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Sample records for dipyridamole 201tl myocardial

  1. Dipyridamole 201Tl scintigraphy in the evaluation of prognosis after myocardial infarction

    SciTech Connect

    Okada, R.D.; Glover, D.K.; Leppo, J.A. )

    1991-09-01

    Dipyridamole 201Tl imaging has been proposed as an alternative to exercise ECG testing for the prehospital discharge evaluation of patients recovering from myocardial infarction. The rationale is that many postinfarction patients with exercise-induced ischemia experience later cardiac events, and the sensitivity of predischarge exercise ECG testing in patients with multivessel disease ranges from only 45% to 62%. In addition, several groups of investigators have shown the sensitivity of submaximum exercise 201Tl imaging to be less than ideal. This report summarizes the current status of dipyridamole 201Tl imaging in the period of 1-13 days after myocardial infarction. Although the number of studies performed to date is limited, the following conclusions can be drawn: dipyridamole 201Tl imaging after myocardial infarction was associated with no serious side effects, and those present could be quickly reversed with aminophylline; redistribution with dipyridamole 201Tl images definitely correlates with prognosis after uncomplicated myocardial infarction; dipyridamole 201Tl imaging is definitely useful in patients unable to exercise for a variety of reasons; and future studies are definitely indicated to further define the role of dipyridamole 201Tl imaging for assessing prognosis, especially in those patients undergoing interventional therapy after acute myocardial infarction.

  2. Spontaneous changes in /sup 201/Tl myocardial perfusion imaging after myocardial infarction

    SciTech Connect

    Buda, A.J.; Dubbin, J.D.; MacDonald, I.L.; Strauss, H.D.; Orr, S.A.; Meindok, H.

    1982-12-01

    To examine regional myocardial perfusion after myocardial infarction, 26 patients underwent exercise electrocardiographic testing with /sup 201/Tl myocardial perfusion imaging 3 weeks and 3 months after infarction. At 3 weeks, 9 of 26 patients (35%) had myocardial ischemia by exercise electrocardiographic testing, whereas 18 of 26 (69%) had ischemia by /sup 201/Tl imaging. The /sup 201/Tl scintigrams were scored by dividing each image, in 3 views, into 5 segments, using a 5-point scoring scheme. The exercise /sup 201/Tl score was 44.3 +/- 1.2 and increased to 47.3 +/- 1.2 in the redistribution study (p less than 0.001). Three months after infarction, although there was a significantly greater rate-pressure product which would predict a larger ischemic defect and a decrease in the stress /sup 201/Tl score, the stress score was improved (48.3 +/- 1.1, p less than 0.001). The redistribution score was similar, that is, 48.9 +/- 1.0. The improvement in /sup 201/Tl myocardial perfusion was associated with a loss of stress-induced ischemia in 8 patients (30%). These results indicate that spontaneous improvements in /sup 201/Tl myocardial perfusion imaging may occur after myocardial infarction.

  3. Caffeine reduces dipyridamole-induced myocardial ischemia

    SciTech Connect

    Smits, P.; Aengevaeren, W.R.; Corstens, F.H.; Thien, T. )

    1989-10-01

    The mechanism of action of coronary vasodilation after dipyridamole may be based on inhibition of cellular uptake of circulating endogenous adenosine. Since caffeine has been reported to be a competitive antagonist of adenosine we studied the effect of caffeine on the outcome of dipiridamole-{sup 201}Tl cardiac imaging in one patient. During caffeine abstinence dipyridamole induced myocardial ischemia with down-slope ST depressions on the ECG, and reversible perfusion defects on the scintigrams. When the test was repeated 1 wk later on similar conditions, but now shortly after infusion of caffeine (4 mg/kg), the ECG showed nodepressions, and the scintigrams only slight signs of ischemia. We conclude that when caffeine abstinence is not sufficient, the widespread use of coffee and related products may be responsible for false-negative findings in dipyridamole-201Tl cardiac imaging.

  4. Detection of coronary artery stenosis in children with Kawasaki disease. Usefulness of pharmacologic stress sup 201 Tl myocardial tomography

    SciTech Connect

    Kondo, C.; Hiroe, M.; Nakanishi, T.; Takao, A. )

    1989-09-01

    This study determined the feasibility and accuracy of quantitative 201Tl myocardial single-photon emission computed tomography (SPECT) after dipyridamole infusion to detect coronary obstructive lesions in children with Kawasaki disease. 201Tl distribution after dipyridamole infusion was measured in 23 normal children, and with these normal values, quantitative analysis of SPECT was performed in 49 patients. Thirty-four patients had coronary stenosis 90% or greater on angiograms. Side effects resulting from systemic vasodilation were observed in about 70%. Angina pectoris and ischemic ST changes were observed only in patients with coronary stenosis. These symptoms disappeared after aminophylline infusion. Results of visual and quantitative analysis of SPECT were compared. SPECT data were shown on two-dimensional polar maps, and the extent and severity scores were calculated. The sensitivity of SPECT for detection of overall coronary stenosis was 91% (visual analysis) and 88% (quantitative analysis). The specificity of SPECT was 60% visually and 93% quantitatively. The sensitivity of quantitative analysis to detect individual coronary stenosis was similar to that of visual analysis. However, the specificity of visual analysis to detect individual coronary artery stenosis was significantly less than that of quantitative analysis. From these data, we conclude that quantitative analysis of myocardial SPECT after dipyridamole infusion is a safe and accurate diagnostic method for identifying coronary stenosis in children with Kawasaki disease.

  5. Value of planar 201Tl imaging in risk stratification of patients recovering from acute myocardial infarction

    SciTech Connect

    Gibson, R.S.; Watson, D.D. )

    1991-09-01

    Although exercise ECG testing has been shown to have important prognostic value after acute myocardial infarction, exercise 201Tl scintigraphy offers several potential advantages, including: (1) increased sensitivity for detecting residual myocardial ischemia; (2) the ability to localize ischemia to a specific area or areas subtended by a specific coronary artery; (3) the ability to identify exercise-induced left ventricular dysfunction, which is manifested by increased lung uptake or transient left ventricular dilation; and (4) more reliable risk stratification of individual patients. The more optimal prognostic efficiency of 201Tl scintigraphy partially results from the fact that the error rate in falsely classifying patients as low risk is significantly smaller with 201Tl scintigraphy than with stress ECG. Because of these substantial advantages, there seems to be adequate rationale for recommending exercise perfusion imaging rather than exercise ECG alone as the preferred method for evaluating mortality and morbidity risks after acute myocardial infarction.

  6. [Effect of wall thickness of left ventricle on 201Tl myocardial SPECT images: myocardial phantom study].

    PubMed

    Koto, M; Namura, H; Kawase, O; Yamasaki, K; Kono, M

    1996-07-01

    201Tl myocardial SPECT is known for better sensitivity, specificity, and accuracy than planar images in detecting coronary artery disease and diagnosing myocardial viability. SPECT images are also superior to planar images in diagnostic sensitivity and anatomical orientation. However, as limitation of the spatial resolution of the machine, we often encounter poor SPECT plower image quality in patients with decreased wall thickness. To test the accuracy of SPECT images in patients with marked thinning of the left ventricular wall, as occurs in dilated cardiomyopathy, we performed a experimental study using myocardial phantom with 7 mm wall thickness. Tomographic image of the phantom images were rather heterogeneous, though no artificial defect was located. Dilated cardiomyopathy is thought to be characterized by patchy defects in the left ventricle. Careful attention should be given to elucidating myocardial perfusion in patients with a thin left ventricle wall, as there are technical limitations in addition to clinical features.

  7. False-negative dipyridamole-thallium-201 myocardial imaging after caffeine infusion

    SciTech Connect

    Smits, P.; Corstens, F.H.; Aengevaeren, W.R.; Wackers, F.J.; Thien, T. )

    1991-08-01

    The vasodilator effect of intravenously administered dipyridamole may be caused by an increase in endogenous plasma adenosine levels. The authors evaluated the effect of caffeine, an adenosine receptor antagonist, on the diagnostic results of dipyridamole-201Tl myocardial imaging in eight patients with coronary artery disease. Caffeine infusion significantly attenuated the dipyridamole-induced fall in blood pressure and the accompanied increase in heart rate. The infusion of dipyridamole alone resulted in chest pain and ST-segment depressions on the electrocardiogram in four patients, whereas none of these problems occurred when the tests were repeated after caffeine. In six of eight patients, caffeine was responsible for false-negative dipyridamole-201Tl tests. Semiquantitive scores of the dipyridamole-induced 201Tl perfusion defects were decreased by caffeine from 9.0 {plus minus} 0.9 to 2.0 {plus minus} 1.1 points (p less than 0.05). Computerized analysis revealed a caffeine-mediated reduction in the percent reversibility of the images from 46% {plus minus} 16% to 6% {plus minus} 10% (p less than 0.05). They conclude that the use of caffeinated products prior to dipyridamole-201Tl testing may be responsible for false-negative findings.

  8. Gamma radiation measurements and Monte Carlo computations following myocardial perfusion imaging with 201Tl.

    PubMed

    Clouvas, A; Xanthos, S

    2012-12-01

    In the current study, the time-dependent retention of (201)Tl-thallous chloride (111 MBq) was measured in a 56-y-old man undergoing myocardial perfusion imaging. For 23 d following the (201)Tl injection, total-body retained activity was measured by (i) in situ gamma spectrometry using a portable high-purity germanium (HPGe) detector and (ii) ex vivo urine radioassay using a shielded HPGe detector. The time-dependent decrease in total-body activity followed a monoexponential function, exp(-0.011 t), with an excellent correlation (R(2)=0.9988) between the experimental data and the fitted values. The effective half-life, Teff, of (201)Tl (physical half-life, Tph: 72.9 h) was therefore 63 h and the biological half-life, Tb, 463 h=19.3 d, identical to those measured in the same patient in 1997 (i.e. 14 y ago). The time-dependent decrease in the urine activity concentration, which followed a monoexponential function, exp(-0.0115 t), corroborated the foregoing results. The correlation (R(2)=0.9939) between the experimental data and the fitted values was again excellent. The effective half-life, Teff, was 60.26 h and the biological half-life, Tb, 348 h=14.5 d. Monte Carlo simulation using a simple model of the patient as a unit-density cylinder filled with water and containing a uniform distribution of (201)Tl yielded photon flux results in reasonable agreement with the measured data. PMID:22611205

  9. Experimental regional myocardial ischaemia and myocardial uptake of potassium analogues; intercomparison of 42K, 86Rb and 201Tl.

    PubMed

    Kasalický, J; Mrhová, O; Stýs, V

    1983-01-01

    The uptake of 42K, 86Rb and 201Tl by non-ischaemic and ischaemic myocardium was determined in rats with coronary artery ligature lasting 10, 30, 60 and 120 min, and in control rats without ischaemia. Whereas the myocardial concentration of 201Tl and 42K in control rats was similar and higher than that of 86Rb, 201Tl was superior to the other two radionuclides due to its significantly higher accumulation in non-ischaemic myocardium and the higher ratio of non-ischaemic to ischaemic radioactivity. The 86Rb accumulation in non-ischaemic myocardium and non-ischaemic/ischaemic ratio began to decrease from its maximum at 10 min. 201Tl, 42K and 86Rb blood levels in intact animals decreased rapidly after intravenous injection to low and nearly stabilized values at 5 min. Na+K+-ATPase activity in the ischaemic myocardium was high in the acutely ischaemic myocardium and decreased to below control levels after 4 h of ischaemia; changes in activity could not influence the low uptake of potassium analogues in fresh ischaemic myocardium.

  10. Myocardial imaging in dogs treated with grisorixin: relationship between /sup 201/Tl uptake and coronary blood flow

    SciTech Connect

    Moins, N.; Gachon, P.; Maublant, J.

    1982-04-01

    /sup 201/Tl myocardial imaging was performed in dogs after pretreatment with grisorixin, which appeared to increase the myocardial uptake of /sup 201/Tl. This effect of grisorixin was found to be dose dependent, with an optimal dose of 60 microgram/kg. The myocardial-to-background ratio, which was 1.92 in the control dogs, rose to 4.45. The increase in the absolute myocardial uptake was demonstrated in guinea pigs that received /sup 201/Tl after similar pretreatment with grisorixin. In the animals treated with 500 microgram/kg, the uptake of /sup 201/Tl by the heart was 35% over the control value. With 60 microgram/kg grisorixin, the coronary blood flow increased from 40 to 176 ml/min 5 min after the injection. This dose, optimal for imaging, induced the maximum vasodilator effect with only a very slight concomitant increase in the left-ventricular pressure and myocardial contractility. Above 60 microgram/kg, grisorixin appeared to be a potent inotropic agent, whereas below this dose it showed only coronary vasodilator properties. Some evidence for an ionophore effect of this compound was found in dogs pretreated with 60 microgram/kg. In these the radionuclide was injected when the coronary vasodilatation had become insignificant, but a significant improvement of the M/B ratio was still evident.

  11. Comparison of myocardial /sup 201/Tl clearance after maximal and submaximal exercise: implications for diagnosis of coronary disease: concise communication

    SciTech Connect

    Massie, B.M.; Wisneski, J.; Kramer, B.; Hollenberg, M.; Gertz, E.; Stern, D.

    1982-05-01

    Recently the quantitation of regional /sup 201/Tl clearance has been shown to increase the sensitivity of the scintigraphic detection of coronary disease. Although /sup 201/Tl clearance rates might be expected to vary with the degree of exercise, this relationship has not been explored. We therefore evaluated the rate of decrease in myocardial /sup 201/Tl activity following maximal and submaximal stress in seven normal subjects and 21 patients with chest pain, using the seven-pinhole tomographic reconstruction technique. In normals, the mean /sup 201/Tl clearance rate declined from 41% +/- 7 over a 3-hr period with maximal exercise to 25% +/- 5 after 3 hr at a submaximal level (p less than 0.001). Similar differences in clearance rates were found in the normally perfused regions of the left ventricle in patients with chest pain, depending on whether or not a maximal end point (defined as either the appearance of ischemia or reaching 85% of age-predicted heart rate) was achieved. In five patients who did not reach these end points, 3-hr clearance rates in uninvolved regions averaged 25% +/- 2, in contrast to a mean of 38% +/- 5 for such regions in 15 patients who exercised to ischemia or an adequate heart rate. These findings indicate that clearance criteria derived from normals can be applied to patients who are stressed maximally, even if the duration of exercise is limited, but that caution must be used in interpreting clearance rates in those who do not exercise to an accepted end point.

  12. Estimation of infarct size by myocardial emission computed tomography with /sup 201/Tl and its relation to creatine kinase-MB release after myocardial infarction in man

    SciTech Connect

    Tamaki, S.; Nakajima, H.; Murakami, T.

    1982-11-01

    We evaluated emission computed tomography (ECT) /sup 201/Tl myocardial imaging in estimating infarct size (IS). In 18 patients in whom IS was estimated enzymatically at the time of the acute episode, planar /sup 201/Tl perfusion scintigraphy and ECT with a rotating gamma camera were performed 4 weeks after the first myocardial infarction. From the size of /sup 201/Tl perfusion defects, the infarct area in planar images and the infarct volume in reconstructed ECT images were measured by computerized planimetry. When scintigraphic IS was compared with the accumulated creatine kinase-MB isoenzyme release (CK-MBr), infarct volume determined from ECT correlated closely with CK-MBr (r . 0.89), whereas infarct area measured from planar images correlated less satisfactorily with the enzymatic IS (for an average infarct area from three views, r . 0.69; for the largest infarct area, r . 0.73). Although conventional scintigraphic evaluation is useful for detecting and localizing infarction, quantification of ischemic injury with this two-dimensional technique has a significant inherent limitation. The ECT approach can provide a more accurate three-dimensional quantitative estimate of infarction, and can corroborate the enzymatic estimate of IS.

  13. A prospective comparison of rubidium-82 PET and thallium-201 SPECT myocardial perfusion imaging utilizing a single dipyridamole stress in the diagnosis of coronary artery disease

    SciTech Connect

    Go, R.T.; Marwick, T.H.; MacIntyre, W.J.; Saha, G.B.; Neumann, D.R.; Underwood, D.A.; Simpfendorfer, C.C. )

    1990-12-01

    The purpose of the present study is to prospectively compare myocardial perfusion imaging with rubidium-82 ({sup 82}Rb) by positron emission tomography (PET) with thallium-201 ({sup 201}Tl) imaging by single-photon emission tomography (SPECT) by recording both studies with a single dipyridamole handgrip stress, and reading both sets of images with the same display technique. In a series of 202 patients with previous coronary arteriography, the sensitivity, specificity, and accuracy of {sup 82}Rb PET were 93%, 78%, and 90% and for {sup 201}Tl SPECT 76%, 80%, and 77%, respectively. When 70 patients with previous therapeutic interventions were excluded, the remaining 132 patients showed a sensitivity, specificity, and accuracy of 95%, 82% and 92% for {sup 82}Rb PET and 79%, 76%, and 78% for {sup 201}Tl SPECT. The improved contrast resolution of PET resulted in markedly superior images and a more confident identification of defects.

  14. [Development and clinical application of an expert system for supporting diagnosis of 201Tl stress myocardial SPECT].

    PubMed

    Horino, M; Hosoba, M; Wani, H; Oriuchi, N; Tateno, M; Inoue, T; Sasaki, Y; Igarashi, H; Iizuka, T

    1990-02-01

    A consultation expert system which supports our computer aided reporting system was developed. The system was used for the evaluation of the two dimensional polar (bull's eye) display of 201Tl myocardial SPECT. The system consists of patients management (PM) and consultation expert systems (ES). The former is connected to image processors coupled with scinticameras. The bull's eye display of myocardial SPECT is transferred from image processor to the data base of PM. When inference request is made, the feature extraction program extracts information on localization, extent and severity of focal defects comparing count-rates pixel by pixel with the reference obtained from seven normal controls. The inference engine is activated to determine presence of focal defects utilizing diagnostic rules in the knowledge base. The results are sent back to PM and reported with the probability of assurance. Fifty eight patients with old myocardial infarction (OMI), angina pectoris (AP) and other diseases as well as normal controls were included in the study. The decision for presence or absence of focal defects by ES agreed with that by nuclear physicians (NP) in 301 segments among 330 (91%) in stress images. The presence of redistribution in delayed images agreed in 43 segments among 67 (64%). Image interpretation by ES agreed well with that of NP in patients with OMI (19/20) and AP (9/11). Seven were interpreted as normal by both ES and NP. The system is useful, as it provides NP with complementary and supportive information applicable to decision making and reporting. Further clinical experiences can improve knowledge base for better ES function.

  15. NOTE: Comparison of correction techniques for simultaneous 201Tl/99mTc myocardial perfusion SPECT imaging: a dog study

    NASA Astrophysics Data System (ADS)

    Knesaurek, Karin; Machac, Josef

    2000-11-01

    We compared two correction methods for simultaneous 201Tl/99mTc dual-isotope single-photon emission computed tomography (SPECT). Both approaches use the information from the third energy window placed between the photopeak windows of the 201Tl and 99mTc. The first approach, described by Moore et al, corrects only for the contribution of the 99mTc to the 201Tl primary 70 keV window. We developed the three-window transformation dual-isotope correction method, which is a simultaneous cross-talk correction. The two correction methods were compared in a simultaneous 201Tl/99mTc sestamibi cardiac dog study. Three separate acquisitions were performed in this dog study: two single-isotope and one dual-isotope acquisition. The 201Tl single-isotope images were used as references. The total number of counts, and the contrast between the left ventricular cavity (LVC) and the myocardium, were used in 70 keV short-axis slices as parameters for evaluating the results of the dual-isotope correction methods. Three consecutive short-axis slices were used to calculate averaged contrast and the averaged total number of counts. The total number of the counts was 667 000 ± 500 and 414 500 ± 400 counts for the dual-isotope (201Tl + 99mTc) and single-isotope (201Tl-only) 70 keV images, respectively. The corrected dual-isotope images had 514 700 ± 700 and 368 000 ± 600 counts for Moore's correction and our approach, respectively. Moore's method improved contrast in the dual-isotope 70 keV image to 0.14 ± 0.03 from 0.11 ± 0.02, which was the value in the 70 keV non-corrected dual-isotope image. Our method improved the same contrast to 0.22 ± 0.03. The contrast in the 201Tl single-isotope 70 keV image was 0.28 ± 0.02. Both methods improved the 70 keV dual-isotope images. However, our approach provided slightly better images than Moore's correction when compared with 201Tl-only 70 keV images.

  16. Double-nuclide study of the myocardium using 201Tl and 123I-labeled fatty acids in non-ischemic myocardial diseases.

    PubMed

    Knapp, W H; Vyska, K; Machulla, H J; Notohamiprodjo, G; Schmidt, U; Knust, E J; Gleichmann, U

    1988-06-01

    Metabolic impairment and perfusion abnormalities are known to occur in hypertensive heart disease (HHD) and in cardiomyopathies. Free fatty acid (FFA) extraction is severely inhibited in a number of pathobiochemical reactions. This parameter was assessed using the radiolabeled FFA analogue 123I-(p-iodo-phenyl-)-pentadecanoic acid (IPPA) and 201Tl as perfusion marker, both of them injected at maximal physical workload. The regional extraction fraction of IPPA (IPPA-EF) was estimated by relating the regional IPPA and 201Tl uptake to each other. In HHD (normal coronary arteries) with posterior wall thickness less than or equal to 12 mm IPPA-EF was 77 +/- 18% (SD) in septum and 92 +/- 17% in the posterolateral wall (N = 13), with thickness of greater than 12 mm 60 +/- 23% in septum and 61 +/- 20% in the posterolateral wall (N = 8) when compared with IPPA-EF in normal subjects (= 100%, N = 9). In hypertrophic cardiomyopathy (HCM) IPPA-EF averaged 51 +/- 20% in septum and 87 +/- 10% in the posterolateral wall (N = 11). In these patient groups no systematic regional changes in 201TI uptake were observed. In dilated cardiomyopathy (DCM) both IPPA-EF and 201Tl uptake showed distinct regional variations and a great interindividual variability with a mean IPPA-EF reduction of 12% (N = 9). Thus, IPPA uptake in primarily non-ischemic myocardial disease may already be compromised when 201Tl uptake is unchanged. The double-nuclide method for IPPA-EF determination allows to eliminate the influence of flow in FFA imaging and enhances the potential of scintigraphy in the differential diagnosis of HHD versus coronary artery disease. PMID:3405780

  17. Exercise supplementation of dipyridamole for myocardial perfusion imaging

    SciTech Connect

    DePuey, E.G.

    1991-08-01

    The substitution of intravenous dipyridamole for symptom-limited treadmill exercise has provided a non-invasive means to diagnose coronary artery disease with 201Tl scintigraphy in patients unable to adequately exercise. Limitations of dipyridamole/thallium imaging are primarily due to suboptimal image quality secondary to hepatic tracer concentration and decreased test sensitivity in patients who are dipyridamole non-responders. Low-level treadmill exercise supplementation improves image quality, whereas handgrip has little, if any, benefit. The effect of low-level exercise in augmenting coronary blood flow is unknown and reports regarding the effect of handgrip are conflicting. The diagnostic benefit of these maneuvers in improving test sensitivity and decreasing the number of non-responders has not been documented. The combination of maximal, symptom-limited treadmill exercise and intravenous dipyridamole is a theoretically attractive option to improve overall test sensitivity, but the physiologic consequences and potential side effects should be more thoroughly investigated.

  18. Tomographic thallium-201 myocardial perfusion scintigrams after maximal coronary artery vasodilation with intravenous dipyridamole: comparison of qualitative and quantitative approaches

    SciTech Connect

    Francisco, D.A.; Collins, S.M.; Go, R.T.; Ehrhardt, J.C.; Van Kirk, O.C.; Marcus, M.L.

    1982-08-01

    Eighty-six patients had thallium-201 (/sup 201/Tl) myocardial perfusion scintigrams after intense coronary artery dilation with i.v. dipyridamole. Tomographic and planar /sup 201/Tl scintigrams were obtained in each patient. Tomographic scintigrams were interpreted using quantitative or visual criteria; planar scintigrams were assessed using visual criteria only. When visual criteria were used, interobserver variability was 40% for tomographic scintigrams and 44% for planar scintigrams. In the 24 patients with normal or nonsignificant CAD, quantitative analysis of the tomograms (range approach) indicated that one of 24 (4%) had a positive image (specificity 96%%); in contrast, when visual criteria were used to interpret the tomographic or planar /sup 201/Tl scintigrams, eight of 24 (33%) had positive scintigrams (specificity 67%). In the 51 abnormal patients, the sensitivity of detecting CAD was 46 of 51 (90%) for tomographic scintigrams interpreted quantitatively, 39 of 51 (76%) for tomographic scintigrams interpreted visually and 41 of 51 (80%) for planar scintigrams assessed visually. The tomographic imaging procedure (quantitative interpretation) also demonstrated a high sensitivity (89%) and specificity (100%) in 28 patients (10 normal and 18 CAD), with a clinical diagnosis of unstable angina pectoris. Overall, the predictive accuracy of an abnormal scintigram with quantitative tomographic imaging (98%) was significantly better (p<0.05) than either qualitative planar or pinhole imaging. (JMT)

  19. [Comparison between 123I-BMIPP and 201TlCl myocardial imaging by circumferential profile analysis in patients with myocardial infarction--evaluation of effects of vascular reconstruction in patients with myocardial infarction].

    PubMed

    Ohsumi, Y; Watanabe, T; Nagano, T

    1994-10-01

    We quantitatively evaluated the effects of vascular reconstruction according to the stage by 123I-BMIPP and 201TlCl using circumferential profile (CP) curve method in patients with myocardial infarction. (1) Comparison of the CP curves for the two nuclides in normal volunteers (n = 9) showed no difference in distribution. (2) In patient with myocardial infarction (n = 32) the severity score was evaluated using the CP curves obtained in the normal volunteers. Type B (marked decrease in 123I-BMIPP accumulation) accounted for 83% in the group in whom vascular reconstruction was performed in the acute stage (Group I) and 91% in the group in whom vascular reconstruction was performed in the chronic stage (Group II). On the other hand, type E (similar accumulation between the two nuclides) accounted for 79% in the group in whom vascular reconstruction was unsuccessful or was not performed (Group III). The severity score for each nuclide did not significantly differ among Group I, II and III. The 123I-BMIPP/201TlCl ratio was the highest in Group II, followed in order by Group I and Group III (p < 0.05). The assessment of the ratio of "severity scores" for both nuclides is considered to be useful for evaluation of the surviving myocardium, rather than the assessment of a single nuclide. PMID:7807719

  20. Quantification of infarct size by /sup 201/Tl single-photon emission computed tomography during acute myocardial infarction in humans. Comparison with enzymatic estimates

    SciTech Connect

    Mahmarian, J.J.; Pratt, C.M.; Borges-Neto, S.; Cashion, W.R.; Roberts, R.; Verani, M.S.

    1988-10-01

    We prospectively investigated whether /sup 201/Tl single-photon emission computed tomography (SPECT) could accurately diagnose the presence and quantify the extent of acute myocardial infarction when compared with infarct size assessed by plasma MB-creatine kinase activity. Thirty patients with enzymatic evidence of infarction were imaged within 12-36 hours of chest pain (mean, 23.4 hours). No patient had a previous infarction, and none underwent intervention seeking to restore coronary patency. Infarct size was quantified with computer-generated polar maps of the myocardial radioactivity and expressed as a percentage of the total left ventricular volume. To assess left and right ventricular performance, blood-pool gated radionuclide angiography was performed immediately after SPECT. All 30 patients had perfusion defects consistent with myocardial infarction. Scintigraphic and enzymatic estimates of infarct size correlated well for the group as a whole (r = 0.78, p less than 0.001, SEE = 9.1) but especially for those patients with anterior infarction (r = 0.91, p less than 0.001, SEE = 7.9). The poor correlation observed in patients with inferior infarction (r = 0.50, p less than 0.05, SEE = 10.0) was believed to be related to the frequent occurrence of right ventricular involvement because SPECT assessed only left ventricular damage, whereas the enzymatic method estimated the myocardial injury in both ventricles. A quantitative index of right ventricular infarct size, derived from the relation between the scintigraphic and enzymatic estimates, had a strong inverse correlation with right ventricular ejection fraction (r = -0.89, p less than 0.001, SEE = 3.6).

  1. Prediction of functional recovery and prognosis in patients with acute myocardial infarction by 123I-BMIPP and 201Tl myocardial single photon emission computed tomography: a multicenter trial.

    PubMed

    Nishimura, T; Nishimura, S; Kajiya, T; Sugihara, H; Kitahara, K; Imai, K; Muramatsu, T; Takahashi, N; Yoshida, H; Osada, T; Terada, K; Ito, T; Naruse, H; Iwabuchi, M

    1998-10-01

    123I-BMIPP [15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid] was developed for metabolic imaging with SPECT. A multicenter collaborative study was conducted on a large patient series to determine whether 123I-BMIPP and 201Tl myocardial SPECT are of use in predicting the prognosis and ventricular function after acute myocardial infarction (AMI). Patients with uncomplicated first AMI underwent resting 123I-BMIPP and 201Tl myocardial SPECT in the subacute phase after the onset of AMI. Of these, 167 patients who had been followed up for an average of 22 months were retrospectively reviewed to predict serious cardiac events and recurrent ischemia. In addition, the association between changes in radionuclide parameters and recurrent ischemia was investigated in Subgroup A (58 patients) who had repeated SPECT in the chronic phase. Furthermore, prediction of the ejection fraction (EF) was investigated in Subgroup B (94 patients) and Subgroup C (76 patients) in whom left ventriculography was performed at the time of discharge and 90 days or more after the onset, respectively. The prognosis was generally favorable, with 4 cases of cardiac death (2%), 3 of heart failure (2%), 4 of nonfatal reMI (2%), and 25 of recurrent ischemia (15%). The results of Cox multivariate regression analysis revealed a high probability of serious cardiac events in patients who were elderly (p = 0.04), who had 90% or more residual stenosis of the infarct-related artery (p = 0.09), and who had a high BMIPP defect score (p = 0.17). There was a high probability of recurrent ischemia in elderly patients (p = 0.10) who had multi-vessel disease (p = 0.03), but no association was found with radionuclide parameters in the subacute phase. In Subgroup A, however, the probability of recurrent ischemia tended to be high in patients with a large mismatch scorebetween 123I-BMIPP and 201Tl in the subacute to chronic phase. An important observation was that the extent of BMIPP defect was more strongly

  2. Incidental Detection of Shoulder Peripheral T-Cell Lymphoma During the Redistribution Phase of 201Tl Myocardial Perfusion Scintigraphy.

    PubMed

    Chen, Yu-Ren; Hsieh, Te-Chun; Yen, Kuo-Yang; Kao, Chia-Hung

    2015-10-01

    A 74-year-old woman underwent Tl myocardial perfusion scan for cardiac symptoms; increased radiotracer accumulation in the left shoulder was found in the redistribution images only, and the shoulder was normal in the stress images. Suspecting septic arthritis subsequent investigations were performed, and peripheral T-cell lymphoma was diagnosed. Attention should also be paid to extracardiac sites in interpreting redistribution images taken as late as 4 hours apart from stress images because some clinically pertinent ancillary findings may be found in redistribution images only. PMID:26018700

  3. Effect of maintenance oral theophylline on dipyridamole-thallium-201 myocardial imaging using SPECT and dipyridamole-induced hemodynamic changes

    SciTech Connect

    Daley, P.J.; Mahn, T.H.; Zielonka, J.S.; Krubsack, A.J.; Akhtar, R.; Bamrah, V.S.

    1988-06-01

    To evaluate the effect of maintenance oral theophylline therapy on the diagnostic efficacy of dipyridamole-thallium-201 single photon emission computed tomography (SPECT) imaging for coronary artery disease, dipyridamole-thallium-201 SPECT imaging was performed in eight men with documented coronary artery disease before initiation of theophylline treatment and repeated while these patients were receiving therapeutic doses of oral theophylline. Before theophylline treatment, intravenous dipyridamole caused a significant increase in heart rate, decrease in blood pressure, angina in seven of eight patients, and ST segment depression in four of eight patients. While they were being treated with theophylline, none of the patients had angina or ST segment depression, and there were no hemodynamic changes with intravenous dipyridamole. Before theophylline treatment, dipyridamole-thallium-201 SPECT imaging showed reversible perfusion defects in myocardial segments supplied by stenotic coronary arteries. With theophylline treatment, dipyridamole-thallium-201 SPECT showed total absence of reversible perfusion defects. Treatment with theophylline markedly reduced the diagnostic accuracy of dipyridamole-thallium-201 imaging for coronary artery disease.

  4. Reversibility by dipyridamole of thallium-201 myocardial scan defects in patients with sarcoidosis

    SciTech Connect

    Tellier, P.; Paycha, F.; Antony, I.; Nitenberg, A.; Valeyre, D.; Foult, J.M.; Battesti, J.P.

    1988-08-01

    In order to clarify the significance of anginal pain and myocardial thallium-201 scan defects in cardiac sarcoidosis, the pharmacologic effect of dipyridamole on myocardial perfusion was assessed by planar thallium-201 myocardial scintigraphy in patients with sarcoidosis. Thallium-201 myocardial scintigraphy was performed at rest and after 0.56 mg/kg intravenous dipyridamole during four minutes in 16 patients with sarcoidosis. The myocardial scan (45-degree and 70-degree left anterior oblique, and anterior views) was divided into 15 segments. Results were evaluated by the number of segmental defects and with a global perfusion score (from 0 to 60) by a semi-quantitative index depending on the size and severity of myocardial thallium-201 defects. Thirteen of the 16 patients showed partial or total reversion of their thallium-201 defects on redistribution scanning either at rest or after dipyridamole. The mean (+/- SD) number of myocardial perfusion defects that were present in all the patients decreased from 5.31 +/- 1.78 at rest to 3.25 +/- 2.52 after redistribution (p less than 0.001) and to 2.19 +/- 2.10 after dipyridamole (p less than 0.001). The mean global perfusion score increased from 53.2 +/- 3.0 at rest to 56.2 +/- 2.9 after redistribution (p less than 0.001) and to 57.2 +/- 2.7 after dipyridamole (p less than 0.001). A significant correlation (r = 0.82, p less than 0.001) was found between the increase of global perfusion score on redistribution and after dipyridamole. The reversibility of myocardial scan defects is a common finding in sarcoidosis. It makes unlikely the role of scar fibrosis or extensive confluent granulomas as a mechanism for such defects. The effect of dipyridamole suggests the presence of reversible disorders lying at the coronary microvascular level.

  5. Dipyridamole thallium-201 scintigraphy as a preoperative screening test. A reexamination of its predictive potential. Study of Perioperative Ischemia Research Group

    SciTech Connect

    Mangano, D.T.; London, M.J.; Tubau, J.F.; Browner, W.S.; Hollenberg, M.; Krupski, W.; Layug, E.L.; Massie, B. )

    1991-08-01

    The authors examined the value of dipyridamole thallium-201 (201Tl) scintigraphy as a preoperative screening test for perioperative myocardial ischemia and infarction. They prospectively studied 60 patients undergoing elective vascular surgery. They performed 201Tl scintigraphy preoperatively and blinded all treating physicians to the results. Historical, clinical, laboratory, and physiological data were gathered throughout hospitalization. Myocardial ischemia was assessed during the intraoperative period using continuous 12-lead electrocardiography (ECG) and transesophageal echocardiography (TEE) and during the postoperative period using continuous two-lead ambulatory ECG. Adverse cardiac outcomes (cardiac death, myocardial infarction, unstable angina, severe ischemia, or congestive heart failure) were assessed daily throughout hospitalization. Twenty-two patients (37%) had defects that improved or reversed on delayed scintigrams (redistribution defects), 18 (30%) had persistent defects, and 20 (33%) had no defects on 201Tl scintigraphy. There was no association between redistribution defects and adverse cardiac outcomes: 54% (seven of 13) of adverse outcomes occurred in patients without redistribution defects, and the risk of an adverse outcome was not significantly increased in patients with redistribution defects. Consistent with these findings, there was also no association between redistribution defects and perioperative ischemia: 54% (19 of all 35) of perioperative ECG and TEE ischemic episodes and 58% (14 of 24) of severe ischemic episodes occurred in patients without redistribution defects. The sensitivity of 201Tl scintigraphy for perioperative ischemia and adverse outcomes ranged from 40% to 54%, specificity from 65% to 71%, positive predictive value from 27% to 47% and negative predictive value from 61% to 82%.

  6. Maximizing myocardial perfusion with combined dipyridamole and phenylephrine

    SciTech Connect

    Lyons, K.P.; Lyons, J.; Eugene, J.; McColgan, S.; Gelezunas, V.; Swan, L.

    1984-01-01

    Intravenous dipyridamole (DP), a potent coronary vasodilator, has been used as a pharmacological exercise substitute for Thallium scintigraphy. Increased coronary artery flow occurs in animals. Humans with severe coronary disease have been imaged with Thallium using this technique. However, in both animals and man, the systemic blood pressure decreases especially at higher dosages. Myocardial perfusion (MP) is dependent on delivery pressure as well as the diameter of the coronary artery. The authors therefore maintained blood pressure by infusion of phenylephrine (PE) during maximal coronary artery dilatation from DP. Seven anesthetized, mongrel, open chest dogs weighing 20-25 kgs were infused with DP alone, 0.075 mg/kg/min for 10 minutes. Mp was measured in a highly localized small volume (0.5 cm/sup 3/) of myocardium using a silicon avalanche radiation detector to record the washout of a 2-5 mCi bolus of xenon in saline using the Kety-Schmidt formula. Polyethylene tubing (O.D. 0.03 inches) was directed into the proximal LAD using a brass canula introduced through the carotid artery. In 5 other dogs, 0.1 mg of PE was added to the DP. DP alone caused only a minor elevation of MP (15%) while the blood pressure decreased. In contrast with PE, the pressure was maintained and MP more than doubled. With continued infusion, both pressure and MP fell. In conclusion, elevation of MP by a coronary dilator DP can be enhanced when combined with a vasopressor (PE) and may be better for pharmacological stimulation of MP for Thallium imaging. Prolonged administration of DP may decrease rather than increase MP even during infusion of phenylephrine.

  7. Effect of Dipyridamole Injected for Myocardial Perfusion Imaging on Blood Glucose Concentration; A Preliminary Study

    PubMed Central

    Arabi, Mohsen; Akhavein, Alireza; Seyedabadi, Mohammad; Eftekhari, Mansooreh; Javadi, Hamid; Nabipour, Iraj; Assadi, Majid

    2016-01-01

    Introduction Dipyridamole inhibits adenosine reuptake and increases cyclic Adenosine Monophosphate (cAMP) levels in platelets, erythrocytes and endothelial cells, all of which influence blood glucose. Acute hyperglycaemia reduces endothelium-dependent vasodilation and suppresses coronary microcirculation; which, in theory, can alter the outcome of a radionuclide scan. Aim The present study was conducted with the aim to investigate the changes in blood glucose level of patients receiving dipyridamole for cardiac scan. Materials and Methods A total of 293 patients (85 men and 208 women, age: 60.59±10.43 years) were included in the study. Fasting Blood Glucose (FBG) was measured before and 8 min after dipyridamole (0.568 mg/kg) injection during myocardial perfusion imaging. The data in different groups were analysed by paired t-test. Results There was not a significant difference between first (106.89 ± 19.21mg/dL) and second (107.98 ± 17.57 mg/dL) FBG measurements (p= 0.293). However, when the patients were grouped based on the quartiles of first measurement, there was an increase in FBG following dipyridamole injection in the first quartile (mean difference: 7.15±21.27 mg/dL, p<0.01); in contrast, FBG levels showed a significant decrease after dipyridamole administration in the 4th quartile (mean difference: -9.53±18.20 mg/dL, p<0.001). The differences in 2nd and 3rd quartiles were negligible. The patients were divided into normal, ischemic and fixed lesions based on the outcome of scans, then the possible correlation of dipyridamole-induced FBG alteration and scan results were investigated. There were no significant difference between the FBG values before and after dipyridamole injection and the final outcome of scan. Conclusion The effects of dipyridamole on blood glucose highly depend on the initial blood glucose level. PMID:27656528

  8. Dipyridamole-thallium-201 scintigraphy in the prediction of future cardiac events after acute myocardial infarction

    SciTech Connect

    Leppo, J.A.; O'Brien, J.; Rothendler, J.A.; Getchell, J.D.; Lee, V.W.

    1984-04-19

    To evaluate the safety and usefulness of serial thallium scanning immediately after intravenous dipyridamole, we studied 51 patients recovering from acute myocardial infarction. Eight patients experienced angina during the procedure, but there were no serious complications. Patients were followed for a mean period of 19 months after hospital discharge. Eleven of 12 patients who died during follow-up or had another infarction had shown transient defects (redistribution) on their predischarge scan, as had 22 of the 24 patients who needed readmission for management of angina. Among all the other clinical or scintigraphic criteria tested, the presence of redistribution on the dipyridamole-thallium scan was the only significant predictor of these serious cardiac events. Twenty-six patients were also given a submaximal exercise test before discharge, of whom 13 subsequently had serious cardiac events. The exercise test had been positive in only 6 of these 13 patients, whereas the dipyridamole-thallium scan had shown a redistribution pattern in 12 (P less than 0.001). We conclude from this preliminary study that dipyridamole-thallium scintigraphy after myocardial infraction is relatively safe. It appears to be a more sensitive predictor of subsequent cardiac events than a submaximal exercise test and may therefore prove useful in evaluating patients after recovery from a myocardial infarction.

  9. Acute myocardial infarction associated with intravenous dipyridamole for rubidium-82 PET imaging

    SciTech Connect

    Marwick, T.H.; Hollman, J. )

    1990-03-01

    This report describes the occurrence of chest pain and electrocardiographic features of acute myocardial infarction following intravenous dipyridamole-handgrip stress. Myocardial perfusion imaging (Rb-82 PET) demonstrated a stress-induced perfusion defect. Following failure to respond to medical therapy, urgent cardiac catheterization demonstrated total occlusion of the left anterior descending coronary artery. The vessel was revascularized, with limitation of myocardial damage evidenced by failure to develop anterior Q waves and only modest elevation of cardiac enzyme levels. Complications of intravenous dipyridamole stress are rare, this case constituting the first major problem in over 500 such procedures at this institution. However, this experience demonstrates the importance of vigilant observation during the performance of this technique.

  10. Dipyridamole thallium-201 scintigraphy for early risk stratification of patients after uncomplicated myocardial infarction

    PubMed Central

    Hung, J.; Moshiri, M.; Groom, G.; Van der Schaaf, A. A; Parsons, R.; Hands, M.

    1997-01-01

    Objective—To determine the safety and prognostic value of dipyridamole thallium-201 scintigraphy performed in patients within three to five days of acute myocardial infarction, including those receiving thrombolytic treatment.
Design—A prospective study of dipyridamole thallium-201 scintigraphy in patients early after acute myocardial infarction.
Setting—University hospital.
Patients—200 patients who were clinically uncomplicated at day 3 after infarction, 92 (46%) of whom had received thrombolysis.
Main outcome measures—Incidence of cardiac death, non-fatal reinfarction, readmission to hospital for unstable angina, or non-elective revascularisation procedure within six months' follow up. 
Results—No patient had a serious complication from the dipyridamole study. At six month follow up, 55 patients (28%) had suffered a defined cardiac event. Patients who received thrombolysis had the same extent of thallium-201 redistribution and the same occurrence of subsequent cardiac events as those not receiving thrombolysis. Patients who subsequently had an event had more myocardial segments showing thallium-201 redistribution than event free patients: 2.7 (SD 1.9) v 1.2 (1.4), respectively (p < 0.001). Among all clinical and scintigraphic variables, multivariate analysis identified the extent of thallium-201 redistribution as the only independent predictor of outcome (p < 0.001). Among 63 patients (32%) of the study cohort who showed more than two myocardial segments with thallium-201 redistribution, the adjusted risk ratio for a cardiac event was 7.5 (95% confidence interval 2.9 to 19.1) compared with patients without any redistribution.
Conclusions—Dipyridamole thallium-201 scintigraphy can be performed safely within a few days of the event in patients with uncomplicated myocardial infarction, including those who received thrombolysis, and can identify a subgroup of patients at high risk of future ischaemic events.

 Keywords

  11. Pentoxifylline (Trental) does not inhibit dipyridamole-induced coronary hyperemia: Implications for dipyridamole-thallium-201 myocardial imaging

    SciTech Connect

    Brown, K.A.; Slinker, B.K. )

    1990-06-01

    Dipyridamole-thallium-201 imaging is often performed in patients unable to exercise because of peripheral vascular disease. Many of these patients are taking pentoxifylline (Trental), a methylxanthine derivative which may improve intermittent claudication. Whether pentoxifylline inhibits dipyridamole-induced coronary hyperemia like other methylxanthines such as theophylline and should be stopped prior to dipyridamole-thallium-201 imaging is unknown. Therefore, we studied the hyperemic response to dipyridamole in seven open-chest anesthetized dogs after pretreatment with either pentoxifylline (0, 7.5, or 15 mg/kg i.v.) or theophylline (3 mg/kg i.v.). Baseline circumflex coronary blood flows did not differ significantly among treatment groups. Dipyridamole significantly increased coronary blood flow before and after 7.5 or 15 mm/kg i.v. pentoxifylline (p less than 0.002). Neither dose of pentoxifylline significantly decreased the dipyridamole-induced hyperemia, while peak coronary blood flow was significantly lower after theophylline (p less than 0.01). We conclude that pentoxyifylline does not inhibit dipyridamole-induced coronary hyperemia even at high doses.

  12. Prognostic value of intravenous dipyridamole thallium scintigraphy after an acute myocardial ischemic event

    SciTech Connect

    Younis, L.T.; Byers, S.; Shaw, L.; Barth, G.; Goodgold, H.; Chaitman, B.R.

    1989-07-15

    Seventy-seven patients recovering from an acute coronary event were studied by intravenous dipyridamole thallium scintigraphy to evaluate the prognostic value and safety of the test in this patient subset. Forty-four patients (58%) had unstable angina and 33 (42%) had an acute myocardial infarction. One death occurred within 24 hours of testing. Sixty-eight patients were followed for an average of 12 months; 25, 31 and 23% had a fixed, reversible or combined thallium defect on their predischarge thallium scan. During follow-up, 10 patients died or had a nonfatal myocardial infarction; in each case, a reversible or combined myocardial thallium defect was present. Univariate analysis of 17 clinical, scintigraphic and angiographic variables showed that a reversible thallium defect and the angiographically determined extent of coronary artery disease were predictors of future cardiac events. The extent of coronary disease and global left ventricular ejection fraction were predictors of subsequent reinfarction or death. Logistic regression analyses revealed that a reversible thallium defect (p less than 0.001) and the extent of coronary disease (p less than 0.009) were the only significant predictors of a cardiac event. When death or reinfarction were the outcome variables, the extent of coronary disease (p less than 0.02) and left ventricular ejection fraction (p less than 0.06) were the only variables selected. Thus, intravenous dipyridamole thallium scintigraphy after an acute coronary ischemic syndrome is a useful and relatively safe noninvasive test to predict subsequent cardiac events.

  13. Evaluation of simultaneous 201Tl/99mTc dual-isotope cardiac SPECT imaging with model-based crosstalk compensation using canine studies

    PubMed Central

    Du, Y.; Links, J. M.; Becker, L.; DiPaula, A. F.; Frank, T.; Schuleri, K. H.; Lardo, A. C.; Frey, E. C.

    2014-01-01

    Background Simultaneous 201Tl/99mTc-Sestamibi dual-isotope myocardial perfusion SPECT imaging can reduce imaging time and produce perfectly registered rest/stress images. However, crosstalk from 99mTc into 201Tl images can significantly reduce 201Tl image quality. We have developed a model-based compensation (MBC) method to compensate for this crosstalk. The method has previously been validated with phantom and simulation studies. In this study, we evaluated the MBC method using a canine model. Methods Left anterior descending or left circumflex coronary artery stenoses were created in 50 adult mongrel dogs weighing 20–30 kg. The dogs were injected with 111 MBq (3 mCi) of 201Tl at rest, and a SPECT study acquired. Stress was induced by administering adenosine to the dog, followed by injection of 740 MBq (20 mCi) of 99mTc-Sestamibi at peak stress. A second SPECT study was performed with data acquired in both 201Tl and 99mTc energy windows to provide simultaneous dual-isotope projection data. The images were reconstructed using the ordered subsets-expectation maximization (OS-EM) reconstruction algorithm with compensation for attenuation, scatter and detector response. For simultaneously acquired 201Tl data, we also applied the MBC method to compensate for crosstalk contamination from 99mTc. Results Without compensation, 99mTc crosstalk increased the estimated 201Tl activity concentration in the rest images and reduced defect contrast. After MBC, the 201Tl images were in good agreement with the registered single isotope images and ex vivo count data. The ischemic (IS) to non-ischemic (NIS) region 201Tl activity concentration ratios were computed for single isotope and dual isotope studies. The correlation with ex vivo IS-NIS ratios was 0.815 after MBC, compared to the 0.495 from data without compensation. In addition, the regression line for the IS-NIS ratios with MBC was almost parallel to the line of identity with a slope of 0.93, compared to a slope of 0

  14. Prognostic importance of silent myocardial ischemia detected by intravenous dipyridamole thallium myocardial imaging in asymptomatic patients with coronary artery disease

    SciTech Connect

    Younis, L.T.; Byers, S.; Shaw, L.; Barth, G.; Goodgold, H.; Chaitman, B.R. )

    1989-12-01

    One hundred seven asymptomatic patients who underwent intravenous dipyridamole thallium imaging were evaluated to determine prognostic indicators of subsequent cardiac events over an average follow-up period of 14 +/- 10 months. Univariate analysis of 18 clinical, scintigraphic and angiographic variables revealed that a reversible thallium defect, a combined fixed and reversible thallium defect, number of segmental thallium defects and extent of coronary artery disease were significant predictors of subsequent cardiac events. Of the 13 patients who died or had a nonfatal infarction, 12 had a reversible thallium defect. Stepwise logistic regression analysis selected a reversible thallium defect as the only significant predictor of cardiac events. When death or myocardial infarction was the outcome variable, a combined fixed and reversible thallium defect was the only predictor of outcome. In patients without previous myocardial infarction, the cardiac event rate was significantly greater in those with an abnormal versus normal thallium scan (55% versus 12%, p less than 0.001). Thus, intravenous dipyridamole thallium scintigraphy is a useful noninvasive test to risk stratify asymptomatic patients with coronary artery disease. A reversible thallium defect most likely indicates silent myocardial ischemia in a sizable fraction of patients in this clinical subset and is associated with an unfavorable prognosis.

  15. Assessment by dipyridamole-thallium-201 myocardial scintigraphy of coronary risk before peripheral vascular surgery

    SciTech Connect

    Sachs, R.N.; Tellier, P.; Larmignat, P.; Azorin, J.; Fischbein, L.; Beaudet, B.; Cadilhac, P.; Cupa, M.; De Saint Florent, G.; Vulpillat, M.

    1988-05-01

    From October 1983 to January 1985, 46 patients (38 men and 8 women; average age, 60 years; range, 37 to 83 years) underwent peripheral vascular surgery of either the internal carotid artery or the arteries of the lower limbs. Each patient had a thorough clinical examination, an ECG, and a dipyridamole-thallium-201 myocardial scan before operation. On the basis of results, they were divided into two groups: 20 patients with and 26 patients without chronic ischemic heart disease. Three major cardiac events were noted during or after a period of 1 month after surgery: There were two deaths due to cardiac ischemic events and one patient had postoperative unstable angina pectoris. These three patients were classified in the coronary group (NS). When the patients were classified on the basis of whether or not there was thallium redistribution on serial images after infusion of dipyridamole, 14 with redistribution and 32 without redistribution were noted. The three patients who had major cardiac events were in the former group (p less than 0.04). Our data suggest that patients in whom redistribution occurs have a high incidence of postoperative ischemic events. These patients should be considered for particular preoperative coronary care to avoid major postoperative cardiac events and to increase chances of survival.

  16. Selection of patients for preoperative coronary angiography: use of dipyridamole-stress--thallium myocardial imaging

    SciTech Connect

    Brewster, D.C.; Okada, R.D.; Strauss, H.W.; Abbott, W.M.; Darling, R.C.; Boucher, C.A.

    1985-05-01

    To identify patients likely to benefit from preoperative coronary angiography, a method utilizing pharmacologically induced coronary vasodilatation in conjunction with serial thallium 201 myocardial perfusion imaging was investigated. Fifty-four patients admitted for elective aortic or femoropopliteal procedures were studied. There were no cardiac ischemic complications in 32 patients with normal scans or persistent defects (scar). In contrast, 7 of 15 patients with thallium redistribution (ischemia) on pre-operative scanning had perioperative ischemic events, including one death and two acute infarcts. An additional seven patients with positive scans (redistribution) underwent coronary angiography prior to vascular surgery; surgically important two- or three-vessel disease was confirmed in all. Dipyridamole-thallium imaging facilitates selection of the subset of truly high-risk patients in whom preoperative coronary angiography may be warranted.

  17. Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block

    PubMed Central

    Cabeda, Estêvan Vieira; Falcão, Andréa Maria Gomes; Soares Jr., José; Rochitte, Carlos Eduardo; Nomura, César Higa; Ávila, Luiz Francisco Rodrigues; Parga, José Rodrigues

    2015-01-01

    Background Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB). Objective To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP) by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA) (stenosis ≥ 70%) as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA) and compare the results with those of single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy. Methods Thirty patients with LBBB who had undergone SPECT for the investigation of coronary artery disease were referred for stress tomography. Independent examiners performed per-patient and per-coronary territory assessments. All patients gave written informed consent to participate in the study that was approved by the institution’s ethics committee. Results The patients’ mean age was 62 ± 10 years. The mean dose of radiation for the tomography protocol was 9.3 ± 4.6 mSv. With regard to CTP, the per-patient values for sensitivity, specificity, positive and negative predictive values, and accuracy were 86%, 81%, 80%, 87%, and 83%, respectively (p = 0.001). The per-territory values were 63%, 86%, 65%, 84%, and 79%, respectively (p < 0.001). In both analyses, the addition of CTP to CTA achieved higher diagnostic accuracy for detecting myocardial ischemia than SPECT (p < 0.001). Conclusion The use of the stress tomography protocol is feasible and has good diagnostic accuracy for assessing myocardial ischemia in patients with LBBB. PMID:26421532

  18. Silent myocardial ischemia and infarction in diabetics with peripheral vascular disease: Assessment by dipyridamole thallium-201 scintigraphy

    SciTech Connect

    Nesto, R.W.; Watson, F.S.; Kowalchuk, G.J.; Zarich, S.W.; Hill, T.; Lewis, S.M.; Lane, S.E. )

    1990-11-01

    We investigated the incidence of silent myocardial ischemia and infarction as assessed by dipyridamole thallium scintigraphy in 30 diabetic patients with peripheral vascular disease and without clinical suspicion of coronary artery disease. Seventeen patients (57%) had thallium abnormalities, with reversible thallium defects compatible with ischemia in 14 patients (47%) and evidence of prior, clinically silent myocardial infarction in 11 patients (37%). Thallium abnormalities were most frequent in patients with concomitant hypertension and cigarette smoking (p = 0.001). These results suggest that unsuspected coronary artery disease is common in this particular group of patients with diabetes mellitus.

