis. A prospective, randomized study comparing urgent and delayed surgery, as well as nonsurgical treatment, will be necessary to define more precisely optimal management of this subgroup of cardiac patients. PMID:6401205

  6. Myocardial contusion in patients with blunt chest trauma as evaluated by thallium 201 myocardial scintigraphy

    SciTech Connect

    Bodin, L.; Rouby, J.J.; Viars, P.

    1988-07-01

    Fifty five patients suffering from blunt chest trauma were studied to assess the diagnosis of myocardial contusion using thallium 201 myocardial scintigraphy. Thirty-eight patients had consistent scintigraphic defects and were considered to have a myocardial contusion. All patients with scintigraphic defects had paroxysmal arrhythmias and/or ECG abnormalities. Of 38 patients, 32 had localized ST-T segment abnormalities; 29, ST-T segment abnormalities suggesting involvement of the same cardiac area as scintigraphic defects; 21, echocardiographic abnormalities. Sixteen patients had segmental hypokinesia involving the same cardiac area as the scintigraphic defects. Fifteen patients had clinical signs suggestive of myocardial contusion and scintigraphic defects. Almost 70 percent of patients with blunt chest trauma had scintigraphic defects related to areas of myocardial contusion. When thallium 201 myocardial scintigraphy directly showed myocardial lesion, two-dimensional echocardiography and standard ECG detected related functional consequences of cardiac trauma.

  7. Characterization of macrolesions induced by myocardial cavitation-enabled therapy.

    PubMed

    Zhu, Yiying I; Miller, Douglas L; Dou, Chunyan; Kripfgans, Oliver D

    2015-02-01

    Intermittent high intensity ultrasound pulses with circulating contrast agent microbubbles can induce scattered cavitation caused myocardial microlesions of potential value for tissue reduction therapy. Here, computer-aided histological evaluation of the effective treated volume was implemented to optimize ultrasound pulse parameters, exposure duration, and contrast agent dose. Rats were treated with 1.5 MHz focused ultrasound bursts and Evans blue staining indicates lethal cardiomyocytic injury. Each heart was sectioned to provide samples covering the entire exposed myocardial volume. Both brightfield and fluorescence images were taken for up to 40 tissue sections. Tissue identification and microlesion detection were first done based on 2-D images to form microlesion masks containing the outline of the heart and the stained cell regions. Image registration was then performed on the microlesion masks to reconstruct a volume-based model according to the morphology of the heart. The therapeutic beam path was estimated from the 3-D stacked microlesions, and finally the total microlesion volume, here termed macrolesion, was characterized along the therapeutic beam axis. Radially symmetric fractional macrolesions were characterized via stepping disks of variable radius determined by the local distribution of microlesions. Treated groups showed significant macrolesions of a median volume of 87.3 μL, 2.7 mm radius, 4.8 mm length, and 14.0% lesion density compared to zero radius, length, and lesion density for sham. The proposed radially symmetric lesion model is a robust evaluation for myocardial cavitation-enabled therapy. Future work will include validating the proposed method with varying acoustic exposures and optimizing involved parameters to provide macrolesion characterization. PMID:25347871

  8. Contrast Intravasation During Hysterosalpingography

    PubMed Central

    Bhoil, Rohit; Sood, Dinesh; Sharma, Tanupriya; Sood, Shilpa; Sharma, Jiten; Kumar, Nitesh; Ahluwalia, Ajay; Parekh, Dipen; Mistry, Kewal A.; Sood, Saurav

    2016-01-01

    Summary Hysterosalpingography is an imaging method to evaluate the endometrial and uterine morphology and fallopian tube patency. Contrast intravasation implies backflow of injected contrast into the adjoining vessels mostly the veins and may be related to factors altering endometrial vascularity and permeability. Radiologists and gynaecologists should be well acquainted with the technique of hysterosalpingography, its interpretation, and intravasation of contrast agents for safer procedure and to minimize the associated complications. PMID:27279925