  19. Leg arteritis exploration by quantitative muscle scintigraphy with 201Tl

    SciTech Connect

    Robert, J.; Thouvenot, P.; Schmidt, C.; Escanye, J.M.; Schmitt, J.

    1984-10-01

    Detection and localization of peripheral arterial disease was evaluated by an intravenous injection of 201Tl at peak exercise in 18 subjects and at rest in 6 patients. Images of the skull (S), thighs (T), knees (K), calves (C) and feet (F) were obtained at rest or after exercise and stored in a computer. Intraleg (T/K, T/C, T/F), and left to right interleg (TL/TR,...) count ratios were calculated. In addition, all patients were submitted to routine functional tests (walk perimeter, serial local arterial blood pressure measurement, Strandness test, venous occlusion plethysmography). Correlations between functional tests and the intra and interleg ratios were calculated. After exercise, there is a medium correlation between the tissular blood flow under hyperemia at the calf level and the T/C and C/K ratios. At the calf level a good correlation is obtained for CL/CR and the flux under hyperemia (r = 0.81, P 0.001). A ratio between the counting rates of limb segments after exercise and those of skull was established. The ratios T/S and C/S compared with the systolic pressure index of the most affected limb after a Strandness test give a correlation of 0.72 (P 0.02) for the thigh and of 0.86 (P 0.001) for the calf. For hyperemic flux, the correlation are 0.58 (P 0.005) with T/S and 0.75 (P 0.001) with C/S. In order to find the best quantitative scintigraphic index of the arterial illness, we compared the different ratio values with the distance walked. For T/S we found a relationship very close to a linear one and for C/S a less significant exponential one. Thus, quantitative scintigraphy using 201Tl appears as an accurate method to measure local muscular perfusion deficit in the cases of lower limb arterial disease.

  20. Comparison of coronary angiography and early oral dipyridamole thallium-201 scintigraphy in patients receiving thrombolytic therapy for acute myocardial infarction

    SciTech Connect

    Jain, A.; Hicks, R.R.; Myers, G.H.; McCarthy, J.J.; Perry, J.R.; Adams, K.F. )

    1990-10-01

    We evaluated 50 consecutive patients who received thrombolytic therapy for acute myocardial infarction using thallium-201 single photon emission computed tomography in combination with oral dipyridamole to assess the frequency of residual myocardial ischemia. Thallium studies were performed early after myocardial infarction at a mean of 4.6 days. The time from the onset of chest pain to the administration of thrombolytic therapy was 2.6 hours (range 0.5 to 5.5). Q wave myocardial infarction was evident in 46 patients; four patients had a non-Q wave infarction (anterior infarction in 31 patients and inferior infarction in 19 patients). The serum mean peak creatinine kinase was 1503 IU/L (range 127 to 6500). Coronary angiography was performed in all patients at a mean of 3.1 days (range 2 to 10) and revealed the infarct-related vessel to be patent in 36 patients (72%). The ejection fraction was 48% (range 26% to 67%). After dipyridamole administration, 13 patients (26%) developed angina that was easily reversed with the administration of intravenous aminophylline. Systolic blood pressure decreased from 122 to 115 mm Hg (p less than 0.05) and the heart rate increased from 76 to 85 beats/min (p less than 0.05). None of the patients had significant hypotension, arrhythmias, or evidence of infarct extension. Perfusion abnormalities were present on the initial thallium images in 48 patients. Redistribution suggestive of ischemia was present in 36 patients (72%). Ischemia confined to the vascular distribution of the infarct vessel was evident in 22 patients. Seven patients had ischemia in the infarct zone as well as in a remote myocardial segment. Thus 29 patients (58%) had ischemia in the distribution of the infarct vessel. Ischemia in the infarct zone was evident in 19 of 36 patients with open infarct vessels and in 10 of 14 patients with occluded infarct vessels.

  1. Effect of dipyridamole on myocardial reperfusion injury: A double-blind randomized controlled trial in patients undergoing elective coronary artery bypass surgery.

    PubMed

    El Messaoudi, S; Wouters, C W; van Swieten, H A; Pickkers, P; Noyez, L; Kievit, P C; Abbink, E J; Rasing-Hoogveld, A; Bouw, T P; Peters, J G; Coenen, M J H; Donders, A R T; Riksen, N P; Rongen, G A

    2016-04-01

    Dipyridamole reduces reperfusion-injury in preclinical trials and may be beneficial in patients undergoing coronary angioplasty, but its effect on patients undergoing coronary artery bypass grafting (CABG) is unknown. We hypothesized that dipyridamole limits myocardial reperfusion-injury in patients undergoing CABG. The trial design was a double-blind trial randomizing between pretreatment with dipyridamole or placebo. In all, 94 patients undergoing elective on-pump CABG were recruited between February 2010 and June 2012. The primary endpoint was plasma high-sensitive (hs-) troponin-I at 6, 12, and 24 hours after reperfusion. Secondary endpoints were the occurrence of bleeding, arrhythmias, need for inotropic support, and intensive care unit length of stay. Finally, 79 patients (33 dipyridamole) were included in the per-protocol analysis. Dipyridamole did not significantly affect postoperative hs-troponin-I (change in plasma hs-troponin I -3% [95% confidence interval -23% to 36%]; P > 0.1). Secondary endpoints did not differ between groups. Dipyridamole prior to CABG does not significantly reduce postoperative hs-troponin release.

  2. Effects of dipyridamole and aminophylline on hemodynamics, regional myocardial blood flow and thallium-201 washout in the setting of a critical coronary stenosis

    SciTech Connect

    Granato, J.E.; Watson, D.D.; Belardinelli, L.; Cannon, J.M.; Beller, G.A. )

    1990-12-01

    Experiments were performed to characterize the interaction of intravenous dipyridamole and aminophylline on thallium-201 transport kinetics, regional myocardial blood flow and systemic hemodynamics in the presence of a critical coronary artery stenosis. In 12 dogs with a critical left anterior descending coronary artery stenosis, arterial pressure decreased from a mean value (+/- SEM) of 107 +/- 6 to 94 +/- 3 mm Hg and distal left anterior descending artery pressure decreased from 70 +/- 7 to 55 +/- 4 mm Hg after intravenous administration of dipyridamole. In the left anterior descending perfusion zone, the endocardial/epicardial flow ratio decreased from 0.70 to 0.36 and the intrinsic thallium washout rate was significantly prolonged. Intravenous aminophylline reversed the dipyridamole-induced systemic hypotension and transmural coronary steal and restored the thallium washout rate to baseline values. In six other dogs, aminophylline alone resulted in no alterations in systemic and coronary hemodynamics or regional myocardial blood flow. As expected, dipyridamole-induced vasodilation and coronary steal were prevented by aminophylline pretreatment. These data show that in a canine model of partial coronary stenosis, systemic hypotension, adverse regional flow effects and prolonged thallium-201 washout consequent to intravenously administered dipyridamole are promptly reversed by intravenous aminophylline administration. Aminophylline alone had no significant hemodynamic and coronary flow effects. This study provides further insight into the altered thallium kinetics occurring as a consequence of dipyridamole-induced vasodilation and suggests that the prompt reversal of symptoms and signs of ischemia with aminophylline in patients receiving intravenous dipyridamole for clinical imaging studies probably reflects the reversal of transmural coronary steal.

  3. Cardiac arrest during dipyridamole imaging

    SciTech Connect

    Blumenthal, M.S.; McCauley, C.S.

    1988-05-01

    A case of cardiac arrest and subsequent acute myocardial infarction occurring during thallium-201 imaging with oral dipyridamole augmentation is presented. Previous reports emphasizing the safety of this procedure are briefly reviewed and a recommendation for close hemodynamic and arrhythmia monitoring during the study is made. Large doses of oral dipyridamole may be contraindicated in patients with unstable angina.

  4. Prognostic utility of predischarge dipyridamole-thallium imaging compared to predischarge submaximal exercise electrocardiography and maximal exercise thallium imaging after uncomplicated acute myocardial infarction

    SciTech Connect

    Gimple, L.W.; Hutter, A.M. Jr.; Guiney, T.E.; Boucher, C.A. )

    1989-12-01

    The prognostic value of predischarge dipyridamole-thallium scanning after uncomplicated myocardial infarction was determined by comparison with submaximal exercise electrocardiography and 6-week maximal exercise thallium imaging and by correlation with clinical events. Two endpoints were defined: cardiac events and severe ischemic potential. Of the 40 patients studied, 8 had cardiac events within 6 months (1 died, 3 had myocardial infarction and 4 had unstable angina requiring hospitalization). The finding of any redistribution on dipyridamole-thallium scanning was common (77%) in these patients and had poor specificity (29%). Redistribution outside of the infarct zone, however, had equivalent sensitivity (63%) and better specificity (75%) for events (p less than 0.05). Both predischarge dipyridamole-thallium and submaximal exercise electrocardiography identified 5 of the 8 events (p = 0.04 and 0.07, respectively). The negative predictive accuracy for events for both dipyridamole-thallium and submaximal exercise electrocardiography was 88%. In addition to the 8 patients with events, 16 other patients had severe ischemic potential (6 had coronary bypass surgery, 1 had inoperable 3-vessel disease and 9 had markedly abnormal 6-week maximal exercise tests). Predischarge dipyridamole-thallium and submaximal exercise testing also identified 8 and 7 of these 16 patients with severe ischemic potential, respectively. Six of the 8 cardiac events occurred before 6-week follow-up. A maximal exercise thallium test at 6 weeks identified 1 of the 2 additional events within 6 months correctly. Thallium redistribution after dipyridamole in coronary territories outside the infarct zone is a sensitive and specific predictor of subsequent cardiac events and identifies patients with severe ischemic potential.

  5. Prognostic utility of predischarge dipyridamole-thallium imaging compared to predischarge submaximal exercise electrocardiography and maximal exercise thallium imaging after uncomplicated acute myocardial infarction.

    PubMed

    Gimple, L W; Hutter, A M; Guiney, T E; Boucher, C A

    1989-12-01

    The prognostic value of predischarge dipyridamole-thallium scanning after uncomplicated myocardial infarction was determined by comparison with submaximal exercise electrocardiography and 6-week maximal exercise thallium imaging and by correlation with clinical events. Two endpoints were defined: cardiac events and severe ischemic potential. Of the 40 patients studied, 8 had cardiac events within 6 months (1 died, 3 had myocardial infarction and 4 had unstable angina requiring hospitalization). The finding of any redistribution on dipyridamole-thallium scanning was common (77%) in these patients and had poor specificity (29%). Redistribution outside of the infarct zone, however, had equivalent sensitivity (63%) and better specificity (75%) for events (p less than 0.05). Both predischarge dipyridamole-thallium and submaximal exercise electrocardiography identified 5 of the 8 events (p = 0.04 and 0.07, respectively). The negative predictive accuracy for events for both dipyridamole-thallium and submaximal exercise electrocardiography was 88%. In addition to the 8 patients with events, 16 other patients had severe ischemic potential (6 had coronary bypass surgery, 1 had inoperable 3-vessel disease and 9 had markedly abnormal 6-week maximal exercise tests). Predischarge dipyridamole-thallium and submaximal exercise testing also identified 8 and 7 of these 16 patients with severe ischemic potential, respectively. Six of the 8 cardiac events occurred before 6-week follow-up. A maximal exercise thallium test at 6 weeks identified 1 of the 2 additional events within 6 months correctly. Thallium redistribution after dipyridamole in coronary territories outside the infarct zone is a sensitive and specific predictor of subsequent cardiac events and identifies patients with severe ischemic potential.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Technetium-99m sestamibi myocardial imaging: Same-day rest-stress studies and dipyridamole

    SciTech Connect

    Taillefer, R. )

    1990-10-16

    Unlike thallium-201, technetium-99m (Tc-99m) sestamibi does not redistribute in the myocardium after injection. Thus, 2 separate injections, 1 at rest and the other at stress (or after dipyridamole), are required to differentiate ischemia from scar. From a physical viewpoint, a 24-hour interval between the 2 injections is preferable for detection of coronary artery disease (CAD) with Tc-99m sestamibi imaging. However, same-day studies are more convenient in clinical practice. Results of studies using different Tc-99m sestamibi injection protocols are presented with emphasis on the advantages of a rest-stress injection sequence with a low dose at rest (7 mCi) followed 2 hours later by a higher dose at stress (25 mCi). A prospective study was conducted in a patient population with proven CAD using same-day studies to compare a rest-stress (7 and 25 mCi, respectively) to a stress-rest (7 and 25 mCi) Tc-99m sestamibi injection sequence. There was an agreement in 87.3% of the analyzed segments between the 2 protocols. However, the largest discordance for type of defect applied to 7.4% of the segments judged ischemic in the rest-stress protocol, which were called scars on stress-rest. This study showed that a rest-stress sequence is preferable when using a same-day protocol with a short time interval (less than 2 hours) between the 2 Tc-99m sestamibi injections because the rest image performed initially represents a true rest study, which is not necessarily the case with the stress-rest sequence. Preliminary studies were performed to evaluate dipyridamole with Tc-99m sestamibi imaging in normal subjects and in patients with CAD. These studies showed that treadmill and dipyridamole Tc-99m sestamibi imaging are comparable and the results are similar to those obtained with thallium-201.

  7. Myocardial metabolic, hemodynamic, and electrocardiographic significance of reversible thallium-201 abnormalities in hypertrophic cardiomyopathy

    SciTech Connect

    Cannon, R.O. 3d.; Dilsizian, V.; O'Gara, P.T.; Udelson, J.E.; Schenke, W.H.; Quyyumi, A.; Fananapazir, L.; Bonow, R.O. )

    1991-05-01

    Exercise-induced abnormalities during thallium-201 scintigraphy that normalize at rest frequently occur in patients with hypertrophic cardiomyopathy. However, it is not known whether these abnormalities are indicative of myocardial ischemia. Fifty patients with hypertrophic cardiomyopathy underwent exercise {sup 201}Tl scintigraphy and, during the same week, measurement of myocardial lactate metabolism and hemodynamics during pacing stress. Thirty-seven patients (74%) had one or more {sup 201}Tl abnormalities that completely normalized after 3 hours of rest; 26 had regional myocardial {sup 201}Tl defects, and 26 had apparent left ventricular cavity dilatation with exercise, with 15 having coexistence of these abnormal findings. Of the 37 patients with reversible {sup 201}Tl abnormalities, 27 (73%) had metabolic evidence of myocardial ischemia during rapid atrial pacing compared with four of 13 patients (31%) with normal {sup 201}Tl scans (p less than 0.01). Eleven patients had apparent cavity dilatation as their only {sup 201}Tl abnormality; their mean postpacing left ventricular end-diastolic pressure was significantly higher than that of the 13 patients with normal {sup 201}Tl studies (33 +/- 5 versus 21 +/- 10 mm Hg, p less than 0.001). There was no correlation between the angiographic presence of systolic septal or epicardial coronary arterial compression and the presence or distribution of {sup 201}Tl abnormalities. Patients with ischemic ST segment responses to exercise had an 80% prevalence rate of reversible {sup 201}Tl abnormalities and a 70% prevalence rate of pacing-induced ischemia. However, 69% of patients with nonischemic ST segment responses had reversible {sup 201}Tl abnormalities, and 55% had pacing-induced ischemia. Reversible {sup 201}Tl abnormalities during exercise stress are markers of myocardial ischemia in hypertrophic cardiomyopathy and most likely identify relatively underperfused myocardium.

  8. 201Tl+-labelled Prussian blue nanoparticles as contrast agents for SPECT scintigraphy

    NASA Astrophysics Data System (ADS)

    Perrier, M.; Busson, M.; Massasso, G.; Long, J.; Boudousq, V.; Pouget, J.-P.; Peyrottes, S.; Perigaud, Ch.; Porredon-Guarch, C.; de Lapuente, J.; Borras, M.; Larionova, J.; Guari, Y.

    2014-10-01

    Prussian blue (PB) and its analogues on the nanometric scale are exciting nano-objects that combine the advantages of molecular-based materials and nanochemistry. Herein, we demonstrate that ultra-small PB nanoparticles of 2-3 nm can be easily labelled with radioactive 201Tl+ to obtain new nanoprobes as radiotracers for 201-thallium-based imaging.Prussian blue (PB) and its analogues on the nanometric scale are exciting nano-objects that combine the advantages of molecular-based materials and nanochemistry. Herein, we demonstrate that ultra-small PB nanoparticles of 2-3 nm can be easily labelled with radioactive 201Tl+ to obtain new nanoprobes as radiotracers for 201-thallium-based imaging. Electronic supplementary information (ESI) available: Experimental details and procedures, toxicological data, PXRD, TEM images, kinetics and adsorption isotherms, SPECT/CT images, Tl+ captation profiles. See DOI: 10.1039/c4nr03044c

  9. Comparison of early exercise treadmill test and oral dipyridamole thallium-201 tomography for the identification of jeopardized myocardium in patients receiving thrombolytic therapy for acute Q-wave myocardial infarction

    SciTech Connect

    Jain, A.; Hicks, R.R.; Frantz, D.M.; Myers, G.H.; Rowe, M.W. )

    1990-09-01

    Thrombolytic therapy has become the treatment of choice for patients with acute myocardial infarction. Researchers are not yet able to identify patients with salvage of myocardium who are at risk for recurrent coronary events. Thus, a prospective trial was performed in 46 patients with myocardial infarction (28 anterior and 18 inferior) who received thrombolytic therapy to determine if early thallium tomography (4.7 days) using oral dipyridamole would identify more patients with residual ischemia than early symptom-limited exercise treadmill tests (5.5 days). There were no complications during the exercise treadmill tests or oral dipyridamole thallium tomography. Mean duration of exercise was 11 +/- 3 minutes and the peak heart rate was 126 beats/min. Thirteen patients had positive test results. After oral dipyridamole all patients had abnormal thallium uptake on the early images. Positive scans with partial filling in of the initial perfusion defects were evident in 34 patients. Angina developed in 13 patients and was easily reversed with intravenous aminophylline. Both symptom-limited exercise treadmill tests and thallium tomography using oral dipyridamole were safely performed early after myocardial infarction in patients receiving thrombolytic therapy. Thallium tomography identified more patients with residual ischemia than exercise treadmill tests (74 vs 28%). Further studies are required to determine whether the results of thallium tomography after oral dipyridamole can be used to optimize patient management and eliminate the need for coronary angiography in some patients.

  10. Dipyridamole technetium-99m sestamibi myocardial tomography in patients evaluated for elective vascular surgery: prognostic value for perioperative and late cardiac events.

    PubMed

    Stratmann, H G; Younis, L T; Wittry, M D; Amato, M; Miller, D D

    1996-05-01

    Dipyridamole thallium-201 myocardial imaging can provide information regarding risk of perioperative cardiac events in patients being considered for vascular surgery. The value for this purpose of myocardial imaging with technetium-99m sestamibi (MIBI), a radiotracer with biokinetic and imaging properties different from thallium-201, has not been established. To this end the prognostic value of dipyridamole MIBI tomography for perioperative and late cardiac events was evaluated in 229 consecutive patients being considered for elective vascular surgery. Vascular surgery was done < or = 3 months after testing in 197 of these patients. Perioperative cardiac events (cardiac death, nonfatal myocardial infarction, unstable angina, or ischemic pulmonary edema) occurred in 9 (5%) patients. The rate of such events was 3% in patients with normal MIBI results, 5% in those with abnormal results, and 6% in patients with a reversible MIBI defect (both p = NS). When patients with abnormal MIBI results who had preoperative cardiac interventions (coronary revascularization or an increase in antiischemic medical therapy) were compared with with those who did not, no significant differences in the occurrence of perioperative cardiac events were found between these two groups either. A group of 172 medically treated patients who survived vascular surgery and did not have a nonfatal perioperative cardiac event was then monitored (mean 21 +/- 14 months) for the occurrence of a serious late cardiac event (nonfatal myocardial infarction or cardiac death). Event-free survival (Mantel-Cox) was significantly less in patients with abnormal studies compared with those with normal scan results. Late cardiac events occurred in 26 (15%) patients, with those having an abnormal MIBI result showing a significantly greater event rate than those with normal results (26% vs 4%, p < 0.0001). The rate of late cardiac events was 33% in patients with a reversible MIBI defect (p < 0.001) and 23% in those

  11. Respiratory arrest during dipyridamole stress testing.

    PubMed Central

    Hillis, G. S.; al-Mohammad, A.; Jennings, K. P.

    1997-01-01

    There is an increasing usage of radionuclide scanning to assess myocardial perfusion, with dipyridamole, the most commonly used stress agent. Although this is an effective, and usually very safe, means by which to assess myocardial blood supply, there have been several incidents of acute bronchospasm in asthmatic patients. There have, however, been no previous reports of respiratory arrest occurring in patients with emphysema. This case illustrates the dangers of administering intravenous dipyridamole, or even adenosine, to patients with chronic lung disease. PMID:9196707

  12. Activity determination of a 201Tl solution by 4πβ-γ and sum-peak coincidence methods

    NASA Astrophysics Data System (ADS)

    Ruzzarin, A.; da Silva, M. A. L.; Iwahara, A.; da Silva, R. L.; Filho, O. L. T.; Poledna, R.; Lopes, R. T.

    2016-07-01

    201Tl is used in nuclear medicine in cardiac imaging for evaluating the injury level in cardiac muscle at rest and exercise. In this work the activity concentration of a 201 Tl radioactive solution has been absolutely determined using the 4πβ-γ coincidence and sum-peak coincidence methods. The presence of 202Tl radioactive impurity that imposes some difficult in the activity measurements was taken into account in the measurements. In the sum-peak method a planar germanium detector was used. The half-lives were evaluated by the reference source method and the results obtained were (3.033 ± 0.004) d and (12.320 ± 0.163) d, respectively, for 201Tl and 202Tl.

  13. A noninvasive method for evaluating portal circulation by administration of /sup 201/Tl per rectum

    SciTech Connect

    Tonami, N.; Nakajima, K.; Hisada, K.; Tanaka, N.; Kobayashi, K.

    1982-11-01

    A new method for evaluating portal systemic circulation by administration of /sup 201/Tl per rectum was performed in 13 control subjects and in 65 patients with various liver diseases. In normal controls, the liver was visualized on the 0--5-min image whereas the images of other organs such as the heart, spleen, and lungs were very poor. In patients with liver cirrhosis associated with portal-systemic shunt, and in many other patients with hepatocellular damage, the liver was not so clearly visualized, whereas radioactivity in other organs, especially the heart, became evident. The heart-to-liver uptake ratio at 20 min after administration (H/L ratio) was significantly higher in liver cirrhosis than in normals and patients with chronic hepatitis (p less than 0.001). The patients with esophageal varices showed a significantly higher H/L ratio compared with that in cirrhotic patients without esophageal varices (p less than 0.001). The H/L ratio also showed a significant difference (p less than 0.01) between Stage 1 and Stage 3 esophageal varices. Since there were many other patients with hepatocellular damage who had high H/L ratios similar to those in liver cirrhosis, the effect that hepatocellular damage has on the liver uptake of /sup 201/Tl is also considered. Our present data suggest that this noninvasive method seems to be useful in evaluating portal-to-systemic shunting.

  14. Effect of eating on thallium myocardial imaging

    SciTech Connect

    Wilson, R.A.; Sullivan, P.J.; Okada, R.D.; Boucher, C.A.; Morris, C.; Pohost, G.M.; Strauss, H.W.

    1986-02-01

    To determine if eating between initial and delayed thallium images alters the appearance of the delayed thallium scan, a prospective study was performed; 184 subjects sent for routine thallium imaging were randomized into two groups, those who ate a meal high in carbohydrates between initial and delayed thallium myocardial images (n = 106), and those who fasted (n = 78). The /sup 201/Tl images were interpreted in blinded fashion for global myocardial and pulmonary clearance of /sup 201/Tl myocardial defects. The eating group had a significantly lower incidence of transient myocardial defects compared to the noneating group (7 percent vs 18 percent, respectively; p less than 0.05). The time between initial and delayed images and the incidence of exercise-induced ischemic ST-segment depression or pathologic Q waves on the electrocardiogram were not significantly different between the two groups. These data suggest that eating a high-carbohydrate meal between initial and delayed /sup 201/Tl images causes increased /sup 201/Tl myocardial clearance rates and may alter /sup 201/Tl myocardial redistribution over time.

  15. Effect of thallium-201 blood levels on reversible myocardial defects

    SciTech Connect

    Nelson, C.W.; Wilson, R.A.; Angello, D.A.; Palac, R.T.

    1989-07-01

    To determine if /sup 201/Tl plasma blood levels correlate with the presence of reversible myocardial defects during exercise testing, 14 patients with stable coronary artery disease underwent two separate exercise /sup 201/Tl stress tests. Between initial and delayed imaging, on one test the patients drank an instant breakfast drink (eating) and on the other they drank an equivalent volume of water as a control (H/sub 2/O). Thallium-201 imaging was performed immediately postexercise, immediately after eating/H/sub 2/O and 210 min after eating/H/sub 2/O. Between initial and immediate post eating/H/sub 2/O images 201Tl reversible defects occurred in 27/38 regions in the H/sub 2/O test versus 15/38 regions in the eating test (p = 0.02). Over this early time period, plasma /sup 201/Tl activity was significantly higher in the H/sub 2/O test than eating test (p less than 0.05). In conclusion, early reversal of /sup 201/Tl defects may, in part, be the result of higher plasma /sup 201/Tl activity early after initial postexercise /sup 201/Tl imaging.

  16. Thallium-201/technetium-99m-RP-30A disparity in the course of myocardial infarction after attempted reperfusion

    SciTech Connect

    Tatum, J.L.; Rehr, R.B.; DiSciascio, G.; Romhilt, D.W.; Fratkin, M.J.

    1988-07-01

    Recent reports have established that /sup 201/Tl may be taken up in areas of recent myocardial infarction after myocardial blood flow is re-established. In addition, there is accelerated /sup 201/Tl washout from these regions producing a pattern of reverse redistribution. We present a case in which these phenomena may have contributed to a disparity of findings between a /sup 201/Tl stress imaging study and a repeat stress imaging study performed with a (/sup 99m/Tc) isonitrile (/sup 99m/Tc-RP-30A).

  17. Noninvasive cardiac risk stratification of diabetic and nondiabetic uremic renal allograft candidates using dipyridamole-thallium-201 imaging and radionuclide ventriculography

    SciTech Connect

    Brown, K.A.; Rimmer, J.; Haisch, C. )

    1989-11-01

    The ability of noninvasive risk stratification using dipyridamole-thallium-201 (Tl-201) imaging and radionuclide ventriculography to predict perioperative and long-term cardiac events (myocardial infarction or cardiac death) was evaluated in 36 uremic diabetic and 29 nondiabetic candidates for renal allograft surgery. Of the 35 patients who underwent renal allograft surgery 8 +/- 7 months after the study, none had transient Tl-201 defects (although 13 had depressed left ventricular ejection fraction) and none developed perioperative cardiac events. During a mean follow-up of 23 +/- 11 months, 6 (9%) patients developed cardiac events. Logistic regression analysis was used to compare the predictive value of clinical data (including age, sex, diabetes, chest pain history, allograft recipient) and radionuclide data. Presence of transient Tl-201 defect and left ventricular ejection fraction were the only significant predictors of future cardiac events (p less than 0.01). No other patient variables, including diabetes or receiving a renal allograft, had either univariate or multivariate predictive value. All 3 patients with transient Tl-201 defects had cardiac events compared with only 3 of 62 (5%) patients without transient Tl-201 defect (p less than 0.0001). Mean left ventricular ejection fraction was lower in patients with cardiac events (44 +/- 13%) compared with patients without cardiac events (57 +/- 9%, p less than 0.005). Overall, 5 of 6 patients with cardiac events had either transient Tl-201 defects or depressed left ventricular ejection fraction. Dipyridamole-Tl-201 imaging and radionuclide ventriculography may be helpful in identifying uremic candidates for renal allograft surgery who are at low risk for perioperative and long-term cardiac events.

  18. Fast washout of thallium-201 from area of myocardial infarction: possible artifact of background subtraction

    SciTech Connect

    Brown, K.A.; Benoit, L.; Clements, J.P.; Wackers, F.J.

    1987-06-01

    A recent report described a pattern of reverse redistribution on poststreptokinase /sup 201/Tl studies which was believed to be due to rapid washout of /sup 201/Tl from the infarct area related to reperfusion of the infarct vessel. We have also observed the phenomenon of rapid washout of /sup 201/Tl from the area of infarction in the absence of thrombolytic therapy. This study was undertaken to test the hypothesis that rapid washout of /sup 201/Tl from an area of infarction is an artifact of background subtraction usually employed in analysis of washout. A total of 61 patients with previous myocardial infarction who underwent cardiac catheterization and exercise /sup 201/Tl imaging were examined. Thallium-201 images were analyzed using a validated quantitative method employing interpolative background correction. Abnormally increased /sup 201/Tl washout was noted in 11 infarct segments in 10 (18%) patients. Infarct segments with rapid washout had significantly less initial uptake, and more severe associated wall motion abnormalities than infarct segments with normal washout. When quantitative analysis was repeated without background subtraction, no segments with rapid washout were observed. A phantom model was constructed to further test our hypothesis. The frequency of observed rapid washout was directly related to the severity of the initial defect and was entirely dependent upon utilizing background correction during the quantitative analysis. Our study suggests that rapid washout of /sup 201/Tl in an area of previous infarction reflects an artifact of background subtraction involved with standard quantitative analysis.

  19. Contamination and radiation exposure from sup 201 Tl in patients undergoing dialysis after a nuclear medicine study

    SciTech Connect

    Serrano, M.; Olson, A.; Man, C.; Galonsky, R.; Stein, R. )

    1991-03-01

    Our institution is a major kidney research and transplant center. Hemodialysis patients that are scheduled for renal transplant are given a 201Tl stress test. Possible radiation exposure and contamination are of concern to attending personnel. We investigated this situation and found measurable activity in the effluent of patients receiving dialysis but no significant contamination of equipment. We determined that dialysis personnel received minimal radiation exposure.

  20. Thallium-201 is comparable to technetium-99m-sestamibi for estimating cardiac function in patients with abnormal myocardial perfusion imaging.

    PubMed

    Wu, Ming-Che; Tsai, Cheng-Ting; Lin, Hui-Chun; Sun, Fang-Ju; Lin, Ku-Hung

    2015-11-01

    We analyzed the left-ventricular functional data obtained by cardiac-gated single-photon emission computed tomography myocardial perfusion imaging (MPI) with thallium-201 (Tl-201) and technetium-99m-sestamibi (MIBI) protocols in different groups of patients, and compared the data between Tl-201 and MIBI. Two hundred and seventy-two patients undergoing dipyridamole stress/redistribution Tl-201 MPI and 563 patients undergoing 1-day rest/dipyridamole stress MIBI MPI were included. Higher mean stress ejection fraction (EF), rest EF, and change in EF (ΔEF) were noticed in the normal MPI groups by both Tl-201 and MIBI protocols. Higher mean EF was observed in the females with normal MPI results despite their higher mean age. Comparisons between the Tl-201 and MIBI groups suggested a significant difference in all functional parameters, except for the rest end diastolic volume/end systolic volume and ΔEF between groups with negative MPI results. For the positive MPI groups, there was no significant difference in all parameters, except for the change in end diastolic volume and change in end systolic volume after stress between both protocols. The Tl-201 provides comparable left-ventricular functional data to MIBI cardiac-gated single-photon emission computed tomography in patients with positive MPI results, and may therefore be undertaken routinely for incremental functional information that is especially valuable to this patient group.

  1. Thallium-201 is comparable to technetium-99m-sestamibi for estimating cardiac function in patients with abnormal myocardial perfusion imaging.

    PubMed

    Wu, Ming-Che; Tsai, Cheng-Ting; Lin, Hui-Chun; Sun, Fang-Ju; Lin, Ku-Hung

    2015-11-01

    We analyzed the left-ventricular functional data obtained by cardiac-gated single-photon emission computed tomography myocardial perfusion imaging (MPI) with thallium-201 (Tl-201) and technetium-99m-sestamibi (MIBI) protocols in different groups of patients, and compared the data between Tl-201 and MIBI. Two hundred and seventy-two patients undergoing dipyridamole stress/redistribution Tl-201 MPI and 563 patients undergoing 1-day rest/dipyridamole stress MIBI MPI were included. Higher mean stress ejection fraction (EF), rest EF, and change in EF (ΔEF) were noticed in the normal MPI groups by both Tl-201 and MIBI protocols. Higher mean EF was observed in the females with normal MPI results despite their higher mean age. Comparisons between the Tl-201 and MIBI groups suggested a significant difference in all functional parameters, except for the rest end diastolic volume/end systolic volume and ΔEF between groups with negative MPI results. For the positive MPI groups, there was no significant difference in all parameters, except for the change in end diastolic volume and change in end systolic volume after stress between both protocols. The Tl-201 provides comparable left-ventricular functional data to MIBI cardiac-gated single-photon emission computed tomography in patients with positive MPI results, and may therefore be undertaken routinely for incremental functional information that is especially valuable to this patient group. PMID:26678935

  2. Myocardial uptake of thallium and rubidium during alterations in perfusion and oxygenation in isolated rabbit hearts

    SciTech Connect

    Leppo, J.A.

    1987-05-01

    The comparative effects of altered cellular function and coronary perfusion on myocardial /sup 201/Tl and /sup 83/Rb uptake were evaluated in three groups of isolated rabbit hearts having isovolumic contractions. Paired-indication dilution experiments were performed with /sup 201/Tl, /sup 83/Rb, and /sup 111/In-labeled albumin as an intravascular reference marker. In Group A hearts (n = 12), isotope transport was determined during control, hypoxia, and ischemia. In Group B hearts (n = 8), isotope transport was measured at control flow and again at a 50% and 80% reduction. In Group C hearts (n = 8) only /sup 201/Tl uptake was determined at control and following coronary reperfusion. Myocardial /sup 201/Tl and /sup 83/Rb transport were not significantly different and were proportional to flow. Although all interventions caused significant hemodynamic alterations, neither tracer was affected by hypoxia at constant flow. Thallium-201 permeation, however, was transiently decreased immediately after coronary reperfusion. We conclude that myocardial uptake of /sup 201/Tl and /sup 83/Rb are similar and directly related to flow, but do not reflect hypoxia induced cellular dysfunction.

  3. Radionuclide imaging in myocardial sarcoidosis. Demonstration of myocardial uptake of /sup 99m/Tc pyrophosphate and gallium

    SciTech Connect

    Forman, M.B.; Sandler, M.P.; Sacks, G.A.; Kronenberg, M.W.; Powers, T.A.

    1983-03-01

    A patient had severe congestive cardiomyopathy secondary to myocardial sarcoidosis. The clinical diagnosis was confirmed by radionuclide ventriculography, /sup 201/Tl, /sup 67/Ga, and /sup 99m/Tc pyrophosphate (TcPYP) scintigraphy. Myocardial TcPYP uptake has not been reported previously in sarcoidosis. In this patient, TcPYP was as useful as gallium scanning and thallium imaging in documenting the myocardial process.

  4. Kinetic analysis of 18F-fluorodihydrorotenone as a deposited myocardial flow tracer: Comparison to thallium-201.

    SciTech Connect

    Marshall, Robert C.; Powers-Risius, Patricia; Reutter, Bryan W.; O'Neil, James P.; La Belle, Michael; Huesman, Ronald H.; VanBrocklin, Henry F.

    2004-03-01

    The goal of this investigation was to assess the accuracy of 18F-fluorodihydrorotenone (18F-FDHR) as a new deposited myocardial flow tracer and compare the results to those for 201Tl. Methods. The kinetics of these flow tracers were evaluated in 22 isolated, erythrocyte- and albumin-perfused rabbit hearts over a flow range encountered in patients. The two flow tracers plus a vascular reference tracer (131I-albumin) were introduced as a bolus through a port just above the aortic cannula. Myocardial extraction, retention, washout, and uptake parameters were computed from the venous outflow curves using the multiple indicator dilution technique and spectral analysis. Results. The mean initial extraction fractions of 18F-FDHR (0.85 +- 0.07) and 201Tl (0.87 +- 0.05) were not significantly different, although the initial extraction fraction for 18F-FDHR declined with flow (P < 0.0001), whereas the initial extraction fraction of 201Tl did not. Washout of 201Tl was faster (P < 0.001) and more affected by flow (P < 0.05) than 18F-FDHR washout. Except for initial extraction fraction, 18F-FDHR retention was greater (P < 0.001) and less affected by flow (P < 0.05) than 201Tl retention. Reflecting its superior retention, net uptake of 18F-FDHR was better correlated with flow than 201Tl uptake at both one and fifteen minutes after tracer introduction (P < 0.0001 for both comparisons). Conclusion. The superior correlation of 18F-FDHR uptake with flow indicates that it is a better flow tracer than 201Tl in the isolated rabbit heart. Compared to the other currently available positron-emitting flow tracers (82Rb, 13N-ammonia, and 15O-water), 18F-FDHR has the potential of providing excellent image resolution without the need for an on-site cyclotron.

  5. [Dual isotope myocardial scintigraphy (201thallium at rest/99 M technetium tetrofosmin with exercise) in the detection of reversible hypoperfusion].

    PubMed

    Peix González, A; López Díaz, A; Ponce Vicente, F; Maltas Pineda, A M; García Fernández, R; Barrera Sarduy, J D; García Barreto, D

    2000-02-01

    The dual-isotope technique (rest 201Tl and stress 99mTc-sestamibi) is useful to assess myocardial perfusion in coronary disease patients. 99mTc-labeled tetrofosmin is a radiopharmaceutical whose characteristics are similar to sestamibi. Thus, we decided to use it to detect reversible myocardial hypoperfusion in patients with a background of myocardial infarction and ischemia. A sequential dual-isotope scintigraphy (3 mCi rest 201Tl and 25 mCi stress 99mTc-tetrofosmin) with 24-hour 201Tl redistribution (RD) was performed in 20 patients with previously confirmed myocardial infarction and clinical and ergometric signs of ischemia. Each patient also underwent a stress-redistribution protocol with redistribution at 4 and 24 hours post injection with 201Tl scintigraphy within two weeks of the first study. The qualitative uptake analysis showed no significant differences in the number of myocardial segments with severe reduction of tracer uptake on stress that improved at rest or in RD images, even if 24-hour RD images were considered. The quantitative global uptake analysis showed a similar defect reversibility with both protocols; however if 24-hour RD images were considered the uptake improvement was significant only when compared with the rest 201Tl images in dual-isotope scintigraphy protocol (75+/-8% vs. 81+/-9% of peak activity, rest vs. 24-hour RD; p<0.01) and not when compared with the 4-hour RD in the 201Tl scintigraphy. On the other hand, when only the segments with severely reduced uptake (<50% of peak activity) were analyzed, the 24-hour RD improved myocardial uptake significantly (p<0.001 vs. rest and vs 4-hour RD) in both protocols. We conclude that a sequential dual-isotope rest 201Tl/stress 99mTc-tetrofosmin scintigraphy is comparable with stress-redistribution 201Tl scintigraphy to detect reversible myocardial hypoperfusion; however in both cases, the addition of 24-hour images increases its usefulness in severely hypoperfused segments, if the uptake of

  6. Thallium-201 scintigraphy for diagnosis of old myocardial infarction: comparison with electrocardiographic, ventriculographic, and coronary arteriographic findings.

    PubMed Central

    Uthurralt, N; Parodi, O; Severi, S; Davies, G; Maseri, A

    1980-01-01

    Myocardial scintigraphy with 201Tl was performed at rest in a selected group of 36 patients with unequivocal clinical and electrocardiographic evidence of old myocardial infarction. The scintigraphic findings were correlated with electrocardiographic pattern, and with regional left ventricular wall motion and the severity of coronary artery disease defined by contrast angiography. Detection was dependent on the extent of the infarct but was independent of QRS morphology and of the severity of coronary disease. When positive, 201Tl scintigraphy was often a more precise method than the electrocardiogram for localising and delineating the extent of the infarct. Furthermore, the perfusion defect corresponded in location and extent to abnormalities of left ventricular wall motion. The site or severity of coronary artery disease could not be determined from the 201Tl scintigram. Images PMID:7378212

  7. Using adaptive neuro-fuzzy inference system technique for crosstalk correction in simultaneous 99mTc/201Tl SPECT imaging: A Monte Carlo simulation study

    NASA Astrophysics Data System (ADS)

    Heidary, Saeed; Setayeshi, Saeed

    2015-01-01

    This work presents a simulation based study by Monte Carlo which uses two adaptive neuro-fuzzy inference systems (ANFIS) for cross talk compensation of simultaneous 99mTc/201Tl dual-radioisotope SPECT imaging. We have compared two neuro-fuzzy systems based on fuzzy c-means (FCM) and subtractive (SUB) clustering. Our approach incorporates eight energy-windows image acquisition from 28 keV to 156 keV and two main photo peaks of 201Tl (77±10% keV) and 99mTc (140±10% keV). The Geant4 application in emission tomography (GATE) is used as a Monte Carlo simulator for three cylindrical and a NURBS Based Cardiac Torso (NCAT) phantom study. Three separate acquisitions including two single-isotopes and one dual isotope were performed in this study. Cross talk and scatter corrected projections are reconstructed by an iterative ordered subsets expectation maximization (OSEM) algorithm which models the non-uniform attenuation in the projection/back-projection. ANFIS-FCM/SUB structures are tuned to create three to sixteen fuzzy rules for modeling the photon cross-talk of the two radioisotopes. Applying seven to nine fuzzy rules leads to a total improvement of the contrast and the bias comparatively. It is found that there is an out performance for the ANFIS-FCM due to its acceleration and accurate results.

  8. 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.

  9. Update on intravenous dipyridamole cardiac imaging in the assessment of ischemic heart disease

    SciTech Connect

    Younis, L.T.; Chaitman, B.R. )

    1990-01-01

    Intravenous dipyridamole is a relative selective coronary vasodilator which, when combined with thallium-201, provides a useful technique to assess myocardial perfusion. The intravenous dipyridamole is administered as an infusion at a rate of 0.14 mg/kg/min for 4 minutes. In the presence of significant coronary artery disease the increase of coronary blood flow is disproportionate between vessels with and without significant coronary lesions, providing the basis for detecting regional differences in flow using thallium-201. The test can be used alone or combined with low level exercise to increase test sensitivity. The test is safe when performed under medical supervision and when patient selection is done appropriately. Most of the side effects induced by dipyridamole infusion are well tolerated by patients and readily reversed with intravenous aminophylline and sublingual nitroglycerin. The average sensitivity and specificity of the dipyridamole thallium scintigraphy test from the major studies are 76% and 70%, respectively. The test is very useful in providing prognostic information in patients who are unable to exercise. A reversible thallium defect after dipyridamole infusion has been shown to be associated with significant mortality and morbidity in patients with documented or suspected coronary artery disease. The use of intravenous dipyridamole has been extended into other modalities of imaging, including 2-dimensional and Doppler echocardiography, to study functional changes in the left ventricular induced by the infusion of intravenous dipyridamole. 52 references.

  10. Dipyridamole dilates large cerebral arteries concomitant to headache induction in healthy subjects.

    PubMed

    Kruuse, C; Jacobsen, T B; Lassen, L H; Thomsen, L L; Hasselbalch, S G; Dige-Petersen, H; Olesen, J

    2000-09-01

    Dipyridamole is used for secondary prophylaxis in ischemic stroke and as a vasodilator agent in myocardial scintigraphy. An important side effect to administering dipyridamole is headache. The aim of the current study was to investigate the effects of dipyridamole on cerebral blood flow, large artery diameter, and headache induction. Twelve healthy subjects were included in this single-blind placebo-controlled study in which placebo (0.9% NaCl) and dipyridamole 0.142 mg/kg x min were administered intravenously over 4 minutes 1 hour apart. Blood flow velocity in the middle cerebral artery (Vmax) was recorded by transcranial Doppler and regional cerebral blood flow in the middle cerebral artery (rCBFmca) was measured using single photon emission computed tomography and 133Xenon-inhalation. Blood pressure, heart rate, and pCO2 were measured repeatedly. Headache response was scored every 10 minutes on a verbal scale from 0 to 10 (10 = worst). Dipyridamole caused a decrease in pCO2 (P < 0.001). pCO2 corrected rCBFmca was 41.7 +/- 6.9 mL/100 g x min after placebo versus 41.2 +/- 6.9 after dipyridamole (P > or = 0.05). pCO2 corrected Vmca decreased 8.4% +/- 11.7 (P < 0.001) after dipyridamole, indicating a mean 5.6% +/- 6.7 (P = 0.005) relative increase of the arterial diameter. After dipyridamole the median peak headache score was 2 (range 0 to 7) compared with 0 (range 0 to 3) after placebo (P = 0.02). Dilatation of the middle cerebral artery outlasted the headache response. In conclusion, dipyridamole causes a modest pCO2 independent dilatation of the MCA, which is time-linked to the onset, but not to the cessation, of headache.

  11. 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.

  12. Rectal bleeding induced by Dipyridamole.

    PubMed

    Bayer, I; Kyzer, S; Creter, D; Lewinski, U H

    1986-02-01

    Nineteen patients treated continuously with Dipyridamole were evaluated for rectal bleeding. Thirteen suffered from overt rectal bleeding and six served as controls. Hemorrhoids were found in all patients. Contact bleeding was found in 16. The bleeding continued despite rubber band ligation, and stopped only on withdrawal of the drug. PMID:3484697

  13. Imaging of cocaine-induced global and regional myocardial ischemia

    SciTech Connect

    Oster, Z.H.; Som, P.; Wang, G.J.; Weber, D.A. )

    1991-08-01

    Severe and often fatal cardiac complications have been reported in cocaine users with narrowed coronary arteries caused by atherosclerosis as well as in young adults with normal coronaries. The authors have found that in normal dogs cocaine induces severe temporary hypoperfusion of the left ventricle as indicated by a significantly lower 201Tl concentration compared to the baseline state. The most significant decrease in uptake occurred 5 min after injection and was more pronounced in the septal and apical segments. Following intravenous administration of cocaine, instead of gradual disappearance of 201Tl from the left ventricle, there was continuous increase in 201Tl concentration in the left ventricle. These imaging experiments indicate that the deleterious effects of cocaine on the heart are probably due to spasm of the coronaries and decreased myocardial perfusion. Since spasm of the large subpericardial vessels does not seem to explain the magnitude of the increased coronary resistance and decreased coronary flow after cocaine as described in the literature, it is suggested that microvascular spasm of smaller vessels plays a major role in the temporary decrease in perfusion. The data may also suggest that severe temporary myocardial ischemia is probably the initiating factor for the cardiac complications induced by cocaine.

  14. Risk stratification after myocardial infarction. Clinical overview

    SciTech Connect

    O'Rourke, R.A. )

    1991-09-01

    Many patients with an acute myocardial infarction can be stratified into subgroups that are at high risk for morbidity and mortality on the basis of clinical characteristics that indicate recurrent myocardial ischemia, persistent left ventricular dysfunction, and/or recurrent cardiac arrhythmias. In patients with uncomplicated myocardial infarction the assessment of symptoms, physical findings, and ECG changes during predischarge exercise testing often identifies patients at increased risk for further cardiac events. Because of the suboptimum sensitivity and specificity of the exercise ECG for detecting myocardial ischemia, myocardial perfusion imaging with 201Tl and/or assessment of global and segmental ventricular function by two-dimensional echocardiography or radionuclide cineangiography during or immediately after exercise are often added to the predischarge risk stratification.

  15. Myocardial accumulation of iodinated beta-methyl-branched fatty acid analogue, iodine-125-15-(p-iodophenyl)-3-(R,S)methylpentadecanoic acid (BMIPP), in relation to ATP concentration

    SciTech Connect

    Fujibayashi, Y.; Yonekura, Y.; Takemura, Y.; Wada, K.; Matsumoto, K.; Tamaki, N.; Yamamoto, K.; Konishi, J.; Yokoyama, A. )

    1990-11-01

    To clarify the relationship between the myocardial accumulation of {sup 125}I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) and intracellular adenosine-5'-triphosphate (ATP) content, the effect of 2,4-dinitrophenol (DNP, an electron transport uncoupler) on myocardial BMIPP accumulation was studied, in comparison with that of thallium-201-chloride ({sup 201}Tl-Cl). In the mouse myocardium, DNP decreased the intracellular ATP and ADP levels, without affecting either acyl-CoA synthetase activity or the level of CoA-SH. Following treatment with DNP, decreases in myocardial BMIPP accumulation correlated well with those of ATP, while {sup 201}Tl-Cl showed slightly increased accumulation in the myocardium. Thus, in some diseases, BMIPP may be useful in evaluating myocardial ATP levels.

  16. Estimation of infarct size by myocardial emission computed tomography with thallium-201 and its relation to creatine kinase-MB release after myocardial infarction in man

    SciTech Connect

    Tamaki, S.; Nakajima, H.; Murakami, T.

    1982-11-01

    Emission computed tomography (ECT) for thallium-201 (/sup 201/Tl) myocardial imaging was evaluated in estimating infarct size (IS). In 18 patients in whom IS was estimated enzymatically at the time of the acute episode, planar /sup 201/Tl perfusion scintigraphy and ECT with a rotating gamma camera were performed 4 weeks after the first myocardial infarction. From the size of /sup 201/Tl perfusion defects, the infarct area in planar images and the infarct volume in reconsturcted ECT images were measured by computerized planimetry. When scintigraphic IS was compared with the accumulated creatine kinase-MB isoenzyme release (CK-MBr), infarct volume determined from ECT correlated closely with CK-MBr (r=0.89), whereas infarct area measured from planar images correlated less satisfactorily with the enzymatic IS (for an average infarct area from three views, r=0.69; for the largest infarct area, r=0.73). Although conventional scintigraphic evaluation is useful for detecting and localizing infarction, quantification of ischemic injury with this two-dimensional technique has a significant inherent limitation. The ECT approach can provide a more accurate three-dimensional quantitative estimate of infarction, and can corroborate the enzymatic estimate of IS.

  17. Thallium-201 perfusion imaging with atrial pacing or dipyridamole stress testing for evaluation of cardiac risk prior to nonvascular surgery

    SciTech Connect

    Stratmann, H.G.; Mark, A.L.; Williams, G.A. )

    1990-09-01

    Preoperative assessment of cardiac risk using thallium-201 scintigraphy and atrial pacing (n = 42) or dipyridamole stress testing (n = 35) was performed in 77 patients (mean age 65 +/- 7 years), who subsequently underwent elective nonvascular surgery. All patients were at low cardiac risk by clinical criteria; none could perform exercise stress testing due to physical limitations. ST depression consistent with ischemia occurred in 11 patients during atrial pacing and in 1 patient during dipyridamole stress testing (p less than 0.01). Nine patients had reversible perfusion defects with atrial pacing, and 10 patients with dipyridamole stress testing; fixed defects were present in 15 and 8 patients, respectively. Only one patient (fixed perfusion defect with atrial pacing, left main disease on coronary angiography) underwent preoperative coronary revascularization. Two patients subsequently had postoperative cardiac events. One patient (reversible perfusion defect with dipyridamole stress testing) experienced sudden death after a nonvascular procedure, while a second patient (normal thallium images with dipyridamole testing) had a nonfatal myocardial infarction. In patients having atrial pacing or dipyridamole stress testing, thallium-201 scans that are normal or show only a fixed perfusion defect confirm a low risk of cardiac complications following nonvascular surgery. The presence of a reversible perfusion defect does not preclude a postoperative course free of cardiac complications in patients at low cardiac risk by clinical criteria.

  18. [Evaluation of reconstruction arc in myocardial SPECT imaging using a cardiac phantom--comparison between 360 degrees and 180 degrees arcs].

    PubMed

    Kashikura, K; Kashikura, A; Terada, S; Kobayashi, H

    1996-10-01

    In order to investigate the effect of reconstruction arc on myocardial SPECT images, a series of phantom studies was performed with and without plastic chambers simulating perfusion defects using 201Tl and 99mTc. Coefficient of variations (CV) of the counts among the ROIs and defect contrast were evaluated in 360 degrees and 180 degrees images reconstructed from the same 360 degrees projection data. Reconstruction processes were identical for all images. In the absence of defects, the CV of the counts were approximately the same in 360 degrees and 180 degrees images. The CV of the counts in the 360 degrees 201Tl image, among 4 defects located on the anterior, lateral, inferoposterior, and septal walls, was superior to those in the 180 degrees images. In contrast, in the 99mTc images, the CV of the counts among the 4 defects in the 180 degrees image was superior to those of the 360 degrees image. The defect contrast was changed both by the location of the defect and by the reconstruction arc (201Tl, 99mTc). The defect contrast of the 180 degrees images, in both 201Tl and 99mTc experiments, was closer to the true contrast value as calculated by the count ratio between myocardium and defect. Although the defect contrast in the anterior, lateral and septal walls was more emphasized in the 180 degrees images, the defect contrast in the inferoposterior wall was less emphasized in the 180 degrees images compared to the 360 degrees (201Tl, 99mTc).

  19. Simultaneous low level treadmill exercise and intravenous dipyridamole stress thallium imaging

    SciTech Connect

    Casale, P.N.; Guiney, T.E.; Strauss, H.W.; Boucher, C.A.

    1988-10-01

    Intravenous dipyridamole-thallium imaging unmasks ischemia in patients unable to exercise adequately. However, some of these patients can perform limited exercise, which, if added, may provide useful information. Treadmill exercise combined with dipyridamole-thallium imaging was performed in 100 patients and results compared with those of 100 other blindly age- and sex-matched patients who received dipyridamole alone. Exercise began after completion of the dipyridamole infusion. Mean +/- 1 standard deviation peak heart rate (109 +/- 19 vs 83 +/- 12 beats/min, p less than 0.0001) and peak systolic and diastolic blood pressure (146 +/- 28/77 +/- 14 vs 125 +/- 24/68 +/- 11 mm Hg, p less than 0.0001) were higher in the exercise group compared with the nonexercise group. There was no difference in the occurrence of chest pain, but more patients in the exercise group developed ST-segment depression (26 vs 12%, p less than 0.0001). The exercise group had fewer noncardiac side effects (4 vs 12%, p less than 0.01) and a higher target (heart) to background (liver) count ratio (2.1 +/- 0.7 vs 1.2 +/- 0.3; p less than 0.01), due to fewer liver counts. There were no deaths, myocardial infarctions or sustained arrhythmias in either group. Combined treadmill exercise and dipyridamole testing is safe, associated with fewer noncardiac side effects, a higher target to background ratio and a higher incidence of clinical electrocardiographic ischemia than dipyridamole alone. Therefore, it is recommended whenever possible.

  20. Aspirin and Extended-Release Dipyridamole

    MedlinePlus

    ... It is used to reduce the risk of stroke in patients who have had or are at risk of stroke. ... release dipyridamole decreases the risk of having a stroke but does not eliminate that risk. Continue to ...

  1. Quantitative comparison of thallium-201 scintigraphy after exercise and dipyridamole in coronary artery disease

    SciTech Connect

    Varma, S.K.; Watson, D.D.; Beller, G.A. )

    1989-10-15

    Data comparing myocardial thallium-201 imaging after exercise and intravenous dipyridamole infusion in the same patients are scarce. Accordingly, this study is a segment-by-segment quantitative analysis of regional uptake and washout of thallium-201 after dipyridamole (0.56 mg/kg) and symptom-limited exercise testing in 21 patients (ages 58 +/- 9.2 years) with chest pain studied 2.5 +/- 1.0 weeks apart. Thallium-201 activity in 9 myocardial segments was measured in initial and delayed anterior and 45 degree left anterior oblique views, producing 184 pairs of segments in the distribution of 63 coronary supply regions for direct comparison. The number of segments with normal thallium-201 uptake and the number of numerically significant defects were similar with exercise and dipyridamole (76 vs 73%, 24 vs 27%, respectively, difference not significant). A slightly higher proportion of redistribution defects was found after dipyridamole infusion compared to exercise (17 vs 10%, p less than 0.05). Agreement between 87% (165 of 189) of segment pairs was found when each was classified as either normal or abnormal. Although 24 of 189 segments were discordant, agreement was observed in 92% (61 of 63) of coronary supply regions determined to be normal (41 of 41) or abnormal (20 of 22). In 15 patients who underwent cardiac catheterization, exercise and dipyridamole-thallium-201 scintigraphy detected 61% (16 of 26) vs 61% (16 of 26) of stenoses greater than 50% (difference not significant) and 100% (19 of 19) vs 100% (19 of 19) (difference not significant) normal vessels, respectively.

  2. Prognostic value of dipyridamole thallium scintigraphy for evaluation of ischemic heart disease

    SciTech Connect

    Hendel, R.C.; Layden, J.J.; Leppo, J.A. )

    1990-01-01

    Exercise testing alone or in combination with thallium scintigraphy has significant prognostic value. In contrast, dipyridamole thallium imaging is not dependent on patients achieving adequate levels of exercise, but no long-term prognostic studies have been reported. Accordingly, imaging results of 516 consecutive patients referred for dipyridamole thallium studies were correlated with subsequent cardiac events, death (n = 23) and myocardial infarction (n = 43) over a mean follow-up period of 21 months. Patients with a history of congestive heart failure, prior myocardial infarction, diabetes mellitus or abnormal scans were significantly more likely to have a cardiac event (p less than 0.03). With use of logistic regression analysis, an abnormal scan was an independent and significant predictor of subsequent myocardial infarction or cardiac death and increased the relative risk of any event more than threefold. The presence of redistribution on thallium scanning further increased the risk of a cardiac event. Survival analysis demonstrated a significant difference between patients with an abnormal or normal thallium scan over a 30 month period. In conclusion, dipyridamole thallium scintigraphy demonstrates prognostic value in a large unselected population and may be an adequate clinical alternative to physiologic exercise testing in the evaluation of coronary heart disease.

  3. Comparison of an adaptive neuro-fuzzy inference system and an artificial neural network in the cross-talk correction of simultaneous 99 m Tc / 201Tl SPECT imaging using a GATE Monte-Carlo simulation

    NASA Astrophysics Data System (ADS)

    Heidary, Saeed; Setayeshi, Saeed; Ghannadi-Maragheh, Mohammad

    2014-09-01

    The aim of this study is to compare the adaptive neuro-fuzzy inference system (ANFIS) and the artificial neural network (ANN) to estimate the cross-talk contamination of 99 m Tc / 201 Tl image acquisition in the 201 Tl energy window (77 ± 15% keV). GATE (Geant4 Application in Emission and Tomography) is employed due to its ability to simulate multiple radioactive sources concurrently. Two kinds of phantoms, including two digital and one physical phantom, are used. In the real and the simulation studies, data acquisition is carried out using eight energy windows. The ANN and the ANFIS are prepared in MATLAB, and the GATE results are used as a training data set. Three indications are evaluated and compared. The ANFIS method yields better outcomes for two indications (Spearman's rank correlation coefficient and contrast) and the two phantom results in each category. The maximum image biasing, which is the third indication, is found to be 6% more than that for the ANN.

  4. Identification of hemodynamically significant coronary artery stenoses by dipyridamole-magnetic resonance imaging and 99mTc-methoxyisobutyl-isonitrile-SPECT.

    PubMed

    Baer, F M; Smolarz, K; Theissen, P; Voth, E; Schicha, H; Sechtem, U

    1993-06-01

    Magnetic resonance imaging (MRI) has been used in conjunction with dipyridamole induced wall motion abnormalities for the noninvasive detection of coronary artery disease (CAD). To assess the clinical usefulness of dipyridamole-MRI for the localization of CAD and to evaluate the relation between dipyridamole induced wall motion abnormalities and myocardial perfusion 33 patients with severe CAD (> 70% diameter reduction) underwent MRI at rest and after dipyridamole infusion (0.75 mg dipyridamole/kg over a period of 10 minutes). All patients performed exercise stress testing and 20 patients of the study group additionally had rest and exercise stress 99mTc-methoxyisobutyl-isonitrile-SPECT (MIBI-SPECT). Two patients (6%) could not be evaluated due to severe motion artifacts during dipyridamole MRI. Segmental wall motion and perfusion of corresponding short axis planes were related to the major coronary arteries using a standardized segmental coronary artery perfusion pattern. Detection of wall motion abnormalities or perfusion defects by 2 blinded observers in consensus was the criterion for grading a segment normal or pathologic. For localization of CAD, segmental gradings were related to the presumed coronary artery territories. Stress-ECG was pathologic in 19/31 patients yielding a sensitivity of 61% and dipyridamole induced angina was present in 68% (21/31) of patients. Dipyridamole-MRI detected coronary artery disease with a sensitivity of 84% (26/31 patients) and all patients with new wall motion abnormalities also had dipyridamole induced angina. For the subgroup of 20 patients with MIBI-SPECT images, CAD was detected by both MIBI-SPECT and Dipyridamole-MRI in 90% (18/20) of patients. Dipyridamole-MRI and MIBI-SPECT gradings agreed in 55/60 (92%) coronary artery perfusion territories. There were no significant differences with respect to the sensitivities of Dipyridamole-MRI/MIBI-SPECT for the localization of individual coronary artery stenoses yielding 81

  5. Prevalence and prognostic significance of exercise-induced silent myocardial ischemia detected by thallium scintigraphy and electrocardiography in asymptomatic volunteers

    SciTech Connect

    Fleg, J.L.; Gerstenblith, G.; Zonderman, A.B.; Becker, L.C.; Weisfeldt, M.L.; Costa, P.T. Jr.; Lakatta, E.G. )

    1990-02-01

    Although a silent ischemic electrocardiographic response to treadmill exercise in clinically healthy populations is associated with an increased likelihood of future coronary events (i.e., angina pectoris, myocardial infarction, or cardiac death), such a response has a low predictive value for future events because of the low prevalence of disease in asymptomatic populations. To examine whether detection of reduced regional perfusion by thallium scintigraphy improved the predictive value of exercise-induced ST segment depression, we performed maximal treadmill exercise electrocardiography (ECG) and thallium scintigraphy (201Tl) in 407 asymptomatic volunteers 40-96 years of age (mean = 60) from the Baltimore Longitudinal Study on Aging. The prevalence of exercise-induced silent ischemia, defined by concordant ST segment depression and a thallium perfusion defect, increased more than sevenfold from 2% in the fifth and sixth decades to 15% in the ninth decade. Over a mean follow-up period of 4.6 years, cardiac events developed in 9.8% of subjects and consisted of 20 cases of new angina pectoris, 13 myocardial infarctions, and seven deaths. Events occurred in 7% of individuals with both negative 201Tl and ECG, 8% of those with either test positive, and 48% of those in whom both tests were positive (p less than 0.001). By proportional hazards analysis, age, hypertension, exercise duration, and a concordant positive ECG and 201Tl result were independent predictors of coronary events. Furthermore, those with positive ECG and 201Tl had a 3.6-fold relative risk for subsequent coronary events, independent of conventional risk factors.

  6. Detection of right ventricular pressure overloading by thallium-201 myocardial scintigraphy. Results in 57 patients with chronic respiratory diseases

    SciTech Connect

    Weitzenblum, E.; Moyses, B.; Dickele, M.C.; Methlin, G.

    1984-02-01

    The diagnostic value of thallium 201 (/sup 201/Tl) myocardial imaging was studied in 57 patients with chronic respiratory diseases, most with COPD (n . 46), by comparing the results to hemodynamic findings. In healthy subjects, the right ventricle (RV) is not visualized; therefore, any recorded activity of the RV was considered as indicating RV hypertrophy due to RV pressure overloading (RVPO). RV activity was graded from 0 (no activity) to 3 (activity greater than or equal to that of the left ventricle). Patients were divided into three groups according to the level of the pulmonary artery mean pressure (PPA): PPA less than or equal to 20 mm Hg (no pulmonary arterial hypertension (PAH) ) . group 1, n . 20; PPA ranging from 21 to 30 mm Hg (mild to moderate PAH) . group 2, n . 20; PPA greater than 30 mm Hg (marked PAH) . group 3, n . 17. RV was visualized in 14 patients in group 3 (82 percent) and in 13 patients in group 2 (65 percent). For all patients with PAH (2 + 3) the sensitivity of /sup 201/Tl imaging for the diagnosis of RVPO was of 73 percent, higher than that of ECG and echocardiography (both 51 percent). The sensitivity of /sup 201/Tl, even if moderate (65 percent) was better than that of ECG (30 percent) or echo (40 percent) in patients with mild-to-moderate PAH (group 2). A high RV activity (grade 3) was observed in only three patients. The specificity of this method (obtained from results in group 1) was of 80 percent vs 89 percent for echo and 100 percent for ECG. These results suggest that 201Tl myocardial imaging is a rather sensitive method and could be of interest for the noninvasive diagnosis of RVPO in COPD patients.

  7. Effects of modified pharmacologic stress approaches on hyperemic myocardial blood flow

    SciTech Connect

    Czernin, J.; Auerbach, M.; Sun, K.T.

    1995-04-01

    Pharmacologic stress testing with 0.56 mg/kg of intravenous dipyridamole is frequently used to noninvasively detect coronary artery disease (CAD). However, high-dose dipyridamole (0.80 mg/kg) or the combination of standard-dose dipyridamole (0.56 mg/kg) with the isometric handgrip maneuver might evoke a greater coronary hyperemic response. To evaluate the effect of modified pharmacologic stress tests, myocardial blood flow was quantified in 11 male subjects (mean age: 27 {plus_minus} 7 yr) during standard-dose dipyridamole (0.56 mg/kg), high-dose dipyridamole (0.80 mg/kg) and standard-dose dipyridamole combined with the isometric handgrip exercise using dynamic PET and a two-compartment model for {sup 13}N-ammonia. Systolic blood pressure, heart rate and rate pressure product remained unchanged from standard to high-dose dipyridamole but increased with the addition of the isometric handgrip. Myocardial blood flow was unchanged from standard to high-dose dipyridamole but was lower with the addition of the isometric handgrip. The hyperemic response induced by standard-dose dipyridamole cannot be further enhanced by high-dose dipyridamole. The addition of the isometric handgrip exercise results in a modest, but significant decline in hyperemic blood flow possibly due to increased extravascular resistive forces or an increase in a mediated coronary vasoconstriction associated with exercise. 31 refs., 2 figs., 1 tab.

  8. The comparison of 2-18F-2-deoxyglucose and 15-(ortho-123I-phenyl)-pentadecanoic acid uptake in persisting defects on thallium-201 tomography in myocardial infarction

    SciTech Connect

    Henrich, M.M.; Vester, E.; von der Lohe, E.; Herzog, H.; Simon, H.; Kuikka, J.T.; Feinendegen, L.E. )

    1991-07-01

    The myocardial uptake of glucose and fatty acids into 201Tl redistribution defects were studied in 32 patients with myocardial infarction by tomography using 2-18F-2-deoxyglucose (FDG) and 15-(ortho-123I-phenyl)-pentadecanoic acid (oPPA). A total of 1153 segments were analyzed, 408 (35%) of which showed a persistent thallium-defect in stress-redistribution images. Of the segments with a decreased 201Tl uptake in these redistribution tomograms, 50.5% had a decreased uptake of both FDG and oPPA; in 21.8% FDG as well as oPPA uptake was within normal range. Normal FDG uptake but decreased oPPA uptake was detected in 17.4%, whereas 10.3% of the segments had normal oPPA uptake but decreased FDG uptake (chi-square test, p less than 0.001). A significant correlation of FDG and oPPA uptake (r = 0.51) was found in the segments with persistent 201Tl defect. Thus, a substantial fraction of persistent thallium-defects after healed myocardial infarction exhibit FDG as well as oPPA uptake, probably due to residual fatty acid metabolism in partially ischemic regions.

  9. Dobutamine stress-redistribution-reinjection versus rest-redistribution thallium-201 SPECT in the assessment of myocardial viability.

    PubMed

    Cornel, J H; Bax, J J; Elhendy, A; Reijs, A E; Fioretti, P M

    1997-02-01

    The aim of this study was to evaluate the value of thallium-201 chloride (201Tl) reinjection imaging following dobutamine stress (DRi) to identify viable myocardium in comparison with a rest-redistribution 201Tl protocol (RR). The identification of viable myocardium bears important consequences for adequate selection of patients with poor left ventricular function, often unable to exercise, who are considered for revascularization. Twenty-six patients with chronic coronary artery disease and depressed left ventricular function (ejection fraction 36 +/- 10%) were studied by both DRi and RR single photon emission computed tomography (SPECT). Semi-quantitative analysis of regional 201Tl activity (5-point score) and wall motion by echocardiography using a 16-segment model was performed. Regions were classified as viable (normal/reversible/fixed moderate defects) or non-viable (fixed severe defects) and related to regional wall motion. Target heart rate was reached in 25 patients. Myocardial viability was demonstrated in 353/416 (85%) by DRi SPECT and in 346/416 (83%) by RR SPECT. The agreement between the 2 protocols was 98% with a K-value of 0.94; similar results were obtained when the analysis was limited to dyscontractile segments. In conclusion, this study demonstrates the feasibility and diagnostic value of DRi SPECT to identify viable myocardium.

  10. Myocardial redistribution of technetium-99m-methoxyisobutyl isonitrile (SESTAMIBI)

    SciTech Connect

    Li, Q.S.; Solot, G.; Frank, T.L.; Wagner, H.N. Jr.; Becker, L.C. )

    1990-06-01

    To determine whether technetium-99m-hexakis-2-methoxyisobutyl isonitrile (SESTAMIBI) remains fixed in the myocardium following its initial uptake or undergoes time-related redistribution, anesthetized dogs underwent occlusion of the anterior descending coronary artery for 6 min, followed by 3-hr reperfusion. Technetium-99m-SESTAMIBI and thallium-201 (201Tl) were injected intravenously after 1 min occlusion and regional myocardial blood flow was measured with radioactive microspheres. Tomographic imaging of Tc-SESTAMIBI revealed a perfusion defect with slight but definite filling in over 2 hr. Quantitative analysis indicated a significant rise in the nadir and decrease in the width of the defect in circumferential profile curves. After 3-hr of reperfusion, Tc-SESTAMIBI activity in the previously ischemic area was always greater than the activity of microspheres injected during coronary occlusion (mean normalized values, 0.32 versus 0.11, p less than 0.0001). Our results indicate that following transient ischemia and reperfusion, Tc-SESTAMIBI clearly undergoes myocardial redistribution, although more slowly and less completely than {sup 201}Tl.

  11. Effect of exercise supplementation on dipyridamole thallium-201 image quality

    SciTech Connect

    Stern, S.; Greenberg, I.D.; Corne, R. )

    1991-08-01

    To determine the effect of different types of exercise supplementation on dipyridamole thallium image quality, 78 patients were prospectively randomized to one of three protocols: dipyridamole infusion alone, dipyridamole supplemented with isometric handgrip, and dipyridamole with low-level treadmill exercise. Heart-to-lung, heart-to-liver, and heart-to-adjacent infradiaphragmatic activity ratios were generated from anterior images acquired immediately following the test. Additionally, heart-to-total infradiaphragmatic activity was graded semiquantitatively. Results showed a significantly higher ratio of heart to subdiaphragmatic activity in the treadmill group as compared with dipyridamole alone (p less than 0.001) and dipyridamole supplemented with isometric handgrip exercise (p less than 0.001). No significant difference was observed between patients receiving the dipyridamole infusion, and dipyridamole supplemented with isometric handgrip exercise. The authors conclude that low-level treadmill exercise supplementation of dipyridamole infusion is an effective means of improving image quality. Supplementation with isometric handgrip does not improve image quality over dipyridamole alone.

  12. Usefulness of semiquantitative analysis of dipyridamole-thallium-201 redistribution for improving risk stratification before vascular surgery

    SciTech Connect

    Levinson, J.R.; Boucher, C.A.; Coley, C.M.; Guiney, T.E.; Strauss, H.W.; Eagle, K.A. )

    1990-08-15

    Preoperative dipyridamole-thallium-201 scanning is sensitive in identifying patients prone to ischemic cardiac complications after vascular surgery, but most patients with redistribution do not have an event after surgery. Therefore, its positive predictive value is limited. To determine which patients with thallium redistribution are at highest risk, dipyridamole-thallium-201 images were interpreted semiquantitatively. Sixty-two consecutive patients with redistribution on preoperative dipyridamole-thallium-201 planar imaging studies were identified. Each thallium scan was then analyzed independently by 2 observers for the number of myocardial segments out of 15, the number of thallium views out of 3 and the number of coronary artery territories with redistribution. Seventeen patients (27%) had postoperative ischemic events, including unstable angina pectoris, ischemic pulmonary edema, myocardial infarction and cardiac death. Thallium predictors of ischemic operative complications included thallium redistribution greater than or equal to 4 myocardial segments (p = 0.03), greater than or equal to 2 of the 3 planar views (p = 0.005) and greater than or equal to 2 coronary territories (p = 0.007). No patient with redistribution in only 1 view had an ischemic event (0 of 15). Thus, determining the extent of redistribution by dipyridamole-thallium-201 scanning improves risk stratification before vascular surgery. Patients with greater numbers of myocardial segments and greater numbers of coronary territories showing thallium-201 redistribution are at higher risk for ischemic cardiac complications. In contrast, when the extent of thallium redistribution is limited, there is a lower risk despite the presence of redistribution.

  13. Dipyridamole-thallium scanning in patients undergoing vascular surgery. Optimizing preoperative evaluation of cardiac risk

    SciTech Connect

    Eagle, K.A.; Singer, D.E.; Brewster, D.C.; Darling, R.C.; Mulley, A.G.; Boucher, C.A.

    1987-04-24

    Dipyridamole-thallium imaging has been suggested as a method of preoperatively assessing cardiac risk in patients undergoing major surgery. To define more clearly its proper role in preoperative assessment, we prospectively evaluated 111 patients undergoing vascular surgery. In the first set of 61 patients, our data confirmed the value of preoperative dipyridamole-thallium scanning in identifying the patients who suffered postoperative ischemic events. Events occurred in eight of 18 patients with reversible defects on preoperative imaging, compared with no events in 43 patients with no thallium redistribution (confidence interval for the risk difference: 0.624, 0.256). The results also suggested that clinical factors might allow identification of a low-risk subset of patients. To test the hypothesis that patients with no evidence of congestive heart failure, angina, prior myocardial infarction, or diabetes do not require further preoperative testing, we evaluated an additional 50 patients having vascular procedures. None of the 23 without the clinical markers had untoward outcomes, while ten of 27 patients with one or more of these clinical markers suffered postoperative ischemic events (confidence interval for the risk difference: 0.592, 0.148). In the clinical high-risk subset, further risk stratification is achieved with dipyridamole-thallium scanning.

  14. Dipyridamole and paracetamol overdose resulting in multi-organ failure.

    PubMed

    Cullis, P S; Watson, D; Cameron, A; McKee, R F

    2013-08-01

    Dipyridamole intoxication is rare and few reports exist amongst the current literature. A case of dipyridamole and paracetamol overdose is described in a previously healthy 58-year-old woman, which resulted in multi-organ failure requiring dialysis, inotropic support, ventilation and extensive surgical intervention for small bowel ischaemia. This case highlights the dangers of an unusually large overdose of a commonly prescribed drug, and reviews current knowledge of dipyridamole intoxication.

  15. Effects of CT-based attenuation correction of rat microSPECT images on relative myocardial perfusion and quantitative tracer uptake

    SciTech Connect

    Strydhorst, Jared H. Ruddy, Terrence D.; Wells, R. Glenn

    2015-04-15

    Purpose: Our goal in this work was to investigate the impact of CT-based attenuation correction on measurements of rat myocardial perfusion with {sup 99m}Tc and {sup 201}Tl single photon emission computed tomography (SPECT). Methods: Eight male Sprague-Dawley rats were injected with {sup 99m}Tc-tetrofosmin and scanned in a small animal pinhole SPECT/CT scanner. Scans were repeated weekly over a period of 5 weeks. Eight additional rats were injected with {sup 201}Tl and also scanned following a similar protocol. The images were reconstructed with and without attenuation correction, and the relative perfusion was analyzed with the commercial cardiac analysis software. The absolute uptake of {sup 99m}Tc in the heart was also quantified with and without attenuation correction. Results: For {sup 99m}Tc imaging, relative segmental perfusion changed by up to +2.1%/−1.8% as a result of attenuation correction. Relative changes of +3.6%/−1.0% were observed for the {sup 201}Tl images. Interscan and inter-rat reproducibilities of relative segmental perfusion were 2.7% and 3.9%, respectively, for the uncorrected {sup 99m}Tc scans, and 3.6% and 4.3%, respectively, for the {sup 201}Tl scans, and were not significantly affected by attenuation correction for either tracer. Attenuation correction also significantly increased the measured absolute uptake of tetrofosmin and significantly altered the relationship between the rat weight and tracer uptake. Conclusions: Our results show that attenuation correction has a small but statistically significant impact on the relative perfusion measurements in some segments of the heart and does not adversely affect reproducibility. Attenuation correction had a small but statistically significant impact on measured absolute tracer uptake.

  16. New Exercise-Dipyridamole Combined Test for Nuclear Cardiology in Insufficient Effort: Appropriate Diagnostic Sensitivity Keeping Exercise Prognosis

    PubMed Central

    Cortinas, Inés Vidal; Beretta, Mario; Alonso, Omar; Mut, Fernando

    2015-01-01

    Background Myocardial perfusion scintigraphy (MPS) in patients not reaching 85% of the maximum predicted heart rate (MPHR) has reduced sensitivity. Objectives In an attempt to maintain diagnostic sensitivity without losing functional exercise data, a new exercise and dipyridamole combined protocol (EDCP) was developed. Our aim was to evaluate the feasibility and safety of this protocol and to compare its diagnostic sensitivity against standard exercise and dipyridamole protocols. Methods In patients not reaching a sufficient exercise (SE) test and with no contraindications, 0.56 mg/kg of dipyridamole were IV administered over 1 minute simultaneously with exercise, followed by 99mTc-MIBI injection. Results Of 155 patients, 41 had MPS with EDCP, 47 had a SE test (≥ 85% MPHR) and 67 underwent the dipyridamole alone test (DIP). They all underwent coronary angiography within 3 months. The three stress methods for diagnosis of coronary lesions had their sensitivity compared. For stenosis ≥ 70%, EDCP yielded 97% sensitivity, SE 90% and DIP 95% (p = 0.43). For lesions ≥ 50%, the sensitivities were 94%, 88% and 95%, respectively (p = 0.35). Side effects of EDCP were present in only 12% of the patients, significantly less than with DIP (p < 0.001). Conclusions The proposed combined protocol is a valid and safe method that yields adequate diagnostic sensitivity, keeping exercise prognostic information in patients unable to reach target heart rate, with fewer side effects than the DIP. PMID:26039661

  17. The effects of dipyridamole on blood flow and oxygen handling in the acutely ischaemic and normal canine myocardium

    PubMed Central

    Marshall, R. J.; Parratt, J. R.

    1973-01-01

    1. The effects of the intravenous administration of dipyridamole (0·25 mg/kg) were examined in a canine preparation that enabled simultaneous measurements to be made of blood flow in ischaemic and in essentially normal areas of the myocardium and also of oxygen handling (availability, consumption and extraction) in both these regions. 2. When administered to dogs anaesthetized with trichlorethylene 2-3 h after acute ligation of the descending branch of the left coronary artery, dipyridamole markedly increased blood flow in essentially normal regions (left circumflex flow) but failed to increase flow in the area supplied by the ligated vessel (measured by 133xenon clearance and by retrograde flow). In five of the six animals definite decreases in flow (` stealing ') were observed in the ischaemic region. These flow changes were related to the decreased trans-ventricular perfusion pressure (diastolic peripheral coronary pressure minus left ventricular end-diastolic pressure) and were accompanied by electrocardiographic evidence of increasingly severe myocardial ischaemia. The results support the suggestion that only increasing the perfusion gradient will usefully improve blood flow (and hence oxygen availability) to the acutely ischaemic myocardium. 3. Despite these effects on ischaemic muscle blood flow, the oxygen tension of the blood draining the infarcting muscle was markedly elevated. The conclusion is drawn that dipyridamole decreases the efficiency of the myocardial circulation by opening up vessels that do not take part in tissue exchange. PMID:4777702

  18. Regadenoson and adenosine are equivalent vasodilators and are superior than dipyridamole- a study of first pass quantitative perfusion cardiovascular magnetic resonance

    PubMed Central

    2013-01-01

    Background Regadenoson, dipyridamole and adenosine are commonly used vasodilators in myocardial perfusion imaging for the detection of obstructive coronary artery disease. There are few comparative studies of the vasodilator properties of regadenoson, adenosine and dipyridamole in humans. The specific aim of this study was to determine the relative potency of these three vasodilators by quantifying stress and rest myocardial perfusion in humans using cardiovascular magnetic resonance (CMR). Methods Fifteen healthy normal volunteers, with Framingham score less than 1% underwent vasodilator stress testing with regadenoson (400 μg bolus), dipyridamole (0.56 mg/kg) and adenosine (140 μg /kg/min) on separate days. Rest perfusion imaging was performed initially. Twenty minutes later, stress imaging was performed at peak vasodilation, i.e. 70 seconds after regadenoson, 4 minutes after dipyridamole infusion and between 3–4 minutes of the adenosine infusion. Myocardial blood flow (MBF) in ml/min/g and myocardial perfusion reserve (MPR) were quantified using a fully quantitative model constrained deconvolution. Results Regadenoson produced higher stress MBF than dipyridamole and adenosine (3.58 ± 0.58 vs. 2.81 ± 0.67 vs. 2.78 ± 0.61 ml/min/g, p = 0.0009 and p = 0.0008 respectively). Regadenoson had a much higher heart rate response than adenosine and dipyridamole respectively (95 ± 11 vs. 76 ± 13 vs. 86 ± 12 beats/ minute) When stress MBF was adjusted for heart rate, there were no differences between regadenoson and adenosine (37.8 ± 6 vs. 36.6 ± 4 μl/sec/g, p = NS), but differences between regadenoson and dipyridamole persisted (37.8 ± 6 vs. 32.6 ± 5 μl/sec/g, p = 0.03). The unadjusted MPR was higher with regadenoson (3.11 ± 0.63) when compared with adenosine (2.7 ± 0.61, p = 0.02) and when compared with dipyridamole (2.61 ± 0.57, p = 0.04). Similar to stress MBF, these differences in MPR between regadenoson and adenosine were abolished when adjusted

  19. Iterative deconvolution of simultaneous 99mTc and 201Tl projection data measured on a CdZnTe-based cardiac SPECT scanner

    NASA Astrophysics Data System (ADS)

    Kacperski, Krzysztof; Erlandsson, Kjell; Ben-Haim, Simona; Hutton, Brian F.

    2011-03-01

    We present a method of correcting self-scatter and crosstalk effects in simultaneous technetium-99m/thallium-201 stress/rest myocardial perfusion (single photon emission computed tomography) SPECT scans. The method, which is in essence a hybrid between the triple energy window method and scatter modelling, is based on a model of spatial and spectral distribution of projection counts in several selected energy windows. The parameters of the model are determined from measurements of thin rod sources in air when no in-object scatter or attenuation effects are present. The model equations are solved using the iterative maximum likelihood expectation maximization algorithm in the projection space to find estimates of the primary photopeak counts of both radionuclides. The method has been developed particularly for a novel dedicated cardiac camera based on CdZnTe pixellated detectors, although it can also be adapted to a conventional scintillator camera. The method has been validated in anthropomorphic phantom experiments. Significant improvement in defect contrast has been observed with only moderate increase in image noise. The application of the method to patient data is illustrated.

  20. Iterative deconvolution of simultaneous 99mTc and 201Tl projection data measured on a CdZnTe-based cardiac SPECT scanner.

    PubMed

    Kacperski, Krzysztof; Erlandsson, Kjell; Ben-Haim, Simona; Hutton, Brian F

    2011-03-01

    We present a method of correcting self-scatter and crosstalk effects in simultaneous technetium-99m/thallium-201 stress/rest myocardial perfusion (single photon emission computed tomography) SPECT scans. The method, which is in essence a hybrid between the triple energy window method and scatter modelling, is based on a model of spatial and spectral distribution of projection counts in several selected energy windows. The parameters of the model are determined from measurements of thin rod sources in air when no in-object scatter or attenuation effects are present. The model equations are solved using the iterative maximum likelihood expectation maximization algorithm in the projection space to find estimates of the primary photopeak counts of both radionuclides. The method has been developed particularly for a novel dedicated cardiac camera based on CdZnTe pixellated detectors, although it can also be adapted to a conventional scintillator camera. The method has been validated in anthropomorphic phantom experiments. Significant improvement in defect contrast has been observed with only moderate increase in image noise. The application of the method to patient data is illustrated.

  1. Iterative deconvolution of simultaneous 99mTc and 201Tl projection data measured on a CdZnTe based cardiac SPECT scanner

    PubMed Central

    Kacperski, Krzysztof; Erlandsson, Kjell; Ben-Haim, Simona; Hutton, Brian F.

    2011-01-01

    We present a method of correcting self-scatter and crosstalk effects in simultaneous technetium-99m/thallium-201 stress/rest myocardial perfusion SPECT scans. The method, which is in essence a hybrid between the TEW method and scatter modelling, is based on a model of spatial and spectral distribution of projection counts in several selected energy windows. The parameters of the model are determined from measurements of thin rod sources in air when no in-object scatter or attenuation effects are present. The model equations are solved using the iterative Maximum Likelihood Expectation Maximisation (ML-EM) algorithm in the projection space to find estimates of the primary photopeak counts of both radionuclides. The method has been developed particularly for a novel dedicated cardiac camera based on CdZnTe pixellated detectors, although it can also be adapted to a conventional scintillator camera. The method has been validated in anthropomorphic phantom experiments. Significant improvement in defect contrast has been observed with only moderate increase in image noise. The application of the method to patient data is ilustrated. PMID:21317483

  2. Investigation of optimal acquisition time of myocardial perfusion scintigraphy using cardiac focusing-collimator

    NASA Astrophysics Data System (ADS)

    Niwa, Arisa; Abe, Shinji; Fujita, Naotoshi; Kono, Hidetaka; Odagawa, Tetsuro; Fujita, Yusuke; Tsuchiya, Saki; Kato, Katsuhiko

    2015-03-01

    Recently myocardial perfusion SPECT imaging acquired using the cardiac focusing-collimator (CF) has been developed in the field of nuclear cardiology. Previously we have investigated the basic characteristics of CF using physical phantoms. This study was aimed at determining the acquisition time for CF that enables to acquire the SPECT images equivalent to those acquired by the conventional method in 201TlCl myocardial perfusion SPECT. In this study, Siemens Symbia T6 was used by setting the torso phantom equipped with the cardiac, pulmonary, and hepatic components. 201TlCl solution were filled in the left ventricular (LV) myocardium and liver. Each of CF, the low energy high resolution collimator (LEHR), and the low medium energy general purpose collimator (LMEGP) was set on the SPECT equipment. Data acquisitions were made by regarding the center of the phantom as the center of the heart in CF at various acquisition times. Acquired data were reconstructed, and the polar maps were created from the reconstructed images. Coefficient of variation (CV) was calculated as the mean counts determined on the polar maps with their standard deviations. When CF was used, CV was lower at longer acquisition times. CV calculated from the polar maps acquired using CF at 2.83 min of acquisition time was equivalent to CV calculated from those acquired using LEHR in a 180°acquisition range at 20 min of acquisition time.

  3. Interstitial adenosine concentration is increased by dipyridamole

    SciTech Connect

    Gorman, M.W.; Wangler, R.D.; DeWitt, D.F.; Wang, C.Y.; Bassingthwaighte, J.B.; Sparks, H.V.

    1986-03-01

    The authors used the multiple indicator dilution technique to observe the capillary transport of adenosine (ADO) in isolated guinea pig hearts. Radiolabelled albumin, sucrose and ADO were injected on the arterial side and measured in venous samples collected during the following 20 seconds. Transport parameters calculated from these data include permeability-surface area products (PS) for transendothelial diffusion, endothelial cell (EC) uptake at the lumenal and ablumenal membranes, and EC metabolism. With simultaneous measurements of arterial and venous ADO concentrations and flow, the authors calculated the steady-state interstitial fluid (ISF) ADO concentration. Under control conditions the venous ADO concentration was 7.1 +/- 2.8 nM. The calculated ISF concentration depends on whether they assume the venous ADO comes from the ISF, or directly from ECs. These ISF concentrations are 25 +/- 12 nM and 9.8 +/- 4.0 nM, respectively. During dipyridamole infusion (10 uM) the EC transport parameters became nearly zero. Venous and ISF ADO concentrations increased to 33 +/- 8.9 nM and 169 +/- 42 nM, respectively. The authors conclude that the ISF ADO concentration is 1.5-4 fold higher than the venous concentration at rest, and the ISF concentration increases greatly with dipyridamole.

  4. Intravenous dipyridamole thallium-201 SPECT imaging methodology, applications, and interpretations

    SciTech Connect

    Rockett, J.F.; Magill, H.L.; Loveless, V.S.; Murray, G.L. )

    1990-10-01

    Dipyridamole TI-201 imaging is an ideal alternative to exercise TI-201 scintigraphy in patients who are unwilling or unable to perform maximum exercise stress. The use of intravenous dipyridamole, alone or in combination with exercise, has not been approved for clinical practice by the Food and Drug Administration. Once approval is granted, the test will become a widely used and important component of the cardiac work-up. The indications, methodology, side effects, and utility of dipyridamole cardiac imaging in the clinical setting are discussed and a variety of examples presented.59 references.

  5. Dipyridamole in the treatment of dengue haemorrhagic fever.

    PubMed

    Kho, L K; Wulur, H; Himawan, T

    1979-09-01

    Clinical studies in the treatment of 54 children suffering from DHF with a combination of dipyridamole and ASA as an adjuvant of our standard therapy consisted of fluid, electrolytes, blood, plasma and plasma expanders were evaluated. Heparin was administered in cases of DIC. It appeared that dipyridamole and ASA did not change the mortality significantly, but it prevented the progress of the severity of the disease from grade I and II to grade III and IV.

  6. Reverse redistribution of thallium-201 detected by SPECT imaging after dipyridamole in angina pectoris

    SciTech Connect

    Popma, J.J.; Smitherman, T.C.; Walker, B.S.; Simon, T.R.; Dehmer, G.J. )

    1990-05-15

    Reverse redistribution refers to a thallium-201 perfusion defect that develops or becomes more evident on delayed imaging compared with the initial image immediately after stress. To determine the diagnostic importance of reverse redistribution after intravenous dipyridamole, thallium-201 single photon emission computed tomography and quantitative coronary arteriography were performed in 90 men with angina pectoris. Of the 250 myocardial segments analyzed, reverse redistribution was present in 17 (7%). Minimal coronary cross-sectional area in proximal vessel segments was less than or equal to 2.0 mm2 more often in regions with transient perfusion abnormalities than in regions with reverse redistribution (66 vs 29%, p less than 0.05). Compared with regions exhibiting transient perfusion abnormalities, regions with reverse redistribution had larger proximal arterial diameters (1.9 +/- 1.1 vs 1.3 +/- 1.1 mm, p less than 0.001) and cross-sectional areas (3.9 +/- 3.1 vs 2.2 +/- 2.6 mm2, p less than 0.001). Coronary artery dimensions and relative stenosis severity did not differ between those regions with normal perfusion and those with reverse redistribution. Reverse redistribution detected by thallium-201 single photon emission computed tomographic imaging after dipyridamole is uncommon, appears to occur as frequently in normal subjects as in patients undergoing coronary arteriography and does not indicate the presence of severe coronary artery disease.

  7. [Identification of viable myocardium in ischemic heart disease with severe left ventricular contractile dysfunction: comparison of myocardial scintigraphy with 99mTc-sestamabi and with 201-thallium].

    PubMed

    Brandao, S; Cagnac, R; Roncalli, J; Lotterie, J A; Elbaz, M; Richez, F; Galinier, M; Carrie, D; Alibelli-Chemarin, M J

    2005-06-01

    The aim of this study was to compare quantitatively uptake of 99mTc-Sestamibi at rest and that of late redistribution of 201Tl in the same patients with severe ischaemic left ventricular dysfunction, and to correlate the uptake of the tracer to regional ventricular dysfunction studied by ECG grated 99Tc-Sestamini. A double isotope myocardial scintigraphy, 201 Thallium at rest/redistribution and 99Tc-Sestamibi at rest and on exercise, was performed in 28 patients with severe postinfarction ischaemic cardiomyopathy (EF= 29 +/- 4%). Quantitative analysis for each patient and each isotope were performed with respect to the number of hits expressed in percentage of the activity of a normal zone in 17 circumferential profiles distributed in 4 zones, that is to say in 476 segments. A score allowed counting of viable and non-viable segments and evaluation of contractile function of the 17 segments with respect to wall motion and systolic thickening. Total concordance of global uptake of the two isotopes was observed in 430 of the 476 segments (90.3%) (r= 0.814, p< 0.0001), but the 99mTc-Sestamibi uptake was less than 201 Th (71 +/- 23% vs 73 +/- 21%, p= 0.0001). With respect to left ventricular wall motion, uptake of 99mTc-Sestamibi was greater than that of 201Tl in normal or hypokinetic segments but less in akinetic and dyskinetic segments. The difference between the two isotopes was most marked in segments with very severe contractile dysfunction. The authors conclude that the uptake of 99mTc-Sestamibi is correlated with that of late distribution of 201Tl when left ventricular contraction is not too poor and should no longer be considered as only a marker of perfusion but can also be useful in the investigation of myocardial viability.

  8. [Evaluation of non-uniform attenuation correction using simultaneous transmission and emission computed tomography--basic analysis with myocardial phantom].

    PubMed

    Otake, H; Yukihiro, M; Fukushima, Y; Imai, T; Hosono, K; Hatori, N; Watanabe, N; Hirano, T; Inoue, T; Takahashi, M; Ban, R; Endo, K

    1996-03-01

    Simultaneous transmission emission protocol (STEP), developed for the non-uniform attenuation correction of single photon emission computed tomography (SPECT) was evaluated using the cardiac phantom prepared with and without a myocardial wall defect. Emission computed tomography (ECT) of the cardiac phantom using 201Tl was acquired. Transmission data (TCT) were taken using a line source of 99mTc. Myocardial images with STEP method were superior in the homogeneity of intramyocardial radioactivity and spatial resolution to the conventional SPECT images. This is an excellent method because of the accurate matching position between TCT and ECT images and shortening the examination time by simultaneous data acquisition. It would be clinically useful for diagnosing various myocardial diseases.

  9. Prevalence and correlates of increased lung/heart ratio of thallium-201 during dipyridamole stress imaging for suspected coronary artery disease

    SciTech Connect

    Villanueva, F.S.; Kaul, S.; Smith, W.H.; Watson, D.D.; Varma, S.K.; Beller, G.A. )

    1990-12-01

    There is little information concerning the prevalence and clinical correlates of increased pulmonary thallium-201 uptake during dipyridamole thallium-201 stress imaging. Accordingly, the clinical characteristics and quantitative thallium-201 findings were correlated with quantitative lung/heart thallium-201 ratio in 87 patients undergoing dipyridamole thallium-201 stress testing. Nineteen patients (22%) had an elevated ratio (greater than 0.51). These patients were more likely to have had an infarction, to be taking beta blockers, and have a lower rate-pressure product after dipyridamole administration than those with a normal ratio (p less than 0.03). An elevated ratio was associated with a greater likelihood of initial, redistribution and persistent defects, as well as left ventricular cavity dilatation on thallium-201 imaging (p less than 0.05). In addition, the number of myocardial segments demonstrating initial, redistribution and persistent defects was also greater in patients with increased ratios (p less than 0.03). Multivariate analysis demonstrated that the presence of redistribution and left ventricular cavity dilatation were the most significant correlates of lung/heart thallium-201 ratio. It is concluded that the prevalence of increased lung/heart thallium-201 ratio with dipyridamole thallium-201 stress imaging is similar to that seen with exercise stress imaging. As with exercise thallium-201 imaging, increased pulmonary thallium-201 uptake may be a marker of functionally more significant coronary artery disease.

  10. Dipyridamole-thallium tests are predictive of severe cardiac arrhythmias in patients with left ventricular hypertrophy

    SciTech Connect

    Saragoca, M.A.; Canziani, M.E.; Gil, M.A.; Castiglioni, M.L.; Cassiolato, J.L.; Barbieri, A.; Lima, V.C.; Draibe, S.A.; Martinez, E.E. )

    1991-01-01

    In a population of patients with chronic renal failure (CRF) and a high prevalence of left ventricular hypertrophy (LVH) undergoing chronic hemodialysis, the authors investigated the association between the results of dipyridamole-thallium tests (DTTs) and the occurrence of ventricular arrhythmias. They observed a positive significant association between positive DTTs and the occurrence of severe forms of ventricular arrhythmias. A significant association was also observed between the presence of severe LVH and the occurrence of severe ventricular arrhythmias. However, no association was found between the presence of LVH and the positivity of the DTT. As most of their patients with positive DTTs had unimpaired coronary circulations, they conclude that positive DTTs, although falsely indicative of impaired myocardial blood supply, does have an important clinical relevance, indicating increased risk of morbidity (and, possibly, mortality) due to ventricular arrhythmias in a population of CRF patients submitted to chronic renal function replacement program.

  11. Effects of propranolol and nifedipine on exercise-induced attack in patients variant angina: assessment by exercise thallium-201 myocardial scintigraphy with quantitative rotational tomography

    SciTech Connect

    Kugiyama, K.; Yasue, H.; Horio, Y.; Morikami, Y.; Fujii, H.; Koga, Y.; Kojima, A.; Takahashi, M.

    1986-08-01

    To examine the effects of propranolol and nifedipine on exercise-induced attack in patients with variant angina, exercise /sup 201/Tl myocardial scintigraphy with quantitative analysis by emission-computed tomography was performed in 20 patients with variant angina after oral propranolol (80 mg), nifedipine (20 mg), and placebo. Exercise-induced attack occurred in 11 patients on placebo, in 14 on propranolol, and in none on nifedipine. The exercise duration was significantly shorter in those on propranolol (p less than .05), but significantly longer in patients on nifedipine (p less than .05) than in those on placebo. The peak rate-pressure product was significantly lower in patients on propranolol (p less than .01), but did not change in those on nifedipine, as compared with that in patients on placebo. The size of the perfusion defect as measured by /sup 201/Tl tomography was significantly greater in patients on propranolol (p less than .05), but significantly less in those on nifedipine (p less than .01) than in those on placebo. In conclusion, propranolol does not suppress but rather may aggravate exercise-induced attack in patients with variant angina, while nifedipine suppresses it. This unfavorable effect of propranolol on exercise-induced attack in patients with variant angina is likely to be due to a reduction of regional myocardial blood flow.

  12. Effect of dipyridamole on QT dispersion in vasospastic angina pectoris.

    PubMed

    Ashikaga, T; Nishizaki, M; Arita, M; Yamawake, N; Suzuki, M; Hashimoto, Y; Kishi, Y; Numano, F; Hiraoka, M

    1999-10-01

    Life-threatening ventricular arrhythmias have frequently been documented in patients with vasospastic angina. Moreover, the incidence of ventricular arrhythmias has been closely associated with increased QT dispersion. However, the underlying mechanism responsible for this arrhythmogenesis has not been clarified. The effects of dipyridamole and subsequent aminophylline administration on QT dispersion were examined in 35 patients with vasospastic angina and 30 patients with atypical chest pain. None of the patients enrolled in this study revealed any significant stenosis in coronary angiography. QT dispersion during dipyridamole followed by aminophylline administration was compared between the 2 groups. The baseline QT dispersion was similar in both groups (vasospastic angina: 27 +/- 8 ms; atypical chest pain: 28 +/- 7 ms). No significant changes in QT dispersion were observed in patients with atypical chest pain by dipyridamole (23 +/- 9 ms) and subsequent aminophylline administration (23 +/- 5 ms). However, the QT dispersion in patients with vasospastic angina increased significantly by dipyridamole administration (53 +/- 14 ms, p <0.0001) and returned to baseline by subsequent aminophylline administration (26 +/- 10 ms). Our data suggest that the disparity of ventricular repolarization in vasospastic angina may be mediated by increased endogenous adenosine.

  13. Myocardial scintigraphy with 201thallium in pediatric cardiology: A review of 52 cases

    SciTech Connect

    Bjoerkhem, G.E.; Evander, E.; White, T.; Lundstroem, N.R. )

    1990-01-01

    We report our experience of myocardial scintigraphy with 201thallium (201Tl) in 52 children, aged 4 days to 18 years, in which 80 studies were made primarily to demonstrate or exclude impaired myocardial perfusion. For analysis, the patients were divided into the following eight groups: group I, coronary artery malformations (five patients); group II, Kawasaki's syndrome (six patients); group III, arterial switch operation (seven patients); group IV, dilated cardiomyopathy (18 patients); group V, hypertrophic cardiomyopathy (four patients); group VI, myocardial dysfunction after surgery for congenital heart disease (five patients); group VII, pulmonary atresia (three patients); and group VIII, miscellaneous (four patients). Myocardial scintigraphy was performed with a planar or tomographic technique at rest or after exercise (four patients). Isotope-uptake defects, indicating impaired myocardial perfusion, were present in 14 patients, including small infants. Defects were seen in all groups except those with hypertrophic cardiomyopathy and pulmonary atresia. The absence of such defects in several of the patients with Kawasaki's syndrome was particularly valuable as it made coronary angiography unnecessary. In the other groups of patients myocardial scintigraphy was a valuable adjunct to other investigations.

  14. Usefulness of the severity and extent of reversible perfusion defects during thallium-dipyridamole imaging for cardiac risk assessment before noncardiac surgery.

    PubMed

    Lette, J; Waters, D; Lapointe, J; Gagnon, A; Picard, M; Cerino, M; Kerouac, M

    1989-08-01

    Thallium-dipyridamole imaging is a very sensitive test for predicting cardiac events after noncardiac surgery, but it lacks specificity. To improve specificity, a semiquantitative scoring system was developed that combined dipyridamole-induced reversible left ventricular dilatation with scintigraphic indexes for severity and extent of reversible perfusion defects. Using this scoring system, patients were classified into low, intermediate and high risk subgroups. Thallium-dipyridamole imaging was performed in 66 patients before major general and vascular surgery. Thirty-nine patients classified as low risk (30 with normal scans and 9 with fixed defects) underwent surgery uneventfully. Surgery was cancelled in 6 patients with extensive thallium redistribution and coronary angiography was performed because of severe coronary artery disease in 5 and idiopathic dilated cardiomyopathy in 1. In the remaining 21 patients with thallium redistribution, a positive statistical correlation (p = 0.001) between scintigraphic indexes of severity and extent, and cardiac events was noted. Using cutoff values for the scintigraphic indexes, patients with reversible defects could be classified into intermediate and high risk subgroups. Only 1 of 11 patients at intermediate risk developed a complication, whereas 8 of 10 patients at high risk had a postoperative event (7 deaths and 1 myocardial infarction). Thus, using scintigraphic indexes for severity and extent, patients with reversible defects can be stratified into an intermediate risk subgroup that can safely undergo surgery and a high risk subgroup that requires coronary angiography.

  15. Usefulness of the severity and extent of reversible perfusion defects during thallium-dipyridamole imaging for cardiac risk assessment before noncardiac surgery

    SciTech Connect

    Lette, J.; Waters, D.; Lapointe, J.; Gagnon, A.; Picard, M.; Cerino, M.; Kerouac, M. )

    1989-08-01

    Thallium-dipyridamole imaging is a very sensitive test for predicting cardiac events after noncardiac surgery, but it lacks specificity. To improve specificity, a semiquantitative scoring system was developed that combined dipyridamole-induced reversible left ventricular dilatation with scintigraphic indexes for severity and extent of reversible perfusion defects. Using this scoring system, patients were classified into low, intermediate and high risk subgroups. Thallium-dipyridamole imaging was performed in 66 patients before major general and vascular surgery. Thirty-nine patients classified as low risk (30 with normal scans and 9 with fixed defects) underwent surgery uneventfully. Surgery was cancelled in 6 patients with extensive thallium redistribution and coronary angiography was performed because of severe coronary artery disease in 5 and idiopathic dilated cardiomyopathy in 1. In the remaining 21 patients with thallium redistribution, a positive statistical correlation (p = 0.001) between scintigraphic indexes of severity and extent, and cardiac events was noted. Using cutoff values for the scintigraphic indexes, patients with reversible defects could be classified into intermediate and high risk subgroups. Only 1 of 11 patients at intermediate risk developed a complication, whereas 8 of 10 patients at high risk had a postoperative event (7 deaths and 1 myocardial infarction). Thus, using scintigraphic indexes for severity and extent, patients with reversible defects can be stratified into an intermediate risk subgroup that can safely undergo surgery and a high risk subgroup that requires coronary angiography.

  16. Multivariate clinical models and quantitative dipyridamole-thallium imaging to predict cardiac morbidity and death after vascular reconstruction

    SciTech Connect

    Lette, J.; Waters, D.; Lassonde, J.; Rene, P.; Picard, M.; Laurendeau, F.; Levy, R.; Cerino, M.; Nattel, S. )

    1991-08-01

    Patients with peripheral vascular disease have a high prevalence of coronary artery disease and are at increased risk for cardiac morbidity and death after vascular reconstruction. The present study was undertaken to assess the value of 18 clinical parameters, of 7 clinical scoring systems, and of quantitative dipyridamole-thallium imaging for predicting the occurrence of postoperative myocardial infarction or cardiac death. Vascular surgery was performed in 125 patients. Thirteen postoperative cardiac events occurred, including 10 cardiac deaths and 3 nonfatal infarctions. Clinical parameters were not useful in predicting postoperative outcome. All 63 patients with normal scan results or fixed perfusion defects underwent surgery uneventfully, whereas 21% (13/62) of patients with reversible defects had a postoperative cardiac complication. By use of quantitative scintigraphic indexes we found that patients with reversible defects could be stratified into intermediate and high-risk subgroups with postoperative event rates of 5% (2/47) and 85% (11/13), respectively, despite intensive postoperative monitoring and antianginal medication. Thus in patients unable to complete a standard exercise stress test, postoperative outcome cannot be predicted clinically, whereas dipyridamole-thallium imaging successfully identified all patients who had a postoperative cardiac event. By use of quantification we found that patients with reversible defects can be stratified into an intermediate risk subgroup that can undergo surgery with minimal complication rate and a high-risk subgroup that requires coronary angiography.

  17. Selective intraperitoneal biochemical modulation of methotrexate by dipyridamole.

    PubMed

    Goel, R; Cleary, S M; Horton, C; Balis, F M; Zimm, S; Kirmani, S; Howell, S B

    1989-02-01

    Dipyridamole increases the toxicity of methotrexate in a concentration-dependent manner. We hypothesized that concurrent intraperitoneal administration of both drugs would result in high peritoneal concentrations with much lower plasma concentrations, permitting a selective increase in the activity of methotrexate against intraperitoneal tumors without enhancing systemic toxicity. Initially, 2.16 mg/m2/d methotrexate and 12 mg/m2/d dipyridamole were delivered together as a constant intraperitoneal infusion for 48 hours. With escalation of chemotherapy, eventually 4.32 mg/m2/d methotrexate was administered for 168 hours. Forty-seven courses were administered to 18 patients. The mean peritoneal to plasma concentration ratios of methotrexate and non-protein bound dipyridamole were 71.6 +/- 34.8 and over 2,300, respectively. Chemical peritonitis was the dose-limiting toxicity. Three patients had some evidence of a response (two with decreasing tumor markers, and the third with a reduction in ascites). We conclude that the drug concentrations are in an appropriate range for selective intraperitoneal biochemical modulation of methotrexate, and that it is feasible to expose tumors confined to the peritoneal cavity to these drugs for long periods of time.

  18. Effect of eating on thallium-201 myocardial redistribution after myocardial ischemia

    SciTech Connect

    Angello, D.A.; Wilson, R.A.; Palac, R.T.