  9. PPAR-gamma activation fails to provide myocardial protection in ischemia and reperfusion in pigs.

    PubMed

    Xu, Ya; Gen, Michael; Lu, Li; Fox, Jennifer; Weiss, Sara O; Brown, R Dale; Perlov, Daniel; Ahmad, Hasan; Zhu, Peili; Greyson, Clifford; Long, Carlin S; Schwartz, Gregory G

    2005-03-01

    Peroxisome proliferator-activated receptor (PPAR)-gamma modulates substrate metabolism and inflammatory responses. In experimental rats subjected to myocardial ischemia-reperfusion (I/R), thiazolidinedione PPAR-gamma activators reduce infarct size and preserve left ventricular function. Troglitazone is the only PPAR-gamma activator that has been shown to be protective in I/R in large animals. However, because troglitazone contains both alpha-tocopherol and thiazolidinedione moieties, whether PPAR-gamma activation per se is protective in myocardial I/R in large animals remains uncertain. To address this question, 56 pigs were treated orally for 8 wk with troglitazone (75 mg x kg(-1) x day(-1)), rosiglitazone (3 mg x kg(-1) x day(-1)), or alpha-tocopherol (73 mg x kg(-1) x day(-1), equimolar to troglitazone dose) or received no treatment. Pigs were then anesthetized and subjected to 90 min of low-flow regional myocardial ischemia and 90 min of reperfusion. Myocardial expression of PPAR-gamma, determined by ribonuclease protection assay, increased with troglitazone and rosiglitazone compared with no treatment. Rosiglitazone had no significant effect on myocardial contractile function (Frank-Starling relations), substrate uptake, or expression of proinflammatory cytokines during I/R compared with untreated pigs. In contrast, preservation of myocardial contractile function and lactate uptake were greater and cytokine expression was attenuated in pigs treated with troglitazone or alpha-tocopherol compared with untreated pigs. Multivariate analysis indicated that presence of an alpha-tocopherol, but not a thiazolidinedione, moiety in the test compound was significantly related to greater contractile function and lactate uptake and lower cytokine expression during I/R. We conclude that PPAR-gamma activation is not protective in a porcine model of myocardial I/R. Protective effects of troglitazone are attributable to its alpha-tocopherol moiety. These findings, in

  10. Effects of hydrogen sulfide on myocardial fibrosis and PI3K/AKT1-regulated autophagy in diabetic rats.

    PubMed

    Xiao, Ting; Luo, Jian; Wu, Zhixiong; Li, Fang; Zeng, Ou; Yang, Jun

    2016-02-01

    Myocardial fibrosis is the predominant pathological characteristic of diabetic myocardial damage. Previous studies have indicated that hydrogen sulfide (H2S) has beneficial effects in the treatment of various cardiovascular diseases. However, there is little research investigating the effect of H2S on myocardial fibrosis in diabetes. The present study aimed to investigate the effects of H2S on the progression of myocardial fibrosis induced by diabetes. Diabetes was induced in rats by intraperitoneal injection of streptozotocin. Sodium hydrosulfide (NaHS) was used as an exogenous donor of H2S. After 8 weeks, expression levels of cystathionine-γ-lyase were determined by western blot analysis and morphological changes in the myocardium were assessed by hematoxylin and eosin staining and Masson staining. The hydroxyproline content and fibrosis markers were determined by a basic hydrolysis method and western blot analysis, respectively. Autophagosomes were observed under transmission electron microscopy. Expression levels of autophagy-associated proteins and their upstream signaling molecules were also evaluated by western blotting. The results of the current study indicated that diabetes induced marked myocardial fibrosis, enhanced myocardial autophagy and suppressed the phosphatidylinositol-4,5-bisphosphate 3-kinase/RAC-α serine/threonine-protein kinase (PI3K/AKT1) signaling pathway. By contrast, following treatment with NaHS, myocardial fibrosis was ameliorated, myocardial autophagy was decreased and the PI3K/AKT1 pathway suppression was reversed. The results of the present study demonstrated that the protective effect of H2S against diabetes-induced myocardial fibrosis may be associated with the attenuation of autophagy via the upregulation of the PI3K/AKT1 signaling pathway. PMID:26676365