    1987-09-01

    To determine whether eating a high-carbohydrate meal between initial and delayed postexercise thallium-201 (Tl-201) imaging affects detection of Tl-201 redistribution during exercise stress testing, 16 patients with stable angina performed 2 Tl-201 treadmill exercise stress tests within a 14-day interval. Immediately after initial postexercise imaging, patients either drank a commercially available instant breakfast preparation for the intervention test or drank an equivalent volume of water for the control test. Comparable exercise workloads were achieved by exercising patients to the same heart rate for both tests. The order of the 2 (intervention and control) tests were randomized. All patients had at least 1 region of Tl-201 myocardial redistribution on either their eating or control test scans, although only 7 of the 16 had positive treadmill exercise test responses. Forty-six regions showing Tl-201 myocardial redistribution were identified in all 144 regions examined. Significantly more of these regions were identified on control test scans than on eating test scans: 11 of 46 on both test scans, 6 of 46 only on eating test scans and 29 of 46 only on control scans (p less than 0.001). Consistent with results of the quantitative regional analysis, the percentage of Tl-201 clearance over 4 hours in the 46 Tl-201 myocardial redistribution regions was 39 +/- 8% for the eating tests and 29 +/- 8% for control tests (mean +/- standard deviation, p less than 0.003). In 4 patients diagnosis of transient ischemia would have been missed because their 14 Tl-201 myocardial redistribution regions were detected only on the control test scans.

  19. Adenosine triphosphate stress echocardiography in the detection of myocardial ischemia.

    PubMed

    Fukai, T; Koyanagi, S; Tashiro, H; Ichiki, T; Tsutsui, H; Matsumoto, T; Takeshita, A

    1995-10-01

    The purpose of this study was to assess feasibility and safety in the diagnosis of coronary artery in the diagnosis of coronary artery disease and myocardial ischemia using adenosine triphosphate (ATP) stress echocardiography. ATP, a product of human myocardial tissue, is more potent than adenosine in increasing coronary blood flow. Like adenosine, ATP also has a short half-life (<10 s). Left ventricular echocardiograms were recorded during step-wise infusions of ATP in 86 patients who underwent coronary angiography and stress thallium 201 scintigraphy. No serious complications occurred with ATP infusion and most of the side effects were mild and transient. Significant coronary artery disease (>75% diameter stenosis) was present in 34 of 48 patients who had normal echocardiograms at rest. The sensitivity and specificity of ATP-induced wall motion abnormalities for coronary artery disease was 65% (22 of 34) and 100% (14 of 14), respectively. The sensitivity was 50% (10 of 20) in those with one-vessel disease and 86% (12 of 14) in those with multivessel disease (P < .05). In patients with normal echocardiograms at rest and without prior myocardial infarction, the sensitivity of ATP stress echocardiography for the detection of myocardial ischemia assessed by 201Tl single proton emission computed tomography was 58%, with a specificity of 76%, and a diagnostic accuracy of 66%. The sensitivity was 43% in those with one-vessel disease, and 86% in those with multivessel disease (P = .05). In patients with prior myocardial infarction, the sensitivity of ATP stress echocardiography for the detection of viable but jeopardized myocardium was 81%, with a specificity of 91%. The patients with well-developed collateral circulation had a higher incidence of developing wall motion abnormality than those without collaterals (70% v 40%, P < .01). ATP stress echocardiography is valuable for the assessment of coronary artery disease in patients with multivessel disease, coronary

  20. Verapamil prevents silent myocardial perfusion abnormalities during exercise in asymptomatic patients with hypertrophic cardiomyopathy

    SciTech Connect

    Udelson, J.E.; Bonow, R.O.; O'Gara, P.T.; Maron, B.J.; Van Lingen, A.; Bacharach, S.L.; Epstein, S.E.

    1989-05-01

    Recent studies indicate that reversible 201Tl perfusion defects, compatible with silent myocardial ischemia, commonly develop during exercise in asymptomatic or mildly symptomatic patients with hypertrophic cardiomyopathy (HCM). To determine whether this represents a dynamic process that may be modified favorably by medical therapy, we studied 29 asymptomatic or minimally symptomatic patients with HCM, aged 12-55 years (mean, 28), with exercise 201Tl emission computed tomography under control conditions and again after 1 week of oral verapamil (mean dosage, 453 mg/day). Treadmill time increased slightly during verapamil (21.0 +/- 3.6 to 21.9 +/- 2.7 minutes, p less than 0.005), but peak heart rate-blood pressure product was unchanged (26.3 +/- 6.0 X 10(3)) compared with 25.0 +/- 6.4 X 10(3). Two midventricular short-axis images per study were divided into five regions each, and each of these 10 regions was then analyzed on a 0-2 scale by three observers blinded with regard to the patients' therapy. Average regional scores of 1.5 or less were considered to represent perfusion defects, and a change in regional score of 0.5 or more was considered to constitute a significant change. During control studies, 15 patients (52%) developed perfusion defects with exercise (average, 3.7 regions per patient). In 14 of these patients, all perfusion defects completely reversed after 3 hours of rest; one patient had fixed defects. After administration of verapamil, exercise perfusion scores improved in 10 of the 14 patients (71%) with reversible defects; there was overall improvement in 34 of 50 (68%) regions with initially reversible perfusion defects.

  1. Aspirin and Extended-Release Dipyridamole versus Clopidogrel for Recurrent Stroke

    PubMed Central

    Sacco, Ralph L.; Diener, Hans-Christoph; Yusuf, Salim; Cotton, Daniel; Ôunpuu, Stephanie; Lawton, William A.; Palesch, Yuko; Martin, Reneé H.; Albers, Gregory W.; Bath, Philip; Bornstein, Natan; Chan, Bernard P.L.; Chen, Sien-Tsong; Cunha, Luis; Dahlöf, Björn; De Keyser, Jacques; Donnan, Geoffrey A.; Estol, Conrado; Gorelick, Philip; Gu, Vivian; Hermansson, Karin; Hilbrich, Lutz; Kaste, Markku; Lu, Chuanzhen; Machnig, Thomas; Pais, Prem; Roberts, Robin; Skvortsova, Veronika; Teal, Philip; Toni, Danilo; VanderMaelen, Cam; Voigt, Thor; Weber, Michael; Yoon, Byung-Woo

    2009-01-01

    BACKGROUND Recurrent stroke is a frequent, disabling event after ischemic stroke. This study compared the efficacy and safety of two antiplatelet regimens — aspirin plus extendedrelease dipyridamole (ASA–ERDP) versus clopidogrel. METHODS In this double-blind, 2-by-2 factorial trial, we randomly assigned patients to receive 25 mg of aspirin plus 200 mg of extended-release dipyridamole twice daily or to receive 75 mg of clopidogrel daily. The primary outcome was first recurrence of stroke. The secondary outcome was a composite of stroke, myocardial infarction, or death from vascular causes. Sequential statistical testing of noninferiority (margin of 1.075), followed by superiority testing, was planned. RESULTS A total of 20,332 patients were followed for a mean of 2.5 years. Recurrent stroke occurred in 916 patients (9.0%) receiving ASA–ERDP and in 898 patients (8.8%) receiving clopidogrel (hazard ratio, 1.01; 95% confidence interval [CI], 0.92 to 1.11). The secondary outcome occurred in 1333 patients (13.1%) in each group (hazard ratio for ASA–ERDP, 0.99; 95% CI, 0.92 to 1.07). There were more major hemorrhagic events among ASA–ERDP recipients (419 [4.1%]) than among clopidogrel recipients (365 [3.6%]) (hazard ratio, 1.15; 95% CI, 1.00 to 1.32), including intracranial hemorrhage (hazard ratio, 1.42; 95% CI, 1.11 to 1.83). The net risk of recurrent stroke or major hemorrhagic event was similar in the two groups (1194 ASA–ERDP recipients [11.7%], vs. 1156 clopidogrel recipients [11.4%]; hazard ratio, 1.03; 95% CI, 0.95 to 1.11). CONCLUSIONS The trial did not meet the predefined criteria for noninferiority but showed similar rates of recurrent stroke with ASA–ERDP and with clopidogrel. There is no evidence that either of the two treatments was superior to the other in the prevention of recurrent stroke. PMID:18753638

  2. Performance of Myocardial Perfusion Imaging Using Multi-focus Fan Beam Collimator with Resolution Recovery Reconstruction in a Comparison with Conventional SPECT

    PubMed Central

    Matsutomo, Norikazu; Nagaki, Akio; Sasaki, Masayuki

    2014-01-01

    Objective(s): IQ-SPECT is an advanced high-speed SPECT modality for myocardial perfusion imaging (MPI), which uses a multi-focus fan beam collimator with resolution recovery reconstruction. The aim of this study was to compare IQ-SPECT with conventional SPECT in terms of performance, based on standard clinical protocols. In addition, we examined the concordance between conventional and IQ_SPECT in patients with coronary artery disease (CAD). Methods: Fifty-three patients, undergoing rest-gated MPI for the evaluation of known or suspected CAD, were enrolled in this study. In each patient, conventional SPECT (99mTc-tetrofosmin, 9.6 min and 201Tl, 12.9 min) was performed, immediately followed by IQ-SPECT, using a short acquisition time (4.3 min for 99mTc-tetrofosmin and 6.2 min for 201Tl). A quantitative analysis was performed on an MPI polar map, using a 20-segment model of the left ventricle. An automated analysis by gated SPECT was carried out to determine the left ventricular volume and function including end-diastolic volume (EDV), end-systolic volume (ESV), and left ventricular ejection fraction (LVEF). The degree of concordance between conventional SPECT and IQ-SPECT images was evaluated according to linear regression and Bland-Altman analyses. Results: The segmental percent uptake exhibited a significant correlation between IQ-SPECT and conventional SPECT (P<0.05). The mean differences in 99mTc-tetrofosmin studies were 1.1±6.6% (apex), 2.8±5.7% (anterior wall), 2.9±6.2% (septal wall), 4.9±6.7% (lateral wall), and 1.8±5.6% (inferior wall). Meanwhile, regarding the 201Tl-SPECT studies, these values were 1.6±6.9%, 2.0±6.6%, 2.1±5.9%, 3.3±7.2%, and 2.4±5.8%, respectively. Although the mean LVEF in IQ-SPECT tended to be higher than that observed in conventional SPECT (conventional SPECT=64.8±11.8% and IQ-SPECT=68.3±12.1% for 99mTc-tetrofosmin; conventional SPECT= 56.0±11.7% and IQ-SPECT=61.5±12.2% for 201Tl), quantitative parameters were not

  3. Acute electrophysiological effects of dipyridamole on sinus node function in patients with sick sinus syndrome.

    PubMed

    Yeşil, M; Bayata, S; Postaci, N; Aydin, C

    1997-12-01

    One of the most widely used tests for evaluation of sinus node function is sinus node recovery time (SNRT), which requires right heart catheterization. On the other hand SNRT has high specificity but only moderate sensitivity in the diagnosis of sick sinus syndrome (SSS). The authors studied acute electrophysiologic effects of dipyridamole (0.40 mg/kg IV) in 16 patients with clinical SSS. All of them had normal SNRT and had undergone permanent DDD pacemaker implantation. By the aid of temporary pacing inhibition, the authors noninvasively measured the corrected sinus node recovery time (SNRTc) and sinus cycle length (SCL) before and after dipyridamole administration. SCL was slightly decreased from a mean basal value of 1025 +/-323 to 913+/-213 msec after dipyridamole administration (mean -10%), but this was not statistically significant. SNRTc was increased from a mean basal value of 344+/-91 to 606+/-156 msec after dipyridamole administration (+76% P< or =0.004). These results suggest that dipyridamole must be used cautiously in patients with SSS. Intravenous dipyridamole may be a useful test to assess sinus node function. SNRT measurement after intravenous dipyridamole may increase sensitivity of this test in patients with suspected SSS and normal SNRT.

  4. Severe bronchospasm followed by respiratory arrest during thallium-dipyridamole imaging

    SciTech Connect

    Lette, J.; Cerino, M.; Laverdiere, M.; Tremblay, J.; Prenovault, J.

    1989-06-01

    We describe the occurrence of sudden severe bronchospasm and respiratory arrest following dipyridamole infusion in a patient with chronic obstructive pulmonary disease predominantly of the emphysematous type. The severe reaction was unexpected because the patient had tolerated well withdrawal of aminophylline derivatives for 48 hours and was receiving chronic prednisone 20 mg qd. Although the diagnostic and prognostic gains from dipyridamole imaging far outweigh the small risk associated with the test, patients with chronic pulmonary obstructive disease must be closely monitored during thallium-dipyridamole imaging.

  5. Comparison of stress-only vs. stress/rest with technetium-99m methoxyisobutylisonitrile myocardial perfusion imaging.

    PubMed

    Worsley, D F; Fung, A Y; Coupland, D B; Rexworthy, C G; Sexsmith, G P; Lentle, B C

    1992-01-01

    Unlike conventional thallium-201 myocardial imaging, technetium-99m methoxyisobutylisonitrile (MIBI) requires separate stress and rest injections. We prospectively studied 148 consecutive patients referred for myocardial perfusion studies to determine the diagnostic value of rest images once normal exercise or dipyridamole tomographic images had been obtained. In patients referred with no history of previous myocardial infarction in whom the diagnosis of coronary artery disease was suspected, 45 of 109 (41%) patients had normal stress tomographic images. Obtaining rest images did not alter the final interpretation in any of these cases. From this we infer that in patients with normal images after exercise or dipyridamole administration and no past history of myocardial infarction, 99mTc-MIBI rest images are not required. This provides several advantages including increased speed of diagnosis, decreased patient radiation exposure, improved cost efficiency and decreased demand on tomographic camera time.

  6. Myocardial perfusion imaging with technetium-99m sestamibi SPECT in the evaluation of coronary artery disease

    SciTech Connect

    Maddahi, J.; Kiat, H.; Van Train, K.F.; Prigent, F.; Friedman, J.; Garcia, E.V.; Alazraki, N.; DePuey, E.G.; Nichols, K.; Berman, D.S. )

    1990-10-16

    Technetium-99m (Tc-99m) sestamibi is a new myocardial perfusion imaging agent that offers significant advantages over thallium-201 (Tl-201) for myocardial perfusion imaging. The results of the current clinical trials using acquisition and processing parameters similar to those for Tl-201 and a separate (2-day) injection protocol suggest that Tc-99m sestamibi and Tl-201 single photon emission computed tomography (SPECT) provide similar information with respect to detection of myocardial perfusion defects, assessment of the pattern of defect reversibility, overall detection of coronary artery disease (CAD) and detection of disease in individual coronary arteries. Tc-99m sestamibi SPECT appears to be superior to Tc-99m sestamibi planar imaging because the former provides a higher defect contrast and is more accurate for detection of disease in individual coronary arteries. Research is currently under way addressing optimization of acquisition and processing of Tc-99m sestamibi studies and development of quantitative algorithms for detection and localization of CAD and sizing of transmural and nontransmural myocardial perfusion defects. It is expected that with the implementation of the final results of these new developments, further significant improvement in image quality will be attained, which in turn will further increase the confidence in image interpretation. Development of algorithms for analysis of end-diastolic myocardial images may allow better evaluation of small and nontransmural myocardial defects. Furthermore, gated studies may provide valuable information with respect to regional myocardial wall motion and wall thickening. With the implementation of algorithms for attenuation and scatter correction, the overall specificity of Tc-99m sestamibi SPECT should improve significantly. 32 references.

  7. Effect of alpha 1-adrenoceptor blockade on resting and hyperemic myocardial blood flow in normal humans.

    PubMed

    Lorenzoni, R; Rosen, S D; Camici, P G

    1996-10-01

    In the present study we aimed to assess the effect of alpha 1-adrenoceptor blockade on resting and hyperemic myocardial blood flow in normal humans. Myocardial blood flow, at baseline and after dipyridamole, was measured with positron emission tomography and 15O-labeled water in 11 normal volunteers at control and during alpha 1-blockade with doxazosin. Baseline myocardial blood flow during alpha 1-blockade was not different from control, whereas coronary resistance was significantly lower (73.48 +/- 18.31 vs. 89.84 +/- 27.96 mmHg.min.ml-1.g-1; P < 0.05). After dipyridamole, myocardial blood flow during alpha 1-blockade was significantly higher (3.50 +/- 0.75 vs. 2.58 +/- 0.54 ml.min-1.g-1; P < 0.01) and coronary resistance lower (25.30 +/- 7.37 vs. 33.89 +/- 7.04 mmHg.min.ml-1.g-1; P < 0.01) compared with control. In conclusion, in normal humans, dipyridamole-induced increase in myocardial blood flow is limited by alpha 1-mediated coronary vasoconstriction.

  8. Myocardial perfusion of infarcted and normal myocardium in propofol-anesthetized minipigs using (82)Rubidium PET.

    PubMed

    Rasmussen, Thomas; Follin, Bjarke; Kastrup, Jens; Christensen, Thomas Emil; Hammelev, Karsten Pharao; Kjær, Andreas; Hasbak, Philip

    2016-06-01

    Cardiac Rubidium-82 ((82)Rb) positron-emission-tomography (PET) is a good method for quantification of myocardial blood flow in man. Quantification of myocardial blood flow in animals to evaluate new treatment strategies or to understand underlying disease is also of great interest but raises some challenges. Animals, which have been anesthetized during PET acquisition, might react differently to used stress medications, and therefore difficulties might exist while evaluating the resulting PET images using standard software packages from commercial vendors optimized for human hearts. Furthermore propofol, used for anesthesia, can influence myocardial perfusion and coronary flow reserve due to its vasorelaxant effect, and interactions might exist between propofol and used stress agents, potentially affecting the result of the examination. We present cardiac (82)Rb-PET studies performed in propofol-anesthetized minipigs with normal and infarcted myocardium stressed with both adenosine and dipyridamole. Despite the mentioned challenges, we were able to trace the small minipig heart with software designed for human cardiac PET and to achieve blood flow measurements comparable with results in humans with both adenosine and dipyridamole. We found dipyridamole to be a superior stress agent for this experimental setup. Finally, we were able to clearly identify the myocardial perfusion defect after an induced myocardial infarction. PMID:26931633

  9. Ocular Applications of Dipyridamole: A Review of Indications and Routes of Administration

    PubMed Central

    Isakov, Itzhak; Wlassoff, Wjatschesslaw; Ingram, April; Barishak, Y. Robert

    2016-01-01

    Abstract Dipyridamole was introduced decades ago as a treatment for angina, subsequently found to inhibit platelet aggregation. It is most commonly used, and approved for use in thromboembolism prevention, following surgery. Some of its recognized effects such as adenosine uptake inhibition, elevation of cAMP and cGMP levels, vasodilation, and tissue perfusion are important in various ocular disorders. For this reason, dipyridamole represents an interesting candidate as a therapeutic target for the treatment of eye disorders affecting different ocular structures. The aim of this article is to review the evidence and current understanding of the mechanisms by which dipyridamole exerts its effects on different ocular tissues, discuss the role of dipyridamole in clinical practice, and highlight areas of use and routes of administration. PMID:26696547

  10. Comparison of dipyridamole-handgrip test and bicycle exercise test for thallium tomographic imaging

    SciTech Connect

    Huikuri, H.V.; Korhonen, U.R.; Airaksinen, J.; Ikaeheimo, M.J.H.; Heikkilae, J.T.; Takkunen, J.T.

    1988-02-01

    Seventy-three patients with angina pectoris and 20 with atypical chest pain, who underwent coronary angiography, were examined by single-photon emission computed thallium tomography (TI-SPECT) using a combined dipyridamole-handgrip stress test. Perfusion defects were detected in 78 of 81 patients with angiographically significant coronary artery disease (CAD) (sensitivity 96%). In 9 of 12 patients without CAD, the thallium images were normal (specificity 75%). Thirty-five patients with CAD were reexamined by TI-SPECT using a dynamic bicycle exercise stress test. The sensitivity of the dipyridamole-handgrip test did not differ from the bicycle exercise test in diagnosing the CAD (97% vs 94%). Multiple thallium defects were seen in 19 of 22 (86%) patients with multivessel CAD by the dipyridamole-handgrip test but only in 14 of 22 (64%) by the bicycle exercise test. Noncardiac side-effects occurred in 17 of 93 (18%) patients after dipyridamole infusion. Cardiac symptoms were less common during the dipyridamole-handgrip test than during the bicycle exercise (15% vs 76%, p less than 0.01). These data suggest that the dipyridamole-handgrip test is a useful alternative stress method for thallium perfusion imaging, particularly in detecting multivessel CAD.

  11. Clinical experience with technetium-99m teboroxime, a neutral, lipophilic myocardial perfusion imaging agent

    SciTech Connect

    Johnson, L.L.; Seldin, D.W. )

    1990-10-16

    Technetium-99m (Tc-99m) teboroxime is a new technetium-based myocardial perfusion imaging agent (investigational code = SQ30217 (Cardiotec, Squibb Diagnostics)). A member of a class of neutral, lipophilic, technetium-containing complexes known as boronic acid adducts of technetium dioxime (BATO) complexes, this agent is chemically very different from the cationic tracer thallium-201 (Tl-201) and from the cationic technetium complex Tc-99m sestamibi (Cardiolite, Du Pont Imaging Agents). Tc-99m teboroxime has high myocardial extraction, rapid blood clearance, little lung uptake and rapid myocardial washout. A biexponential pattern of myocardial washout is demonstrated in animals and in man. Effective half-lives of the 2 washout components in man are 5.2 minutes and 3.8 hours and represent approximately 66 and 33% of the myocardial activity, respectively. The first half-life for the myocardium is approximately 11 minutes. As the agent washes out of the heart, hepatic uptake occurs, peaking at about 5 minutes after injection. The liver is the major organ of excretion and receives, along with the large bowel, the largest radiation dose. Rapid imaging protocols using standard cameras have achieved good myocardial counts from 3 planar views acquired over a 4- to 5-minute period or for single photon emission computed tomography (SPECT) images acquired over a 10-minute period. An entire stress/rest procedure can be completed in 1 hour. Analysis of data from 155 patients from 4 centers using planar or SPECT imaging showed a sensitivity and specificity for blinded readings of 82 and 91%, respectively, when compared against overall clinical impression. 13 references.

  12. Imaging of myocardial viability: a head-to-head comparison among nuclear, echocardiographic, and angiographic techniques.

    PubMed

    Marzullo, P; Parodi, O; Picano, E; Sambuceti, G; Reisenhofer, B; Gimelli, A; Distante, A; L'Abbate, A

    1993-09-01

    The relationship between radioisotopic, echocardiographic, and angiographic markers of myocardial viability is still to be defined. To this purpose, 14 patients with previous myocardial infarction were studied using a multiparametric approach. Each patient underwent, on separate days, rest thallium 201 and technetium 99m Sestamibi planar scintigraphy, dobutamine/dipyridamole stress echocardiography, and coronary angiography; 11 of these patients underwent also dipyridamole echocardiographic testing. Thallium 201 and Sestamibi uptakes at rest were expressed as percentage of maximal activity in each projection using a 13 segment model. Dobutamine and dipyridamole stress echocardiography were analyzed using a score index ranging from 1 (normokinesis) to 4 (dyskinesis) and a similar segmentation. Coronary angiography was analyzed by quantitative approach. In all patients, follow-up echocardiography was performed following coronary revascularization. Before revascularization, 75 segments showed regional dyssynergies. Thallium 201 showed the highest sensitivity and specificity in the preoperative identification of viability, whereas Sestamibi was affected by a significant number of false-negative studies. Among echocardiographic techniques, dobutamine was slightly superior to dipyridamole in the detection of viable segments. The degree of coronary stenosis failed to predict the recovery of function following by-pass graft or angioplasty in almost all segments; however, in case of occlusion, most viable segments were perfused by adequately collateralized coronary arteries.

  13. Semi-automated measurements of heart-to-mediastinum ratio on 123I-MIBG myocardial scintigrams by using image fusion method with chest X-ray images

    NASA Astrophysics Data System (ADS)

    Kawai, Ryosuke; Hara, Takeshi; Katafuchi, Tetsuro; Ishihara, Tadahiko; Zhou, Xiangrong; Muramatsu, Chisako; Abe, Yoshiteru; Fujita, Hiroshi

    2015-03-01

    MIBG (iodine-123-meta-iodobenzylguanidine) is a radioactive medicine that is used to help diagnose not only myocardial diseases but also Parkinson's diseases (PD) and dementia with Lewy Bodies (DLB). The difficulty of the segmentation around the myocardium often reduces the consistency of measurement results. One of the most common measurement methods is the ratio of the uptake values of the heart to mediastinum (H/M). This ratio will be a stable independent of the operators when the uptake value in the myocardium region is clearly higher than that in background, however, it will be unreliable indices when the myocardium region is unclear because of the low uptake values. This study aims to develop a new measurement method by using the image fusion of three modalities of MIBG scintigrams, 201-Tl scintigrams, and chest radiograms, to increase the reliability of the H/M measurement results. Our automated method consists of the following steps: (1) construct left ventricular (LV) map from 201-Tl myocardium image database, (2) determine heart region in chest radiograms, (3) determine mediastinum region in chest radiograms, (4) perform image fusion of chest radiograms and MIBG scintigrams, and 5) perform H/M measurements on MIBG scintigrams by using the locations of heart and mediastinum determined on the chest radiograms. We collected 165 cases with 201-Tl scintigrams and chest radiograms to construct the LV map. Another 65 cases with MIBG scintigrams and chest radiograms were also collected for the measurements. Four radiological technologists (RTs) manually measured the H/M in the MIBG images. We compared the four RTs' results with our computer outputs by using Pearson's correlation, the Bland-Altman method, and the equivalency test method. As a result, the correlations of the H/M between four the RTs and the computer were 0.85 to 0.88. We confirmed systematic errors between the four RTs and the computer as well as among the four RTs. The variation range of the H

  14. Experimental studies of the physiologic properties of technetium-99m agents: Myocardial transport of perfusion imaging agents

    SciTech Connect

    Meerdink, D.J.; Leppo, J.A. )

    1990-10-16

    The physiologic properties of new technetium-99m-labeled myocardial imaging agents (Tc-99m sestamibi, an isonitrile; and Tc-99m teboroxime, a boronic acid adduct of technetium dioxime) are discussed and compared to thallium-201 (Tl-201). Studies with isolated hearts, subcellular fractions and cell cultures indicate that Tc-99m sestamibi, Tc-99m teboroxime and Tl-201 do not share common transport or sequestration mechanisms. Although peak Tc-99m sestamibi myocardial extraction over time is about half that of Tl-201 at equivalent coronary blood flows, the amount of Tc-99m sestamibi that remains in the heart is similar to that of Tl-201 because of its higher retention efficiency. The high retention efficiency for Tc-99m sestamibi also results in minimal redistribution. In contrast, Tc-99m teboroxime myocardial extraction is higher than that of Tl-201, but its retention is less efficient, resulting in relatively rapid washout characteristics which may quickly result in tracer redistribution. During reperfusion after a no-flow period, Tc-99m sestamibi extraction and retention increase, but for Tc-99m teboroxime and Tl-201 these values tend to decrease. All tracers show adequate transport characteristics for perfusion imaging, and differences in transport and retention should lead to the development of new clinical protocols.27 references.

  15. Self-microemulsifying drug delivery system for improved oral bioavailability of dipyridamole: preparation and evaluation.

    PubMed

    Guo, Feng; Zhong, Haijun; He, Jing; Xie, Baogang; Liu, Fen; Xu, Helin; Liu, Minmin; Xu, Chunlian

    2011-07-01

    Dipyridamole shows poor and variable bioavailability after oral administration due to pHdependent solubility, low biomembrane permeability as well as being a substrate of P-glycoprotein. In order to improve the oral absorption of dipyridamole, a self-microemulsifying drug delivery system (SMEDDS) for dipyridamole was prepared and evaluated in vitro and in vivo. The optimum formulation was 18% oleic acid, 12% Labrafac lipophile WL 1349, 42% Solutol HS 15 and 28% isopropyl alcohol. It was found that the performance of self-microemulsification with the combination of oleic acid and Labrafac lipophile WL 1349 increased compared with just one oil. The results obtained from an in vitro dissolution assay indicated that dipyridamole in SMEDDS dissolved rapidly and completely in pH 6.8 aqueous media, while the commercial drug tablet was less soluble. An oral bioavailability study in rats showed that dipyridamole in the SMEDDS formulation had a 2.06-fold increased absorption compared with the simple drug suspension. It was evident that SMEDDS may be an effective approach to improve the oral absorption for drugs having pH-dependent solubility.

  16. The clinical impact of perfusion scintigraphy with dipyridamole

    SciTech Connect

    Schechtmann, N.; Dae, M.; Lanzer, P.; Sajardo, L.; Faulkner, D.; Botvinick, E.

    1984-01-01

    In order to assess their clinical impact, the authors analyzed perfusion scintigrams (PS) with dipyridamole (D) and the resultant clinical management in 41 consecutive patients (PTS). Population mean age was 67, with 22 males and represented 14% of those having PS. Fifteen PTS had rest chest pain of unknown cause and 26 PTS had pain typical or suggestive of angina but couldn't undergo dynamic stress due to claudication, arthritis, amputation, stroke, recent surgery or other disability. Four PTS were studies for surgical clearance, 3 following angiography to assess coronary pathophysiology and 9 had prior negative or equivocal stress PS at suboptimal levels. Among 18 PTS with reversible scintigraphic abnormalities, 10 underwent subsequent catheterization, with successful CABG in 7, PTCA in 1, aggressive medical treatment of ischemia in 11, and 2 had noncoronary surgery delayed. One PT with associated extensive fixed abnormalities underwent CABG and died late in heart failure. Among 23 PTS without significant scintigraphic reversibility, 8 with normal studies were discharged, 3 went on to uncomplicated noncardiac surgery and 11 PTS, 9 with dilated cardiomyopathy, were managed without therapeutic change. D infusion was uncomplicated and related findings on PS correlated well with coronary angiography, where available in 19 of 20 PTS. PS with D: 1) is safe; 2) correlates closely with coronary anatomy; and 3) adds unique, important pathophysiologic information to clinical evaluation and impacts strongly on the management of a large number of PTS with known or suspected coronary disease.

  17. Dipyridamole, an inhibitor of mengovirus replication in FL and L cells.

    PubMed

    Tonew, M; Dzeguze, D

    1977-01-01

    Dipyridamole showed an antiviral activity aganinst mengovirus in FL cells using the agar diffusion plaque inhibition test, plaque reduction test, tube titration test, and virus yield test after one replication cycle. With the last two tests mentioned above the inhibitory action was also confirmed in L cells. In consequence of the known transport inhibition of uridine into the cell in presence of dipyridamole only a very small incorporation of 3H-uridine into acid-insoluble material could be demonstrated. Applying the method of prelabelling of FL cells at 16 degrees C for 1 h with subsequent addition of dipyridamole the drug failed to show an effect on cellular RNA synthesis per se in uninfected cells whereas the viral RNA synthesis in mengo-virus-infected L cells was completely depressed.

  18. Dipyridamole-induced stress - variability in {sup 82}Rb PET kinetic studies in the anesthetized canine

    SciTech Connect

    Coxson, P.G.; Brennan, K.M.; Taylor, S.E.

    1996-05-01

    Reproducibility and variability of dipyridamole-induced stress in the myocardium as measured with {sup 82}Rb PET kinetics was tested in a series of replicated studies on six dogs using the Donner 600-Crystal Positron Tomograph (4.5mm FWHM with {sup 82}Rb). A single lateral slice through the myocardium was imaged in a baseline resting state, and again immediately after an infusion of dipyridamole (0.6 mg/kg over 4 min). Blood samples taken at 1 minute intervals were assayed with HPLC. A two compartment model with parameters k{sub 1} (uptake rate), k{sub 2} (wash-out rate), and f{sub v} (vascular fraction) was fit to the data. Stress-state k{sub 1} estimates were compared with rest-state k{sub 1} estimates and dipyridamole levels in the blood to ascertain any dependencies between them. In a multiple regression of the stress-k{sub 1} on both the rest-k{sub 1} and the mean dipyridamole concentration (0-4 min), the rest-k{sub 1} is significant (p=0.032) as a predictor and the dipyridamole concentration is borderline significant (p=0.060). Together they explain about 35% of the variability in the stress-k{sub 1}. Analysis of variance shows no significant between-animal effects for either the rest-k{sub 1} or the stress-k{sub 1} estimates but a significant (p=0.032) between-animal effect for the dipyridamole concentration. Dipyridamole is routinely used to induce stress for kinetic PET cardiac studies, but its contribution to variability in the rest-stress test has not been examined. These studies show that dipyridamole pharmacokinetic variability within and between animals has an effect on the stress-k{sub 1} estimate, but the effect is small. The statistically significant correlation of the rest- and stress-k{sub 1} values suggests that the ratio of K{sub 1} (stress/rest) is a more stable indicator of the stress response than the stress-k{sub 1} values alone.

  19. Determination of dipyridamole in pharmaceutical preparations using square wave voltammetry.

    PubMed

    de Toledo, Renata Alves; Castilho, Marilza; Mazo, Luiz Henrique

    2005-01-01

    An analytical methodology using square wave voltammetry (SWV) at a hanging mercury drop electrode (HMDE) was developed for the quantitative determination of dipyridamole (DIP), a drug used for the treatment of several cardiovascular diseases, in pharmaceutical tablets and injections of Persantin in phosphate buffer (pH 3.0; 0.1M). After optimization of the parameters for SWV, analytical curves were obtained for application in the range of 1.28 x 10(-6)M to 7.02 x 10(-6)M. It was found a detection limit (DL) of 1.88 x 10(-8)M (9.50 ng/ml). The repeatability and the reproducibility of the method were determinated by successive measurements of DIP solutions on the range of the analytical curve with a coefficient variation of 0.97% (n=5) and 1.15%, respectively. The apparent recoveries were obtained by the IUPAC recommended procedure using the second reduction peak. Recoveries obtained by SWV were compared with the UV-vis spectrophotometric method. It was found that the determination of DIP in Persantin tablets gave a mean value of 75.6+/-0.4 mg (100.8%) and 68.9+/-0.3 mg (91.8%) for SWV and UV-vis spectrophotometry, respectively. In the case of injections, it was found 10.4+/-0.1 mg (103.4%) and 9.9+/-0.2 mg (99.9%) for SWV and UV-vis spectrophotometry. Both apparent recoveries for the two types of formulations are in good accordance with the declared value of 75 mg (tablets) and 10 mg (injections).

  20. Prevalence and clinical significance of painless ST segment depression during early postinfarction exercise testing

    SciTech Connect

    Gibson, R.S.; Beller, G.A.; Kaiser, D.L.

    1987-03-01

    In a recent study of 190 survivors of acute myocardial infarction, the authors sought to determine whether exercise-induced painless ST segments depression indicates residual myocardial ischemia, as defined by /sup 201/Tl scintigraphic criteria. 2 weeks after uncomplicated myocardial infarction, and whether quantitative /sup 201/Tl imaging enhances the prognostic value of such an exercise electrocardiographic response.

  1. Two-dimensional Doppler echocardiographic correlation of dipyridamole-thallium stress testing with isometric handgrip

    SciTech Connect

    Whitfield, S.; Aurigemma, G.; Pape, L.; Leppo, J. )

    1991-05-01

    To determine how frequently new wall-motion abnormalities that are indicative of ischemia accompany thallium redistribution, 47 consecutive patients underwent two-dimensional, echocardiography during routine dipyridamole-thallium stress testing. A secondary aim of the study was to determine whether the addition of isometric handgrip exercises to the standard dipyridamole imaging protocol increased the frequency of wall-motion abnormalities or thallium redistribution. Echocardiograms and thallium scans were independently interpreted, and wall-motion abnormalities that appeared with dipyridamole, handgrip exercise, or both were compared with results of thallium imaging. Five of 24 patients with thallium redistribution had new wall-motion abnormalities, and the extent (number of segments) of thallium redistribution in these five patients was significantly greater than in those who did not have well-motion abnormalities (p less than 0.03). The addition of isometric handgrip exercises to the imaging protocol did not distinguish between patients with and without new wall-motion abnormalities or thallium redistribution. Thus new wall-motion abnormalities infrequently accompany thallium redistribution in routine dipyridamole stress testing in spite of the addition of handgrip exercises, but when new wall-motion abnormalities are present, they are associated with a greater area of thallium redistribution.

  2. Quantitative analysis of planar technetium-99m-sestamibi myocardial perfusion images using modified background subtraction

    SciTech Connect

    Koster, K.; Wackers, F.J.; Mattera, J.A.; Fetterman, R.C. )

    1990-08-01

    Standard interpolative background subtraction, as used for thallium-201 ({sup 201}Tl), may create artifacts when applied to planar technetium-99m-Sestamibi ({sup 99m}Tc-Sestamibi) images, apparently because of the oversubtraction of relatively high extra-cardiac activity. A modified background subtraction algorithm was developed and compared to standard background subtraction in 16 patients who had both exercise-delayed {sup 201}Tl and exercise-rest {sup 99m}Tc-Sestamibi imaging. Furthermore, a new normal data base was generated. Normal {sup 99m}Tc-Sestamibi distribution was slightly different compared to {sup 201}Tl. Using standard background subtraction, mean defect reversibility was significantly underestimated by {sup 99m}Tc-Sestamibi compared to {sup 201}Tl (2.8 +/- 4.9 versus -1.8 +/- 8.4, p less than 0.05). Using the modified background subtraction, mean defect reversibility on {sup 201}Tl and {sup 99m}Tc-Sestamibi images was comparable (2.8 +/- 4.9 versus 1.7 +/- 5.2, p = NS). We conclude, that for quantification of {sup 99m}Tc-Sestamibi images a new normal data base, as well as a modification of the interpolative background subtraction method should be employed to obtain quantitative results comparable to those with {sup 201}Tl.

  3. Performance of a polyurethane vascular prosthesis carrying a dipyridamole (Persantin) coating on its lumenal surface.

    PubMed

    Aldenhoff, Y B; van Der Veen, F H; ter Woorst, J; Habets, J; Poole-Warren, L A; Koole, L H

    2001-02-01

    A porous polyurethane vascular prosthesis with an internal diameter of 5 mm was studied. The graft carries a coating of immobilized dipyridamole (Persantin(R)) on the surface of its lumen. Dipyridamole is a potent nontoxic inhibitor of platelet activation/aggregation, and also a strong inhibitor of vascular smooth muscle cell proliferation. The polyurethane material is also known as Chronoflex(R), and already finds use as a vascular access graft. The coated vascular graft was studied in vitro (hemocompatibility, interaction with blood platelets and cultured endothelial cells), as well as in two established in vivo models. In the first in vivo study, coated grafts were implanted in goats, as a bypass of the carotid artery (four animals, eight grafts, length of the graft was approximately 12 cm). Four uncoated grafts were used as controls in otherwise identical experiments. In the second in vivo experiment, eight sheep were used. Each animal received one coated and one uncoated prosthesis as an interposition graft in the carotid artery (length of the graft was 4 cm). The in vitro experiments revealed that the dipyridamole coating has three beneficial effects: reduced thrombogenicity, reduced adherence of blood platelets, and accommodation of a confluent monolayer of endothelial cells. The goat experiments showed patency of the coated grafts in three of the eight cases. The sheep experiments were not useful for the evaluation of the dipyridamole coating because deterioration of the polyurethane material was observed. The in vivo results indicate that the dipyridamole coating may positively influence the patency rate, probably because the coating promotes the growth of an endothelial cell lining. The sheep data show, however, that the limited stability of the Chronoflex(R) material precludes its issue for the construction of permanent small-bore vascular grafts. PMID:11093182

  4. Effect of nitroglycerin and dipyridamole on regional left ventricular blood flow during coronary artery occlusion.

    PubMed Central

    Becker, L C

    1976-01-01

    Coronary vasodilators have been variously reported to increase, decrease, or have no effect upon blood flow to ischemic myocardium. Consequently, the effects of two different types of dilators, nitroglycerin (TNG) and dipyridamole, were studied with radioactive microspheres in open-chested dogs after coronary artery ligation. Given as a bolus i.v. injection 0.4 mg TNG resulted in an increase in blood flow to nonischemic areas of myocardium and a preservation of flow to ischemic regions, despite a fall in blood pressure. 5 min later blood pressure and nonischemic flow were back to base line, and a small selective increase in flow to ischemic myocardium was found (0.15-0.18 ml/min per g, P less than 0.05). During an 0.2 mg/min infusion of TNG, and also after 1 mg/kg i.v. dipyridamole, ischemic flow was maintained in the face of a 20-30% reduction in blood pressure. In this setting, nonischemic flow was unchanged during TNG and doubled after dipyridamole. With the addition of methoxamine in both dilator groups, blood pressure returned to base line while flow to ischemic areas increased above base-line values (TNG, 0.16-0.20 ml/min per g, P less than 0.01; dipyridamole, 0.18-0.31 ml/min per g, P less than 0.05). Epicardial ST segment elevations increased during TNG infusion and were unchanged after dipyridamole, but with addition of methoxamine, ST segments became less elevated in both drug groups, concomitant with the observed increase in collateral blood flow. These data indicate that both types of coronary vasodilators, when used in conjunction with methoxamine to support blood pressure, reduce collateral resistance, increase collateral flow, and reduce epicardial ST-segment elevations. PMID:825534

  5. Effect of an additional atropine injection during dobutamine infusion for myocardial SPET.

    PubMed

    Caner, B; Karanfil, A; Uysal, U; Tokgozoglu, L; Aksoyek, S; Ugur, O; Ciftci, I; Atalar, E; Kes, S; Bekdik, C

    1997-06-01

    The aim of this study was to examine the value of an additional atropine injection in patients who do not achieve an adequate heart rate during dobutamine infusion for myocardial perfusion SPET (single photon emission tomography). Patients undergoing dobutamine myocardial SPET who failed to achieve > or = 85% of their age-predicted maximal heart rate at the end of dobutamine infusion (D protocol) had a second dobutamine myocardial SPET study on a separate day with the addition of an atropine injection during the dobutamine infusion (D + A protocol). Twenty-nine patients were studied. 201Tl was used in 27 patients and 99Tc(m)-MIBI in two patients. All patients underwent coronary angiography and significant coronary artery disease was found in 19 of 29 patients. The mean heart rate obtained at the peak of dobutamine infusion in the D + A protocol was significantly higher than that in the D protocol (153.8 +/- 13.8 vs 117.5 +/- 15.3 beats min[-1]). The D + A protocol resulted in a higher diagnostic sensitivity for the detection of stenosed coronaries compared with the D protocol (87 vs 80%, P > 0.05) without changing the specificity (89% for both protocols). On the other hand, the frequency of side-effects and ECG changes during the D + A protocol was higher than that with the D protocol (32 vs 47). In conclusion, the addition of an atropine injection during dobutamine infusion resulted in a higher diagnostic sensitivity for identifying stenosed coronaries compared to dobutamine alone.

  6. Identification of Angiogenesis Rich-Viable Myocardium using RGD Dimer based SPECT after Myocardial Infarction

    PubMed Central

    Lee, Min Su; Park, Hyun Soo; Lee, Byung Chul; Jung, Jae Ho; Yoo, Jung Sun; Kim, Sang Eun

    2016-01-01

    Cardiac healing after myocardial ischemia is a complex biological process. Advances in understanding of wound healing response have paved the way for clinical testing of novel molecular imaging to improve clinical outcomes. A key factor for assessing myocardial viability after ischemic injury is the evaluation of angiogenesis accompanying increased expression of integrin αvβ3. Here, we describe the capability of an αvβ3 integrin-targeting SPECT agent, 99mTc-IDA-D-[c(RGDfK)]2, for identification of ischemic but viable myocardium, i.e., hibernating myocardium which is crucial to predict functional recovery after revascularization, the standard care of cardiovascular medicine. In vivo SPECT imaging of rat models with transient coronary occlusion showed significantly high uptake of 99mTc-IDA-D-[c(RGDfK)]2 in the ischemic region. Comparative measurements with 201Tl SPECT and 18F-FDG PET, then, proved that such prominent uptake of 99mTc-IDA-D-[c(RGDfK)]2 exactly matched the hallmark of hibernation, i.e., the perfusion-metabolism mismatch pattern. The uptake of 99mTc-IDA-D-[c(RGDfK)]2 was non-inferior to that of 18F-FDG, confirmed by time-course variation analysis. Immunohistochemical characterization revealed that an intense signal of 99mTc-IDA-D-[c(RGDfK)]2 corresponded to the vibrant angiogenic events with elevated expression of αvβ3 integrin. Together, these results establish that 99mTc-IDA-D-[c(RGDfK)]2 SPECT can serve as a sensitive clinical measure for myocardial salvage to identify the patients who might benefit most from revascularization. PMID:27283041

  7. Identification of Angiogenesis Rich-Viable Myocardium using RGD Dimer based SPECT after Myocardial Infarction.

    PubMed

    Lee, Min Su; Park, Hyun Soo; Lee, Byung Chul; Jung, Jae Ho; Yoo, Jung Sun; Kim, Sang Eun

    2016-06-10

    Cardiac healing after myocardial ischemia is a complex biological process. Advances in understanding of wound healing response have paved the way for clinical testing of novel molecular imaging to improve clinical outcomes. A key factor for assessing myocardial viability after ischemic injury is the evaluation of angiogenesis accompanying increased expression of integrin αvβ3. Here, we describe the capability of an αvβ3 integrin-targeting SPECT agent, (99m)Tc-IDA-D-[c(RGDfK)]2, for identification of ischemic but viable myocardium, i.e., hibernating myocardium which is crucial to predict functional recovery after revascularization, the standard care of cardiovascular medicine. In vivo SPECT imaging of rat models with transient coronary occlusion showed significantly high uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 in the ischemic region. Comparative measurements with (201)Tl SPECT and (18)F-FDG PET, then, proved that such prominent uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 exactly matched the hallmark of hibernation, i.e., the perfusion-metabolism mismatch pattern. The uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 was non-inferior to that of (18)F-FDG, confirmed by time-course variation analysis. Immunohistochemical characterization revealed that an intense signal of (99m)Tc-IDA-D-[c(RGDfK)]2 corresponded to the vibrant angiogenic events with elevated expression of αvβ3 integrin. Together, these results establish that (99m)Tc-IDA-D-[c(RGDfK)]2 SPECT can serve as a sensitive clinical measure for myocardial salvage to identify the patients who might benefit most from revascularization.

  8. Identification of Angiogenesis Rich-Viable Myocardium using RGD Dimer based SPECT after Myocardial Infarction.

    PubMed

    Lee, Min Su; Park, Hyun Soo; Lee, Byung Chul; Jung, Jae Ho; Yoo, Jung Sun; Kim, Sang Eun

    2016-01-01

    Cardiac healing after myocardial ischemia is a complex biological process. Advances in understanding of wound healing response have paved the way for clinical testing of novel molecular imaging to improve clinical outcomes. A key factor for assessing myocardial viability after ischemic injury is the evaluation of angiogenesis accompanying increased expression of integrin αvβ3. Here, we describe the capability of an αvβ3 integrin-targeting SPECT agent, (99m)Tc-IDA-D-[c(RGDfK)]2, for identification of ischemic but viable myocardium, i.e., hibernating myocardium which is crucial to predict functional recovery after revascularization, the standard care of cardiovascular medicine. In vivo SPECT imaging of rat models with transient coronary occlusion showed significantly high uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 in the ischemic region. Comparative measurements with (201)Tl SPECT and (18)F-FDG PET, then, proved that such prominent uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 exactly matched the hallmark of hibernation, i.e., the perfusion-metabolism mismatch pattern. The uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 was non-inferior to that of (18)F-FDG, confirmed by time-course variation analysis. Immunohistochemical characterization revealed that an intense signal of (99m)Tc-IDA-D-[c(RGDfK)]2 corresponded to the vibrant angiogenic events with elevated expression of αvβ3 integrin. Together, these results establish that (99m)Tc-IDA-D-[c(RGDfK)]2 SPECT can serve as a sensitive clinical measure for myocardial salvage to identify the patients who might benefit most from revascularization. PMID:27283041

  9. Noninvasive assessment of changes in myocardial perfusion and ventricular performance following exercise training

    SciTech Connect

    Tubau, J.; Witztum, K.; Froelicher, V.; Jensen, D.; Atwood, E.; McKirnan, M.D.; Reynolds, J.; Ashburn, W.

    1982-08-01

    Seventeen coronary patients (CAD) underwent /sup 201/Tl treadmill and radionuclide (RNV) ejection fraction supine bicycle testing before and after 5.6 +/- 1.6 (mean +/- SD) months of an exercise program. Thallium data were assessed both using analog images and a computerized circumferential profile technique. Patients exercised on the treadmill to a higher workload after the exercise program, but achieved a similar pressure-rate product. When interpreting the analog thallium images, only 50% agreement was obtained for the assessment of changes in myocardial perfusion (pre/post-training). The computer technique, however, had low inter-intraobserver variability (6%) and better agreement (90.5%). Using the circumferential profile method, five patients improved (a total of 11 regions) and one patient worsened (with two regions). Before the exercise program, the ejection fraction (EF) response to supine bike exercise was normal (an increase greater than 11%) in four, flat in seven, and severely abnormal (a decrease of more than 4%) in six patients. After the exercise program, even though achieving similar or higher pressure-rate products, six patients improved their EF response, nine did not change, and two worsened. Of the five patients who improved their thallium images, one improved his EF response, two remained normal, and two did not change. One patient worsened both his thallium study and the EF response after the exercise program. Changes in thallium exercise images and the EF response to supine exercise occurred in our patients after an exercise program, but were not always concordant. Indeed, of five patients with exercise-induced ischemic ST changes before and after training, the EF response improved in three whereas myocardial perfusion was unchanged. Reasons for this lack of agreement are discussed, and have been considered in the planning of a randomized trial of the effects of an exercise program on myocardial perfusion and function.

  10. B‐type natriuretic peptide identifies silent myocardial ischaemia in stroke survivors

    PubMed Central

    Wong, K Y K; McSwiggan, S; Kennedy, N S J; MacWalter, R S; Struthers, A D

    2006-01-01

    Objective To test the hypothesis that B‐type natriuretic peptide (BNP) predicts reversible myocardial ischaemia in stroke survivors who do not have chest pain or previous myocardial infarction. Methods 56 stroke survivors (mean (SE) age 68 (8) years) underwent tetrofosmin myocardial perfusion scanning with dipyridamole as the stressor. The degree of ischaemia was assessed by a scoring system (out of 64) by an experienced observer blinded to the results of BNP. Results In the whole cohort, BNP was significantly correlated with the degree of myocardial ischaemia on stress scanning (Spearman's r  =  −0.475, p < 0.001). BNP also correlated with the degree of reversible ischaemia (stress score − rest score; Spearman's r  =  0.28, two tailed p  =  0.049). In the cohort who did not have left ventricular systolic dysfunction (n  =  44), BNP remained higher in patients with relevant myocardial ischaemia (mean (SE) BNP 20.9 pg/ml, 95% confidence interval (CI) 15.2 to 26.5 v 12.2 pg/ml, 95% CI 5.95 to 18.5; p  =  0.046); 33 of the 44 patients had no chest pain or history of myocardial infarction. The relation between resting BNP and both inducible ischaemia and dipyridamole stress score remained significant (Spearman's r  =  0.37 and −0.38, respectively). Conclusions BNP correlates with the degree of reversible myocardial ischaemia in patients who do not have chest pain or a history of myocardial infarction or evidence of left ventricular systolic dysfunction. Stroke survivors with a high BNP deserve further investigations to rule out significant reversible myocardial ischaemia, in order to reduce their risk of cardiac death. PMID:16216865

  11. Biphasic thallium 201 SPECT-imaging for the noninvasive diagnosis of myocardial perfusion abnormalities in a child with Kawasaki disease--a case report

    SciTech Connect

    Hausdorf, G.; Nienaber, C.A.; Spielman, R.P.

    1988-02-01

    The mucocutaneous lymph node syndrome (Kawasaki disease) is of increasing importance for the pediatric cardiologist, for coronary aneurysms with the potential of thrombosis and subsequent stenosis can develop in the course of the disease. The authors report a 2 1/2-year-old female child in whom, fourteen months after the acute phase of Kawasaki disease, myocardial infarction occurred. Biphasic thallium 201 SPECT-imaging using dipyridamole depicted anterior wall ischemia and inferolateral infarction. This case demonstrates that noninvasive vasodilation-redistribution thallium 201 SPECT-imaging has the potential to predict reversible myocardial perfusion defects and myocardial necrosis, even in small infants with Kawasaki disease.

  12. 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

  13. A comparison of the redistribution and reinjection techniques in dipyridamole thallium tomography.

    PubMed

    Kennedy, N S; Cook, B; Choy, A M; Bridges, A B; Hanson, J K; McNeill, G P; Pringle, T H

    1993-06-01

    The effect of the injection of additional thallium after a redistribution study and prior to a further resting study was evaluated in 21 patients with angiographically proven coronary artery disease. Using dipyridamole as the stress mechanism, the studies were carried out tomographically and the results analysed quantitatively with the Bull's-eye technique. Two patients had normal scans. Of the remaining 19, 11 patients had a perfusion defect which appeared irreversible on redistribution imaging. However, six of these patients demonstrated improved or normal uptake after the second injection of thallium. Of the eight patients with a reversible defect, two revealed considerably greater reversibility after reinjection. These results indicate that the reinjection of thallium prior to the resting study significantly (P < 0.02) improves the detection rate of ischaemia during dipyridamole thallium tomography.

  14. Reduction of indium-111 platelet deposition on Dacron vascular grafts in humans by aspirin plus dipyridamole

    SciTech Connect

    Stratton, J.R.; Ritchie, J.L.

    1986-02-01

    Aspirin plus dipyridamole reduces platelet accumulation on short-term Dacron vascular grafts in man. To determine whether drug inhibition of platelet deposition is sustained on older grafts, we studied 18 men aged 41 to 87 years who had Dacron aortic bifurcation grafts in place a mean of 43.4 months (range 9.8 to 121.0) before and during short-term therapy with aspirin (325 mg tid) plus dipyridamole (75 mg tid). During both the baseline and drug studies, indium-111 (/sup 111/In) platelet deposition was quantitated by two techniques, standard planar imaging performed at 24, 48, and 72 hr after injection of platelets and single photon emission computed tomographic imaging performed at 24 and 72 hr after injection. All analyses were performed in a blinded fashion. On both the planar and tomographic images, platelet accumulation on the graft was quantitated by a graft/blood ratio that compared activity in the graft to simultaneously collected whole blood /sup 111/In platelet activity. Aspirin plus dipyridamole reduced the tomographic graft/blood ratio at 24 hr (20.6 +/- 3.5 vs 17.3 +/- 2.5) (+/-SEM) and at 72 hr (29.0 +/- 4.8 vs 25.0 +/- 4.1) after injection of platelets (p = .02). Dacron vascular grafts. Similarly, the planar graft/blood ratio was reduced at 24 hr (2.7 +/- 0.5 vs 2.4 +/- 0.5), 48 hr (3.7 +/- 0.9 vs 3.1 +/- 0.7), and 72 hr (4.0 +/- 0.9 vs 3.6 +/- 0.8) (p = .04). We conclude that aspirin (325 mg tid) plus dipyridamole (75 mg tid) reduces platelet accumulation on long-term Dacron vascular grafts.

  15. Prognostic impact of stress testing in coronary artery disease

    SciTech Connect

    Severi, S.; Michelassi, C. )

    1991-05-01

    Observational data prospectively collected permit the examination of a complex set of decisions, including the decision not to perform any stress testing. Patients with or without previous myocardial infarction admitted for coronary evaluation and not submitted to any stress testing because of clinical reasons are at a higher risk for subsequent death. For prognostication, no test has been better validated than exercise electrocardiography: it can identify patients at low and high risk for future cardiac events among those without symptoms, with typical chest pain, and with previous myocardial infarction. In patients with triple-vessel disease, the results of exercise also allow those at low and high risk to be recognized. Both exercise radionuclide angiography and {sup 201}Tl scintigraphy (the latter in larger patient populations) have also demonstrated significant prognostic value on patients with or without previous myocardial infarction. Neither one has shown superiority to the other in prognostication. So far, they have been considered the only viable alternatives to exercise electrocardiography stress testing for diagnosis and prognostication. However, their costs limit their extensive application. Preliminary data suggest that intravenous dipyridamole echocardiography can be used for both diagnosis and prognostication of coronary artery disease; moreover, the prognostic information derived from dipyridamole echocardiography testing seems independent of and additive to that provided by exercise electrocardiography. Further prospective studies on larger patient populations are needed to better define the prognostic value of dipyridamole echocardiography testing.47 references.

  16. Microimaging studies of myocardial substrate utilization and perfusion in two models of non-coronary heart disease

    SciTech Connect

    Som, P.; Oster, Z.H.; Knapp, F.F. Jr.

    1987-01-01

    We have studied two animal models of non-coronary heart disease. The salt-sensitive Dahl strain hypertensive rats and their genetically matched normotensive controls and the cardiomyopathic BIO 53.58 (CM) strain Syrian hamsters with age and sex-matched RB strain controls. The CM strain hamster seems to be a very good model of human congestive cardiomyopathy and the Dahl strain hypertensive rats have also been found to be good models for studying the effects of hypertension on the myocardium. In our studies we compared the utilization of various metabolic substrates, viz., fatty acids, glucose analogs, and the early distribution of /sup 201/Tl, as an indicator of myocardial flow. The routine studies involving dissection of animals for assaying the radioactivity following the injection of radiopharmaceuticals is not suitable for assessing regional changes in metabolism and flow. The use of quantitative autoradiographic microimaging (ARG) enables the visualization of discrete regional as well as global changes from normal and to quantitate them. This paper describes the methodology and results of these investigations. 14 refs., 5 figs.

  17. The routine use of sublingual GTN with resting 99Tcm-tetrofosmin myocardial perfusion imaging.

    PubMed

    Thorley, P J; Sheard, K L; Wright, D J; Sivananthan, U M

    1998-10-01

    Nitrates can be used to improve resting myocardial blood flow in patients with severe coronary artery disease. This may enhance tracer uptake during rest myocardial perfusion imaging. Recent studies using nitrates at rest have shown increased detection of reversible ischaemia in this patient group with the 201Tl and 99Tcm perfusion tracers MIBI and tetrofosmin. However, it is not always possible to assess the severity of coronary artery disease before the rest injection and therefore whether a patient would benefit from nitrate administration. To improve the sensitivity for the detection of reversible ischaemia and to avoid a repeat study with nitrates (especially in patients with 'fixed' defects), a protocol in which all patients routinely receive nitrates prior to the rest injection is required. This prospective study evaluated the effect of nitrate administration prior to rest imaging in a randomly selected group of patients. Thirty patients selected at random from routine referrals had stress, rest and rest + GTN tetrofosmin imaging on three separate days. Changes in reversibility between the rest and rest + GTN images were assessed both visually and using semi-quantitative analysis. Defects at stress were seen in 43 coronary artery territories, 33 of which were reversible at rest and 37 reversible at rest + GTN. Of these 43 defects, 82% demonstrated either increased or the same degree of reversibility at rest + GTN imaging compared to standard rest imaging. All defects with reduced reversibility at rest + GTN imaging (i.e. the remaining 18%) were, however, still reversible compared to the stress images. Some of this reduced reversibility may be due to attenuation artefacts. We conclude that the routine use of GTN with rest tetrofosmin imaging will result in increased detection of ischaemic areas with no loss of sensitivity or specificity.

  18. [Evaluation of the antianginal action of pharmacological substances by the change in the initiation threshold for myocardial ischemia in conscious rabbits].

    PubMed

    Rozonov, Iu B; Morozova, T V

    1984-10-01

    The threshold of the initiation of myocardial ischemia was determined for conscious rabbits with the help of a special preliminary implanted appliance, which made it possible to perform the occlusion and reperfusion of the coronary artery. Nitroglycerin and propranolol were shown to increase the threshold of the initiation of ischemia, while dipyridamole was discovered to reduce it. The method described is offered for evaluation of the drug antianginal effect, since it is adequate and easily reproduced.

  19. Simultaneous determination of dipyridamole and salicylic acid in human plasma by high performance liquid chromatography-mass spectrometry.

    PubMed

    Wang, Na; Xu, Fengguo; Zhang, Zunjian; Yang, Cheng; Sun, Xiuhong; Li, Jinheng

    2008-02-01

    A sensitive, rapid and simple high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) method for simultaneous determination of dipyridamole and salicylic acid in human plasma has been developed and validated. After the addition of diazepam and rosiglitazone as internal standard (IS), plasma samples were prepared by liquid-liquid extraction followed by an isocratic elution with methanol:2 mM ammonium acetate buffer (pH 4.25; 70/30, v/v) on a Shimadzu VP-ODS C(18) column (5 microm, 150 x 2.0 mm I.D.). Detection was performed on a quadrupole mass spectrometer with ESI interface operating in the positive-ion mode for dipyridamole and negative-ion mode for salicylic acid. Calibration curves were linear (r(2) > 0.99) over the concentration range 10-2500 ng/mL for dipyridamole and 30-4000 ng/mL for salicylic acid with acceptable accuracy and precision, respectively. The intra- and inter-batch precisions were less than 15% of the relative standard deviation. The limits of detection of dipyridamole and salicylic acid were 1 and 15 ng/mL, respectively. The validated HPLC-ESI-MS method was successfully applied to a preliminary pharmacokinetic study of fixed-dose combination of sustained-release dipyridamole/aspirin in Chinese healthy male volunteers.

  20. Myocardial Bridging

    PubMed Central

    Yuan, Shi-Min

    2016-01-01

    Myocardial bridging is rare. Myocardial bridges are most commonly localized in the middle segment of the left anterior descending coronary artery. The anatomic features of the bridges vary significantly. Alterations of the endothelial morphology and the vasoactive agents impact on the progression of atherosclerosis of myocardial bridging. Patients may present with chest pain, myocardial infarction, arrhythmia and even sudden death. Patients who respond poorly to the medical treatment with β-blockers warrant a surgical intervention. Myotomy is a preferred surgical procedure for the symptomatic patients. Coronary stent deployment has been in limited use due to the unsatisfactory long-term results. PMID:27074276

  1. Perfusion thallium imaging of type I diabetes patients with end stage renal disease: Comparison of oral and intravenous dipyridamole administration

    SciTech Connect

    Boudreau, R.J.; Strony, J.T.; duCret, R.P.; Kuni, C.C.; Wang, Y.; Wilson, R.F.; Schwartz, J.S.; Castaneda-Zuniga, W.R. )

    1990-04-01

    Eighty patients with type I diabetes and end stage renal disease were prospectively evaluated for coronary artery disease with dipyridamole-thallium-201 scintigraphy and quantitative coronary angiography. Forty patients received dipyridamole orally, and 40 received it intravenously. The prevalence of coronary artery disease was 53%. There were no significant differences in the accuracy of the two dipyridamole tests (sensitivity = 85%, specificity = 85%, accuracy = 85% for the oral group; sensitivity = 86%, specificity = 72%, accuracy = 79% for the intravenous group). Combining the 80 patients into a single group gave a sensitivity of 86%, a specificity of 79%, and an accuracy of 83% for the detection of coronary disease. Although the accuracy of this test in this patient population was similar to that previously reported for other groups, the prevalence of disease was high and resulted in a low predictive value of a negative test (83%).

  2. The possible protective effects of dipyridamole on ischemic reperfusion injury of priapism

    PubMed Central

    Karaguzel, Ersagun; Bayraktar, Cemil; Kutlu, Omer; Yulug, Esin; Mentese, Ahmet; Okatan, Ali Ertan; Colak, Fatih; Ozer, Serap; O.Kazaz, Ilke

    2016-01-01

    ABSTRACT Purpose To investigate the protective effects against ischemia reperfusion injury of dipyridamole in a model of induced priapism in rats. Materials and Methods Twenty-four male Sprague-Dawley rats were divided into four groups, control, P/R, P/R+DMSO and P/R+D. 3ml blood specimens were collected from vena cava inferior in order to determine serum MDA, IMA, TAS, TOS and OSI values, and penile tissue was taken for histopathological examination in control group. Priapism was induced in P/R group. After 1h, priapism was concluded and 30 min reperfusion was performed. In P/R+DMSO group 1ml/kg DMSO was administered intraperitoneally 30 min before reperfusion, while in P/R+D group 10mg/kg dipyridamole was administered intraperitoneally 30 min before reperfusion. Blood and penis specimens were collected after the end of 30 min reperfusion period. Sinusoidal area (µm2), tears in tunica albuginea and injury parameters in sinusoidal endothelium of penis were investigated. Results Histopathological examination revealed no significant changes in term of sinusoidal area. A decrease in tears was observed in P/R+D group compared to P/R group (p<0.05). Endothelial injury decreased in P/R+D group compared to P/R group (p>0.05). There were no significant differences in MDA and IMA values between groups. A significant increase in TOS and OSI values was observed in P/R+D group compared to P/R group. A significant decrease in TAS levels was observed in P/R+D group compared to the P/R group. Conclusions The administration of dipyridamole before reperfusion in ischemic priapism model has a potential protective effect against histopathological injury of the penis. PMID:27136481

  3. Relation between geometric dimensions of coronary artery stenoses and myocardial perfusion reserve in man.

    PubMed

    Goldstein, R A; Kirkeeide, R L; Demer, L L; Merhige, M; Nishikawa, A; Smalling, R W; Mullani, N A; Gould, K L

    1987-05-01

    To determine the relation between stenosis anatomy and perfusion in man, 31 patients had quantitative coronary arteriography and positron imaging (PET) with Rb-82 or N-13 ammonia at rest and after dipyridamole-handgrip stress. 10 patients were also studied after angioplasty (total stenoses = 41). Percent narrowing and absolute cross-sectional luminal area were related through a quadratic function to myocardial perfusion reserve determined with PET. Arteriographically determined coronary flow reserve was linearly related to relative myocardial perfusion reserve as expected, based on the derivation of equations for stenosis flow reserve. All of the correlations had considerable scatter, indicating that no single measurement derived by coronary arteriography was a good indicator of perfusion reserve by PET in individual patients. This study provides the relation between all anatomic dimensions of coronary artery stenoses and myocardial perfusion reserve in man, and suggests that PET indicates the functional significance of coronary artery stenoses for clinical purposes.

  4. Pronounced alterations in T-wave morphology during dipyridamole-induced ischaemia.

    PubMed

    Ferrando-Castagnetto, F; Ricca-Mallada, R; Ferrando-Castagnetto, R

    2016-01-01

    The case describes a 77-year-old woman with multivessel coronary disease exhibiting marked changes of T-wave morphology induced by dipyridamole, an unusual finding in which the diagnostic accuracy in this clinical context is uncertain. Gated-SPECT imaging demonstrated severe ischaemia extending through inferior and posterolateral regions of the left ventricle with normal motility and contractile function in response to vasodilator stress. Possible underlying mechanisms and clinical implications of observed electrocardiographic changes are discussed. T-loop modifications during vasodilator stress SPECT and correlation of these changes with the amount of ischaemic injury need further evaluation.

  5. Changes in myocardial perfusion reserve after PTCA: noninvasive assessment with positron tomography.

    PubMed

    Goldstein, R A; Kirkeeide, R L; Smalling, R W; Nishikawa, A; Merhige, M E; Demer, L L; Mullani, N A; Gould, K L

    1987-08-01

    The effect of percutaneous transluminal coronary angioplasty (PTCA) on myocardial perfusion reserve has not been previously determined. Accordingly, 11 patients underwent positron imaging with [13N]ammonia or 82Rb at rest and following dipyridamole + handgrip stress before and after PTCA. The ratio of stress to rest activity (S:R) was determined for each region of interest. Relative myocardial perfusion reserve by positron tomography (RMPR) was calculated by dividing S:R of the stenotic area by a corresponding value from a normal reference area of the same patient. Automated quantitative coronary arteriography was used to objectively measure the percent diameter (%D) and the percent area narrowing (%A) of the stenoses. In nine patients with successful PTCA, %D and %A improved (68 +/- 10 to 49 +/- 15% and 92 +/- 3 to 72 +/- 5%) and RMPR increased from 0.79 +/- 0.07 to 0.96 +/- 0.05. In the two patients in whom PTCA was unsuccessful, RMPR was unchanged. Changes in RMPR correlated inversely with changes in %D (r = -0.68) and %A (r = -0.92) and directly with improved coronary flow reserve derived from all stenosis measurements (r = 0.73, p less than 0.001 for each). This study suggests that dipyridamole + handgrip stress imaging with PET can be used to assess changes in myocardial perfusion reserve before and after PTCA with the potential for determining restenosis noninvasively.

  6. Changes in myocardial perfusion reserve after PTCA: noninvasive assessment with positron tomography

    SciTech Connect

    Goldstein, R.A.; Kirkeeide, R.L.; Smalling, R.W.; Nishikawa, A.; Merhige, M.E.; Demer, L.L.; Mullani, N.A.; Gould, K.L.

    1987-08-01

    The effect of percutaneous transluminal coronary angioplasty (PTCA) on myocardial perfusion reserve has not been previously determined. Accordingly, 11 patients underwent positron imaging with (/sup 13/N)ammonia or /sup 82/Rb at rest and following dipyridamole + handgrip stress before and after PTCA. The ratio of stress to rest activity (S:R) was determined for each region of interest. Relative myocardial perfusion reserve by positron tomography (RMPR) was calculated by dividing S:R of the stenotic area by a corresponding value from a normal reference area of the same patient. Automated quantitative coronary arteriography was used to objectively measure the percent diameter (%D) and the percent area narrowing (%A) of the stenoses. In nine patients with successful PTCA, %D and %A improved (68 +/- 10 to 49 +/- 15% and 92 +/- 3 to 72 +/- 5%) and RMPR increased from 0.79 +/- 0.07 to 0.96 +/- 0.05. In the two patients in whom PTCA was unsuccessful, RMPR was unchanged. Changes in RMPR correlated inversely with changes in %D (r = -0.68) and %A (r = -0.92) and directly with improved coronary flow reserve derived from all stenosis measurements (r = 0.73, p less than 0.001 for each). This study suggests that dipyridamole + handgrip stress imaging with PET can be used to assess changes in myocardial perfusion reserve before and after PTCA with the potential for determining restenosis noninvasively.

  7. 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.

  8. Predictive value of quantitative dipyridamole-thallium scintigraphy in assessing cardiovascular risk after vascular surgery in diabetes mellitus

    SciTech Connect

    Lane, S.E.; Lewis, S.M.; Pippin, J.J.; Kosinski, E.J.; Campbell, D.; Nesto, R.W.; Hill, T. )

    1989-12-01

    Cardiac complications represent a major risk to patients undergoing vascular surgery. Diabetic patients may be particularly prone to such complications due to the high incidence of concomitant coronary artery disease, the severity of which may be clinically unrecognized. Attempts to stratify groups by clinical criteria have been useful but lack the predictive value of currently used noninvasive techniques such as dipyridamole-thallium scintigraphy. One hundred one diabetic patients were evaluated with dipyridamole-thallium scintigraphy before undergoing vascular surgery. The incidence of thallium abnormalities was high (80%) and did not correlate with clinical markers of coronary disease. Even in a subgroup of patients with no overt clinical evidence of underlying heart disease, thallium abnormalities were present in 59%. Cardiovascular complications, however, occurred in only 11% of all patients. Statistically significant prediction of risk was not achieved with simple assessment of thallium results as normal or abnormal. Quantification of total number of reversible defects, as well as assessment of ischemia in the distribution of the left anterior descending coronary artery was required for optimum predictive accuracy. The prevalence of dipyridamole-thallium abnormalities in a diabetic population is much higher than that reported in nondiabetic patients and cannot be predicted by usual clinical indicators of heart disease. In addition, cardiovascular risk of vascular surgery can be optimally assessed by quantitative analysis of dipyridamole-thallium scintigraphy and identification of high- and low-risk subgroups.

  9. Prevalence and clinical significance of residual myocardial ischemia 2 weeks after uncomplicated non-Q wave infarction: a prospective natural history study

    SciTech Connect

    Gibson, R.S.; Beller, G.A.; Gheorghiade, M.; Nygaard, T.W.; Watson, D.D.; Huey, B.L.; Sayre, S.L.; Kaiser, D.L.

    1986-06-01

    Despite having smaller infarct size and better left ventricular function, patients with non-Q wave myocardial infarction (NQMI) appear to have an unexpectedly high long-term mortality that is ultimately comparable to that of patients with Q-wave myocardial infarction (QMI). Patients with NQMI may lose their initial prognostic advantage because there is more viable tissue in the perfusion zone of the infarct-related vessel, rendering myocardium more prone to reinfarction. We tested this hypothesis in a prospective study of 241 consecutive patients 65 years of age or younger with acute uncomplicated myocardial infarction confirmed by creatine kinase levels (MB fraction). All patients received customary care and none underwent thrombolytic therapy or emergency angioplasty. Predischarge coronary angiography, radionuclide ventriculography, 24 hr Holter monitoring, and quantitative thallium-201 scintigraphy during treadmill exercise were performed 10 +/- 3 days after infarction. Infarcts were designated as QMI (n = 154) or NQMI (n = 87) by accepted criteria applied to serial electrocardiograms obtained on days 1, 2, 3, and 10. The baseline Norris coronary prognostic index, angiographic jeopardy scores, and prevalence of Lown grade ventricular arrhythmias were similar between groups despite evidence for less necrosis with NQMI vs QMI, reflected by lower peak creatine kinase levels (520 vs 1334 IU/liter; p = .0001, 4 hr sampling), higher resting left ventricular ejection fraction (53% vs 46%; p = .0001), fewer akinetic or dyskinetic segments (1.2 vs 2.4; p = .0001), and fewer persistent /sup 201/Tl defects in the infarct zone. Patients with NQMI also had more patent infarct-related vessels and a shorter time from onset of infarction to peak creatine kinase level.

  10. Myocardial kinetics of potassium-38 in humans and comparison with copper-62-PTSM

    SciTech Connect

    Melon, P.G.; Brihaye, C.; Degueldre, C.

    1994-07-01

    The aim of this study was to define the kinetics of {sup 38}K and its suitability to evaluate myocardial blood flow at rest and during pharmacological vasodilation in normal subjects. Potassium-38`s kinetic characteristics were also compared to those of a {sup 62}Cu-pyruvaldehyde bis(n{sup 4}l-methyl-thio-semicarbazone) copper (II) (PTSM) flow tracer. Potassium-38 and {sup 62}Cu-PTSM were injected at rest and after pharmacological vasodilation in six healthy volunteers. Dynamic PET acquisition was performed over 20 min and myocardial tracer retention calculated. Homogeneity of regional myocardial tracer distribution was also evaluated. High image quality of the heart was observed at rest and after dipyridamole with both tracers. Potassium-38 demonstrated prolonged myocardial retention with minimal lung and liver accumulation. in contrast to {sup 38}K, {sup 62}Cu-PTSM demonstrated high liver uptake which may hinder observation of the inferior wall of the myocardium. Copper-62-PTSM dipyridamole-to-rest retention ratio was 1.49. Potassium-38 and {sup 62}Cu-PTSM display suitable kinetics for the qualitative evaluation of blood flow and flow reserve in the human heart. Compared to {sup 62}Cu-PTSM, potassium-38, which does not show high liver uptake, may more accurately estimate blood flow in the inferior wall of the heart. However, accurate quantification of myocardial blood flow using {sup 38}K or {sup 62}Cu-PTSM retention appears to be limited to decreasing retention fraction at hyperhemic states. 29 refs., 5 figs.

  11. In Vitro Dissolution of Fluconazole and Dipyridamole in Gastrointestinal Simulator (GIS), Predicting in Vivo Dissolution and Drug-Drug Interaction Caused by Acid-Reducing Agents.

    PubMed

    Matsui, Kazuki; Tsume, Yasuhiro; Amidon, Gregory E; Amidon, Gordon L

    2015-07-01

    Weakly basic drugs typically exhibit pH-dependent solubility in the physiological pH range, displaying supersaturation or precipitation along the gastrointestinal tract. Additionally, their oral bioavailabilities may be affected by coadministration of acid-reducing agents that elevate gastric pH. The purpose of this study was to assess the feasibility of a multicompartmental in vitro dissolution apparatus, Gastrointestinal Simulator (GIS), in predicting in vivo dissolution of certain oral medications. In vitro dissolution studies of fluconazole, a BCS class I, and dipyridamole, a BCS class II weak bases (class IIb), were performed in the GIS as well as United States Pharmacopeia (USP) apparatus II and compared with the results of clinical drug-drug interaction (DDI) studies. In both USP apparatus II and GIS, fluconazole completely dissolved within 60 min regardless of pH, reflecting no DDI between fluconazole and acid-reducing agents in a clinical study. On the other hand, seven-fold and 15-fold higher concentrations of dipyridamole than saturation solubility were observed in the intestinal compartments in GIS with gastric pH 2.0. Precipitation of dipyridamole was also observed in the GIS, and the percentage of dipyridamole in solution was 45.2 ± 7.0%. In GIS with gastric pH 6.0, mimicking the coadministration of acid-reducing agents, the concentration of dipyridamole was equal to its saturation solubility, and the percentage of drug in solution was 9.3 ± 2.7%. These results are consistent with the clinical DDI study of dipyridamole with famotidine, which significantly reduced the Cmax and area under the curve. An In situ mouse infusion study combined with GIS revealed that high concentration of dipyridamole in the GIS enhanced oral drug absorption, which confirmed the supersaturation of dipyridamole. In conclusion, GIS was shown to be a useful apparatus to predict in vivo dissolution for BCS class IIb drugs.

  12. Prognostic utility of intravenous dipyridamole thallium-201 imaging and exercise testing after an acute infarction

    SciTech Connect

    Leppo, J.A.

    1984-01-01

    To define the prognosis in asymptomatic survivors of acute infarcts (MI), coronary vasodilation was induced with I.V. dipyridamole, followed by Thallium-201 (T1) imaging in 26 patients just prior to discharge. All patients (pts) also had a modified exercise treadmill (MET) test. During the imaging protocol, 10 (39%) pts experienced transient adverse effects and 12 (46%) pts had either angina or ST depression with MET. During a mean follow-up of 17 months, 13 (50%) pts had a cardiac event defined as readmission for control of angina, MI or death. In the 13 pts having cardiac events, 4 (31%) had ST depression and 2 (15%) had angina during MET, but 12 (92%) demonstrated T1 redistribution (RD) as determined by at least 1 segment/scan having a transient defect. A logistic regression analysis using several exercise, scintigraphic and general clinical parameters, showed that the presence of T1 RD was the only significant (p <0.001) predictor for future cardiac events. The predicted probability for events in pts with T1 RD was 80 +- 10% (SD) and was 9 +- 9% in those without T1 RD. The mean number of defects per scan was similar in pts with and without cardiac events, but compared to persistent defects, transient ones are associated with potentially ischemic myocardium. Although the pt population is relatively small, dipyridamole T1 imaging after MI appears to be safe and has demonstrated prognostic value. It also offers an alternative and/or addition to exercise testing in the predischarge evaluation after acute MI.

  13. Pharmacological and other nonexercise alternatives to exercise testing to evaluate myocardial perfusion and left ventricular function with radionuclides

    SciTech Connect

    DePuey, E.G.; Rozanski, A. )

    1991-04-01

    Pharmacological vasodilatation with either dipyridamole or adenosine is a safe and accurate alternative to exercise testing to diagnose coronary artery disease with thallium 201 myocardial perfusion imaging. The technique also provides important prognostic information with regard to future cardiac events in patients undergoing diagnostic testing, in those evaluated preoperatively, and in those with recent myocardial infarctions. Multigated equilibrium and first-pass radionuclide ventriculography also are well suited to evaluate the effects of interventional procedures. Success has been achieved using this methodology in a variety of interventions including conventional exercise testing, pharmacological stress testing, atrial pacing, assessment of myocardial viability with nitroglycerin, mental stress testing, and ambulatory monitoring of left ventricular ejection fraction. 67 references.

  14. Synthesis of a new photoreactive derivative of dipyridamole and its use in the manufacture of artificial surfaces with low thrombogenicity.

    PubMed

    Aldenhoff, Y B; Pijpers, A P; Koole, L H

    1997-01-01

    Photoimmobilization of dipyridamole (Persantin) was accomplished through the use of a new synthetic conjugate molecule, 1. Persantin is a powerful inhibitor of platelet activation and aggregation and is widely used as a vasodilator. Conjugate 1 consists of triply protected dipyridamole [three of the four hydroxyl groups carry a tert-butyldimethylsilyl (TBDMS) protective group) and the photoreactive 4-azidobenzoyl group. A short hydrophilic spacer chain, derived from triethylene glycol, separates the protected dipyridamole system and the photoreactive group. Compound 1 was immobilized on polyurethane sheets (Pellethane D-55) through irradiation with ultraviolet (UV) light, and the protective groups were removed afterward. The resulting modified polyurethane surfaces were characterized by different physicochemical techniques: UV extinction, contact angle measurements (captive bubble technique), and X-ray photoelectron spectroscopy (XPS). The UV extinction measurements showed the presence of 13 +/- 1 nmol of immobilized dipyridamole/cm2. The contact angle measurements revealed that the modified surface was markedly more hydrophilic than the control (i.e. unmodified polyurethane). XPS measurements clearly established the presence of immobilized dipyridamole in the outermost layers of the modified surface. This was especially clear from the XPS spectra recorded at a low take-off angle (approximately 6 degrees). Furthermore, the XPS spectra showed that the TBDMS protective groups had been quantitatively removed during the deprotection/washing treatment. The in vitro blood compatibility of the modified surface was studied with the thrombin generation assay as developed in our group, as well as with scanning electron microscopy. The thrombin generation test produced a lag time of 1275 s for the modified surface, as opposed to 569 s for the control. Scanning electron microscopy showed that far fewer platelets adhere to the modified surface (approximately 7 x 10(3)/mm2) as

  15. Myocardial uptake and clearance of T1-201 in healthy subjects: Comparison of adenosine-induced hyperemia and exercise stress

    SciTech Connect

    Siffring, P.A.; Gupta, N.C.; Mohiuddin, S.M.; Esterbrooks, D.J.; Hilleman, D.E.; Cheng, S.C.; Sketch, M.H. Sr.; Frick, M.P. )

    1989-12-01

    Pharmacologic stress testing with dipyridamole is useful in patients undergoing thallium-201 myocardial perfusion scintigraphy who cannot adequately exercise. Because dipyridamole increases coronary blood flow by reducing the metabolism of adenosine, the authors compared the uptake and clearance of T1-201 following exercise stress testing (EST) and resting intravenous infusion of adenosine (AI) in crossover fashion in 20 healthy men. No perfusion defects or areas of redistribution were noted in any of the scans. Mean absolute myocardial T1-201 uptake was 1.3 times greater with AI than with EST. Mean absolute extracardiac uptake was 2.0 times greater with AI. Mean T1-201 myocardial clearance was virtually the same in all AI and EST views. During AI, 70% of the subjects experienced subjective side effects, mean arterial blood pressure decreased by 15%, and heart rate increased by 48%. The effects of adenosine on T1-201 kinetics in the myocardium are similar to those of EST. Adenosine may be useful as a pharmacologic stress agent in patients undergoing T1-201 myocardial perfusion scintigraphy.

  16. Prognostic Value of Major Cardiac Event Risk Score Estimated With Gated Myocardial Perfusion Imaging in Japanese Patients With Coronary Artery Disease.

    PubMed

    Yoda, Shunichi; Nakanishi, Kanae; Tano, Ayako; Hori, Yusuke; Hayase, Misa; Mineki, Takashi; Suzuki, Yasuyuki; Matsumoto, Naoya; Hirayama, Atsushi

    2016-07-27

    We published a cardiac event risk score (CERS) predicting the risk of major cardiac events (MCEs) within 3 years. The purpose of this study was to verify the prognostic value of the CERS before and after treatment in Japanese patients with coronary artery disease.We retrospectively investigated 612 patients who underwent rest (201)Tl and stress (99m)Tc-tetrofosmin myocardial perfusion single photon emission computed tomography (SPECT) between October 2004 and March 2013 and who had a significant stenosis with ≥ 75% narrowing of the arterial diameter detected by coronary angiography performed after confirmation of ≥ 5% ischemia with the SPECT. The patients underwent treatment including revascularization and medication, and thereafter, were re-evaluated with SPECT during a chronic phase and followed-up to confirm prognosis for ≥ 1 year. The endpoint was the onset of MCEs during the follow-up.During the follow-up (36.7 ± 14.5 months), 50 patients (8.7%) experienced MCEs comprising cardiac death (n = 16), non-fatal myocardial infarction (n = 4), and unstable angina pectoris (n = 30). The multivariate Cox proportional hazards regression model analysis for the actual occurrence of MCEs showed the summed difference score % and MCE risks estimated with the CERS after treatment to be significant independent variables. Ischemic reduction after treatment contributed significantly to a decrease in the MCE risks. The MCE risks estimated with the CERS after treatment were generally consistent with the incidence of the MCEs actually observed.The CERS after treatment is a valuable formula for predicting prognosis in Japanese patients with coronary artery disease. PMID:27357436

  17. Alterations in myocardial metabolism and function at rest in stable angina pectoris: relations with the amount of exercise-induced thallium-201 perfusion defect

    SciTech Connect

    De Kock, M.; Melin, J.A.; Pouleur, H.; Rousseau, M.F.

    1986-01-01

    The relation between the amount of exercise-induced ischemia and alterations in left ventricular (LV) function and metabolism at rest was studied in 18 coronary patients with stable angina pectoris. An ischemic defect area score was computed from quantitative exercise thallium-201 (Tl-201) scintigraphy; this estimation of the amount of ischemic myocardium was used to classify the patients in group I (n = 8; score less than 15%, mean 6.7 +/- 2.5%) and II (n = 10; score greater than 15%; mean 27.2 +/- 8.9%). Hemodynamics and metabolism were studied in basal state. No patient had anginal pain during the study, and the extent of angiographic coronary artery disease (CAD) was comparable in the two groups. Heart rate, aortic pressure, coronary blood flow, and myocardial oxygen uptake were also similar in both groups. However, ejection fraction was reduced in group II (51 +/- 13 vs 63 +/- 5%; p less than 0.01) and LV relaxation was impaired as shown by the increase in time-constant of isovolumic pressure fall (55 +/- 16 vs 44 +/- 6 ms in group I; p less than 0.05); the LV end-diastolic pressure was also increased in group II (19 +/- 8 vs 10 +/- 4 mmHg in group l; p less than 0.05). Furthermore, in group II, myocardial lactate uptake was reduced (4 +/- 19 vs 30 +/- 29 mumole/min in group I; p less than 0.01) and the productions of alanine and glutamine were augmented (-7.5 +/- 4.4 vs -4.6 +/- 1.6 mumole/min in group I; p less than 0.05).

  18. Nuclear cardiology: Myocardial perfusion and function

    SciTech Connect

    Seldin, D.W. )

    1991-08-01

    Myocardial perfusion studies continue to be a major focus of research, with new investigations of the relationship of exercise-redistribution thallium imaging to diagnosis, prognosis, and case management. The redistribution phenomenon, which seemed to be fairly well understood a few years ago, is now recognized to be much more complex than originally thought, and various strategies have been proposed to clarify the meaning of persistent defects. Pharmacologic intervention with dipyridamole and adenosine has become available as an alternative to exercise, and comparisons with exercise imaging and catheterization results have been described. Thallium itself is no longer the sole single-photon perfusion radiopharmaceutical; two new technetium agents are now widely available. In addition to perfusion studies, advances in the study of ventricular function have been made, including reports of studies performed in conjunction with technetium perfusion studies, new insights into cardiac physiology, and the prognostic and case-management information that function studies provide. Finally, work has continued with monoclonal antibodies for the identification of areas of myocyte necrosis. 41 references.

  19. Two Position Supine/Prone Myocardial Perfusion SPECT (MPS) Imaging Improves Visual Inter-Observer Correlation and Agreement

    PubMed Central

    Arsanjani, Reza; Hayes, Sean W.; Fish, Mathews; Shalev, Aryeh; Nakanishi, Rine; Thomson, Louise EJ; Friedman, John D; Germano, Guido; Berman, Daniel S.; Slomka, Piotr

    2014-01-01

    Objectives We aimed to compare the inter-observer agreement between two experienced readers using supine versus combined supine/prone myocardial perfusion SPECT (MPS) in a large population. Methods 1181 consecutive patients without known coronary artery disease (CAD) undergoing rest 201Tl/stress 99mTc-sestamibi MPS studies were evaluated. Visual reads were performed in 2 consecutive steps, with readers scoring the stress supine perfusion images during step 1 and rescoring the images using both supine/prone data during step 2. Visual summed stress scores (SSS) of 2 readers including regional scores in different vascular territories were compared. Results The specificity for both readers improved using combined supine/prone imaging (Reader 1: 92% vs. 86% [P=0.0002], Reader 2: 88% vs. 72% [P<0.0001]. The inter-observer correlation for SSS (0.90 vs. 0.84, P<0.0001) and inter-observer agreement for combined supine/prone reading (bias = 1.0, 95% confidence interval (CI) 0.9-1.2 vs. 3.1, 95% CI 2.8-3.4, P<0.0001) were significantly better than for supine-only reading. The overall correlation between SSS scores for two readers improved with supine/prone imaging for both genders, as well as in the left anterior descending and right coronary territories. New Knowledge Gained Combined supine/prone imaging improves overall inter-observer agreement as well as based on gender and vascular territories. Conclusion The inter-observer correlation and agreement significantly improves using two-position supine/prone versus supine-only imaging. PMID:24807622

  20. Myocardial perfusion scintigraphy and coronary disease risk factors in systemic lupus erythematosus

    PubMed Central

    Sella, E; Sato, E; Leite, W; Filho, J; Barbieri, A

    2003-01-01

    Objective: To evaluate the prevalence of myocardial perfusion abnormalities and the possible association between myocardial perfusion defects and traditional coronary artery disease (CAD) risk factors as well as systemic lupus erythematosus (SLE) related risk factors. Patients and methods: Female patients with SLE, disease duration >5 years, age 18–55 years, who had used steroids for at least one year were enrolled. Traditional CAD risk factors evaluated were arterial hypertension, diabetes mellitus, dyslipidaemia, postmenopausal status, smoking, obesity, and premature family CAD profile. Myocardial perfusion scintigraphy was evaluated by single photon emission computed tomography with technetium 99m-sestamibi at rest and after dipyridamole induced stress. Results: Eight two female patients with SLE without angina pectoris with mean (SD) age 37 (10) years, disease duration 127 (57) months, SLE Disease Activity Index (SLEDAI) score 6 (5), and SLICC/ACR-DI score 2 (2) were evaluated. Myocardial perfusion abnormalities were found in 23 patients (28%). The mean (SD) number of CAD risk factors was 2.2 (1.6). There was a significant positive correlation between age and number of CAD risk factors. Lower high density lipoprotein (HDL) cholesterol level showed a significant association with abnormal scintigraphy. Logistic regression analysis showed that lower HDL cholesterol level and diabetes mellitus were associated with myocardial perfusion abnormalities. Current vasculitis was also associated with abnormal scintigraphy. Conclusions: Lower HDL cholesterol level and diabetes mellitus have a significant influence on abnormal myocardial perfusion results found in asymptomatic patients with SLE. Current vasculitis was associated with abnormal myocardial scintigraphy. These data suggest that abnormal myocardial scintigraphy may be related to subclinical atherosclerosis. PMID:14583569

  1. Myocardial abscess complicating healed myocardial infarction.

    PubMed Central

    Weisz, S.; Young, D. G.

    1977-01-01

    An isolated myocardial abscess due to Bacteroides fragilis developed in the scar of a myocardial infarction. Fever, chills and signs of pericarditis were the main clinical features. Mild enteritis 1 week prior to the onset of symptoms related to the abscess was the most likely cause of the bacteremia. The diagnosis was established at thoracotomy, performed because of cardiac tamponade. Thirteen other cases of isolated bacterial myocardial abscess accompanying myocardial infarction have been reported, but all the infarctions were recent. Surgical resection for a suspected myocardial abscess should be considered in view of the high mortality, largely from cardiac rupture. Images FIG. 1 PMID:861868

  2. Limited myocardial perfusion reserve in patients with left ventricular hypertrophy

    SciTech Connect

    Goldstein, R.A.; Haynie, M. )

    1990-03-01

    Experimental studies in animals have suggested that coronary flow reserve may be limited in patients with left ventricular hypertrophy (LVH). Accordingly, to noninvasively determine the effect of LVH on myocardial perfusion reserve, 25 patients, 9 with LVH and 16 controls, underwent positron imaging with rubidium-82 (82Rb) (30-55 mCi) or nitrogen-13 (13N) ammonia (12-19 mCi) at rest and following intravenous dipyridamole and handgrip stress. LVH was documented by echocardiographic and/or electrocardiographic measurements. LVH patients had either no chest pain (n = 8) and/or a normal coronary angiogram (n = 6). Nine simultaneous transaxial images were acquired, and the mean ratio of stress to rest activity (S:R), based on all regions for each heart, was calculated as an estimate of myocardial perfusion reserve. There were no regional differences in activity (i.e., perfusion defects) in any of the studies. S:R averaged 1.41 +/- 0.10 (s.d.) for controls and 1.06 +/- 0.09 for patients with LVH (p less than 0.0001). These data provide support for an abnormality in perfusion reserve in patients with LVH.

  3. Application of three-class ROC analysis to task-based image quality assessment of simultaneous dual-isotope myocardial perfusion SPECT (MPS).

    PubMed

    He, Xin; Song, Xiyun; Frey, Eric C

    2008-11-01

    The diagnosis of cardiac disease using dual-isotope myocardial perfusion SPECT (MPS) is based on the defect status in both stress and rest images, and can be modeled as a three-class task of classifying patients as having no, reversible, or fixed perfusion defects. Simultaneous acquisition protocols for dual-isotope MPS imaging have gained much interest due to their advantages including perfect registration of the (201)Tl and (99m)Tc images in space and time, increased patient comfort, and higher clinical throughput. As a result of simultaneous acquisition, however, crosstalk contamination, where photons emitted by one isotope contribute to the image of the other isotope, degrades image quality. Minimizing the crosstalk is important in obtaining the best possible image quality. One way to minimize the crosstalk is to optimize the injected activity of the two isotopes by considering the three-class nature of the diagnostic problem. To effectively do so, we have previously developed a three-class receiver operating characteristic (ROC) analysis methodology that extends and unifies the decision theoretic, linear discriminant analysis, and psychophysical foundations of binary ROC analysis in a three-class paradigm. In this work, we applied the proposed three-class ROC methodology to the assessment of the image quality of simultaneous dual-isotope MPS imaging techniques and the determination of the optimal injected activity combination. In addition to this application, the rapid development of diagnostic imaging techniques has produced an increasing number of clinical diagnostic tasks that involve not only disease detection, but also disease characterization and are thus multiclass tasks. This paper provides a practical example of the application of the proposed three-class ROC analysis methodology to medical problems.

  4. Thallium-201 kinetics in nonischemic canine myocardium

    SciTech Connect

    Okada, R.D.; Jacobs, M.L.; Daggett, W.M.

    1982-01-01

    Myocardial thallium-201 (/sup 201/Tl) kinetics have not been precisely defined because reliable techniques to determine continuous activity in vivo have not been available. In this study, an implantable miniature cadmium telluride radiation detection device was inserted through the left ventricular apex, positioned against the endocardium, and used for continuous on-line monitoring of myocardial /sup 201/Tl activity for 260-810 minutes in 18 dogs. Blood was serially sampled and counted. Microsphere-determined myocardial blood flow was measured before administration of /sup 201/Tl and was not significantly different from that measured at the end of the experiment in 11 of 18 dogs. Thallium was administered intravenously. Myocardial and blood activity curves were analyzed using a nonlinear least-squares estimation of the decay constant lambda (min/sup -1/). The mean final blood lambda/sub 3/ was almost identical to the mean myocardial lambda. The data suggest that /sup 201/Tl washout after peak activity is reached in nonischemic myocardium is mono-exponential. The rate of /sup 201/Tl clearance from the myocardium is related to the rate of /sup 201/Tl clearance from the blood after i.v. administration of the tracer.

  5. [Controlled clinical trial of the effect of aspirin and aspirin + dipyridamole on the development of diabetic retinopathy. II. Ophthalmologic protocol].

    PubMed

    1982-12-01

    A description is given of the ophthalmological protocol of the DAMAD (aspirin and dipyridamole + Aspirin) controlled clinical trial in diabetic retinopathy. The 450 patients included in this trial were insulin or noninsulin treated diabetics with an early diabetic retinopathy (i.e. at least five microaneurysms in the posterior pole and/or one zone of capillary non-perfusion). They were randomized in a double blind fashion to treatment with either placebo or aspirin 330 mg or aspirin 330 mg + dipyridamole 75 mg three times daily. A full ophthalmologic examination was performed annually on both eyes of each patient and followed at least three years. Data were recorded on a special form. The main assessment criteria were orientated toward the quantification of the retinal vascular micro-abnormalities, counting of microaneurysm and measurement of the central and peripheral avascular zones. Angiofluorographic photographs were standardized. The two eyes were photographed but only one reference eye was kept for the whole length of this study. A standard reading technique is now used by a technician in charge of coding the quality of the films, the dotting and numbering of the lesions.

  6. Dipyridamole perfusion scintigraphy: The experience with its application in one hundred seventy patients with known or suspected unstable angina

    SciTech Connect

    Zhu, Y.Y.; Chung, W.S.; Botvinick, E.H.; Dae, M.W.; Lim, A.D.; Ports, T.A.; Danforth, J.W.; Wolfe, C.L.; Goldschlager, N.; Chatterjee, K. )

    1991-01-01

    We evaluated the safety, accuracy, and potential clinical utility of intravenous dipyridamole perfusion scintigraphy with thallium-201 in 170 patients, 78 with suspected and 92 with known unstable angina. All had coronary angiography. Noncardiac side effects (26%), induced chest discomfort (44%), and ST segment changes (12%) were similar in the two groups. No significant arrhythmias occurred. Two patients had prolonged chest pain, both with extensive reversible image abnormalities and associated creatinine kinase-MB release. Both had elective bypass surgery. Twenty-eight patients had normal coronary arteries, and 35 had single-vessel disease. Scintigraphic per patient sensitivity and specificity were 91% and 79% with a per vessel sensitivity of 74% and a per vessel specificity of 78% without between-group differences. During a brief follow-up period, 62 patients with image abnormalities had coronary revascularization, and there were seven deaths without intergroup differences. In a similar patient group that did not have angiography, scintigraphic defects were less frequent and less extensive, revascularization was not performed, and subsequent deaths occurred less often. Dipyridamole perfusion scintigraphy is an accurate alternative to exercise testing in the evaluation of patients with unstable angina pectoris. Although not without risk, the method appears relatively safe and should be considered as a guide to diagnosis, and probably to prognosis and management.

  7. In vivo quantitation of platelet deposition on human peripheral arterial bypass grafts using indium-111-labeled platelets. Effect of dipyridamole and aspirin

    SciTech Connect

    Pumphrey, C.W.; Chesebro, J.H.; Dewanjee, M.K.; Wahner, H.W.; Hollier, L.H.; Pairolero, P.C.; Fuster, V.

    1983-03-01

    Indium-111-labeled autologous platelets, injected 48 hours after operation, were used to evaluate the thrombogenicity of prosthetic material and the effect of platelet inhibitor therapy in vivo. Dacron double-velour (Microvel) aortofemoral artery bifurcation grafts were placed in 16 patients and unilateral polytetrafluoroethylene femoropopliteal grafts were placed in 10 patients. Half the patients in each group received platelet inhibitors before operation (dipyridamole, 100 mg 4 times a day) and after operation (dipyridamole, 75 mg, and acetylsalicylic acid, 325 mg 3 times a day); the rest of the patients served as control subjects. Five-minute scintigrams of the graft region were taken with a gamma camera interfaced with a computer 48, 72, and 96 hours after injection of the labeled platelets. Platelet deposition was estimated from the radioactivities of the grafts and expressed as counts per 100 pixels per microcurie injected. Dipyridamole and aspirin therapy significantly reduced the number of platelets deposited on Dacron grafts and prevented platelet accumulation over 3 days. With the small amount of platelet deposition on polytetrafluoroethylene femoropopliteal artery grafts even in control patients, platelet inhibitor therapy had no demonstrable effect on platelet deposition on these grafts. It is concluded that (1) platelet deposition on vascular grafts in vivo can be quantitated by noninvasive methods, and (2) dipyridamole and aspirin therapy reduced platelet deposition on Dacron aortofemoral artery grafts.

  8. Stress Computed Tomography Myocardial Perfusion Imaging: A New Topic in Cardiology.

    PubMed

    Seitun, Sara; Castiglione Morelli, Margherita; Budaj, Irilda; Boccalini, Sara; Galletto Pregliasco, Athena; Valbusa, Alberto; Cademartiri, Filippo; Ferro, Carlo

    2016-02-01

    Since its introduction about 15 years ago, coronary computed tomography angiography has become today the most accurate clinical instrument for noninvasive assessment of coronary atherosclerosis. Important technical developments have led to a continuous stream of new clinical applications together with a significant reduction in radiation dose exposure. Latest generation computed tomography scanners (≥ 64 slices) allow the possibility of performing static or dynamic perfusion imaging during stress by using coronary vasodilator agents (adenosine, dipyridamole, or regadenoson), combining both functional and anatomical information in the same examination. In this article, the emerging role and state-of-the-art of myocardial computed tomography perfusion imaging are reviewed and are illustrated by clinical cases from our experience with a second-generation dual-source 128-slice scanner (Somatom Definition Flash, Siemens; Erlangen, Germany). Technical aspects, data analysis, diagnostic accuracy, radiation dose and future prospects are reviewed.

  9. Stress Computed Tomography Myocardial Perfusion Imaging: A New Topic in Cardiology.

    PubMed

    Seitun, Sara; Castiglione Morelli, Margherita; Budaj, Irilda; Boccalini, Sara; Galletto Pregliasco, Athena; Valbusa, Alberto; Cademartiri, Filippo; Ferro, Carlo

    2016-02-01

    Since its introduction about 15 years ago, coronary computed tomography angiography has become today the most accurate clinical instrument for noninvasive assessment of coronary atherosclerosis. Important technical developments have led to a continuous stream of new clinical applications together with a significant reduction in radiation dose exposure. Latest generation computed tomography scanners (≥ 64 slices) allow the possibility of performing static or dynamic perfusion imaging during stress by using coronary vasodilator agents (adenosine, dipyridamole, or regadenoson), combining both functional and anatomical information in the same examination. In this article, the emerging role and state-of-the-art of myocardial computed tomography perfusion imaging are reviewed and are illustrated by clinical cases from our experience with a second-generation dual-source 128-slice scanner (Somatom Definition Flash, Siemens; Erlangen, Germany). Technical aspects, data analysis, diagnostic accuracy, radiation dose and future prospects are reviewed. PMID:26774540

  10. Interventions during and after acute myocardial infarction.

    PubMed

    Sleight, P

    1983-01-01

    There is now evidence that infarct size in man can be reduced by early treatment and that some cases of threatened infarction can be aborted. Beta blockade, given intravenously within about 6-8 hours after the onset of pain can reduce infarct size and abort some infarctions. So far we have no conclusive data on mortality. Beta blockers may act by a number of mechanisms, namely reduction of cardiac contractility, heart rate and blood pressure thus reducing cardiac work and oxygen requirement, prevention of cardiac rupture by the same mechanism, and by an early effect on R on T ectopic beats and hence serious ventricular arrhythmia. Early myocardial revascularization either by coronary graft, percutaneous angioplasty or intracoronary streptokinase are all promising but so far unproven by adequate clinical trial. Randomized trials suggest that intravenous streptokinase may be effective and hyaluronidase appears promising, possibly by promotion of collateral vessel flow. Calcium channel blockade may also be helpful and there are some early studies which support this. Lowering work by sodium nitroprusside also reduces infarct size. Heparin may have a place in the treatment of threatened infarction. After recovery it now appears established that beta 1-blockade will lower mortality. We do not know how long this effect persists. Other agents are less well established perhaps because the trials have been too small. Anticoagulants may have a place but their use is not widespread. Anti-platelet agents are also controversial. Studies of dipyridamole and sulphinpyrazone have been suggestive but not conclusive; the studies of aspirin are moderately encouraging, when all trials are pooled. Anti-arrhythmic therapy after infarction has been disappointing, with the exception of beta blockade. Perhaps more emphasis should also be put upon changes in lifestyle, notably stopping smoking, reduction of fat intake and encouraging regular exercise.

  11. Effect of aspirin, clopidogrel and dipyridamole on soluble markers of vascular function in normal volunteers and patients with prior ischaemic stroke.

    PubMed

    Zhao, Lian; Gray, Laura; Leonardi-Bee, Jo; Weaver, Chris S; Heptinstall, Stan; Bath, Philip M W

    2006-03-01

    Although the mechanisms of action by which aspirin, clopidogrel and dipyridamole inhibit platelets are well characterised, their effects on soluble modulators of thrombosis, inflammation, and endothelial function have yet to assessed systematically. In this investigation aspirin (A), clopidogrel (C), and dipyridamole (D) were administered singly and in combination (A, C, D, AC, AD, CD, ACD) in random order for 2 weeks (without washout) to 11 healthy subjects and 11 patients with previous ischaemic stroke. At the end of each treatment period plasma cyclic guanosine monophosphate (cGMP), monocyte chemoattractant pertide-1 (MCP-1), nitric oxide metabolites (NO(x)), plasminogen activator inhibitor-1 (PAI-1) and von Willebrand factor (vWf); and serum C-reactive protein (CRP) and platelet derived growth factor (PDGF); were measured blinded to treatment. Dipyridamole reduced plasma vWf levels (%) in both volunteers, -10.0 (4.95), and patients, -10.11 (4.34) (p < 0.05). Dipyridamole also lowered CRP (mg/l) in patients, -0.96 (0.47), but not volunteers. Clopidogrel reduced PAI-1 (ng/ml) in volunteers, -5.30 (2.20) (p < 0.05), and patients, -3.61 (2.75) (non-significant trend). Aspirin lowered PDGF (ng/ml) in volunteers, -3.46 (1.55), but not patients. Triple antiplatelet therapy was superior to dual and mono therapy in reducing vWf levels. In conclusion, antiplatelet agents have non-platelet-related effects on soluble modulators of thrombosis, inflammation, and endothelial function. In particular, dipyridamole reduces plasma vWf and clopidogrel lowers plasma PAI-1 levels. These effects may explain, in part, their roles in preventing atherothrombogenesis. PMID:16421011

  12. 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.

  13. T2 Preparation Method for Measuring Hyperemic Myocardial O2 Consumption: In Vivo Validation by Positron Emission Tomography

    PubMed Central

    McCommis, Kyle S.; O’Connor, Robert; Abendschein, Dana R.; Muccigrosso, David; Gropler, Robert J.; Zheng, Jie

    2013-01-01

    Purpose To validate a new T2-prepared method for the quantification of regional myocardial O2 consumption during pharmacologic stress with positron emission tomography (PET). Materials and Methods A T2 prepared gradient-echo sequence was modified to measure myocardial T2 within a single breath-hold. Six beagle dogs were randomly selected for the induction of coronary artery stenosis. Magnetic resonance imaging (MRI) experiments were performed with the T2 imaging and first-pass perfusion imaging at rest and during either dobutamine- or dipyridamole-induced hyperemia. Myocardial blood flow (MBF) was quantified using a previously developed model-free algorithm. Hyperemic myocardial O2 extraction fraction (OEF) and consumption (MVO2) were calculated using a two-compartment model developed previously. PET imaging using 11C-acetate and 15O-water was performed in the same day to validate OEF, MBF, and MVO2 measurements. Results The T2-prepared mapping sequence measured regional myocardial T2 with a repeatability of 2.3%. By myocardial segment-basis analysis, MBF measured by MRI is closely correlated with that measured by PET (R2 = 0.85, n = 22). Similar correlation coefficients were observed for hyperemic OEF (R2 = 0.90, n = 9, mean difference of PET − MRI = −2.4%) and MVO2 (R2 = 0.83, n = 7, mean difference = 4.2%). Conclusion The T2-prepared imaging method may allow quantitative estimation of regional myocardial oxygenation with relatively good accuracy. The precision of the method remains to be improved. PMID:21274973

  14. Digital angiographic impulse response analysis of regional myocardial perfusion: linearity, reproducibility, accuracy, and comparison with conventional indicator dilution curve parameters in phantom and canine models.

    PubMed

    Eigler, N L; Pfaff, J M; Zeiher, A; Whiting, J S; Forrester, J S

    1989-05-01

    The system mean transit time (Tsys) of the impulse response function describing contrast material transit through the coronary circulation was determined from serial digital angiographic images. The linearity, reproducibility, and relations with regional myocardial perfusion and conventional time-density curve parameters, time to peak concentration (TPC), and exponential washout rate (k) were assessed in a dynamic flow x-ray phantom (n = 46) and in six open-chest dogs (n = 102) while coronary flow was altered by stenosis and/or hyperemic stimuli. In the phantom studies, the inverse of the system mean transit time (Tsys-1) closely predicted flow/volume (r = 0.99, slope = 0.99). In dogs, Tsys-1 was independent of the shape of the contrast bolus injection (single or double-peaked), class of contrast agent (ionic or nonionic), the type of hyperemic stimulus (dipyridamole, dipyridamole plus norepinephrine, transient total occlusion, or ionic contrast media), and was highly reproducible between adjacent myocardial regions served by the same artery (r = 0.98 +/- 0.01). There was a strong correlation between Tsys-1 and regional coronary flow for stenotic and/or hyperemic vessels (r = 0.94, distribution volume = 14.9 ml/100 g) over a wide range (0-514 ml/min/100 g). Tsys-1 performed better than conventional time-density curve parameters TPC-1 and k for predicting phantom flow/volume ratios and regional myocardial blood flow in the dog. These data suggest that both digital coronary angiography and coronary contrast transit can be modeled as linear systems and that impulse response analysis may provide accurate and reproducible estimates of regional myocardial blood flow.

  15. Ineffectiveness of dipyridamole SPECT thallium imaging as a screening technique for coronary artery disease in patients with end-stage renal failure

    SciTech Connect

    Marwick, T.H.; Steinmuller, D.R.; Underwood, D.A.; Hobbs, R.E.; Go, R.T.; Swift, C.; Braun, W.E. )

    1990-01-01

    The efficacy of dipyridamole single photon emission computed tomography (SPECT) thallium as a screening test for coronary artery disease (CAD), was studied in 45 patients with end-stage renal failure undergoing evaluation for renal transplantation. Coronary arteriography, dipyridamole SPECT thallium imaging and clinical follow-up were performed in all patients. Nineteen patients (42%) had an obstruction of 50% or more in at least one coronary artery. Fourteen patients had a positive thallium scan, but 7 of these were false-positives (sensitivity 37%, specificity 73%). The sensitivity was considerably lower than that quoted for non-ESRF patients in the literature, and significantly lower than a control group of 19 patients without ESRF having comparable severity and distribution of CAD. Five of the 6 patients who died of cardiac causes over a mean follow-up period of 25 months had normal thallium imaging, but all had significant coronary artery disease at cardiac catheterization. Dipyridamole SPECT thallium imaging has not proved a useful screening test for angiographically significant CAD, and does not predict cardiac prognosis in this population.

  16. Detection of coronary artery disease by thallium imaging using a combined intravenous dipyridamole and isometric handgrip test in patients with aortic valve stenosis

    SciTech Connect

    Huikuri, H.V.; Korhonen, U.R.; Ikaeheimo, M.J.H.; Heikkilae, J.T.; Takkunen, J.T.

    1987-02-01

    Detection of coronary artery disease (CAD) in patients with aortic valve stenosis (AS) is clinically difficult. Thallium-201 images were generated in 27 patients with AS during combined intravenous dipyridamole and handgrip test, which induces a marked acute increase in coronary blood flow. Isolated AS was noted in 21 patients and combined AS and aortic regurgitation in 6. Thirteen patients had more than 50% diameter stenosis in 1 or more coronary arteries on angiography. Eleven of them had reversible perfusion defects on post-stress thallium scans (sensitivity 85%). Two patients had thallium defects without angiographic evidence of significant CAD (specificity 86%). In the other 12 patients with normal coronary angiographic findings, the thallium scans were normal. Two patients had dizziness and hypotension after dipyridamole infusion, which disappeared during the handgrip test; 2 others had chest pain during handgrip. One of them was treated with aminophylline and the other with aminophylline and nitroglycerin. No other adverse effects were reported by the patients and no major complications occurred during stress testing. Thus, thallium imaging during combined intravenous dipyridamole and handgrip test appears to be a promising noninvasive method of revealing CAD in patients with AS.

  17. Incremental Diagnostic Performance of Combined Parameters in the Detection of Severe Coronary Artery Disease Using Exercise Gated Myocardial Perfusion Imaging

    PubMed Central

    Liu, Chia-Ju; Wu, Yen-Wen; Ko, Kuan-Yin; Chen, Yi-Chieh; Cheng, Mei-Fang; Yen, Ruoh-Fang; Tzen, Kai-Yuan

    2015-01-01

    Purpose Myocardial perfusion imaging (MPI) using gated single-photon emission tomography (gSPECT) may underestimate the severity of coronary artery disease (CAD). This study aimed to evaluate the significance of combined parameters derived from gSPECT, as well as treadmill stress test parameters, in the detection of severe CAD. Methods A total of 211 consecutive patients referred for exercise MPI between June 2011 and June 2013 (who received invasive coronary angiography within six months after MPI) were retrospectively reviewed. Exercise MPI was performed with Bruce protocol and 201Tl injected at peak exercise. Gated SPECT was performed using a cadmium-zinc-telluride camera and processed by QPS/QGS software. Perfusion defect abnormalities such as sum stress score (SSS); sum difference score, algorithm-derived total perfusion deficits, transient ischemic dilatation ratios of end-diastolic volumes and end-systolic volumes, post-stress changes in ejection fraction, and lung/heart ratio (LHR) were calculated. Treadmill parameters, including ST depression (STD) at the 1st and 3rd minutes of recovery stage (1’STD and 3’STD), maximal STD corrected by heart rate increment (ST/HR), heart rate decline in 1st and 3rd minutes of recovery stage, recovery heart rate ratio (HR ratio), systolic and mean blood pressure ratios (SBP ratio and MAP ratio) during recovery phase were recorded. Diagnostic performances of these parameters were analyzed with receiver operating characteristic (ROC) analysis and logistic regression for detection of left main (≥ 50%) or 3-vessel disease (all ≥ 70% luminal stenosis) on invasive angiography. Results Among various MPI and treadmill parameters used for detection of severe CAD, SSS and ST/HR had the highest AUC (0.78, 0.73, p = NS) and best cut-off values (SSS > 6, ST/HR > 17.39 10-2mV/bpm), respectively. By univariate logistic regression, all parameters except 1’HRR, 3’HRR, SBP and MAP ratios increased the odds ratio of severe CAD

  18. [Acute effects of transdermal administration of nitroglycerin on effort tolerance and myocardial perfusion, evaluated by Tl-201 scintigraphy, in patients with stable effort angina].

    PubMed

    Novo, S; Liquori, M; Abrignani, M G; Giuliano, F; Panno, V; Fazio, M; Adamo, L; Corda, M; Indovina, A; di Maria, G

    1991-09-01

    downsloping, objective demonstration of myocardial ischemia. This antianginal and antiischemic effect might follow to the reduction of the preload induced by nitrates, in part also the reduction of the afterload, factors determining a decrease of the wall tension and so of MVO2, but also to a redistribution of the subendocardial flow as demonstrated by 201-Tl scintigraphic images. These effects induce also a global improvement of the left ventricular function as demonstrated by the reduction of the lung/heart index of thallium captation.

  19. Comparison of rubidium-82 positron emission tomography and thallium-201 SPECT imaging for detection of coronary artery disease

    SciTech Connect

    Stewart, R.E.; Schwaiger, M.; Molina, E.; Popma, J.; Gacioch, G.M.; Kalus, M.; Squicciarini, S.; al-Aouar, Z.R.; Schork, A.; Kuhl, D.E. )

    1991-06-15

    The diagnostic performance of rubidium-82 (Rb-82) positron emission tomography (PET) and thallium-201 (Tl-201) single-photon emission-computed tomography (SPECT) for detecting coronary artery disease was investigated in 81 patients (52 men, 29 women). PET studies using 60 mCi of Rb-82 were performed at baseline and after intravenous infusion of 0.56 mg/kg dipyridamole in conjunction with handgrip stress. Tl-201 SPECT was performed after dipyridamole-handgrip stress and, in a subset of patients, after treadmill exercise. Sensitivity, specificity and overall diagnostic accuracy were assessed using both visually and quantitatively interpreted coronary angiograms. The overall sensitivity, specificity and accuracy of PET for detection of coronary artery disease (greater than 50% diameter stenosis) were 84, 88 and 85%, respectively. In comparison, the performance of SPECT revealed a sensitivity of 84%, specificity of 53% (p less than 0.05 vs PET) and accuracy of 79%. Similar results were obtained using either visual or quantitative angiographic criteria for severity of coronary artery disease. In 43 patients without prior myocardial infarction, the sensitivity for detection of disease was 71 and 73%, respectively, similar for both PET and SPECT. There was no significant difference in diagnostic performance between imaging modalities when 2 different modes of stress (exercise treadmill vs intravenous dipyridamole plus handgrip) were used with SPECT imaging. Thus, Rb-82 PET provides improved specificity compared with Tl-201 SPECT for identifying coronary artery disease, most likely due to the higher photon energy of Rb-82 and attenuation correction provided by PET. However, post-test referral cannot be entirely excluded as a potential explanation for the lower specificity of Tl-201 SPECT.

  20. Influence of attenuation correction on transient left ventricular dilation in dual isotope myocardial perfusion imaging in patients with known or suspected coronary artery disease.

    PubMed

    Brodov, Yafim; Frenkel, Alex; Chouraqui, Pierre; Przewloka, Kinga; Rispler, Shmuel; Abadi, Sobhi; Keidar, Zohar

    2012-07-01

    The aim of this study was to assess the effect of attenuation correction (AC) on left ventricular (LV) volumes and LV transient ischemic dilatation (TID) during dual-isotope single-photon emission computer tomographic (SPECT) myocardial perfusion imaging (MPI). Ninety-six patients (mean age 58 ± 11 years, 15% women, 38 patients completed exercise and 58 dipyridamole pharmacologic stress tests) assessed for known or suspected coronary artery disease underwent dual-isotope thallium-201 rest and technetium-99m sestamibi stress SPECT MPI with computed tomography-based AC. The TID ratio was calculated separately for non-AC and AC SPECT MPI studies as the ratio of the LV endocardial volume at stress divided by LV endocardial volume at rest. The mean and range of the gated LV ejection fraction during exercise and pharmacologic stress was 54 ± 12% (29% to 80%) and 58 ± 12% (27% to 80%), respectively. In the exercise stress group, the same mean LV endocardial volumes in non-AC and AC stress (76.4 ± 30 and 76.5 ± 28) and rest (66.3 ± 26 and 66.4 ± 24) studies were found (p = 0.90). There was no statistical difference between the mean exercise TID ratio in non-AC and AC studies (1.27 vs 1.31, respectively, p = 0.10). The same mean LV endocardial volumes in non-AC and AC in pharmacologic stress (79.9 ± 42 and 80 ± 41) and rest (71.4 ± 41 and 72.3 ± 37), respectively, were found (p = 0.50). There was no statistical difference between the mean dipyridamole TID ratio in non-AC and AC studies (1.20 vs 1.17, respectively, p = 0.10). In conclusion, LV volumes and TID indexes obtained on SPECT MPI with exercise or pharmacologic stress using dipyridamole are not affected by AC.

  1. Pharmacologic stress dual-isotope myocardial perfusion single-photon emission computed tomography.

    PubMed

    Matzer, L; Kiat, H; Wang, F P; Van Train, K; Germano, G; Friedman, J; Berman, D S

    1994-12-01

    Separate-acquisition rest thallium-201/exercise technetium-99m sestamibi (sestamibi) dual-isotope single-photon emission computed tomography (SPECT) has been shown to be effective for assessment of myocardial perfusion and viability. The present study was designed to validate the dual-isotope approach when used in conjunction with pharmacologic stress. All patients had rest 201TI SPECT followed immediately by adenosine (n = 82) or dipyridamole (n = 50) infusion and sestamibi injection. Sestamibi SPECT was performed 1 hour later. The entire study lasted < 2.5 hours. The patient population was categorized into three groups: 51 consecutive patients with coronary angiography and no previous myocardial infarction (group I), 58 consecutive patients with a low prescintigraphic test likelihood of coronary artery disease (group II), and 23 consecutive catheterized patients with remote Q-wave myocardial infarction (group III). For group I patients, the sensitivity and specificity for dual-isotope SPECT were 92% (35 of 38) and 85% (11 of 13), respectively, when > or = 50% coronary artery narrowing was considered significant and were 97% (34 of 35) and 81% (13 of 16) respectively, when > or = 70% narrowing was considered significant. The normalcy rate among the 58 patients of group II was 96%. Comparisons for pattern of stress-defect reversibility demonstrated that of the 97 stress defects within the infarct zones (group III), 15% were reversible and 85% were nonreversible. In contrast, of the 227 stress defects within the diseased (> or = 50% stenosis) vessel zones of the group I patients, 93% were reversible and 7% were noreversible (p < 0.001 vs group III). In conclusion, separate acquisition rest 201-TI/pharmacologic stress sestamibi dual-isotope SPECT is an efficient myocardial perfusion imaging protocol with high accuracy for detection and assessment of angiographically significant coronary artery disease.

  2. Chemometrics Tools in Detection and Quantitation of the Main Impurities Present in Aspirin/Dipyridamole Extended-Release Capsules.

    PubMed

    El-Ragehy, Nariman A; Yehia, Ali M; Hassan, Nagiba Y; Tantawy, Mahmoud A; Abdelkawy, Mohamed

    2016-07-01

    Aspirin (ASP) and dipyridamole (DIP) in combination is widely used in the prevention of secondary events after stroke and transient ischemic attack. Salicylic acid is a well-known impurity of ASP, and the DIP extended-release formulation may contain ester impurities originating from the reaction with tartaric acid. UV spectral data analysis of the active ingredients in the presence of their main impurities is presented using multivariate approaches. Four chemometric-assisted spectrophotometric methods, namely, partial least-squares, concentration residuals augmented classical least-squares (CRACLS), multivariate curve resolution (MCR) alternating least-squares (ALS), and artificial neural networks, were developed and validated. The quantitative analyses of all the proposed calibrations were compared by percentage recoveries, root mean square error of prediction, and standard error of prediction. In addition, r(2) values between the pure and estimated spectral profiles were used to evaluate the qualitative analysis of CRACLS and MCR-ALS. The lowest error was obtained by the CRACLS model, whereas the best correlation was achieved using MCR-ALS. The four multivariate calibration methods could successfully be applied for the extended-release formulation analysis. The application results were also validated by analysis of the stored dosage-form solution, which showed a susceptibility of DIP esterification in the extended-release formulation. Statistical comparison between the proposed and official methods showed no significant difference. PMID:27302874

  3. Usefulness of technetium-99m-MIBI and thallium-201 in tomographic imaging combined with high-dose dipyridamole and handgrip exercise for detecting coronary artery disease.

    PubMed

    Kettunen, R; Huikuri, H V; Heikkilä, J; Takkunen, J T

    1991-09-01

    Forty-two patients with known stable coronary artery disease, referred for coronary angiography, were examined with technetium-99m-hexakis-2-methoxy-2-methylpropyl-isonitrile (MIBI) tomography combined with a high-dose dipyridamole infusion (0.7 mg/kg) and handgrip stress. MIBI tomography was unable to show coronary artery disease only in 2 patients, thus yielding a sensitivity figure of 95%. MIBI tomography correctly identified 27 (82%) of 33 stenotic lesions (greater than or equal to 50% diameter stenosis) of the left anterior descending artery, 17 (61%) of 28 of those of the left circumflex artery, and 28 (90%) of 31 of those of the right coronary artery. The overall vessel sensitivity was 78%. The computed lumen diameter stenoses were more advanced in cases detected than in those not detected with MIBI tomography: 87 +/- 14 vs 76 +/- 14% (p less than 0.01). The 50 to 69% stenoses did not show any tendency to produce less positive findings than those with greater than or equal to 70% stenoses. In the subgroup of 21 patients who also presented for thallium scintigraphy, the overall diseased vessel identification rate was 76% for thallium tomography and 83% for MIBI tomography (p = not significant). Minor noncardiac side effects related to the dipyridamole-handgrip test occurred only in 5% of 63 study sessions. A high-dose dipyridamole combined with isometric exercise is a safe stress method, and when used during scintigraphy, MIBI tomography is at least as efficient a tool as thallium tomography in detecting diseased vessel territories in patients in coronary artery disease.

  4. Usefulness of technetium-99m-MIBI and thallium-201 in tomographic imaging combined with high-dose dipyridamole and handgrip exercise for detecting coronary artery disease

    SciTech Connect

    Kettunen, R.; Huikuri, H.V.; Heikkilae, J.T.; Takkunen, J.T. )

    1991-09-01

    Forty-two patients with known stable coronary artery disease, referred for coronary angiography, were examined with technetium-99m-hexakis-2-methoxy-2-methylpropyl-isonitrile (MIBI) tomography combined with a high-dose dipyridamole infusion (0.7 mg/kg) and handgrip stress. MIBI tomography was unable to show coronary artery disease only in 2 patients, thus yielding a sensitivity figure of 95%. MIBI tomography correctly identified 27 (82%) of 33 stenotic lesions (greater than or equal to 50% diameter stenosis) of the left anterior descending artery, 17 (61%) of 28 of those of the left circumflex artery, and 28 (90%) of 31 of those of the right coronary artery. The overall vessel sensitivity was 78%. The computed lumen diameter stenoses were more advanced in cases detected than in those not detected with MIBI tomography: 87 {plus minus} 14 vs 76 {plus minus} 14% (p less than 0.01). The 50 to 69% stenoses did not show any tendency to produce less positive findings than those with greater than or equal to 70% stenoses. In the subgroup of 21 patients who also presented for thallium scintigraphy, the overall diseased vessel identification rate was 76% for thallium tomography and 83% for MIBI tomography (p = not significant). Minor noncardiac side effects related to the dipyridamole-handgrip test occurred only in 5% of 63 study sessions. A high-dose dipyridamole combined with isometric exercise is a safe stress method, and when used during scintigraphy, MIBI tomography is at least as efficient a tool as thallium tomography in detecting diseased vessel territories in patients in coronary artery disease.

  5. An investigation into the crystallization tendency/kinetics of amorphous active pharmaceutical ingredients: A case study with dipyridamole and cinnarizine.

    PubMed

    Baghel, Shrawan; Cathcart, Helen; Redington, Wynette; O'Reilly, Niall J

    2016-07-01

    Amorphous drug formulations have great potential to enhance solubility and thus bioavailability of BCS class II drugs. However, the higher free energy and molecular mobility of the amorphous form drive them towards the crystalline state which makes them unstable. Accurate determination of the crystallization tendency/kinetics is the key to the successful design and development of such systems. In this study, dipyridamole (DPM) and cinnarizine (CNZ) have been selected as model compounds. Thermodynamic fragility (mT) was measured from the heat capacity change at the glass transition temperature (Tg) whereas dynamic fragility (mD) was evaluated using methods based on extrapolation of configurational entropy to zero [Formula: see text] , and heating rate dependence of Tg [Formula: see text] . The mean relaxation time of amorphous drugs was calculated from the Vogel-Tammann-Fulcher (VTF) equation. Furthermore, the correlation between fragility and glass forming ability (GFA) of the model drugs has been established and the relevance of these parameters to crystallization of amorphous drugs is also assessed. Moreover, the crystallization kinetics of model drugs under isothermal conditions has been studied using Johnson-Mehl-Avrami (JMA) approach to determine the Avrami constant 'n' which provides an insight into the mechanism of crystallization. To further probe into the crystallization mechanism, the non-isothermal crystallization kinetics of model systems were also analysed by statistically fitting the crystallization data to 15 different kinetic models and the relevance of model-free kinetic approach has been established. The crystallization mechanism for DPM and CNZ at each extent of transformation has been predicted. The calculated fragility, glass forming ability (GFA) and crystallization kinetics are found to be in good correlation with the stability prediction of amorphous solid dispersions. Thus, this research work involves a multidisciplinary approach to

  6. Transthoracic measurement of left coronary artery flow reserve improves the diagnostic value of routine dipyridamole-atropine stress echocardiogram

    PubMed Central

    Wejner-Mik, Paulina; Nouri, Aria; Szymczyk, Ewa; Krzemińska-Pakuła, Maria; Lipiec, Piotr

    2013-01-01

    Introduction We hypothesized that coronary flow reserve (CFR) in the left anterior descending artery (LAD) can be effectively measured during an accelerated dipyridamole-atropine stress echocardiography (DASE) protocol to improve the diagnostic performance of the test. Material and methods In 64 patients with suspected or known coronary artery disease scheduled for coronary angiography DASE with concomitant CFR measurement in LAD was performed. Results Coronary flow reserve measurement and calculation were feasible in 83% of patients. The positive predictive value of undetectable LAD flow was 81% for severe LAD disease. Measured values of CFR were in the range 1.3–4.1 (mean: 2.2 ±0.7). Significantly lower CFR was found in patients with LAD disease (1.97 ±0.62 vs. 2.55 ±0.57, p = 0.0015). The optimal cutoff for detecting ≥ 50% stenosis was CFR ≤ 2.1 (ROC AUC 0.776), corresponding with 68% sensitivity and 84% specificity. In patients with negative DASE results 67% of patients with LAD disease had abnormal CFR, whereas in patients with a positive DASE result 92% of patients with normal LAD had normal CFR. The DASE diagnostic accuracy for the detection of coronary artery disease (CAD) increased from 75% to 85% when CFR measurement was added to wall motion abnormality (WMA) analysis. No test with both abnormalities was false positive for the detection of coronary disease. Conclusions Incorporation of CFR measurement into WMA-based stress echocardiography is feasible even in an accelerated DASE protocol and can be translated into an approximate gain of 10% in overall test accuracy. PMID:24273560

  7. Myocardial diseases of animals.

    PubMed Central

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

    1986-01-01

    In this review we have attempted a comprehensive compilation of the cardiac morphologic changes that occur in spontaneous and experimental myocardial diseases of animals. Our coverage addresses diseases of mammals and birds and includes these diseases found in both domesticated and wild animals. A similar review of the myocardial diseases in this broad range of animal species has not been attempted previously. We have summarized and illustrated the gross, microscopic, and ultrastructural alterations for these myocardial diseases; and, whenever possible, we have reviewed their biochemical pathogenesis. We have arranged the myocardial diseases for presentation and discussion according to an etiologic classification with seven categories. These include a group of idiopathic or primary cardiomyopathies recognized in man (hypertrophic, dilated, and restrictive types) and a large group of secondary cardiomyopathies with known causes, such as inherited tendency; nutritional deficiency; toxicity; physical injury and shock; endocrine disorders, and myocarditides of viral, bacterial, and protozoal causation. Considerable overlap exists between each of the etiologic groups in the spectrum of pathologic alterations seen in the myocardium. These include various degenerative changes, myocyte necrosis, and inflammatory lesions. However, some diseases show rather characteristic myocardial alterations such as vacuolar degeneration in anthracycline cardiotoxicity, myofibrillar lysis in furazolidone cardiotoxicity, calcification in calcinosis of mice, glycogen accumulation in the glycogenoses, lipofuscinosis in cattle, fatty degeneration in erucic acid cardiotoxicity, myofiber disarray in hypertrophic cardiomyopathy, and lymphocytic inflammation with inclusion bodies in canine parvoviral myocarditis. The myocardial diseases represent the largest group in the spectrum of spontaneous cardiac diseases of animals. Pericardial and endocardial diseases and congential cardiac diseases are

  8. Depression after myocardial infarction.

    PubMed

    Ziegelstein, R C

    2001-01-01

    Depression is an independent risk factor for increased postmyocardial infarction morbidity and mortality, even after controlling for the extent of coronary artery disease, infarct size, and the severity of left ventricular dysfunction. This risk factor takes on added significance when one considers that almost half of patients recovering from a myocardial infarction have major or minor depression and that major depression alone occurs in about one in five of these individuals. Despite the well-documented risk of depression, questions remain about the mechanism of the relationship between mood disturbance and adverse outcome. The link may be explained by an association with lower levels of social support, poor adherence to recommended medical therapy and lifestyle changes intended to reduce the risk of subsequent cardiac events, disturbances in autonomic tone, enhanced platelet activation and aggregation, and systemic immune activation. Unfortunately, questions about the pathophysiologic mechanism of depression in this setting are paralleled by uncertainties about the optimal treatment of depression for patients recovering from a myocardial infarction and by a lack of knowledge about whether treating depression lowers the associated increased mortality risk. Ongoing research studies will help to determine the benefits of psychosocial interventions and of antidepressant therapy for patients soon after myocardial infarction. Although the identification of depression as a risk factor may by itself be a reason to incorporate a comprehensive psychological evaluation into the routine care of patients with myocardial infarction, this practice should certainly become standard if studies show that treating depression reduces the increased mortality risk of these patients.

  9. 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.

  10. Angiogenesis PET Tracer Uptake ((68)Ga-NODAGA-E[(cRGDyK)]₂) in Induced Myocardial Infarction in Minipigs.

    PubMed

    Rasmussen, Thomas; Follin, Bjarke; Kastrup, Jens; Brandt-Larsen, Malene; Madsen, Jacob; Emil Christensen, Thomas; Pharao Hammelev, Karsten; Hasbak, Philip; Kjær, Andreas

    2016-01-01

    Angiogenesis is part of the healing process following an ischemic injury and is vital for the post-ischemic repair of the myocardium. Therefore, it is of particular interest to be able to noninvasively monitor angiogenesis. This might, not only permit risk stratification of patients following myocardial infarction, but could also facilitate development and improvement of new therapies directed towards stimulation of the angiogenic response. During angiogenesis endothelial cells must adhere to one another to form new microvessels. αvβ₃ integrin has been found to be highly expressed in activated endothelial cells and has been identified as a critical modulator of angiogenesis. (68)Ga-NODAGA-E[c(RGDyK)]₂ (RGD) has recently been developed by us as an angiogenesis positron-emission-tomography (PET) ligand targeted towards αvβ₃ integrin. In the present study, we induced myocardial infarction in Göttingen minipigs. Successful infarction was documented by (82)Rubidium-dipyridamole stress PET and computed tomography. RGD uptake was demonstrated in the infarcted myocardium one week and one month after induction of infarction by RGD-PET. In conclusion, we demonstrated angiogenesis by noninvasive imaging using RGD-PET in minipigs hearts, which resemble human hearts. The perspectives are very intriguing and might permit the evaluation of new treatment strategies targeted towards increasing the angiogenetic response, e.g., stem-cell treatment. PMID:27322329

  11. Angiogenesis PET Tracer Uptake (68Ga-NODAGA-E[(cRGDyK)]2) in Induced Myocardial Infarction in Minipigs

    PubMed Central

    Rasmussen, Thomas; Follin, Bjarke; Kastrup, Jens; Brandt-Larsen, Malene; Madsen, Jacob; Emil Christensen, Thomas; Pharao Hammelev, Karsten; Hasbak, Philip; Kjær, Andreas

    2016-01-01

    Angiogenesis is part of the healing process following an ischemic injury and is vital for the post-ischemic repair of the myocardium. Therefore, it is of particular interest to be able to noninvasively monitor angiogenesis. This might, not only permit risk stratification of patients following myocardial infarction, but could also facilitate development and improvement of new therapies directed towards stimulation of the angiogenic response. During angiogenesis endothelial cells must adhere to one another to form new microvessels. αvβ3 integrin has been found to be highly expressed in activated endothelial cells and has been identified as a critical modulator of angiogenesis. 68Ga-NODAGA-E[c(RGDyK)]2 (RGD) has recently been developed by us as an angiogenesis positron-emission-tomography (PET) ligand targeted towards αvβ3 integrin. In the present study, we induced myocardial infarction in Göttingen minipigs. Successful infarction was documented by 82Rubidium-dipyridamole stress PET and computed tomography. RGD uptake was demonstrated in the infarcted myocardium one week and one month after induction of infarction by RGD-PET. In conclusion, we demonstrated angiogenesis by noninvasive imaging using RGD-PET in minipigs hearts, which resemble human hearts. The perspectives are very intriguing and might permit the evaluation of new treatment strategies targeted towards increasing the angiogenetic response, e.g., stem-cell treatment. PMID:27322329

  12. Comparison of 180° and 360° Arc Data Acquisition to Measure Scintigraphic Parameters from Gated Single Photon Emission Computed Tomography Myocardial Perfusion Imaging: Is There Any Difference?

    PubMed Central

    Javadi, Hamid; Mahmoud-Pashazadeh, Ali; Mogharrabi, Mehdi; Iranpour, Darioush; Amini, Abdollatif; Pourbehi, Mohammadreza; Akbarzadeh, Mehdi; Nabipour, Iraj; Assadi, Majid

    2016-01-01

    Objective: The aim of the current study was to compare 180° and 360° data collection modes to measure end diastolic volume (EDV), end systolic volume (ESV) and ejection fraction (EF) values of the cardiac system by gated myocardial perfusion tomography. Methods: Thirty-three patients underwent gated myocardial perfusion tomography. Single photon emission computed tomography data of patients’ heart were acquired by 180°, 45° left posterior oblique to 45° right anterior oblique, and 360° to obtain EDV, ESV, EF and cardiac volume changes (V1, V2, V3, V4, V5, V6, V7 and V8) throughout each cardiac cycle. Results: Results of the current study indicated that there were no significant differences between 180° and 360° angular sampling in terms of measuring EDV, ESV and EF in myocardial perfusion imaging. Cardiac volume change patterns during a cardiac cycle were also similar in 360° and 180° scans. We also observed that there was no difference in EDV, ESV and EF values between the group with stress induced by exercise and the group with stress imposed by dipyridamole. Conclusion: As there is no difference between 180°and 360° cardiac scanning in terms of EDV, ESV and EF, half-orbit scan is recommended to study these cardiac system parameters because it offers more comfort to patients and a shorter scanning time. PMID:27299285

  13. 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

  14. Silent myocardial ischemia.

    PubMed

    Gutterman, David D

    2009-05-01

    Although much progress has been made in reducing mortality from ischemic cardiovascular disease, this condition remains the leading cause of death throughout the world. This might in part be due to the fact that over half of patients have a catastrophic event (heart attack or sudden death) as their initial manifestation of coronary disease. Contributing to this statistic is the observation that the majority of myocardial ischemic episodes are silent, indicating an inability or failure to sense ischemic damage or stress on the heart. This review examines the clinical characteristics of silent myocardial ischemia, and explores mechanisms involved in the generation of angina pectoris. Possible mechanisms for the more common manifestation of injurious reductions in coronary flow; namely, silent ischemia, are also explored. A new theory for the mechanism of silent ischemia is proposed. Finally, the prognostic importance of silent ischemia and potential future directions for research are discussed.

  15. Myocardial apoptosis and SIDS.

    PubMed

    Grasmeyer, Sarah; Madea, Burkhard

    2015-01-01

    Apoptosis mediates cardiac damage in severe forms of myocarditis. In fatal myocarditis, large amounts of cardiomyocytes show apoptotic DNA fragmentation, while in human controls, few apoptotic cardiomyocytes are found. In the present study the frequency of apoptosis in 88 SIDS cases (category 1b according to the San Diego Classification) and 15 control cases was investigated. In every case myocardial samples from 8 standard locations were collected. Detection of apoptotic cardiomyocytes was performed by TUNEL method. Furthermore the myocardial tissue was stained with HE and immunohistochemical methods (LCA, CD68, CD45-R0). More than 90% of the slides did not contain apoptotic cardiomyocytes at all. The detection rate of apoptotic cardiomyocytes was almost equal in control group (26.7%) and SIDS group (23.86%). A quantification of apoptotic cardiomyocytes per mm(2) revealed no significant difference between both groups either. Altogether there is no evidence for a higher rate of apoptosis in SIDS.

  16. Dual tracer autoradiographic study with thallium-201 and radioiodinated fatty acid in cardiomyopathic hamsters

    SciTech Connect

    Kurata, C.; Kobayashi, A.; Yamazaki, N.

    1989-01-01

    To investigate the usefulness of myocardial scintigraphy with radioiodinated 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) in cardiomyopathy, quantitative dual tracer autoradiographic study with /sup 201/Tl and (/sup 125/I)BMIPP was performed in 27 cardiomyopathic Bio 14.6 Syrian hamsters and eight normal hamsters. Furthermore, 16 Bio 14.6 Syrian hamsters aged 21 days were divided into verapamil-treated (during 70 days) and control groups (respectively, n = 8), and autoradiography with /sup 201/Tl and (/sup 125/I)BMIPP was performed. Quantitative autoradiography demonstrated an uncoupling of /sup 201/Tl and (/sup 125/I)BMIPP distributions and a regional heterogeneity of (/sup 125/I)BMIPP distribution in cardiomyopathic hamsters aged more than 2 mo, while normal hamsters showed only mild heterogeneity of (/sup 125/I)BMIPP distribution without an uncoupling of tracers. Age-matched comparison between normal and cardiomyopathic hamsters (5-8 mo old) demonstrated that a difference between their (/sup 125/I)BMIPP distributions are more marked than that between their /sup 201/Tl distributions. Furthermore, (/sup 125/I)BMIPP visualized effects of verapamil on cardiomyopathy more distinctly than did /sup 201/Tl. In conclusion, myocardial imaging with (/sup 123/I)BMIPP could be useful for investigating cardiomyopathy and evaluating the efficacy of therapeutic intervention in patients with cardiomyopathy.

  17. Myocardial gene therapy

    NASA Astrophysics Data System (ADS)

    Isner, Jeffrey M.

    2002-01-01

    Gene therapy is proving likely to be a viable alternative to conventional therapies in coronary artery disease and heart failure. Phase 1 clinical trials indicate high levels of safety and clinical benefits with gene therapy using angiogenic growth factors in myocardial ischaemia. Although gene therapy for heart failure is still at the pre-clinical stage, experimental data indicate that therapeutic angiogenesis using short-term gene expression may elicit functional improvement in affected individuals.

  18. Measurements of myocardial flow vs. extraction of rubidium under varying physiological conditions

    SciTech Connect

    Budinger, T.F.; Yano, Y.; Moyer, B.R.; Twitchell, J.A.; Brennan, K.M.; Huesman, R.H.

    1984-01-01

    The relationship between myocardial rubidium extraction (E) and flow (F) are well described by the single capillary model E = (1-exp(-PS/F)) with a permeability surface product PS = 0.87 cc/min/gm. Some effects of alkalosis and acidosis have been reported. Here the authors investigate the effects of dipyridamole, norepinephrine-atropine, exsanguination, pacing, ouabain and calcium on extraction using Rb-82 PET and Rb-86 acute studies with microspheres in dogs. Thoracotomies were performed for left atrial microsphere infusion. Anesthesia was by N/sub 2/O and methoxyflurane. The degree of exsanguination, drug levels administered and pacing rates were sufficient to produce flow modifications. Extraction was calculated by dividing FE from Rb observations by F from microsphere data. These results of extraction vs. flow do not show a significant dependence on the method used for flow modification. There was less than a 20% change in FE after an infusion of 0.04 mg/kg ouabain over 5 minutes in 3 replicate studies each on 4 dogs. An important finding not previously explained in flow vs. extraction studies is the occurrence of extraction values greater than 1.0 which is possible only if the distribution opportunities of small cations are greater than that of microspheres. This is equivalent to the well known hematocrit effect in small channels.

  19. Myocardial Tagging With SSFP

    PubMed Central

    Herzka, Daniel A.; Guttman, Michael A.; McVeigh, Elliot R.

    2007-01-01

    This work presents the first implementation of myocardial tagging with refocused steady-state free precession (SSFP) and magnetization preparation. The combination of myocardial tagging (a noninvasive method for quantitative measurement of regional and global cardiac function) with the high tissue signal-to-noise ratio (SNR) obtained with SSFP is shown to yield improvements in terms of the myocardium–tag contrast-to-noise ratio (CNR) and tag persistence when compared to the current standard fast gradient-echo (FGRE) tagging protocol. Myocardium–tag CNR and tag persistence were studied using numerical simulations as well as phantom and human experiments. Both quantities were found to decrease with increasing imaging flip angle (α) due to an increased tag decay rate and a decrease in myocardial steady-state signal. However, higher α yielded better blood–myocardium contrast, indicating that optimal α is dependent on the application: higher α for better blood–myocardium boundary visualization, and lower α for better tag persistence. SSFP tagging provided the same myocardium–tag CNR as FGRE tagging when acquired at four times the bandwidth and better tag– and blood–myocardium CNRs than FGRE tagging when acquired at equal or twice the receiver bandwidth (RBW). The increased acquisition efficiency of SSFP allowed decreases in breath-hold duration, or increases in temporal resolution, as compared to FGRE. PMID:12541254

  20. Perioperative myocardial infarction in patients undergoing myocardial revascularization surgery

    PubMed Central

    Pretto, Pericles; Martins, Gerez Fernandes; Biscaro, Andressa; Kruczan, Dany David; Jessen, Barbara

    2015-01-01

    Introduction Perioperative myocardial infarction adversely affects the prognosis of patients undergoing coronary artery bypass graft and its diagnosis was hampered by numerous difficulties, because the pathophysiology is different from the traditional instability atherosclerotic and the clinical difficulty to be characterized. Objective To identify the frequency of perioperative myocardial infarction and its outcome in patients undergoing coronary artery bypass graft. Methods Retrospective cohort study performed in a tertiary hospital specialized in cardiology, from May 01, 2011 to April 30, 2012, which included all records containing coronary artery bypass graft records. To confirm the diagnosis of perioperative myocardial infarction criteria, the Third Universal Definition of Myocardial Infarction was used. Results We analyzed 116 cases. Perioperative myocardial infarction was diagnosed in 28 patients (24.1%). Number of grafts and use and cardiopulmonary bypass time were associated with this diagnosis and the mean age was significantly higher in this group. The diagnostic criteria elevated troponin I, which was positive in 99.1% of cases regardless of diagnosis of perioperative myocardial infarction. No significant difference was found between length of hospital stay and intensive care unit in patients with and without this complication, however patients with perioperative myocardial infarction progressed with worse left ventricular function and more death cases. Conclusion The frequency of perioperative myocardial infarction found in this study was considered high and as a consequence the same observed average higher troponin I, more cases of worsening left ventricular function and death. PMID:25859867

  1. Reproducibility of measurements of regional resting and hyperemic myocardial blood flow assessed with PET

    SciTech Connect

    Nagamachi, S.; Czernin, J.; Kim, A.S.

    1996-10-01

    PET with {sup 13}N-ammonia permits the noninvasive quantification of myocardial blood flow (MBF) in humans. The present study was done to assess the reproducibility of quantitative blood flow measurements at rest and during pharmacologically induced hyperemia in healthy individuals. Thirty healthy volunteers (26 men, 4 women) were studied. Paired measurements of MBF at rest (n = 21), during adenosine (n = 15) and during dipyridamole (n = 7) were performed using a two-compartment model for {sup 13}N-ammonia PET. The mean difference between baseline and follow-up blood flow (% difference) was calculated to assess reproducibility. No significant difference was observed between resting blood flow at baseline or follow-up (15.8% {plus_minus} 15.8%; p = ns). Baseline and follow-up resting blood flow were linearly correlated (r = 0.63, p < 0.005). Normalization of resting blood flow to the rate pressure product improved the reproducibility significantly (15.8% {plus_minus} 15.8% versus 10.1% {plus_minus} 10.5%, p < 0.05). Baseline and follow-up hyperemic myocardial blood flow did not differ (11.8% {plus_minus} 9.4%; p = ns) and were linearly correlated (r = 0.69, p < 0.0005). MBF at rest can be measured reproducibly with {sup 13}N-ammonia PET. The individual response to pharmacologic stress appears to be relatively consistent. Thus, serial blood flow measurements with {sup 13}N-ammonia PET can be used to quantify the effect of various interventions on MBF and vasodilatory reserve. 41 refs., 3 figs., 4 tabs.

  2. Noninvasive assessment of coronary stenoses by myocardial perfusion imaging during pharmacologic coronary vasodilation. VIII. Clinical feasibility of positron cardiac imaging without a cyclotron using generator-produced rubidium-82

    SciTech Connect

    Gould, K.L.; Goldstein, R.A.; Mullani, N.A.; Kirkeeide, R.L.; Wong, W.H.; Tewson, T.J.; Berridge, M.S.; Bolomey, L.A.; Hartz, R.K.; Smalling, R.W.

    1986-04-01

    The purpose of this study was to determine the clinical feasibility of diagnosing significant coronary artery disease by positron imaging of myocardial perfusion without a cyclotron, using generator-produced rubidium-82 (/sup 82/Rb). Fifty patients underwent positron emission tomography of the entire heart using a multislice positron camera and intravenous /sup 82/Rb or nitrogen-13 ammonia (/sup 13/NH/sub 3/) before and after intravenous dipyridamole combined with handgrip stress. Images were read by two observers blinded as to clinical or arteriographic data. Automated quantitative coronary arteriography was obtained for the arteriographic determination of coronary flow reserve, previously demonstrated to be a single integrated measure of stenosis severity accounting for all its geometric dimensions of length, absolute diameter, percent narrowing and asymmetry by quantitative analysis of cine films. Significant coronary artery disease was defined as an arteriographically determined coronary flow reserve of less than 3.0 based on all stenosis dimensions. Any single geometric measure of stenosis severity alone was an inadequate reference standard for comparison with perfusion images. Sensitivity of identifying patients with coronary artery disease having an arteriographically determined coronary flow reserve of less than 3.0 was 95% by positron imaging with a specificity of 100%. The single case that was missed, studied with /sup 13/NH/sub 3/, had a 43% diameter narrowing of a small ramus intermedius off the left coronary artery with no significant narrowing of the major coronary arteries. Positron emission tomography of myocardial perfusion before and after intravenous dipyridamole combined with handgrip stress utilizing generator-produced /sup 82/Rb provides sensitive and specific diagnosis of reduced coronary flow reserve due to coronary artery disease in humans.

  3. Myocardial fibre calcification.

    PubMed Central

    McClure, J; Pieterse, A S; Pounder, D J; Smith, P S

    1981-01-01

    Three cases of myocardial fibre calcification found at post-mortem examination are described. In one case there was antemortem hypercalcaemia and hyperphosphataemia and the case was clearly an example of metastatic calcification. In the other two cases there was ischaemic myocardial necrosis and calcification was seen in fibres which were not overtly necrotic, but which were both in proximity to (the majority) and remote from the necrotic zones. Since renal failure with hyperphosphataemia was present in both cases, these were considered to be examples of augmented (by the hyperphosphataemia) dystrophic calcification. The histological, histochemical and ultrastructural features were identical in the three cases. Hydroxyapatite formation was observed initially in mitochondria, followed by spillage of crystals into the cytosol and ultimately into the interstitium. It is suggested that the fundamental lesion is a dysfunction of the fibre membrane; the similarity of this reaction with the calcification seen in skeletal muscle fibres in various myopathies is noted and a unifying hypothesis of the mechanism of skeletal and cardiac muscle fibre calcification is thereby suggested. Images PMID:7309897

  4. 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

  5. Trauma induced myocardial infarction.

    PubMed

    Lolay, Georges A; Abdel-Latif, Ahmed K

    2016-01-15

    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.

  6. [Ischemia-reperfusion myocardial injury].

    PubMed

    de Micheli, Alfredo; Chávez, Edmundo

    2003-01-01

    In this article, we present some considerations on the myocardial damage due to a deficit of oxygen supply. In fact, this damage properly constitutes a partial diastolic depolarization or injury, i.e., a moderate reduction of the rest transmembrane potential. This phenomenon is characteristic of the acute phase of the myocardial infarction syndrome and is responsible for the main electrical manifestations appearing in this phase: disorders of rhythm and conduction, as well as a reduced contractility of the involved myocardial fibers. All the mentioned phenomena are due to a defect of the myocardial energetic mechanisms, owing to the mitochondrial alterations in myocytes: early reduction of the nicotinamide adenine nucleotides, accumulation of calcium ("calcium overload") into mitochondria, and a drop in oxidative phosphorylation. These changes can present again, more exaggerated, in a following phase of evolution of the myocardial infarction due to myocardial reperfusion. Its severity is related to the duration of the initial ischemia period. Moreover, consequences of the oxidative stress can add producing cellular damage by liberation of reactive oxygen species. Oxidant stress causes also alterations in the mitochondrial DNA, i.e., mutations due to oxidation of nitrogenous bases. During the initial ischemia phase, as well as during reperfusion, metabolic therapy can be very useful as, for example, glucose-insulin-potassium solutions (G-I-K). These could act as scavengers of the free radicals derived from oxygen and avoid or reduce the myocardial damage due to reperfused myocytes. Metabolic drugs, as for example trimetazidine, antioxidants, etc, can also be used in the myocardial reperfusion phase.

  7. Radioprotective efficacy of dipyridamole and AMP combination in fractionated radiation regimen, and its dependence on the time of administration of the drugs prior to irradiation.

    PubMed

    Hofer, M; Pospísil, M; Netíková, J; Znojil, V; Vácha, J; Holá, J

    1995-01-01

    We have recently demonstrated that the combined administration of dipyridamole and adenosine monophospate to mice induces radioprotective effects in terms of postirradiation haemopoietic recovery in animals irradiated with a single dose. The aim of the present experiments was to investigate the radioprotective ability of the drug combination under conditions of fractionated radiation treatment. It has been shown that administration of drugs either 15 or 60 min before each of the five daily 3-Gy doses of gamma-radiation enhances haemopoietic recovery and survival of mice exposed to an additional "top-up" dose of 3.5 Gy. Furthermore, it has been ascertained that the regimen using administration of the drugs 60 min prior to irradiation is more effective than administration of the drugs 15 min prior to irradiation. Due to the evidence that administration of the drugs 15 min prior to irradiation protects the organism mainly via mechanisms of systemic hypoxia while the pretreatment 60 min before irradiation avoids the role of hypoxia and mainly induces cell proliferation effects, our results suggest a more effective protective role of mechanisms stimulating haemopoiesis under conditions of fractionated radiation. The data may provide a basis for more rational use of radioprotection in fractionated radiation regimens.

  8. Rat myocardial protein degradation.

    PubMed

    Steer, J H; Hopkins, B E

    1981-07-01

    1. Myocardial protein degradation rates were determined by following tyrosine release from rat isolated left hemi-atria in vitro. 2. After two 20 min preincubations the rate of tyrosine release from hemi-atria was constant for 4 h. 3. Skeletal muscle protein degradation was determined by following tyrosine release from rat isolated hemi-diaphragm (Fulks, Li & Goldberg, 1975). 4. Insulin (10(-7) M) inhibited tyrosine release from hemi-atria and hemi-diaphragm to a similar extent. A 48 h fast increased tyrosine release rate from hemi-diaphragm and decreased tyrosine release rate from hemi-atria. Hemi-diaphragm tyrosine release was inhibited by 15 mmol/l D-glucose but a variety of concentrations of D-glucose (0, 5, 15 mmol/l) had no effect on tyrosine release from hemi-atria. Five times the normal plasma levels of the branched-chain amino acids leucine, isoleucine and valine had no effect on tyrosine release from either hemi-atria or hemi-diaphragm.

  9. Myocardial mechanics in cardiomyopathies.

    PubMed

    Modesto, Karen; Sengupta, Partho P

    2014-01-01

    Cardiomyopathies are a heterogeneous group of diseases that can be phenotypically recognized by specific patterns of ventricular morphology and function. The authors summarize recent clinical observations that mechanistically link the multidirectional components of left ventricular (LV) deformation with morphological phenotypes of cardiomyopathies for offering key insights into the transmural heterogeneity of myocardial function. Subendocardial dysfunction predominantly alters LV longitudinal shortening, lengthening and suction performance and contributes to the phenotypic patterns of heart failure (HF) with preserved ejection fraction (EF) seen with hypertrophic and restrictive patterns of cardiomyopathy. On the other hand, a more progressive transmural disease results in reduction of LV circumferential and twist mechanics leading to the phenotypic pattern of dilated cardiomyopathy and the clinical syndrome of HF with reduced (EF). A proper characterization of LV transmural mechanics, energetics, and space-time distributions of pressure and shear stress may allow recognition of early functional changes that can forecast progression or reversal of LV remodeling. Furthermore, the interactions between LV muscle and fluid mechanics hold the promise for offering newer mechanistic insights and tracking impact of novel therapies.

  10. A comparison of the overall first-pass kinetics of thallium-201 and technetium-99m MIBI in normoxic and low-flow ischaemic myocardium.

    PubMed

    Ayalew, A; Marie, P Y; Menu, P; Mertes, P M; Hassan, N; Danchin, N; Olivier, P; Karcher, G; Bertrand, A

    2000-11-01

    The specific impact of ischaemia on the myocardial kinetics of thallium-201 and technetium-99m 2-methoxy-2-isobutylisonitrile (MIBI) remains a matter of debate. Using an isolated heart model perfused with red blood cell-enhanced perfusate, we compared the overall first-pass kinetics of 201Tl and MIBI under haemodynamically stable conditions of low-flow ischaemia (> 50% reduction in normal coronary flow and a > or = 20 mmHg fall in systolic contraction pressure, n = 10) and normoxia (n = 11). For both 201Tl and MIBI, we found that under ischaemic conditions (as compared with normoxia) there was a higher initial net extraction fraction (201Tl: 0.78 +/- 0.03 vs 0.72 +/- 0.06, P = 0.006; MIBI: 0.49 +/- 0.10 vs 0.39 +/- 0.11, P = 0.03), a lower clearance rate in the 30 min following extraction (% decrease in cardiac uptake: 201Tl: 30 +/- 12 vs 47 +/- 14, P = 0.02; MIBI: 5 +/- 5 vs 13 +/- 11, P = 0.02) and a higher retention fraction at 30 min (20lTl: 0.54 +/- 0.10 vs 0.39 +/- 0.12, P = 0.004; MIBI: 0.46 +/- 0.08 vs 0.33 +/- 0.12, P = 0.01). Multivariate analyses, however, revealed that all myocardial kinetic parameters of both tracers were dependent only on coronary flow rates, without any additional significant impact of the presence of ischaemia or states of contractility or oxidative metabolism. We conclude that the myocardial fractional retention of both 201Tl and MIBI is strongly correlated with the decrease in coronary flow during ischaemia. This inverse relationship with coronary flow derives from both the flow-dependent increase in the initial myocardial extraction and the decrease in the subsequent myocardial washout of the tracers.

  11. 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.

  12. 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

  13. Myocardial contusion caused by a baseball.

    PubMed

    Morikawa, M; Hirose, K; Mori, T; Kusukawa, J; Tomioka, N; Watanabe, Y

    1996-10-01

    Myocardial contusion is a rare type of sports injury. We report a case of myocardial contusion caused by a baseball. In this patient, arrhythmias were induced by an exercise test 1 week after injury. That patients with myocardial contusion but without arrhythmias at rest need to be treated carefully is emphasized.

  14. Myocardial blood flow assessment with 82rubidium-PET imaging in patients with left bundle branch block

    PubMed Central

    Falcão, Andréa; Chalela, William; Giorgi, Maria Clementina; Imada, Rodrigo; Soares, José; Do Val, Renata; Oliveira, Marco Antonio; Izaki, Marisa; Filho, Roberto Kalil; Meneghetti, José C

    2015-01-01

    OBJECTIVES: Perfusion abnormalities are frequently seen in Single Photon Emission Computed Tomography (SPECT) when a left bundle branch block is present. A few studies have shown decreased coronary flow reserve in the left anterior descending territory, regardless of the presence of coronary artery disease. OBJECTIVE: We sought to investigate rubidium-82 (82Rb) positron emission tomography imaging in the assessment of myocardial blood flow and coronary flow reserve in patients with left bundle branch block. METHODS: Thirty-eight patients with left bundle branch block (GI), median age 63.5 years, 22 (58%) female, 12 with coronary artery disease (≥70%; GI-A) and 26 with no evidence of significant coronary artery disease (GI-B), underwent rest-dipyridamole stress 82Rb-positron emission tomography with absolute quantitative flow measurements using Cedars-Sinai software (mL/min/g). The relative myocardial perfusion and left ventricular ejection fraction were assessed in 17 segments. These parameters were compared with those obtained from 30 patients with normal 82Rb-positron emission tomography studies and without left bundle branch block (GII). RESULTS: Stress myocardial blood flow and coronary flow reserve were significantly lower in GI than in GII (p<0.05). The comparison of coronary flow reserve between GI-A and GI-B showed that it was different from the global coronary flow reserve (p<0.05) and the stress flow was significantly lower in the anterior than in the septal wall for both groups. Perfusion abnormalities were more prevalent in GI-A (p=0.06) and the left ventricular ejection fraction was not different between GI-A and GI-B, whereas it was lower in GI than in GII (p<0.001). CONCLUSION: The data confirm that patients with left bundle branch block had decreased myocardial blood flow and coronary flow reserve and coronary flow reserve assessed by 82Rb-positron emission tomography imaging may be useful in identifying coronary artery disease in patients with

  15. Morphological aspects of myocardial bridges.

    PubMed

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

    2013-11-01

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

  16. Acute myocardial infarction in rats.

    PubMed

    Wu, Yewen; Yin, Xing; Wijaya, Cori; Huang, Ming-He; McConnell, Bradley K

    2011-01-01

    With heart failure leading the cause of death in the USA (Hunt), biomedical research is fundamental to advance medical treatments for cardiovascular diseases. Animal models that mimic human cardiac disease, such as myocardial infarction (MI) and ischemia-reperfusion (IR) that induces heart failure as well as pressure-overload (transverse aortic constriction) that induces cardiac hypertrophy and heart failure (Goldman and Tarnavski), are useful models to study cardiovascular disease. In particular, myocardial ischemia (MI) is a leading cause for cardiovascular morbidity and mortality despite controlling certain risk factors such as arteriosclerosis and treatments via surgical intervention (Thygesen). Furthermore, an acute loss of the myocardium following myocardial ischemia (MI) results in increased loading conditions that induces ventricular remodeling of the infarcted border zone and the remote non-infarcted myocardium. Myocyte apoptosis, necrosis and the resultant increased hemodynamic load activate multiple biochemical intracellular signaling that initiates LV dilatation, hypertrophy, ventricular shape distortion, and collagen scar formation. This pathological remodeling and failure to normalize the increased wall stresses results in progressive dilatation, recruitment of the border zone myocardium into the scar, and eventually deterioration in myocardial contractile function (i.e. heart failure). The progression of LV dysfunction and heart failure in rats is similar to that observed in patients who sustain a large myocardial infarction, survive and subsequently develops heart failure (Goldman). The acute myocardial infarction (AMI) model in rats has been used to mimic human cardiovascular disease; specifically used to study cardiac signaling mechanisms associated with heart failure as well as to assess the contribution of therapeutic strategies for the treatment of heart failure. The method described in this report is the rat model of acute myocardial

  17. 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.

  18. Dobutamine echocardiography and thallium-201 imaging predict functional improvement after revascularisation in severe ischaemic left ventricular dysfunction.

    PubMed Central

    Senior, R.; Glenville, B.; Basu, S.; Sridhara, B. S.; Anagnostou, E.; Stanbridge, R.; Edmondson, S. J.; Handler, C. E.; Raftery, E. B.; Lahiri, A.

    1995-01-01

    OBJECTIVES--To evaluate the concordance between thallium-201 uptake and echocardiographic wall thickening, which are both indicators of potentially reversible myocardial dysfunction, in patients with chronic ischaemic left ventricular failure and to assess their relative contribution to predicting improvement in regional function after revascularisation in a subgroup. PATIENTS AND METHODS--45 patients with chronic ischaemic left ventricular dysfunction (mean (SD) ejection fraction 25 (8)%) underwent echocardiography before and after dobutamine infusion (10 micrograms/kg/min). Of these, 22 patients underwent rest echocardiography at a mean (SD) of 9 (1) weeks after revascularisation. 201Tl imaging was performed during dobutamine echocardiography and at rest, 1, and 4 h after treatment with sublingual glyceryl trinitrate on two separate days. Potentially reversible dysfunction was thought to be present when a myocardial segment contained a Tl score of > or = 3 (ascending score 1-4), or showed improved wall thickening of a dysynergic segment during dobutamine stimulation. RESULTS--Of the 201Tl protocols, the redistribution scan 1 h after treatment with glyceryl trinitrate best demonstrated myocardial viability. Concordance between 201Tl and dobutamine induced wall thickening was 82% (kappa = 0.59) for detecting potentially reversible myocardial dysfunction before revascularisation (n = 45). Regional function improved in 18 of 22 patients after revascularisation. There were 168 dysynergic segments before intervention. The sensitivity of echocardiography and 201Tl imaging for detecting "recoverable" or viable segments after revascularisation was 87% and 92% respectively and specificity was 82% and 78% respectively (P = NS). CONCLUSIONS--Dobutamine echocardiography and 201Tl imaging may be used to predict mechanical improvement in dysynergic segments after revascularisation in patients with chronic ischaemic left ventricular dysfunction. Images PMID:7488446

  19. 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.

  20. Myocardial revascularization in Jehovah Witnesses.

    PubMed

    Seifert, P E; Auer, J E; Hohensee, P

    1989-04-01

    The refusal of certain patients to accept blood transfusions need not be a deterrent to surgery. We report on nine Jehovah's Witnesses who over a one-year period underwent myocardial revascularization without significant blood loss or decrease in hematocrit values. PMID:2786287

  1. [Myocardial infarction in young population].

    PubMed

    Shklovskii, B L; Prokhorchik, A A; Koltunov, A N; Lishchuk, A N; Ryzhman, N N; Ivanov, A V; Navaznov, V V; Baksheev, V I

    2015-03-01

    Description of clinical observation and literature review. Myocardial infarction in patients younger than 45 years is rare, but it is an important clinical, organizational and psychological problem. A case of myocardial infarction in 19-years old patient, who suffered since 6 years from kidney disease, is described. Transmural left-ventricular myocardial infarction has developed on the background of chronic glomerulonephritis, excessive exercise, and traditional risk factors for cardiovascular disease. Coronary venous bypass with the benefit-pleasing outcome is performed. When analysing the literature, the authors emphasize that in comparison with elderly patients, young people have different profiles of risk factors, clinical manfestations and prognosis of myocardial infarction. It is emphasized that kidney chronic disease, regardless the stage, worsen short-term and long-term outcomes of cardiovascular disease. Early stabilization is possible under the condition of risk stratification and-early revascularization, which leads to better clinical outcomes. Particular attention should be given to a comprehensive assessment, it prognostic criteria, risk factor modification, secondary prevention of major and associated diseases, clinical- and -dynamic observation, including patients with asymptomatic course of the disease.

  2. 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…

  3. Myocardial infarction following sternal surgery.

    PubMed Central

    Aggarwal, R. K.; Morrison, W. L.

    1996-01-01

    We report a case of myocardial infarction in a 32-year-old man undergoing sternal surgery. Thrombotic occlusion of the right coronary artery with no underlying atheromatous disease was demonstrated angiographically and successfully treated with intracoronary thrombolysis. Images Figure 1 Figure 2 PMID:8796219

  4. Biochemical Markers of Myocardial Damage

    PubMed Central

    2016-01-01

    Heart diseases, especially coronary artery diseases (CAD), are the leading causes of morbidity and mortality in developed countries. Effective therapy is available to ensure patient survival and to prevent long term sequelae after an acute ischemic event caused by CAD, but appropriate therapy requires rapid and accurate diagnosis. Research into the pathology of CAD have demonstrated the usefulness of measuring concentrations of chemicals released from the injured cardiac muscle can aid the diagnosis of diseases caused by myocardial ischemia. Since the mid-1950s successively better biochemical markers have been described in research publications and applied for the clinical diagnosis of acute ischemic myocardial injury. Aspartate aminotransferase of the 1950s was replaced by other cytosolic enzymes such as lactate dehydrogenase, creatine kinase and their isoenzymes that exhibited better cardiac specificity. With the availability of immunoassays, other muscle proteins, that had no enzymatic activity, were also added to the diagnostic arsenal but their limited tissue specificity and sensitivity lead to suboptimal diagnostic performance. After the discovery that cardiac troponins I and T have the desired specificity, they have replaced the cytosolic enzymes in the role of diagnosing myocardial ischemia and infarction. The use of the troponins provided new knowledge that led to revision and redefinition of ischemic myocardial injury as well as the introduction of biochemicals for estimation of the probability of future ischemic myocardial events. These markers, known as cardiac risk markers, evolved from the diagnostic markers such as CK-MB or troponins, but markers of inflammation also belong to these groups of diagnostic chemicals. This review article presents a brief summary of the most significant developments in the field of biochemical markers of cardiac injury and summarizes the most recent significant recommendations regarding the use of the cardiac markers in

  5. Myocardial disarray. A critical review.

    PubMed Central

    Becker, A E; Caruso, G

    1982-01-01

    Myocardial disarray or disorganisation is at present a contentious topic, not least because its value as a clinical marker for hypertrophic cardiomyopathy has changed considerably over the years. Initially observed as one of the features of asymmetric septal hypertrophy, disarray has since been promoted as its pathognomonic histological feature, regarded by some observers as the morphological manifestation of a genetically transmitted myocardial defect. Recently, however, it has become evident that myocardial disarray is not limited to hypertrophic cardiomyopathy, but is encountered in hearts with both congenital and acquired conditions, and is also observed in normal hearts. The specificity of disarray for hypertrophic cardiomyopathy is thus seriously questioned. Latterly, it has been suggested that disarray, judged from through-and-through sections of the ventricular midseptum is a highly specific and sensitive marker of hypertrophic cardiomyopathy when considered in quantitative rather than qualitative fashion. The present study sets out to answer the question whether disarray could be the histological expression of the normal but intricate fibre architecture of the heart, a consideration also initiated by debatable definitions of normality and abnormality of myocardial histology. Gross fibre dissections in five normal hearts showed that many sites occurred in which disarray was a natural phenomenon. In five more hearts it was found that the plane of section of a tissue block might profoundly influence the histology. In fact, tissue cubicles sampled from different faces showed a change in histology in the vast majority. Thus the diagnostic significance of myocardial disarray as a marker of hypertrophic cardiomyopathy in the clinical setting almost vanishes; a change in orientation of a tissue section may actually turn "normality" into "disarray". Images PMID:7044398

  6. Biochemical Markers of Myocardial Damage.

    PubMed

    Bodor, Geza S

    2016-04-01

    Heart diseases, especially coronary artery diseases (CAD), are the leading causes of morbidity and mortality in developed countries. Effective therapy is available to ensure patient survival and to prevent long term sequelae after an acute ischemic event caused by CAD, but appropriate therapy requires rapid and accurate diagnosis. Research into the pathology of CAD have demonstrated the usefulness of measuring concentrations of chemicals released from the injured cardiac muscle can aid the diagnosis of diseases caused by myocardial ischemia. Since the mid-1950s successively better biochemical markers have been described in research publications and applied for the clinical diagnosis of acute ischemic myocardial injury. Aspartate aminotransferase of the 1950s was replaced by other cytosolic enzymes such as lactate dehydrogenase, creatine kinase and their isoenzymes that exhibited better cardiac specificity. With the availability of immunoassays, other muscle proteins, that had no enzymatic activity, were also added to the diagnostic arsenal but their limited tissue specificity and sensitivity lead to suboptimal diagnostic performance. After the discovery that cardiac troponins I and T have the desired specificity, they have replaced the cytosolic enzymes in the role of diagnosing myocardial ischemia and infarction. The use of the troponins provided new knowledge that led to revision and redefinition of ischemic myocardial injury as well as the introduction of biochemicals for estimation of the probability of future ischemic myocardial events. These markers, known as cardiac risk markers, evolved from the diagnostic markers such as CK-MB or troponins, but markers of inflammation also belong to these groups of diagnostic chemicals. This review article presents a brief summary of the most significant developments in the field of biochemical markers of cardiac injury and summarizes the most recent significant recommendations regarding the use of the cardiac markers in

  7. Myocardial viability in patients with chronic coronary artery disease and previous myocardial infarction: comparison of myocardial contrast echocardiography and myocardial perfusion scintigraphy.

    PubMed

    Vernon, S; Kaul, S; Powers, E R; Camarano, G; Gimple, L W; Ragosta, M

    1997-11-01

    The aim of this study was to compare perfusion patterns on myocardial contrast echocardiography with those on myocardial perfusion scintigraphy for the assessment of myocardial viability in patients with previous myocardial infarction. Accordingly, perfusion scores with the two techniques were compared in 91 ventricular regions in 21 patients with previous (>6 weeks old) myocardial infarction. Complete concordance between the two techniques was found in 63 (69%) regions; 25 (27%) regions were discordant by only 1 grade, and complete discordance (2 grades) was found in only 3 (3%) regions. A kappa statistic of 0.65 indicated good concordance between the two techniques. Although the scores on both techniques demonstrated a relation with the wall motion score, the correlation between the myocardial contrast echocardiography and wall motion scores was closer (r = -0.63 vs r = -0.50, p = 0.05). It is concluded that myocardial contrast echocardiography provides similar information regarding myocardial viability as myocardial perfusion scintigraphy in patients with coronary artery disease and previous myocardial infarction.

  8. Positron Emission Tomography for the Assessment of Myocardial Viability

    PubMed Central

    2010-01-01

    , harmonic imaging, and power doppler imaging may help to improve the diagnostic accuracy of echocardiographic assessment of myocardial viability. Stress Echocardiography with Contrast Intravenous contrast agents, which are high molecular weight inert gas microbubbles that act like red blood cells in the vascular space, can be used during echocardiography to assess myocardial viability. These agents allow for the assessment of myocardial blood flow (perfusion) and contractile function (as described above), as well as the simultaneous assessment of perfusion to make it possible to distinguish between stunned and hibernating myocardium. SPECT SPECT can be performed using thallium-201 (Tl-201), a potassium analogue, or technetium-99 m labelled tracers. When Tl-201 is injected intravenously into a patient, it is taken up by the myocardial cells through regional perfusion, and Tl-201 is retained in the cell due to sodium/potassium ATPase pumps in the myocyte membrane. The stress-redistribution-reinjection protocol involves three sets of images. The first two image sets (taken immediately after stress and then three to four hours after stress) identify perfusion defects that may represent scar tissue or viable tissue that is severely hypoperfused. The third set of images is taken a few minutes after the re-injection of Tl-201 and after the second set of images is completed. These re-injection images identify viable tissue if the defects exhibit significant fill-in (> 10% increase in tracer uptake) on the re-injection images. The other common Tl-201 viability imaging protocol, rest-redistribution, involves SPECT imaging performed at rest five minutes after Tl-201 is injected and again three to four hours later. Viable tissue is identified if the delayed images exhibit significant fill-in of defects identified in the initial scans (> 10% increase in uptake) or if defects are fixed but the tracer activity is greater than 50%. There are two technetium-99 m tracers: sestamibi (MIBI

  9. Chasing myocardial outcomes: perioperative myocardial infarction and cardiac troponin.

    PubMed

    Royo, Marc B; Fleisher, Lee A

    2016-02-01

    Perioperative myocardial infarction represents the most common cardiovascular complication following non-cardiac surgery, but frequently presents without the usual clinical signs and symptoms consistent with acute coronary syndrome. Given the silent nature of this event, a clinician's reliance on risk stratification tools and cardiac specific biomarkers to assist in the identification of at-risk individuals is heightened in the perioperative setting. Although cardiac troponin elevations following non-cardiac surgery have been consistently linked to increased mortality, uncertainty remains over how to clinically intervene to prevent harm. This decision is further complicated by the increasing sensitivity of the newest generation of cardiac biomarker immunoassays. In this narrative review, the growing body of evidence surrounding cardiac troponin elevations in the perioperative setting, how the evidence has been integrated into recent clinical practice guidelines, and its implications for the detection of perioperative myocardial infarction are discussed. PMID:26634279

  10. [Myocardial infarction caused by exertion].

    PubMed

    Bernard, F; Weber, S

    1997-01-01

    Myocardial infarction is the main cause of sudden death during physical exercise, particularly in subjects over 40 and may even occur in high-performance young athletes. Sports and physical activity have a beneficial effect in preventing cardiovascular diseases, but certain rules of prudence must be followed to avoid the risk of a severe coronary event. Myocardial infarction always occurs in particularly susceptible subjects with several risk factors, predominantly smoking, hypercholesterolemia, family history of atherosclerosis. Dietary factors, either before, during or after the exercise, are always found. Distribution of coronary lesions differs with age. Before 40 years, the coronary network is normal in 40% of the cases. The infarction is partially explained by platelet hyperaggregahility and coronary spasms at exercise or in the post-exercise period.

  11. 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

  12. Pharmacology of myocardial calcium-handling.

    PubMed

    Vogler, Julia; Eckardt, Lars

    2012-07-01

    Disturbed myocardial calcium (Ca(+)) handling is one of the pathophysiologic hallmarks of cardiovascular diseases such as congestive heart failure, cardiac hypertrophy, and certain types of tachyarrhythmias. Pharmacologic treatment of these diseases thus focuses on restoring myocardial Ca(2+) homeostasis by interacting with Ca(2+)-dependent signaling pathways. In this article, we review the currently used pharmacologic agents that are able to restore or maintain myocardial Ca(2+) homeostasis and their mechanism of action as well as emerging new substances.

  13. Tombstoning ST-Elevation Myocardial Infarction

    PubMed Central

    Balci, Bahattin

    2009-01-01

    Tombstoning ST elevation myocardial infarction can be described as a STEMI characterized by tombstoning ST-segment elevation. This myocardial infarction is associated with extensive myocardial damage, reduced left ventricle function, serious hospital complications and poor prognosis. Tombstoning ECG pattern is a notion beyond morphological difference and is associated with more serious clinical results. Despite the presence of a few reports on tombstoning ST elevation, there is no report which reviews STEMI demonstrating this electrocardiographic pattern. PMID:21037844

  14. Echocardiographic assessment of myocardial strain.

    PubMed

    Gorcsan, John; Tanaka, Hidekazu

    2011-09-27

    Echocardiographic strain imaging, also known as deformation imaging, has been developed as a means to objectively quantify regional myocardial function. First introduced as post-processing of tissue Doppler imaging velocity converted to strain and strain rate, strain imaging has more recently also been derived from digital speckle tracking analysis. Strain imaging has been used to gain greater understanding into the pathophysiology of cardiac ischemia and infarction, primary diseases of the myocardium, and the effects of valvular disease on myocardial function, and to advance our understanding of diastolic function. Strain imaging has also been used to quantify abnormalities in the timing of mechanical activation for heart failure patients undergoing cardiac resynchronization pacing therapy. Further advances, such as 3-dimensional speckle tracking strain imaging, have emerged to provide even greater insight. Strain imaging has become established as a robust research tool and has great potential to play many roles in routine clinical practice to advance the care of the cardiovascular patient. This perspective reviews the physiology of myocardial strain, the technical features of strain imaging using tissue Doppler imaging and speckle tracking, their strengths and weaknesses, and the state-of-the-art present and potential future clinical applications.

  15. 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

  16. Enhancement of low coronary reflow improves postischemic myocardial function.

    PubMed

    Amrani, M; Shirvani, R; Allen, N J; Ledingham, S; Yacoub, M H

    1992-11-01

    The effect of reperfusion coronary vasodilatation on postischemic myocardial mechanical function has been investigated in the isolated working rat heart. After a working period to assess control function, all the hearts were subjected to a single infusion (10 ml) of St. Thomas' Hospital cardioplegic solution No. 1 at 4 degrees C and were kept immersed in the same solution for 4 hours at 4 degrees C. Then hearts (six in each group) were initially reperfused at 37 degrees C for 10 minutes, either with ordinary reperfusate (Krebs-Henseleit bicarbonate buffer) or with reperfusate containing additional coronary dilator. After this period, all hearts were subjected to a further 5 minutes of ordinary reperfusate before being put back into the working mode to assess functional recovery. Mean reperfusion coronary flows and the steady coronary flow measured after 10 minutes of reperfusion in ml/min +/- SEM were--Krebs (control): 17.4 +/- 0.39 and 13.4 +/- 0.40; adenosine (3.75 mumol/L): 19.9 +/- 0.6 and 16.7 +/- 0.8; papaverine (0.05 mmol/L): 21.8 +/- 2.3 and 17.3 +/- 1.8; dipyridamole (2 mmol/L): 20.7 +/- 1.7 and 17.9 +/- 1.0; nitroglycerin (15 mg/L): 20.5 +/- 0.45 and 19.9 +/- 1.4; diltiazem (0.05 mmol/L): 19.6 +/- 2.98 and 17.7 +/- 1.8; calcitonin gene-related peptide (0.03 mmol/L): 20.8 +/- 0.69 and 18.0 +/- 1.3; 5-hydroxytryptamine (0.01 mmol/L): 19.2 +/- 0.53 and 16.9 +/- 0.80. Mean postischemic recovery of cardiac output, peak aortic pressure, and differentiation of pressure were expressed as percent of preischemic control +/- SEM were--Krebs: 54.1 +/- 2.8, 69.1 +/- 2.8, and 53.9 +/- 3.0; adenosine: 78.0 +/- 5.6, 89.5 +/- 2.9, and 69.1 +/- 1.9; papaverine: 81.8 +/- 3.9, 91.8 +/- 3.1, and 71.0 +/- 4.1; dipyrdamole: 67.3 +/- 3.3, 84.3 +/- 2.3, and 75.0 +/- 2.7; nitroglycerin: 83.1 +/- 4.8, 79.7 +/- 2.7, and 69.0 +/- 0.5; diltiazem: 76.5 +/- 3.7, 85.9 +/- 2.9, and 73.3 +/- 1.7; calcitonin gene-related peptide: 79.5 +/- 3.6, 90.0 +/- 4.9, and 75.4 +/- 3.9; 5

  17. Cocaine, a risk factor for myocardial infarction.

    PubMed

    Galasko, G I

    1997-06-01

    Cocaine usage goes back thousands of years, to the times of the Incas. Over the past 20 years, its use has increased dramatically, especially in America, and adverse cardiovascular reactions to the drug have begun to be reported. The first report of myocardial infarction temporally related to the recreational use of cocaine appeared in 1982. Since then, myocardial infarction has become recognized as the drug's most common cardiovascular consequence, with over 250 cases now documented in the literature. This review discusses the history of cocaine use, its pharmacology, the possible pathological mechanisms underlying the pathogenesis of myocardial ischaemia and infarction, and current ideas on the management of cocaine-induced myocardial infarction.

  18. Usefulness of MRI to demonstrate the mechanisms of myocardial ischemia in hypertrophic cardiomyopathy with myocardial bridge.

    PubMed

    Thomson, Vivien; Botnar, Rene; Croisille, Pierre

    2007-01-01

    We present a case of symptomatic primary hypertrophic cardiomyopathy (HCM) associated with myocardial bridging of the left anterior descending (LAD) artery and suspected ischemia that could be related either to LAD artery compression or to microvascular perfusion abnormalities. MRI demonstrated the morphological appearance of myocardial hypertrophy, and coronary MR angiography evidenced the myocardial bridge and its functional consequences with stress MR perfusion. In conclusion, as a non-invasive comprehensive imaging technique, MRI should be considered in identifying the mechanisms of myocardial ischemia in HCM with myocardial bridge. PMID:16888385

  19. A case of acute myocardial infarction due to coronary spasm in the myocardial bridge.

    PubMed

    Fujibayashi, Daisuke; Morino, Yoshihiro; Ikari, Yuji

    2008-07-01

    A 68-year-old Japanese man with acute inferior myocardial infarction underwent emergent coronary angiography which showed a myocardial bridge, but no coronary stenosis, at the infarctrelated artery. A spasm provocation test using intracoronary acetylcholine revealed a total occlusion due to severe spasm at the site of the myocardial bridge. Thus, the myocardial ischemia in this case was caused by the coronary spasm, but not by the limited flow due to the myocardial bridge. Although a beta-blocker is usually the appropriate drug, it should be avoided for coronary spasm. The spasm provocation test is useful to determine the type of medication needed for treatment.

  20. 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.

  1. Abnormal thallium 201 scintigraphy during low-dose vasopressin infusions

    SciTech Connect

    Davison, R.; Kaplan, K.; Bines, A.; Spies, S.; Reed, M.T.; Lesch, M.

    1986-12-01

    Thallium 201 (/sup 201/Tl) myocardial scans were obtained in 16 patients just prior to the discontinuation of a vasopressin infusion (.1 to .2 units/min) administered for the treatment of upper gastrointestinal bleeding. Repeat scintigraphy was performed two to three hours after the vasopressin was stopped. Eleven of the 16 patients (69 percent) demonstrated areas of decreased myocardial /sup 201/Tl uptake that resolved after the infusion was stopped. Heart rate-blood pressure product was significantly lower at the time of the second scan. Autopsies were secured in three of 11 scan-positive patients: one had severe coronary artery obstruction, one nonsignificant disease, and another had normal coronary arteries. Vasopressin, even at low doses, can induce abnormalities in myocardial perfusion that are probably mediated by a direct effect on the coronary circulation. They are usually not detectable by routine monitoring techniques and conceivably form the basis for the cardiovascular morbidity associated with the use of this agent.

  2. Apoptosis in myocardial ischaemia and infarction.

    PubMed

    Krijnen, P A J; Nijmeijer, R; Meijer, C J L M; Visser, C A; Hack, C E; Niessen, H W M

    2002-11-01

    Recent studies indicate that, in addition to necrosis, apoptosis also plays a role in the process of tissue damage after myocardial infarction, which has pathological and therapeutic implications. This review article will discuss studies in which the role and mechanisms of apoptosis in myocardial infarction were analysed in vivo and in vitro in humans and in animals.

  3. Dual isotope thallium and indium antimyosin SPECT imaging to identify acute infarct patients at further ischemic risk

    SciTech Connect

    Johnson, L.L.; Seldin, D.W.; Keller, A.M.; Wall, R.M.; Bhatia, K.; Bingham, C.O. III; Tresgallo, M.E. )

    1990-01-01

    Forty-two patients (28 men and 14 women) with acute myocardial infarction (35 Q, seven non-Q wave) were injected with 2.0 mCi indium 111-labeled antimyosin (AM) monoclonal antibody (111In AM) within 48 hours of the onset of chest pain. Forty-eight hours later (72-96 hours after onset of chest pain), patients were injected with 2.2 mCi thallium 201, and two sets of single-photon emission computed tomography (SPECT) images were obtained simultaneously using dual energy windows set for the 247 keV indium photopeak and the 70 keV thallium peak. Seventeen patients had repeat scans at 4 hours. 111In AM uptake and 201Tl defects were localized to one or more of 24 coronal and sagittal segments. Scans with only 201Tl defects and corresponding 111In AM uptake were classified as matches; scans with unmatched 201Tl defects in addition to matching regions corresponding to electrocardiographic infarct location were classified as mismatches; and scans with 201Tl and 111In AM uptake in the same segments were classified as overlap. Scan patterns were correlated with clinical evidence for residual ischemia occurring within 6 weeks of infarct and including infarct extension, recurrent angina, and positive predischarge low-level or 6-week symptom-limited stress tests and with coronary anatomy. Fourteen patients had only matching patterns (group 1), 23 had mismatches (group 2), and five had 201Tl-111In overlap as the predominant pattern. None of the patients in group 1 had previous myocardial infarction; in each, the matched area corresponded to the Q wave location on electrocardiogram, and none had further in-hospital ischemic events or positive stress tests.

  4. Myocardial protection with mild hypothermia.

    PubMed

    Tissier, Renaud; Ghaleh, Bijan; Cohen, Michael V; Downey, James M; Berdeaux, Alain

    2012-05-01

    Mild hypothermia, 32-35° C, is very potent at reducing myocardial infarct size in rabbits, dogs, sheep, pigs, and rats. The benefit is directly related to reduction in normothermic ischaemic time, supporting the relevance of early and rapid cooling. The cardioprotective effect of mild hypothermia is not limited to its recognized reduction of infarct size, but also results in conservation of post-ischaemic contractile function, prevention of no-reflow or microvascular obstruction, and ultimately attenuation of left ventricular remodelling. The mechanism of the anti-infarct effect does not appear to be related to diminished energy utilization and metabolic preservation, but rather to survival signalling that involves either the extracellular signal-regulated kinases and/or the Akt/phosphoinositide 3-kinase/mammalian target of rapamycin pathways. Initial clinical trials of hypothermia in patients with ST-segment elevation myocardial infarction were disappointing, probably because cooling was too slow to shorten normothermic ischaemic time appreciably. New approaches to more rapid cooling have recently been described and may soon be available for clinical use. Alternatively, it may be possible to pharmacologically mimic the protection provided by cooling soon after the onset of ischaemia with an activator of mild hypothermia signalling, e.g. extracellular signal-regulated kinase activator, that could be given by emergency medical personnel. Finally, the protection afforded by cooling can be added to that of pre- and post-conditioning because their mechanisms differ. Thus, myocardial salvage might be greatly increased by rapidly cooling patients as soon as possible and then giving a pharmacological post-conditioning agent immediately prior to reperfusion. PMID:22131353

  5. [ST myocardial infarction with spontaneous coronary reperfusion].

    PubMed

    Uriel, Nir; Moravsky, Gil; Blatt, Alex; Vered, Zvi; Krakover, Ricardo; Kaluski, Edo

    2006-05-01

    ST elevation myocardial infarction continues to be a major medical problem even in the beginning of the 21st century. Treatment guidelines for these patients are based on multiple randomized clinical trials. In order to minimize myocardial damage, early patency of the infarct relating artery must be accomplished. This is the major difference in the treatment strategy between ST elevation myocardial infarction and other acute coronary syndromes. Primary percutaneous coronary intervention and fibrinolysis are the two treatment modalities for achieving myocardial reperfusion. The subgroup of ST elevation myocardial infarction with spontaneous coronary artery reperfusion carries a more favorable prognosis. This review addresses the clinical characteristics, natural history, prognosis and treatment strategies for this group, with special emphasis on the optimal timing for revascularization, and the role of glycoprotein IIb/IIIa inhibitors.

  6. Ribose facilitates thallium-201 redistribution in patients with coronary artery disease

    SciTech Connect

    Perlmutter, N.S.; Wilson, R.A.; Angello, D.A.; Palac, R.T.; Lin, J.; Brown, B.G. )

    1991-02-01

    To investigate whether i.v. infusion of ribose, an adenine nucleotide precursor, postischemia facilitates thallium-201 (201Tl) redistribution and improves identification of ischemic myocardium in patients with coronary artery disease (CAD), 17 patients underwent two exercise 201Tl stress tests, performed 1-2 wk apart. After immediate postexercise planar imaging, patients received either i.v. ribose (3.3 mg/kg/min x 30 min) or saline as a control. Additional imaging was performed 1 and 4 hr postexercise. Reversible defects were identified by count-profile analysis. Significantly more (nearly twice as many) reversible 201Tl defects were identified on the post-ribose images compared to the post-saline (control) images at both 1 and 4 hr postexercise (p less than 0.001). Quantitative analyses of the coronary arteriogram was available in 13 patients and confirmed that the additional reversible defects were in myocardial regions supplied by stenosed arteries. We conclude that ribose appears to facilitate 201Tl redistribution in patients with CAD and enhances identification of ischemic myocardium.

  7. Macrophage Roles Following Myocardial Infarction

    PubMed Central

    Lambert, Jessica M.; Lopez, Elizabeth F.; Lindsey, Merry L.

    2010-01-01

    Following myocardial infarction (MI), circulating blood monocytes respond to chemotactic factors, migrate into the infarcted myocardium, and differentiate into macrophages. At the injury site, macrophages remove necrotic cardiac myocytes and apoptotic neutrophils; secrete cytokines, chemokines, and growth factors; and modulate phases of the angiogenic response. As such, the macrophage is a primary responder cell type that is involved in the regulation of post-MI wound healing at multiple levels. This review summarizes what is currently known about macrophage functions post-MI and borrows literature from other injury and inflammatory models to speculate on additional roles. Basic science and clinical avenues that remain to be explored are also discussed. PMID:18656272

  8. Solar activity and myocardial infarction.

    PubMed

    Szczeklik, E; Mergentaler, J; Kotlarek-Haus, S; Kuliszkiewicz-Janus, M; Kucharczyk, J; Janus, W

    1983-01-01

    The correlation between the incidence of myocardial infarction, sudden cardiac death, the solar activity and geomagnetism in the period 1969-1976 was studied, basing on Wrocław hospitals material registered according to WHO standards; sudden death was assumed when a person died within 24 hours after the onset of the disease. The highest number of infarctions and sudden deaths was detected for 1975, which coincided with the lowest solar activity, and the lowest one for the years 1969-1970 coinciding with the highest solar activity. Such an inverse, statistically significant correlation was not found to exist between the studied biological phenomena and geomagnetism. PMID:6851574

  9. Reversal of left ventricular “rigid body rotation” during dipyridamole-induced stress in a patient with stable angina: a case from the three-dimensional speckle tracking echocardiographic MAGYAR-Stress Study

    PubMed Central

    Szántó, Gyula; Kalapos, Anita; Domsik, Péter; Forster, Tamás

    2016-01-01

    The left ventricular (LV) twist is defined as the wringing motion of the heart around its long-axis in systole caused by oppositely directed counterclockwise apical and clockwise basal rotations resulted from the movement of two orthogonally oriented muscular bands. In some clinical circumstances, rotation at both basal and apical levels of the LV occurred in the same clockwise or counterclockwise direction during systole resulting the near absence of LV twist as called left ventricular “rigid body rotation” (LV-RBR). Hereby we present that LV-RBR normalization of LV rotational mechanics could be demonstrated at maximum hyperaemia during dipyridamole-induced stress by three-dimensional (3D) speckle tracking echocardiography in a patient with stable angina. PMID:27429914

  10. Synthesis, characterization and molecular modelling of a novel dipyridamole supramolecule - X-ray structure, quantum mechanics and molecular dynamics study to comprehend the hydrogen bond structure-activity relationship

    NASA Astrophysics Data System (ADS)

    Vepuri, Suresh B.; Devarajegowda, H. C.; Soliman, Mahmoud E.

    2016-02-01

    Hydrochloride salt formation for Active Pharmaceutical Ingredients (APIs) is the primary choice to impart aqueous solubility and to promote dissolution. Dipyridamole (DIP) is a cardiovascular drug which is practically insoluble in water. We discovered a new form of DIP called as dipyridamole hydrochloride trihydrate (DIPHT), which was prepared by an unusual method of reacting the DIP with hydrated hydrochloric acid (HCl) that was liberated in situ by the reaction of ferric chloride with water. The liberated HCl was consumed as reagent in situ by the scavenger (API) and was converted to a hydrochloride trihydrate. The product was characterized by FTIR, mass spectroscopy, PXRD and DSC. Supramolecular structure of this novel DIPHT was revealed by single crystal XRD. A sustained intramolecular hydrogen bond alliance was found in DIP and the DIPHT. Stability of this hydrogen bond was further evaluated by means of molecular modelling studies. We performed electron calculations using quantum mechanics (QM) on both the base and salt structures to compare their geometry and molecular orbital energy levels. Molecular Dynamics (MD) simulations were also conducted in explicit solvent models to provide more insights into the hydrogen bond strength and conformational preferences of the base and salt structure. Together with QM and MD, we were able to explain the influence of hydrogen bonds on proton uptake activity of DIP and stability of DIP and DIPHT. DIPHT which can dissolve faster than DIP in water may enhance the dissolution and bioavailability of the drug. As the current drug development research is shifting to repurpose the existing drugs in order to subside the untoward risks in new drug development, we believe that DIPHT with its intrinsic aqueous solubility could bring more application for DIP and generate interest within the pharmaceutical industry.

  11. Mechanics of the left ventricular myocardial interstitium: effects of acute and chronic myocardial edema.

    PubMed

    Desai, Ketaki V; Laine, Glen A; Stewart, Randolph H; Cox, Charles S; Quick, Christopher M; Allen, Steven J; Fischer, Uwe M

    2008-06-01

    Myocardial interstitial edema forms as a result of several disease states and clinical interventions. Acute myocardial interstitial edema is associated with compromised systolic and diastolic cardiac function and increased stiffness of the left ventricular chamber. Formation of chronic myocardial interstitial edema results in deposition of interstitial collagen, which causes interstitial fibrosis. To assess the effect of myocardial interstitial edema on the mechanical properties of the left ventricle and the myocardial interstitium, we induced acute and chronic interstitial edema in dogs. Acute myocardial edema was generated by coronary sinus pressure elevation, while chronic myocardial edema was generated by chronic pulmonary artery banding. The pressure-volume relationships of the left ventricular myocardial interstitium and left ventricular chamber for control animals were compared with acutely and chronically edematous animals. Collagen content of nonedematous and chronically edematous animals was also compared. Generating acute myocardial interstitial edema resulted in decreased left ventricular chamber compliance compared with nonedematous animals. With chronic edema, the primary form of collagen changed from type I to III. Left ventricular chamber compliance in animals made chronically edematous was significantly higher than nonedematous animals. The change in primary collagen type secondary to chronic left ventricular myocardial interstitial edema provides direct evidence for structural remodeling. The resulting functional adaptation allows the chronically edematous heart to maintain left ventricular chamber compliance when challenged with acute edema, thus preserving cardiac function over a wide range of interstitial fluid pressures. PMID:18375722

  12. Direct Evidence that Myocardial Insulin Resistance following Myocardial Ischemia Contributes to Post-Ischemic Heart Failure.

    PubMed

    Fu, Feng; Zhao, Kun; Li, Jia; Xu, Jie; Zhang, Yuan; Liu, Chengfeng; Yang, Weidong; Gao, Chao; Li, Jun; Zhang, Haifeng; Li, Yan; Cui, Qin; Wang, Haichang; Tao, Ling; Wang, Jing; Quon, Michael J; Gao, Feng

    2015-12-14

    A close link between heart failure (HF) and systemic insulin resistance has been well documented, whereas myocardial insulin resistance and its association with HF are inadequately investigated. This study aims to determine the role of myocardial insulin resistance in ischemic HF and its underlying mechanisms. Male Sprague-Dawley rats subjected to myocardial infarction (MI) developed progressive left ventricular dilation with dysfunction and HF at 4 wk post-MI. Of note, myocardial insulin sensitivity was decreased as early as 1 wk after MI, which was accompanied by increased production of myocardial TNF-α. Overexpression of TNF-α in heart mimicked impaired insulin signaling and cardiac dysfunction leading to HF observed after MI. Treatment of rats with a specific TNF-α inhibitor improved myocardial insulin signaling post-MI. Insulin treatment given immediately following MI suppressed myocardial TNF-α production and improved cardiac insulin sensitivity and opposed cardiac dysfunction/remodeling. Moreover, tamoxifen-induced cardiomyocyte-specific insulin receptor knockout mice exhibited aggravated post-ischemic ventricular remodeling and dysfunction compared with controls. In conclusion, MI induces myocardial insulin resistance (without systemic insulin resistance) mediated partly by ischemia-induced myocardial TNF-α overproduction and promotes the development of HF. Our findings underscore the direct and essential role of myocardial insulin signaling in protection against post-ischemic HF.

  13. Circadian influences on myocardial infarction

    PubMed Central

    Virag, Jitka A. I.; Lust, Robert M.

    2014-01-01

    Components of circadian rhythm maintenance, or “clock genes,” are endogenous entrainable oscillations of about 24 h that regulate biological processes and are found in the suprachaismatic nucleus (SCN) and many peripheral tissues, including the heart. They are influenced by external cues, or Zeitgebers, such as light and heat, and can influence such diverse phenomena as cytokine expression immune cells, metabolic activity of cardiac myocytes, and vasodilator regulation by vascular endothelial cells. While it is known that the central master clock in the SCN synchronizes peripheral physiologic rhythms, the mechanisms by which the information is transmitted are complex and may include hormonal, metabolic, and neuronal inputs. Whether circadian patterns are causally related to the observed periodicity of events, or whether they are simply epi-phenomena is not well established, but a few studies suggest that the circadian effects likely are real in their impact on myocardial infarct incidence. Cycle disturbances may be harbingers of predisposition and subsequent response to acute and chronic cardiac injury, and identifying the complex interactions of circadian rhythms and myocardial infarction may provide insights into possible preventative and therapeutic strategies for susceptible populations. PMID:25400588

  14. [Acute myocardial infarction during sport].

    PubMed

    Fujiwara, M; Asakuma, S; Nakamura, K; Nakamura, T; Yasutomi, N; Iwasaki, T

    1995-10-01

    Thirty patients with acute myocardial infarction which occurred during sport were investigated to identify the type of sport, prodromata, situations at the onset of disease, habit of exercise, preceding medical evaluation, coronary risk factors, and coronary angiographic findings. Infarction occurred during golf in 12 patients, bowling in 4, gateball in 4, jogging or running in 5, baseball in 2, and tennis or table tennis in 3. The majority of the patients were playing ball games. Twenty-seven patients were men (90%) and 3 were women (10%). All patients had played the same kind of sport for several years. Twenty-four patients had one or more coronary risk factors, and especially 18 patients smoked cigarettes. Nine patients had experienced anterior chest pain but only two patients had received medical evaluation. Coronary angiography was performed in 25 patients (83.3%), revealing single-vessel disease in 14, two-vessel disease in 6, three-vessel disease in 4, and disease of all left main coronary trunks in 1. The acute episode of infarction occurred mainly in spring or fall. Many patients with acute myocardial infarction occurring during sport participate in sports of low or moderate dynamic and low static exercises which are generally regarded safe. Many patients had enjoyed their sports regularly for a long time. Though many patients had coronary risk factors, only a few had received a medical check before their heart attack.

  15. Use of thallium 201 myocardial imaging to exclude myocardial infarction after dissection in congenital coarctation of the aorta

    SciTech Connect

    Halon, D.A.; Weiss, A.T.; Tzivoni, D.; Atlan, H.; Gotsman, M.S.

    1981-10-01

    The use of a mobile gamma camera with thallium 201 myocardial imaging is described to exclude myocardial infarction in a patient admitted to the coronary care unit in shock and with clinical, enzyme, and ECG changes consistent with infarction. The patient suffered from acute aortic dissection associated with congenital coarctation of the aorta. The myocardial scan excluded transmural myocardial injury.

  16. Cardioplegia and myocardial preservation during cardiopulmonary bypass.

    PubMed

    Engelman, R M; Levitsky, S; O'Donoghue, M J; Auvil, J

    1978-09-01

    A standard experimental protocol was developed to explore the role of hypothermia and potassium cardioplegia in myocardial preservation during 120 minutes of ischemic arrest followed by 30 minutes of reperfusion. Seven different experimental groups of six animals each were evaluated using an in-vivo pig heart preparation. Hypothermic arrest without cardioplegia and cardioplegic arrest at normothermia were each compared to hypothermic cardioplegia. In addition, the use of an asanguineous hypothermic coronary perfusate without cardioplegia was compared to both multidose cardioplegia and single-dose cardioplegia followed by the same asanguineous perfusate. The parameters measured included: myocardial contractility and compliance, myocardial blood flow, endocardial/epicardial blood flow ratio, and electron microscopic studies. Myocardial preservation was inadequate with hypothermic arrest alone (without cardioplegia; and with cardioplegia at normothermia. In both experimental groups, myocardial contractility and compliance were so depressed that the) could not be accurately measured following ischemia and reperfusion while coronary blood flow remained significantly elevated. Preservation was improved but still inadequate following myocardial washout with a normokalemic or hypokalemic perfusate and following single dose cardioplegia plus myocardial washout. In the latter four groups, contractility ranged from 42 to 78% of control, and there was a decrease in compliance of 16 to 78%. Adequate preservation was found only after hypothermia and multidose potassium (35 mEq/L) cardioplegia. In this group, contractility was 129 +/- 13% of control and compliance increased by 21 +/- 24% compared to that of the control.

  17. Determination of the Role of Oxygen in Suspected Acute Myocardial Infarction by Biomarkers

    ClinicalTrials.gov

    2016-01-25

    Acute Myocardial Infarction (AMI); Acute Coronary Syndrome (ACS); ST Elevation (STEMI) Myocardial Infarction; Ischemic Reperfusion Injury; Non-ST Elevation (NSTEMI) Myocardial Infarction; Angina, Unstable

  18. Serum nickle estimation in acute myocardial infarction.

    PubMed

    Narang, N K; Goyal, R K; Gupta, A K; Balwani, S

    1989-11-01

    Serum nickle was estimated by atomic absorption spectrometer in 20 healthy controls and in 25 cases of acute myocardial infarction at 12 hourly intervals upto 48 hours, after the onset of chest pain. The mean serum nickel was 0.27 micrograms/dl in healthy controls and 0.40,050,049 and 0.30 micrograms/dl in patients of acute myocardial infarction. The serum nickel values were significantly (P less than 0.001) raised upto 36 hours in acute myocardial infarction when compared with controls.

  19. Nanog expression in heart tissues induced by acute myocardial infarction.

    PubMed

    Luo, Huanhuan; Li, Qiong; Pramanik, Jogen; Luo, Jiankai; Guo, Zhikun

    2014-10-01

    Nanog is a potential stem cell marker and is considered a regeneration factor during tissue repair. In the present study, we investigated expression patterns of nanog in the rat heart after acute myocardial infarction by semi-quantitative RT-PCR, immunohistochemistry and Western blot analyses. Our results show that nanog at both mRNA and protein levels is positively expressed in myocardial cells, fibroblasts and small round cells in different myocardial zones at different stages after myocardial infarction, showing a spatio-temporal and dynamic change. After myocardial infarction, the nanog expression in fibroblasts and small round cells in the infarcted zone (IZ) is much stronger than that in the margin zone (MZ) and remote infarcted zone (RIZ). From day 7 after myocardial infarction, the fibroblasts and small cells strongly expressed nanog protein in the IZ, and a few myocardial cells in the MZ and the RIZ and the numbers of nanog-positive fibroblasts and small cells reached the highest peak at 21 days after myocardial infarction, but in this period the number of nanog-positive myocardial cells decreased gradually. At 28 days after myocardial infarction, the numbers of all nanog-positive cells decreased into a low level. Therefore, our data suggest that all myocardial cells, fibroblasts and small round cells are involved in myocardial reconstruction after cardiac infarction. The nanog-positive myocardial cells may respond to early myocardial repair, and the nanog-positive fibroblasts and small round cells are the main source for myocardial reconstruction after cardiac infarction.

  20. Comparison of Hemodynamic Effects and Negative Predictive Value of Normal Adenosine Gated Myocardial Perfusion Scan With or Without Caffeine Abstinence

    PubMed Central

    uz Zaman, Maseeh; Fatima, Nosheen; Zaman, Areeba; Zaman, Unaiza; Tahseen, Rabia

    2016-01-01

    For vasodilator stress, myocardial perfusion imaging (MPI) with at least 12-h caffeine abstinence is recommended, as it attenuates cardiovascular hyperemic response of adenosine and dipyridamole. However, many published conflicting results have shown no significant effect upon perfusion abnormalities in MPI performed without caffeine abstinence. The aim of this study was to compare the hemodynamic changes and negative predictive value (NPV) of normal MPIs with adenosine stress performed with or without caffeine abstinence. This was a prospective study that accrued 50 patients from May 2013 till September 2013 and followed till November 2014. These patients had a normal adenosine-gated MPI (GMPI) with technetium-99m methoxy isobutyl isonitrile (99mTc-MIBI) after 12-h caffeine abstinence (no-caffeine). Next day, all patients had a repeat adenosine stress within 60 min after ingestion of a cup of coffee (about 80 mg of caffeine) followed by no MPI in 30 patients due to concern about radiation dose (prior-caffeine adenosine—no MPI; group A). Twenty patients opted for a repeat MPI (prior-caffeine adenosine—MPI; group B). Adenosine-induced hemodynamic response and NPV of the normal MPI with no-caffeine and prior-caffeine protocols were compared. The mean age of the study cohort was 57 ± 9 years with a male-to-female ratio of 76:24% and mean body mass index (BMI) of 26.915 ± 4.121 kg/m2. Prevalence of hypertension, diabetes, dyslipidemia, and positive family history were 76%, 20%, 22%, and 17%, respectively. Comparison of group A with group B revealed no significant difference in demographic parameters, hemodynamic or electrocardiography (ECG) parameters, or left ventricular (LV) function parameters during adenosine intervention with prior-caffeine and no-caffeine protocols. During the follow-up, no fatal myocardial infarction (MI) was reported but 6 nonfatal MIs were reported based upon the history of short hospitalization for chest pain but without biochemical or

  1. Comparison of Hemodynamic Effects and Negative Predictive Value of Normal Adenosine Gated Myocardial Perfusion Scan With or Without Caffeine Abstinence

    PubMed Central

    uz Zaman, Maseeh; Fatima, Nosheen; Zaman, Areeba; Zaman, Unaiza; Tahseen, Rabia

    2016-01-01

    For vasodilator stress, myocardial perfusion imaging (MPI) with at least 12-h caffeine abstinence is recommended, as it attenuates cardiovascular hyperemic response of adenosine and dipyridamole. However, many published conflicting results have shown no significant effect upon perfusion abnormalities in MPI performed without caffeine abstinence. The aim of this study was to compare the hemodynamic changes and negative predictive value (NPV) of normal MPIs with adenosine stress performed with or without caffeine abstinence. This was a prospective study that accrued 50 patients from May 2013 till September 2013 and followed till November 2014. These patients had a normal adenosine-gated MPI (GMPI) with technetium-99m methoxy isobutyl isonitrile (99mTc-MIBI) after 12-h caffeine abstinence (no-caffeine). Next day, all patients had a repeat adenosine stress within 60 min after ingestion of a cup of coffee (about 80 mg of caffeine) followed by no MPI in 30 patients due to concern about radiation dose (prior-caffeine adenosine—no MPI; group A). Twenty patients opted for a repeat MPI (prior-caffeine adenosine—MPI; group B). Adenosine-induced hemodynamic response and NPV of the normal MPI with no-caffeine and prior-caffeine protocols were compared. The mean age of the study cohort was 57 ± 9 years with a male-to-female ratio of 76:24% and mean body mass index (BMI) of 26.915 ± 4.121 kg/m2. Prevalence of hypertension, diabetes, dyslipidemia, and positive family history were 76%, 20%, 22%, and 17%, respectively. Comparison of group A with group B revealed no significant difference in demographic parameters, hemodynamic or electrocardiography (ECG) parameters, or left ventricular (LV) function parameters during adenosine intervention with prior-caffeine and no-caffeine protocols. During the follow-up, no fatal myocardial infarction (MI) was reported but 6 nonfatal MIs were reported based upon the history of short hospitalization for chest pain but without biochemical or

  2. Comparison of Hemodynamic Effects and Negative Predictive Value of Normal Adenosine Gated Myocardial Perfusion Scan With or Without Caffeine Abstinence.

    PubMed

    Uz Zaman, Maseeh; Fatima, Nosheen; Zaman, Areeba; Zaman, Unaiza; Tahseen, Rabia

    2016-09-01

    For vasodilator stress, myocardial perfusion imaging (MPI) with at least 12-h caffeine abstinence is recommended, as it attenuates cardiovascular hyperemic response of adenosine and dipyridamole. However, many published conflicting results have shown no significant effect upon perfusion abnormalities in MPI performed without caffeine abstinence. The aim of this study was to compare the hemodynamic changes and negative predictive value (NPV) of normal MPIs with adenosine stress performed with or without caffeine abstinence. This was a prospective study that accrued 50 patients from May 2013 till September 2013 and followed till November 2014. These patients had a normal adenosine-gated MPI (GMPI) with technetium-99m methoxy isobutyl isonitrile ((99m)Tc-MIBI) after 12-h caffeine abstinence (no-caffeine). Next day, all patients had a repeat adenosine stress within 60 min after ingestion of a cup of coffee (about 80 mg of caffeine) followed by no MPI in 30 patients due to concern about radiation dose (prior-caffeine adenosine-no MPI; group A). Twenty patients opted for a repeat MPI (prior-caffeine adenosine-MPI; group B). Adenosine-induced hemodynamic response and NPV of the normal MPI with no-caffeine and prior-caffeine protocols were compared. The mean age of the study cohort was 57 ± 9 years with a male-to-female ratio of 76:24% and mean body mass index (BMI) of 26.915 ± 4.121 kg/m(2). Prevalence of hypertension, diabetes, dyslipidemia, and positive family history were 76%, 20%, 22%, and 17%, respectively. Comparison of group A with group B revealed no significant difference in demographic parameters, hemodynamic or electrocardiography (ECG) parameters, or left ventricular (LV) function parameters during adenosine intervention with prior-caffeine and no-caffeine protocols. During the follow-up, no fatal myocardial infarction (MI) was reported but 6 nonfatal MIs were reported based upon the history of short hospitalization for chest pain but without biochemical or

  3. Comparison of thallium 201 (TL) SPECT and F-18 fluoro-deoxyglucose (FDG) PET in the evaluation of MRI lesions in patients with gliomas after therapy

    SciTech Connect

    Wong, F.C.L.; Garcia, J.R.; Yung, W.K.A.

    1994-05-01

    Although both Tl-201 SPECT and F-18 FDG PET are helpful for the detection of recurrent gliomas, there is DO comparative study of these techniques for the same patient group. This study is performed to compare the efficacy of TL SPECT and FDG PET in differentiating recurrent glioma from post-treatment necrosis. Twenty patients (16M/4 F) treated for gliomas (surgery, radiation and/or chemotherapy) with 24 instructive MRI enhancing lesions underwent TL-201 SPECT and F-18 FDG PET within 1 week. The lesions were graded 0 to 4 (by consensus of three nuclear radiologists) with increasing confidence for recurrent tumors. Semiquantitative evaluations include lesion/scalp TL-201 ratios (L/S TL) and lesion/cortex F-18 FDG (L/C FDG) standard uptake value ratios. With clinical follow-up (12/24) and histopathologic confirmation (12/24), sensitivity and specificity for each grade were used to construct the receiver-operator-characteristic (ROC) curve for comparison. Recurrent gliomas were confirmed in 12/24 lesions (9/12 by pathology; 3/12 by follow-up). Post-treatment necrosis was confirmed in 12/24 lesions (9/12 by follow-up; 3/12 by pathology). The L/S TL ratios were [1.99{plus_minus}0.77] for gliomas and [1.14{plus_minus}0.22] for necrosis; the L/C FDG ratios were 0.86{plus_minus}0.43 for gliomas and 0.43{plus_minus}0.15 for necrosis. Although none of the semiquantitative measurements from TL SPECT and FDG PET could completely distinguish gliomas from post-treatment necrosis, FDG PET was superior to TL SPECT on the ROC curves. While TL-201 SPECT and F-18 FDG PET provide different and probably complementary metabolic measurements of brain lesions, this preliminary work suggests FDG PET is a better tool to evaluate enhancing MRI lesions in patients with treated gliomas. Further confirmation will require studies of more patients.

  4. Myocardial infarction in young adults

    PubMed Central

    Egred, M; Viswanathan, G; Davis, G

    2005-01-01

    Although myocardial infarction (MI) mainly occurs in patients older than 45, young men or women can suffer MI. Fortunately, its incidence is not common in patients younger than 45 years. However, the disease carries a significant morbidity, psychological effects, and financial constraints for the person and the family when it occurs at a young age. The causes of MI among patients aged less than 45 can be divided into four groups: (1) atheromatous coronary artery disease; (2) non-atheromatous coronary artery disease; (2) hyper-coagulable states; (4) MI related to substance misuse. There is a considerable overlap between all the groups. This article reviews the literature and highlights the practical issues involved in the management of young adults with MI. PMID:16344295

  5. [Stem cell perspectives in myocardial infarctions].

    PubMed

    Aceves, José Luis; Archundia, Abel; Díaz, Guillermo; Páez, Araceli; Masso, Felipe; Alvarado, Martha; López, Manuel; Aceves, Rocío; Ixcamparij, Carlos; Puente, Adriana; Vilchis, Rafael; Montaño, Luis Felipe

    2005-01-01

    Myocardial infarction is the leading cause of congestive heart failure and death in industrializated countries. The cellular cardiomyoplasty has emerged as an alternative treatment in the regeneration of infarted myocardial tissue. In animals' models, different cellular lines such as cardiomyocites, skeletal myoblasts, embryonic stem cells and adult mesenchymal stem cells have been used, resulting in an improvement in ventricular function and decrease in amount of infarcted tissue. The first three cells lines have disvantages as they are allogenics and are difficult to obtain. The adult mesenchymal stem cells are autologous and can be obtained throught the aspiration of bone marrow or from peripherical circulation, after stimulating with cytokines (G-CSF). The implantation in humans with recent and old myocardial infarction have shown improvements similar to those shown in animal models. These findings encourage the continued investigation in the mechanism of cellular differentiation and implantation methods in infarcted myocardial tissue.

  6. Physiology and pharmacology of myocardial preconditioning.

    PubMed

    Raphael, Jacob

    2010-03-01

    Perioperative myocardial ischemia and infarction are not only major sources of morbidity and mortality in patients undergoing surgery but also important causes of prolonged hospital stay and resource utilization. Ischemic and pharmacological preconditioning and postconditioning have been known for more than two decades to provide protection against myocardial ischemia and reperfusion and limit myocardial infarct size in many experimental animal models, as well as in clinical studies (1-3). This paper will review the physiology and pharmacology of ischemic and drug-induced preconditioning and postconditioning of the myocardium with special emphasis on the mechanisms by which volatile anesthetics provide myocardial protection. Insights gained from animal and clinical studies will be presented and reviewed and recommendations for the use of perioperative anesthetics and medications will be given.

  7. Prognostic Significance of Imaging Myocardial Sympathetic Innervation.

    PubMed

    Malhotra, Saurabh; Fernandez, Stanley F; Fallavollita, James A; Canty, John M

    2015-08-01

    There has been a longstanding interest in understanding whether the presence of inhomogeneity in myocardial sympathetic innervation can predict patients at risk of sudden cardiac arrest from lethal ventricular arrhythmias. The advent of radiolabeled norepinephrine analogs has allowed this to be imaged in patients with ischemic and non-ischemic cardiomyopathy using single, photon emission computed tomography (SPECT) and positron emission tomography (PET). Several observational studies have demonstrated that globally elevated myocardial sympathetic tone (as reflected by reduced myocardial norepinephrine analog uptake) can predict composite cardiac end-points including total cardiovascular mortality. More recent studies have indicated that quantifying the extent of regional denervation can predict the risk of lethal ventricular arrhythmias and sudden cardiac death. This review will summarize our current understanding of the prognostic significance of altered myocardial sympathetic innervation. PMID:26087899

  8. Exosomes and cardiac repair after myocardial infarction.

    PubMed

    Sahoo, Susmita; Losordo, Douglas W

    2014-01-17

    Myocardial infarction is a leading cause of death among all cardiovascular diseases. The analysis of molecular mechanisms by which the ischemic myocardium initiates repair and remodeling indicates that secreted soluble factors are key players in communication to local and distant tissues, such as bone marrow. Recently, actively secreted membrane vesicles, including exosomes, are being recognized as new candidates with important roles in intercellular and tissue-level communication. In this review, we critically examine the emerging role of exosomes in local and distant microcommunication mechanisms after myocardial infarction. A comprehensive understanding of the role of exosomes in cardiac repair after myocardial infarction could bridge a major gap in knowledge of the repair mechanism after myocardial injury.

  9. [The latest treatments for myocardial infarction].

    PubMed

    Leclercq, Florence

    2015-03-01

    Ischemic heart disease and its main complication, myocardial infarction, remain the leading cause of death after the age of forty in developed countries. Myocardial infarction is the consequence of a sudden obstruction of a coronary artery by a thrombus. Thrombolysis and coronary angioplasty are the two emergency coronary artery revascularisation techniques. A medication-based treatment and adapted lifestyle aim to prevent repeat infarction. PMID:26040139

  10. Tachycardia induced myocardial dysfunction. A reversible phenomenon?

    PubMed Central

    McLaran, C J; Gersh, B J; Sugrue, D D; Hammill, S C; Seward, J B; Holmes, D R

    1985-01-01

    Four patients with myocardial dysfunction related to tachycardia underwent electrophysiological studies, which showed a re-entrant supraventricular tachycardia using an accessory atrioventricular connexion. Serial assessment of left ventricular function by echocardiography before and after control of the tachycardia indicated a variable degree of reversibility. Endomyocardial biopsy in two patients detected non-specific histological changes. Because of the possible role of ischaemia in this condition effective control of prolonged tachycardia is needed to prevent deterioration of myocardial function. Images PMID:3970789

  11. Improved exercise myocardial perfusion during lidoflazine therapy

    SciTech Connect

    Shapiro, W.; Narahara, K.A.; Park, J.

    1983-11-01

    Lidoflazine is a synthetic drug with calcium-channel blocking effects. In a study of 6 patients with severe classic angina pectoris, single-blind administration of lidoflazine was associated with improved myocardial perfusion during exercise as determined by thallium-201 stress scintigraphy. These studies demonstrate that lidoflazine therapy is associated with relief of angina, an increased physical work capacity, and improved regional myocardial perfusion during exercise.

  12. Relationship between myocardial bridging and coronary arteriosclerosis.

    PubMed

    Sun, Jian Ling; Huang, Wei Min; Guo, Ji Hong; Li, Xiao Ying; Ma, Xian Lin; Wang, Chong Yu

    2013-04-01

    The objective of the study was to explore the prevalence and characteristics of myocardial bridging in patients who underwent coronary angiography and to also evaluate the correlation between bridged coronary segments and atherosclerosis. For this purpose, clinical materials of 1,500 patients who had received coronary angiography were retrospectively analyzed. The location and length of the myocardial bridge were recorded as well as the extent and location of coronary artery stenosis was described. Segments proximal and distal to the bridging were evaluated for coronary arteriosclerosis as were the remaining coronary segments. We found that myocardial bridging was present in 179 (11.9 %) patients. Bridges were frequently (84.9 %) localized in the mid-distal segment of the left anterior descending (LAD) artery. Myocardial bridging was not considered a significant risk factor for coronary atherosclerosis (odds ratio 0.58) compared with traditional cardiovascular risk factors. The incidence of coronary arteriosclerosis in the distal segments was significantly less affected than the proximal segments (P < 0.01). It was, therefore, concluded that myocardial bridging frequently localized in the mid-distal segment of the LAD artery. The presence of myocardial bridging promotes proximal atherosclerosis but it is not an additional risk factor for coronary atherosclerosis. PMID:23076634

  13. A somatic component to myocardial infarction.

    PubMed Central

    Nicholas, A S; DeBias, D A; Ehrenfeuchter, W; England, K M; England, R W; Greene, C H; Heilig, D; Kirschbaum, M

    1985-01-01

    Sixty two patients were randomised to be seen by osteopathic physicians for palpation of the thoracic paravertebral soft tissue, T1-T8. Twenty five patients had clinically confirmed acute myocardial infarction. Of the remainder, 22 without known cardiovascular disease served as controls and 15 were placed in an excluded group because of diagnosed cardiovascular disease other than myocardial infarction. Observations were described in predetermined standard terminology. The control group was found to have a low incidence of palpable changes throughout the thoracic dorsum, and these changes were uniformly distributed from T1 to T8. Examination of the group with myocardial infarction disclosed a significantly higher incidence of soft tissue changes (increased firmness, warmth, ropiness, oedematous changes, heavy musculature), confined almost entirely to the upper four thoracic levels. The 15 patients who were excluded from the experimental group because they had various cardiovascular diseases other than myocardial infarction also showed significantly different changes on palpation compared with the group with myocardial infarction. These findings suggest that myocardial infarction is accompanied by characteristic paravertebral soft tissue changes which are readily detected by palpation. PMID:3926040

  14. Novel adjunctive treatments of myocardial infarction

    PubMed Central

    Schmidt, Michael Rahbek; Pryds, Kasper; Bøtker, Hans Erik

    2014-01-01

    Myocardial infarction is a major cause of death and disability worldwide and myocardial infarct size is a major determinant of prognosis. Early and successful restoration of myocardial reperfusion following an ischemic event is the most effective strategy to reduce final infarct size and improve clinical outcome, but reperfusion may induce further myocardial damage itself. Development of adjunctive therapies to limit myocardial reperfusion injury beyond opening of the coronary artery gains increasing attention. A vast number of experimental studies have shown cardioprotective effects of ischemic and pharmacological conditioning, but despite decades of research, the translation into clinical effects has been challenging. Recently published clinical studies, however, prompt optimism as novel techniques allow for improved clinical applicability. Cyclosporine A, the GLP-1 analogue exenatide and rapid cooling by endovascular infusion of cold saline all reduce infarct size and may confer clinical benefit for patients admitted with acute myocardial infarcts. Equally promising, three follow-up studies of the effect of remote ischemic conditioning (RIC) show clinical prognostic benefit in patients undergoing coronary surgery and percutaneous coronary intervention. The discovery that RIC can be performed noninvasively using a blood pressure cuff on the upper arm to induce brief episodes of limb ischemia and reperfusion has facilitated the translation of RIC into the clinical arena. This review focus on novel advances in adjunctive therapies in relation to acute and elective coronary procedures. PMID:24976915

  15. Computational modeling of acute myocardial infarction.

    PubMed

    Sáez, P; Kuhl, E

    2016-01-01

    Myocardial infarction, commonly known as heart attack, is caused by reduced blood supply and damages the heart muscle because of a lack of oxygen. Myocardial infarction initiates a cascade of biochemical and mechanical events. In the early stages, cardiomyocytes death, wall thinning, collagen degradation, and ventricular dilation are the immediate consequences of myocardial infarction. In the later stages, collagenous scar formation in the infarcted zone and hypertrophy of the non-infarcted zone are auto-regulatory mechanisms to partly correct for these events. Here we propose a computational model for the short-term adaptation after myocardial infarction using the continuum theory of multiplicative growth. Our model captures the effects of cell death initiating wall thinning, and collagen degradation initiating ventricular dilation. Our simulations agree well with clinical observations in early myocardial infarction. They represent a first step toward simulating the progression of myocardial infarction with the ultimate goal to predict the propensity toward heart failure as a function of infarct intensity, location, and size. PMID:26583449

  16. Sensitive Troponin Assay and the Classification of Myocardial Infarction

    PubMed Central

    Shah, Anoop S.V.; McAllister, David A.; Mills, Rosamund; Lee, Kuan Ken; Churchhouse, Antonia M.D.; Fleming, Kathryn M.; Layden, Elizabeth; Anand, Atul; Fersia, Omar; Joshi, Nikhil V.; Walker, Simon; Jaffe, Allan S.; Fox, Keith A.A.; Newby, David E.; Mills, Nicholas L.

    2015-01-01

    Background Lowering the diagnostic threshold for troponin is controversial because it may disproportionately increase the diagnosis of myocardial infarction in patients without acute coronary syndrome. We assessed the impact of lowering the diagnostic threshold of troponin on the incidence, management, and outcome of patients with type 2 myocardial infarction or myocardial injury. Methods Consecutive patients with elevated plasma troponin I concentrations (≥50 ng/L; n = 2929) were classified with type 1 (50%) myocardial infarction, type 2 myocardial infarction or myocardial injury (48%), and type 3 to 5 myocardial infarction (2%) before and after lowering the diagnostic threshold from 200 to 50 ng/L with a sensitive assay. Event-free survival from death and recurrent myocardial infarction was recorded at 1 year. Results Lowering the threshold increased the diagnosis of type 2 myocardial infarction or myocardial injury more than type 1 myocardial infarction (672 vs 257 additional patients, P < .001). Patients with myocardial injury or type 2 myocardial infarction were at higher risk of death compared with those with type 1 myocardial infarction (37% vs 16%; relative risk [RR], 2.31; 95% confidence interval [CI], 1.98-2.69) but had fewer recurrent myocardial infarctions (4% vs 12%; RR, 0.35; 95% CI, 0.26-0.49). In patients with troponin concentrations 50 to 199 ng/L, lowering the diagnostic threshold was associated with increased healthcare resource use (P < .05) that reduced recurrent myocardial infarction and death for patients with type 1 myocardial infarction (31% vs 20%; RR, 0.64; 95% CI, 0.41-0.99), but not type 2 myocardial infarction or myocardial injury (36% vs 33%; RR, 0.93; 95% CI, 0.75-1.15). Conclusions After implementation of a sensitive troponin assay, the incidence of type 2 myocardial infarction or myocardial injury disproportionately increased and is now as frequent as type 1 myocardial infarction. Outcomes of patients with type 2 myocardial

  17. Myocardial infarction caused by myocardial bridging in a male adolescent athlete.

    PubMed

    Zhu, Cheng-Gang; Liu, Jun; Liu, Wei-Dong; Xu, Yan-Lu; Wu, Na-Qiong; Guo, Yuan-Lin; Tang, Yi-Da; Jiang, Li-Xin; Li, Jian-Jun

    2012-02-01

    Myocardial bridging is a common congenital abnormality of a coronary artery, and is usually thought to be a benign anatomical variant. Although rare, previous studies have reported that patients with myocardial bridging may suffer from myocardial ischemia, myocardial infarction (MI), arrhythmias and even sudden death. Here we report the case of an 18-year-old adolescent athlete with myocardial bridging resulting in MI. Coronary angiography revealed 80% luminal narrowing by systolic compression in the proximal and mid segments of the left anterior descending coronary artery, which returned to normal during diastole. We considered that heavy sports might be a potential trigger for his MI attack. Therefore, special attention should be paid to this kind of athlete, especially if adolescent.

  18. Incidence of acute myocardial infarction in patients with exercise-induced silent myocardial ischemia

    SciTech Connect

    Assey, M.E.; Walters, G.L.; Hendrix, G.H.; Carabello, B.A.; Usher, B.W.; Spann, J.F. Jr.

    1987-03-01

    Fifty-five patients with angiographically proved coronary artery disease (CAD) underwent Bruce protocol exercise stress testing with thallium-201 imaging. Twenty-seven patients (group I) showed myocardial hypoperfusion without angina pectoris during stress, which normalized at rest, and 28 patients (group II) had a similar pattern of reversible myocardial hypoperfusion but also had angina during stress. Patients were followed for at least 30 months. Six patients in group I had an acute myocardial infarction (AMI), 3 of whom died, and only 1 patient in group II had an AMI (p = 0.05), and did not die. Silent myocardial ischemia uncovered during exercise stress thallium testing may predispose to subsequent AMI. The presence of silent myocardial ischemia identified in this manner is of prognostic value, independent of angiographic variables such as extent of CAD and left ventricular ejection fraction.

  19. Radionuclide imaging of myocardial perfusion and viability in assessment of acute myocardial infarction

    SciTech Connect

    Berman, D.S.; Kiat, H.; Maddahi, J.; Shah, P.K.

    1989-07-18

    Technical advances in radionuclide imaging have important implications for the management of patients with acute myocardial infarction. Single-photon emission computerized tomography with thallium 201 (TI-201) offers greater accuracy than planar imaging in detecting, localizing and sizing myocardial perfusion defects. Use of single-photon emission computerized tomography with TI-201 should allow for a more accurate assessment of prognosis after myocardial infarction. A new radiopharmaceutical, technetium 99-m methoxyisobutyl isonitrile, provides a number of advantages over TI-201, including higher quality images, lack of redistribution, and the ability to assess first-pass ventricular function. Applications of TI-201 and technetium 99-m methoxyisobutyl isonitrile include assessment of arterial patency and myocardial salvage immediately after thrombolytic therapy, detection of resting ischemia after thrombolytic therapy, targeting of subsets of patients for further intervention, and predischarge assessment to predict the future course of patients after an acute myocardial infarction.

  20. [Occupational stress and myocardial infarction].

    PubMed

    Consoli, Silla M

    2015-01-01

    Besides the best-known role of depressed mood, occupational stress deserves to be taken as a coronary risk factor. There are two basic models to define occupational stress: Karasek's model (high job psychological demands associated with low decision latitude, or even low social support at work) and Siegrist's model (imbalance between efforts and rewards received). The combination of the two models better reflects the coronary risk than each model alone. Occupational stress appears both as a risk factor and a prognostic factor after the occurrence of myocardial infarction. The relevance of the models is best in men or in younger age subjects. In women, role conflicts (occupational/domestic), the existence of excessive "intrinsic" efforts (job over investment) and association with marital stress provide more specific information. Burnout, particularly among health professionals, and bullying at work are also linked to cardiovascular risk. Occupational stress is a collective indicator of health at work, valuable to the employer. At an individual level, it can lead to therapeutic preventive approaches. PMID:26150284

  1. 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

  2. [Occupational stress and myocardial infarction].

    PubMed

    Consoli, Silla M

    2015-01-01

    Besides the best-known role of depressed mood, occupational stress deserves to be taken as a coronary risk factor. There are two basic models to define occupational stress: Karasek's model (high job psychological demands associated with low decision latitude, or even low social support at work) and Siegrist's model (imbalance between efforts and rewards received). The combination of the two models better reflects the coronary risk than each model alone. Occupational stress appears both as a risk factor and a prognostic factor after the occurrence of myocardial infarction. The relevance of the models is best in men or in younger age subjects. In women, role conflicts (occupational/domestic), the existence of excessive "intrinsic" efforts (job over investment) and association with marital stress provide more specific information. Burnout, particularly among health professionals, and bullying at work are also linked to cardiovascular risk. Occupational stress is a collective indicator of health at work, valuable to the employer. At an individual level, it can lead to therapeutic preventive approaches.

  3. Pediatric myocardial protection: an overview.

    PubMed

    Allen, B S; Barth, M J; Ilbawi, M N

    2001-01-01

    This article describes the experimental infrastructure and subsequent successful clinical application of a comprehensive bypass and cardioplegic strategy that limits intraoperative injury and improves postoperative outcomes in pediatric patients. The infant heart is at high risk of damage from poor protection because of preoperative hypertrophy, cyanosis, and ischemia. The background factors of vulnerability to damage caused by cyanosis and ischemia are discussed, together with studies of the infrastructure of strategies to use normoxia versus hyperoxia as bypass starts, white blood cell filtration, warm induction and reperfusion with substrate enhancements, multidose blood cardioplegia, and an integrated approach to allow ischemia only when vision is needed in pediatric surgeries. Data on cardioplegic management, including reducing calcium, increasing magnesium, and reducing perfusion pressure are shown, as used during this technique. These principles were applied to a consecutive series of 567 patients at the Heart Institute for Children and University of Illinois hospital over a 2-year period. Included also were 72 patients with hypoplastic left heart over a 4-year period with this myocardial management strategy. Application of these concepts may improve the safety of protection in infant hearts. PMID:11309728

  4. Molecular genetics of myocardial infarction

    PubMed Central

    Ichihara, Sahoko; Nishida, Tamotsu

    2008-01-01

    Abstract Myocardial infarction (MI) is an important clinical problem because of its large contribution to mortality. The main causal and treatable risk factors for MI include hypertension, hypercholesterolemia or dyslipidemia, diabetes mellitus, and smoking. In addition to these risk factors, recent studies have shown the importance of genetic factors and interactions between multiple genes and environmental factors. Disease prevention is an important strategy for reducing the overall burden of MI, with the identification of markers for disease risk being key both for risk prediction and for potential intervention to lower the chance of future events. Although genetic linkage analyses of families and sib-pairs as well as candidate gene and genome-wide association studies have implicated several loci and candidate genes in predisposition to coronary heart disease (CHD) or MI, the genes that contribute to genetic susceptibility to these conditions remain to be identified definitively. In this review, we summarize both candidate loci for CHD or MI identified by linkage analyses and candidate genes examined by association studies. We also review in more detail studies that have revealed the association with MI or CHD of polymorphisms in MTHFR, LPL, and APOE by the candidate gene approach and those in LTA and at chromosomal region 9p21.3 by genome-wide scans. Such studies may provide insight into the function of implicated genes as well as into the role of genetic factors in the development of CHD and MI. PMID:18704761

  5. 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

  6. [Holiday effect in myocardial infarct].

    PubMed

    Otto, W; Hempel, W E; Goebel, H; Erkens, R

    1975-03-15

    Aimed measures of the organisation of the combat against infarction demand also the observation of temporary frequencies. On the basis of the evaluation of certificates of death of the month December of the years 1969 to 1973 of the GDR with differentiation according to so-called prehospital dead (persons who died at home and on the way to the hospital) and patients who died in the hospital with high significance an unwarrantedly high prehospital mortality during the period from Christmas to the end of the year (25th to 31st December) was established compared with the preceding week (18th to 24th December). Since in contrast to this the hospital cases and the cases "on the way" do not show any significant differences main tasks for the beginning of improvements concerning health policy may be deduced, all the more since the so-called holiday effect, expressed by a high home/clinic-relation of patients who died of myocardial infarction, could be restricted to 6 counties of the GDR on account of the analysis of further localities. From the results the tendency of a retrogression of the holiday effect is to be read off in the course of years. In the discussion an explantation of this peculiarity is attempted, and practicable conclusions for the removal and thus for the improvement the infarct situation are formulated.

  7. Regional myocardial contractile function: multiparametric strain mapping.

    PubMed

    Cupps, Brian P; Taggar, Ajay K; Reynolds, Lina M; Lawton, Jennifer S; Pasque, Michael K

    2010-06-01

    Magnetic resonance imaging (MRI) with tissue tagging enables the quantification of multiple strain indices that can be combined through normalization into a single multiparametric index of regional myocardial contractile function. The aim of this study was to test the ability of multiparametric strain analysis to quantify regional differences in contractile function in an ovine model of myocardial injury. Regional variance in myocardial contractile function was induced in eight sheep by the ligation of the blood supply to the anterior and apical left ventricular (LV) myocardial walls. LV systolic strain was obtained from tissue tagged MRI images. A normal strain database (n=50) defines all parameters of systolic strain and allows normalization of regional function at 15,300 LV points by calculation of a z-score. Multiparametric systolic strain z-scores were therefore determined for 15,300 points in each injured sheep left ventricle. Multiparametric z-scores were found to vary significantly by region (P<0.001). z-Scores in regions remote to the infarct were found to be significantly smaller than those in the regions most likely to include infarcted myocardium. In this pre-clinical evaluation of MRI-based multiparametric strain analysis, it accurately quantified and visually defined regional differences in myocardial contractile function.

  8. Myocardial perfusion imaging with dual energy CT.

    PubMed

    Jin, Kwang Nam; De Cecco, Carlo N; Caruso, Damiano; Tesche, Christian; Spandorfer, Adam; Varga-Szemes, Akos; Schoepf, U Joseph

    2016-10-01

    Dual-energy CT (DECT) enables simultaneous use of two different tube voltages, thus different x-ray absorption characteristics are acquired in the same anatomic location with two different X-ray spectra. The various DECT techniques allow material decomposition and mapping of the iodine distribution within the myocardium. Static dual-energy myocardial perfusion imaging (sCTMPI) using pharmacological stress agents demonstrate myocardial ischemia by single snapshot images of myocardial iodine distribution. sCTMPI gives incremental values to coronary artery stenosis detected on coronary CT angiography (CCTA) by showing consequent reversible or fixed myocardial perfusion defects. The comprehensive acquisition of CCTA and sCTMPI offers extensive morphological and functional evaluation of coronary artery disease. Recent studies have revealed that dual-energy sCTMPI shows promising diagnostic accuracy for the detection of hemodynamically significant coronary artery disease compared to single-photon emission computed tomography, invasive coronary angiography, and cardiac MRI. The aim of this review is to present currently available DECT techniques for static myocardial perfusion imaging and recent clinical applications and ongoing investigations.

  9. Cardiac BMIPP imaging in acute myocardial infarction.

    PubMed

    Nakata, T; Hashimoto, A; Eguchi, M

    1999-02-01

    Fatty acid metabolism functions as a major energy-producing system under aerobic conditions, but it is impaired immediately after myocardial ischaemia. This imaging can provide intracellular information which cannot be obtained by angiographical, perfusional or functional analysis. 123I-BMIPP and perfusion imagings in patients with acute myocardial infarction have demonstrated three different correlations between myocardial perfusion and fatty acid metabolism: concordant defects of perfusion and BMIPP which represent scar or non-viable tissue; lower BMIPP uptake relative to perfusion (perfusion-BMIPP mismatch) which implicates metabolically damaged, often dysynergic, but viable myocardium; and equivalently normal uptakes of perfusion and BMIPP in completely salvaged myocardium. Identification of these perfusion-metabolism correlations contributes to the detection of ischaemia-related myocardial injury in viable and non-viable myocardium, to the prediction of post-ischaemic or post-interventional functional recovery and to the identification of patients who have myocardium at ischaemic risk. Further clinical investigations might reveal more clearly the pathophysiological and prognostic implications of cardiac BMIPP imaging in patients with acute myocardial infarction.

  10. Myocardial Factor Revisited: The Importance of Myocardial Fibrosis in Adults with Congenital Heart Disease

    PubMed Central

    Broberg, Craig S.; Burchill, Luke J.

    2015-01-01

    Pioneers in congenital heart surgery observed that exercise capacity did not return to normal levels despite successful surgical repair, leading some to cite a “myocardial factor” playing a role. They conjectured that residual alterations in myocardial function would be significant for patients’ long-term outlook. In fulfillment of their early observations, today’s adult congenital heart disease (ACHD) population shows well-recognized features of heart failure, even among patients without clear residual anatomic or hemodynamic abnormalities, demonstrating the vital role of the myocardium in their morbidity and mortality. Whereas the ‘myocardial factor’ was an elusive concept in the early history of congenital heart care, we now have imaging techniques to detect and quantify one such factor – myocardial fibrosis. Understanding the importance of myocardial fibrosis as a final common pathway in a variety of congenital lesions provides a framework for both the study and treatment of clinical heart failure in this context. While typical heart failure pharmacology should reduce or attenuate fibrogenesis, efforts to show meaningful improvements with standard pharmacotherapy in ACHD repeatedly fall short. This paper considers the importance of myocardial fibrosis and function, the current body of evidence for myocardial fibrosis in ACHD, and its implications for research and treatment. PMID:25897907

  11. Transient myocardial bridging of the left anterior descending coronary artery in acute inferior myocardial infarction.

    PubMed

    Kilic, Harun; Akdemir, Ramazan; Bicer, Asuman; Dogan, Mehmet

    2009-01-24

    We observed transient myocardial bridging of left anterior descending coronary artery (LAD) in 18.75% (12 of the total 64) of the patients during acute inferior myocardial infarction (MI). Myocardial bridging occurred only in the acute phase of inferior MI and not in the chronic phase. In the acute phase of inferior MI, compensatory hypercontraction of the anterior wall is assumed to occur in response to the decrease in the movement of the infarct-related walls. In the chronic phase, disappearance of the myocardial bridging observed due to the resolution of compensatory anterior wall hypercontraction, as a result of the reperfusion of infarct-related coronary artery. Most of the myocardial bridges seen in autopsy series are not seen angiographically. Variation at angiography may in part be attributable to small and thin bridges causing little compression. Adrenergic stimulation or afterload reduction by nitroglycerin facilitates diagnosis of myocardial bridging by increasing coronary compression. Both of these conditions are almost always present in acute MI. We concluded that transient myocardial bridging of LAD can be observed in some patients with acute inferior MI during acute stage. PMID:17920712

  12. Panic attack triggering myocardial ischemia documented by myocardial perfusion imaging study. A case report

    PubMed Central

    2012-01-01

    Background Chest pain, a key element in the investigation of coronary artery disease is often regarded as a benign prognosis when present in panic attacks. However, panic disorder has been suggested as an independent risk factor for long-term prognosis of cardiovascular diseases and a trigger of acute myocardial infarction. Objective Faced with the extreme importance in differentiate from ischemic to non-ischemic chest pain, we report a case of panic attack induced by inhalation of 35% carbon dioxide triggering myocardial ischemia, documented by myocardial perfusion imaging study. Discussion Panic attack is undoubtedly a strong component of mental stress. Patients with coronary artery disease may present myocardial ischemia in mental stress response by two ways: an increase in coronary vasomotor tone or a sympathetic hyperactivity leading to a rise in myocardial oxygen consumption. Coronary artery spasm was presumed to be present in cases of cardiac ischemia linked to panic disorder. Possibly the carbon dioxide challenge test could trigger myocardial ischemia by the same mechanisms. Conclusion The use of mental stress has been suggested as an alternative method for myocardial ischemia investigation. Based on translational medicine objectives the use of CO2 challenge followed by Sestamibi SPECT could be a useful method to allow improved application of research-based knowledge to the medical field, specifically at the interface of PD and cardiovascular disease. PMID:22999016

  13. Role of myocardial perfusion imaging in evaluating thrombolytic therapy for acute myocardial infarction

    SciTech Connect

    Beller, G.A.

    1987-03-01

    Myocardial thallium-201 scintigraphy is being increasingly employed as a method for assessing the efficacy of coronary reperfusion in acute myocardial infarction. New thallium uptake after intracoronary tracer administration after successful recanalization indicates that nutrient blood flow has been successfully restored. One may also presume that some myocardial salvage occurred if thallium administered in this manner is transported intracellularly by myocytes with intact sarcolemmal membranes. However, if one injects thallium by way of the intracoronary route immediately after reperfusion, the initial uptake of thallium in reperfused myocardium may predominantly represent hyperemic flow and regional thallium counts measured may not be proportional to the mass of viable myocytes. When thallium is injected intravenously during the occlusion phase the degree of redistribution after thrombolysis is proportional to the degree of flow restoration and myocardial viability. When thallium is injected for the first time intravenously immediately after reperfusion, an overestimation of myocardial salvage may occur because of excess thallium uptake in the infarct zone consequent to significant hyperemia. Another approach to myocardial thallium scintigraphy in patients undergoing thrombolytic therapy is to administer two separate intravenous injections before and 24 hours or later after treatment. Finally, patients with acute myocardial infarction who receive intravenous thrombolytic therapy are candidates for predischarge exercise thallium-201 scintigraphy for risk stratification and detection of residual ischemia.

  14. Association of stroke and myocardial infarction in children.

    PubMed

    Nakashima, M; Takashima, S; Hashimoto, K; Shiraishi, M

    1982-02-01

    A 9-year-old boy with cerebrovascular accident (CVA) and old myocardial infarction with mural thrombi is reported. The cause of the myocardial infarction was congenital coronary artery fistula originating from the left coronary artery and emptying into the right atrium. Although a common cause of strokes in adults, myocardial infarction has infrequently been reported as the source of emboli in children.

  15. Prediction of death, myocardial infarction, and worsening chest pain using thallium scintigraphy and exercise electrocardiography

    SciTech Connect

    Staniloff, H.M.; Forrester, J.S.; Berman, D.S.; Swan, H.J.

    1986-12-01

    Although used extensively, there is little published information on the prognostic ability of exercise /sup 201/Tl scintigraphy. Accordingly, 1 yr after testing we contacted 819 patients without previous MI or CABG seen in our laboratory during a 2-yr period. Events were defined as death from a cardiovascular cause, nonfatal MI, or worsening clinical state requiring CABG. The event rate was 3.9 events per 100 patients per year. There was univariate prognostic information when comparing the highest and lowest categories as risk ratios for chest pain characteristics (2.7), sex (2.3), exercise duration (3.1), ST slope (2.5), and thallium pattern (11.6), intensity of perfusion defect (17.2), and number of abnormal regions (8.7). However, the strongest predictors were also the least common. Prognostic ability was improved by combining the results categorically, as the number of abnormal tests (13.9). The highest risk ratio, 20.5:1, was obtained by combining results through discriminant function analysis. We conclude that exercise thallium scintigraphy provides prognostic information, although the most predictive patterns are uncommon. Combining the results of multiple test results improves the prognostic ability.

  16. [The perioperative myocardial infarction - an interdisciplinary task].

    PubMed

    Karatolios, Konstantinos; Rolfes, Caroline; Wulf, Hinnerk; Schieffer, Bernhard

    2016-09-01

    Cardiovascular complications, particularly perioperative myocardial infarction (PMI), are major contributors to mortaliyt after noncardiac surgery. PMI often occurs unnoticed without symptoms or ECG changes. Despite ist silent presentation, PMI is associated with increased mortality. The combination of high associated mortality and diagnostic challenges mandates increased awareness of PMI. Perioperative myocardial infarction may result from plaque rupture (PMI type I) or be caused by a myocardial supply-demand imbalance of oxygen without plaque rupture (PMI type II). Most PMIs occur within the first 3 days after surgery, highlighting the need for clinical monitoring in order to allow fast diagnosis and initiation of appropriate therapy. Measurement of cardiac troponin and 12-lead ECG are the diagnostic cornerstone. Therapy of PMI represents a challenge for physicians and requires a collaboration of surgeons, anesthesiologists and cardiologists. PMID:27631445

  17. Winter weather conditions and myocardial infarctions.

    PubMed

    Ohlson, C G; Bodin, L; Bryngelsson, I L; Helsing, M; Malmberg, L

    1991-03-01

    The daily number of cases of myocardial infarctions admitted to a hospital in middle Sweden over three winter seasons 1984-87 was correlated to the weather conditions on a day-to-day basis. The study encompassed 634 days and all cases younger than 70 years, living within the catchment area, in all 382 subjects. Information on temperature, wind force, precipitation and atmospheric pressure was obtained from the Swedish Institute of Meteorology and Hydrology. A low number of myocardial infarctions was seen on Saturdays and Sundays with a mild wind chill factor and on days with moderate snowfall and high atmospheric pressure. A high number was observed for workdays, especially Mondays, as day of diagnosis. Heterogeneity of the study population and a misclassification of the time relationships between dates of diagnosis and weather changes may have caused an underestimation of the impact of weather conditions. However, weather conditions do not seem to be a major triggering factor of myocardial infarctions in Sweden.

  18. Action of acetylstrophanthidin on experimental myocardial infarction.

    NASA Technical Reports Server (NTRS)

    Nola, G. T.; Pope, S. E.; Harrison, D. C.

    1972-01-01

    An experimental animal model with acute myocardial infarction of a size insufficient to produce profound heart failure or shock was used to study the effects of acute infarction on digitalis tolerance and the hemodynamic changes produced by moderate and large doses of acetylstrophanthidin. With acute myocardial infarction, digitalis toxic arrhythmias could be precipitated with significantly lower doses of digitalis than in animals without myocardial infarction. There was no precise correlation between the size of infarction and the toxic dose of glycoside. Coronary artery ligation produced a stable but relatively depressed circulatory state, as evidenced by lowered cardiac output and stroke volume and elevated systemic vascular resistance and left atrial mean pressure. When digitalis was infused, the following significant changes were observed at nontoxic doses: (1) elevation of aortic and left ventricular pressures; (2) further decline in cardiac output; and (3) decreased left atrial mean pressure.

  19. Myocardial disarray in Noonan syndrome

    PubMed Central

    Burch, Michael; Mann, Jessica M; Sharland, Michael; Shinebourne, Elliot A; Patton, Michael A; McKenna, William J

    1992-01-01

    Objective—To characterise the histopathology of the left ventricular hypertrophy commonly associated with Noonan syndrome by assessing the extent of myocyte disarray and therefore to define one aspect of the relation between this disease and idiopathic hypertrophic cardiomyopathy. Design—Blinded histological analysis. Setting—Hospital medical school. Patients—Six hearts of children with the Noonan phenotype and isolated ventricular hypertrophy were compared with age and sex matched controls. Methods—Histological analysis was performed with an image analyser under light microscopy. Representative sections from the entire left ventricular free wall were examined. Results were expressed as the percentage of fields showing disarray related to the number of fields evaluated: 100 fields were examined for each patient. Results—In the patients with Noonan syndrome myocardial disarray was present in the ventricular septum in 24 (5·7)% (mean (SD)) of fields and in the free wall in 22·2 (6·8)%. In the controls disarray was present in the septum in 3·8 (2·3)% of fields and in the free wall in 2·4 (2·8)%. In both regions the extent of disarray was significantly greater in patients with Noonan syndrome (p < 0·0005; 95% confidence interval 14 to 26·3 for the septum: p < 0·005, 95% confidence interval 11·4 to 28·2 for the free wall). Conclusions—The ventricular hypertrophy associated with Noonan syndrome is histologically similar to hypertrophic cardiomyopathy but whether the two diseases are the expression of the same genetic defect remains to be determined. PMID:1467053

  20. Myocardial Infarction: Symptoms and Treatments.

    PubMed

    Lu, Lei; Liu, Min; Sun, RongRong; Zheng, Yi; Zhang, Peiying

    2015-07-01

    Myocardial infarction (MI) is a term used for an event of heart attack which is due to formation of plaques in the interior walls of the arteries resulting in reduced blood flow to the heart and injuring heart muscles because of lack of oxygen supply. The symptoms of MI include chest pain, which travels from left arm to neck, shortness of breath, sweating, nausea, vomiting, abnormal heart beating, anxiety, fatigue, weakness, stress, depression, and other factors. The immediate treatment of MI include, taking aspirin, which prevents blood from clotting, and nitro-glycerin to treat chest pain and oxygen. The heart attack can be prevented by taking an earlier action to lower those risks by controlling diet, fat, cholesterol, salt, smoking, nicotine, alcohol, drugs, monitoring of blood pressure every week, doing exercise every day, and loosing body weight. The treatment of MI includes, aspirin tablets, and to dissolve arterial blockage injection of thrombolytic or clot dissolving drugs such as tissue plasminogen activator, streptokinase or urokinase in blood within 3 h of the onset of a heart attack. The painkillers such as morphine or meperidine can be administered to relieve pain. Nitroglycerin and antihypertensive drugs such as beta-blockers, ACE inhibitors or calcium channel blockers may also be used to lower blood pressure and to improve the oxygen demand of heart. The ECG, coronary angiography and X-ray of heart and blood vessels can be performed to observe the narrowing of coronary arteries. In this article the causes, symptoms and treatments of MI are described. PMID:25638347

  1. Myocardial Infarction: Symptoms and Treatments.

    PubMed

    Lu, Lei; Liu, Min; Sun, RongRong; Zheng, Yi; Zhang, Peiying

    2015-07-01

    Myocardial infarction (MI) is a term used for an event of heart attack which is due to formation of plaques in the interior walls of the arteries resulting in reduced blood flow to the heart and injuring heart muscles because of lack of oxygen supply. The symptoms of MI include chest pain, which travels from left arm to neck, shortness of breath, sweating, nausea, vomiting, abnormal heart beating, anxiety, fatigue, weakness, stress, depression, and other factors. The immediate treatment of MI include, taking aspirin, which prevents blood from clotting, and nitro-glycerin to treat chest pain and oxygen. The heart attack can be prevented by taking an earlier action to lower those risks by controlling diet, fat, cholesterol, salt, smoking, nicotine, alcohol, drugs, monitoring of blood pressure every week, doing exercise every day, and loosing body weight. The treatment of MI includes, aspirin tablets, and to dissolve arterial blockage injection of thrombolytic or clot dissolving drugs such as tissue plasminogen activator, streptokinase or urokinase in blood within 3 h of the onset of a heart attack. The painkillers such as morphine or meperidine can be administered to relieve pain. Nitroglycerin and antihypertensive drugs such as beta-blockers, ACE inhibitors or calcium channel blockers may also be used to lower blood pressure and to improve the oxygen demand of heart. The ECG, coronary angiography and X-ray of heart and blood vessels can be performed to observe the narrowing of coronary arteries. In this article the causes, symptoms and treatments of MI are described.

  2. 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.

  3. Recurrent myocardial infarction with patent coronary arteries.

    PubMed Central

    Haywood, L. J.; Khan, A. H.; Bornheimer, J.; Finck, E.; Tatter, D.

    1997-01-01

    Two separate episodes of severe chest pain occurred several years apart in a 25-year-old male patient with typical clinical findings of acute myocardial infarction with each episode. Cardiac catheterization following the second infarction confirmed the presence of myocardial dysfunction with apical akinesis and dyskinesis. Both coronary arteries were radiologically patent; however, there was evidence of probable recanalization of the right coronary artery. Several months later, the patient developed flank pain, hematuria, progressive renal failure, and cardiac decompensation, and died with intractable arrhythmias. At autopsy, a large apical mitral thrombosis was found and was the presumptive source of multiple systemic emboli. Images Figure 3 Figure 4 PMID:9195802

  4. Visualizing myocardial function using HARP MRI

    NASA Astrophysics Data System (ADS)

    Osman, Nael F.; Prince, Jerry L.

    2000-06-01

    Harmonic phase magnetic resonance imaging (HARP) is a new technique for measuring the motion of the left ventricle of the heart. HARP uses magnetic resonance tagging, Fourier filtering and special processing algorithms to calculate key indices of myocardial motion including Eulerian and Lagrangian strain. This paper presents several new methods for visualizing myocardial motion based on HARP. Quantities that are computed and visualized include motion grids, velocity fields, strain rates, pathlines, tracked Eulerian strain, and contraction angle. The computations are fast and fully automated and have the potential for clinical application.

  5. Stimulating Myocardial Regeneration with Periostin Peptide in Large Mammals Improves Function Post-Myocardial Infarction but Increases Myocardial Fibrosis

    PubMed Central

    Ladage, Dennis; Yaniz-Galende, Elisa; Rapti, Kleopatra; Ishikawa, Kiyotake; Tilemann, Lisa; Shapiro, Scott; Takewa, Yoshiaki; Muller-Ehmsen, Jochen; Schwarz, Martin; Garcia, Mario J.; Sanz, Javier; Hajjar, Roger J.; Kawase, Yoshiaki

    2013-01-01

    Aims Mammalian myocardium has a finite but limited capacity to regenerate. Experimentally stimulating proliferation of cardiomyocytes with extracellular regeneration factors like periostin enhances cardiac repair in rodents. The aim of this study was to develop a safe method for delivering regeneration factors to the heart and to test the functional and structural effects of periostin peptide treatment in a large animal model of myocardial infarction (MI). Methods and Results We developed a controlled release system to deliver recombinant periostin peptide into the pericardial space. A single application of this method was performed two days after experimental MI in swine. Animals were randomly assigned to receive either saline or periostin peptide. Experimental groups were compared at baseline, day 2, 1 month and 3 months. Treatment with periostin peptide increased the EF from 31% to 41% and decreased by 22% the infarct size within 12 weeks. Periostin peptide-treated animals had newly formed myocardium strips within the infarct scar, leading to locally improved myocardial function. In addition the capillary density was increased in animals receiving periostin. However, periostin peptide treatment increased myocardial fibrosis in the remote region at one week and 12 weeks post-treatment. Conclusion Our study shows that myocardial regeneration through targeted peptides is possible. However, in the case of periostin the effects on cardiac fibrosis may limit its clinical application as a viable therapeutic strategy. PMID:23700403

  6. Assessment of Myocardial Fibrosis with Cardiac Magnetic Resonance

    PubMed Central

    Nathan, Mewton; Ying, Liu Chia; Pierre, Croisille; David, Bluemke; João, Lima

    2011-01-01

    Diffuse interstitial or replacement myocardial fibrosis are common features of a broad variety of cardiomyopathies. Myocardial fibrosis leads to impaired cardiac diastolic and systolic function and is related to adverse cardiovascular events. Cardiac magnetic resonance (CMR) may uniquely characterize the extent of replacement fibrosis and may have prognostic value in various cardiomyopathies. Myocardial T1 mapping is an emerging technique that could improve CMR’s diagnostic accuracy especially for interstitial diffuse myocardial fibrosis. As such, CMR could be integrated in the monitoring and the therapeutic management of a large number of patients. This review summarizes the advantages and limitations of CMR for the assessment of myocardial fibrosis. PMID:21329834

  7. Assessment of myocardial fibrosis with cardiovascular magnetic resonance.

    PubMed

    Mewton, Nathan; Liu, Chia Ying; Croisille, Pierre; Bluemke, David; Lima, João A C

    2011-02-22

    Diffuse interstitial or replacement myocardial fibrosis is a common feature of a broad variety of cardiomyopathies. Myocardial fibrosis leads to impaired cardiac diastolic and systolic function and is related to adverse cardiovascular events. Cardiovascular magnetic resonance (CMR) may uniquely characterize the extent of replacement fibrosis and may have prognostic value in various cardiomyopathies. Myocardial longitudinal relaxation time mapping is an emerging technique that could improve CMR's diagnostic accuracy, especially for interstitial diffuse myocardial fibrosis. As such, CMR could be integrated in the monitoring and therapeutic management of a large number of patients. This review summarizes the advantages and limitations of CMR for the assessment of myocardial fibrosis. PMID:21329834

  8. Relationship between post-cardiac arrest myocardial oxidative stress and myocardial dysfunction in the rat

    PubMed Central

    2014-01-01

    Background Reperfusion after resuscitation from cardiac arrest (CA) is an event that increases reactive oxygen species production leading to oxidative stress. More specifically, myocardial oxidative stress may play a role in the severity of post-CA myocardial dysfunction. This study investigated the relationship between myocardial oxidative stress and post-CA myocardial injury and dysfunction in a rat model of CA and cardiopulmonary resuscitation (CPR). Ventricular fibrillation was induced in 26 rats and was untreated for 6 min. CPR, including mechanical chest compression, ventilation, and epinephrine, was then initiated and continued for additional 6 min prior to defibrillations. Resuscitated animals were sacrificed at two h (n = 9), 4 h (n = 6) and 72 h (n = 8) following resuscitation, and plasma collected for assessment of: high sensitivity cardiac troponin T (hs-cTnT), as marker of myocardial injury; isoprostanes (IsoP), as marker of lipid peroxidation; and 8-hydroxyguanosine (8-OHG), as marker of DNA oxidative damage. Hearts were also harvested for measurement of tissue IsoP and 8-OHG. Myocardial function was assessed by echocardiography at the corresponding time points. Additional 8 rats were not subjected to CA and served as baseline controls. Results Compared to baseline, left ventricular ejection fraction (LVEF) was reduced at 2 and 4 h following resuscitation (p < 0.01), while it was similar at 72 h. Inversely, plasma hs-cTnT increased, compared to baseline, at 2 and 4 h post-CA (p < 0.01), and then recovered at 72 h. Similarly, plasma and myocardial tissue IsoP and 8-OHG levels increased at 2 and 4 h post-resuscitation (p < 0.01 vs. baseline), while returned to baseline 72 h later. Myocardial IsoP were directly related to hs-cTnT levels (r = 0.760, p < 0.01) and inversely related to LVEF (r = -0.770, p < 0.01). Myocardial 8-OHG were also directly related to hs-cTnT levels (r = 0.409, p < 0.05) and

  9. Myocardial Ischemia: Lack of Coronary Blood Flow or Myocardial Oxygen Supply/Demand Imbalance?

    PubMed

    Heusch, Gerd

    2016-07-01

    Regional myocardial blood flow and contractile function in ischemic myocardium are well matched, and there is no evidence for an oxygen supply/demand imbalance. Thus, myocardial ischemia is lack of coronary blood flow with electric, functional, metabolic, and structural consequences for the myocardium. All therapeutic interventions must aim to improve blood flow to ischemic myocardium as much and as quickly as possible. PMID:27390331

  10. Association of fragmented QRS complex with myocardial reperfusion in acute ST-elevated myocardial infarction.

    PubMed

    Erdem, Fatma Hizal; Tavil, Yusuf; Yazici, Hüseyin; Aygül, Nazif; Abaci, Adnan; Boyaci, Bülent

    2013-01-01

    In this study, we aimed to evaluate the relationship between TIMI myocardial perfusion (TMP) grade, as an indicator of myocardial reperfusion, and fragmented QRS (fQRS) in standard 12-lead electrocardiogram. Also, we evaluate fQRS is an additional indicator of myocardial reperfusion. One hundred patients admitted with first STEMI to Coronary Intensive Care Unit and who were used thrombolytic therapy was included in this retrospective study. Standard 12-lead electrocardiogram records of patients simultaneous with coronary angiography (second day) were assessed and analysed for the presence of fQRS. Also, coronary angiography images were analyzed to identify the infarct related artery, TIMI grade of infarct related artery and TMP grade of infarct related artery. The patients with fQRS demonstrated a significantly lower TMP grade, TIMI grade and ejection fraction compared with the non-fQRS patients (P = 0.004, P = 0.003, P = 0.02 respectively). The patients with inadequate myocardial reperfusion demonstrated a significantly higher fQRS compared with the adequate myocardial reperfusion patients. (56.9% versus 23.5%, P = 0.002 respectively). On correlation analysis, there was a significant negative correlation between fQRS and left ventricular ejection fraction (r = -232, P = 0.02) TMP grade and adequate myocardial reperfusion (TMP 3) showed significant negative correlation with fQRS (r = -0.370, P = 0.000; r = -0.318, P = 0.001 respectively). Presence of fragmented QRS in STEMI patients was associated with inadequate myocardial reperfusion and it can be used as a simple, noninvasive parameter to evaluate myocardial reperfusion.

  11. Relation of impaired Thrombolysis In Myocardial Infarction myocardial perfusion grades to residual thrombus following the restoration of epicardial patency in ST-elevation myocardial infarction.

    PubMed

    Kirtane, Ajay J; Weisbord, Aaron; Karmpaliotis, Dimitrios; Murphy, Sabina A; Giugliano, Robert P; Cannon, Christopher P; Antman, Elliott M; Ohman, E Magnus; Roe, Matthew T; Braunwald, Eugene; Gibson, C Michael

    2005-01-15

    Clinical and angiographic data were analyzed from 929 patients who had ST-elevation myocardial infarction and open epicardial arteries after fibrinolytic therapy. Residual angiographically evident thrombus was associated with more frequent Thrombolysis In Myocardial Infarction (TIMI) grade 2 flow (33.6% vs 26.8%, p = 0.03), higher corrected TIMI frame counts (34 vs 31 frames, p = 0.0003), and lower TIMI myocardial perfusion grades (43.0% vs 32.0% TIMI myocardial perfusion grades 0/1, p = 0.001) among all patients and among patients who had TIMI grade 3 flow (33.5% vs 26.0% TIMI myocardial perfusion grades 0/1, p = 0.043). In multivariate analyses, angiographically evident thrombus was associated with higher corrected TIMI frame counts and worsened myocardial perfusion independent of clinical and angiographic covariates, including TIMI grade 3 flow.

  12. Role of lymphocytes in myocardial injury, healing, and remodeling after myocardial infarction.

    PubMed

    Hofmann, Ulrich; Frantz, Stefan

    2015-01-16

    A large body of evidence produced during decades of research indicates that myocardial injury activates innate immunity. On the one hand, innate immunity both aggravates ischemic injury and impedes remodeling after myocardial infarction (MI). On the other hand, innate immunity activation contributes to myocardial healing, as exemplified by monocytes' central role in the formation of a stable scar and protection against intraventricular thrombi after acute infarction. Although innate leukocytes can recognize a wide array of self-antigens via pattern recognition receptors, adaptive immunity activation requires highly specific cooperation between antigen-presenting cells and distinct antigen-specific receptors on lymphocytes. We have only recently begun to examine lymphocyte activation's relationship to adaptive immunity and significance in the context of ischemic myocardial injury. There is some experimental evidence that CD4(+) T-cells contribute to ischemia-reperfusion injury. Several studies have shown that CD4(+) T-cells, especially CD4(+) T-regulatory cells, improve wound healing after MI, whereas depleting B-cells is beneficial post MI. That T-cell activation after MI is induced by T-cell receptor signaling implicates autoantigens that have not yet been identified in this context. Also, the significance of lymphocytes in humans post MI remains unclear, primarily as a result of methodology. This review summarizes current experimental evidence of lymphocytes' activation, functional role, and crosstalk with innate leukocytes in myocardial ischemia-reperfusion injury, wound healing, and remodeling after myocardial infarction.

  13. Myocardial ischemic protection in natural mammalian hibernation.

    PubMed

    Yan, Lin; Kudej, Raymond K; Vatner, Dorothy E; Vatner, Stephen F

    2015-03-01

    Hibernating myocardium is an important clinical syndrome protecting the heart with chronic myocardial ischemia, named for its assumed resemblance to hibernating mammals in winter. However, the effects of myocardial ischemic protection have never been studied in true mammalian hibernation, which is a unique strategy for surviving extreme winter environmental stress. The goal of this investigation was to test the hypothesis that ischemic stress may also be protected in woodchucks as they hibernate in winter. Myocardial infarction was induced by coronary occlusion followed by reperfusion in naturally hibernating woodchucks in winter with and without hibernation and in summer, when not hibernating. The ischemic area at risk was similar among groups. Myocardial infarction was significantly less in woodchucks in winter, whether hibernating or not, compared with summer, and was similar to that resulting after ischemic preconditioning. Whereas several genes were up or downregulated in both hibernating woodchuck and with ischemic preconditioning, one mechanism was unique to hibernation, i.e., activation of cAMP-response element binding protein (CREB). When CREB was upregulated in summer, it induced protection similar to that observed in the woodchuck heart in winter. The cardioprotection in hibernation was also mediated by endothelial nitric oxide synthase, rather than inducible nitric oxide synthase. Thus, the hibernating woodchuck heart is a novel model to study cardioprotection for two major reasons: (1) powerful cardioprotection occurs naturally in winter months in the absence of any preconditioning stimuli, and (2) it resembles ischemic preconditioning, but with novel mechanisms, making this model potentially useful for clinical translation.

  14. Myocardial ischemic protection in natural mammalian hibernation.

    PubMed

    Yan, Lin; Kudej, Raymond K; Vatner, Dorothy E; Vatner, Stephen F

    2015-03-01

    Hibernating myocardium is an important clinical syndrome protecting the heart with chronic myocardial ischemia, named for its assumed resemblance to hibernating mammals in winter. However, the effects of myocardial ischemic protection have never been studied in true mammalian hibernation, which is a unique strategy for surviving extreme winter environmental stress. The goal of this investigation was to test the hypothesis that ischemic stress may also be protected in woodchucks as they hibernate in winter. Myocardial infarction was induced by coronary occlusion followed by reperfusion in naturally hibernating woodchucks in winter with and without hibernation and in summer, when not hibernating. The ischemic area at risk was similar among groups. Myocardial infarction was significantly less in woodchucks in winter, whether hibernating or not, compared with summer, and was similar to that resulting after ischemic preconditioning. Whereas several genes were up or downregulated in both hibernating woodchuck and with ischemic preconditioning, one mechanism was unique to hibernation, i.e., activation of cAMP-response element binding protein (CREB). When CREB was upregulated in summer, it induced protection similar to that observed in the woodchuck heart in winter. The cardioprotection in hibernation was also mediated by endothelial nitric oxide synthase, rather than inducible nitric oxide synthase. Thus, the hibernating woodchuck heart is a novel model to study cardioprotection for two major reasons: (1) powerful cardioprotection occurs naturally in winter months in the absence of any preconditioning stimuli, and (2) it resembles ischemic preconditioning, but with novel mechanisms, making this model potentially useful for clinical translation. PMID:25613166

  15. Myocardial infection due to Fusobacterium nucleatum.

    PubMed

    Storm, Jeremy C; Ford, Bradley A; Streit, Judy A

    2013-12-01

    Fusobacterium nucleatum is an anaerobic gram-negative bacillus, which inhabits the oropharynx, gastrointestinal tract, and female genital tract. Infections classically affect the head and neck. We report a patient with a myocardial mass due to F. nucleatum, initially thought to be a neoplasm, and discuss anaerobic cardiac infections.

  16. Rehabilitation of Patients Following Myocardial Infarction.

    ERIC Educational Resources Information Center

    Blumenthal, James A.; Emery, Charles F.

    1988-01-01

    Examines three behavioral strategies in cardiac rehabilitation (CR) for formal treatment for physical and psychosocial sequelae of myocardial infarction (MI): exercise therapy, Type A modification, and nonspecific psychological therapies. Concludes CR improves the quality of life among post-MI patients, but does not prolong life or significantly…

  17. 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.

  18. Circadian rhythms in myocardial metabolism and function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Circadian rhythms in myocardial function and dysfunction are firmly established in both animal models and humans. For example, the incidence of arrhythmias and sudden cardiac death increases when organisms awaken. Such observations have classically been explained by circadian rhythms in neurohumoral...

  19. [Myocardial infarction after conduction electrical weapon shock].

    PubMed

    Ben Ahmed, H; Bouzouita, K; Selmi, K; Chelli, M; Mokaddem, A; Ben Ameur, Y; Boujnah, M R

    2013-04-01

    Controversy persists over the safety of conducted electrical weapons, which are increasingly used by law enforcement agencies around the world. We report a case of 33-year-old man who had an acute inferior myocardial infarction after he was shot in the chest with an electrical weapon.

  20. Cardiac MRI evaluation of myocardial disease.

    PubMed

    Captur, Gabriella; Manisty, Charlotte; Moon, James C

    2016-09-15

    Cardiovascular magnetic resonance (CMR) is a key imaging technique for cardiac phenotyping with a major clinical role. It can assess advanced aspects of cardiac structure and function, scar burden and other myocardial tissue characteristics but there is new information that can now be derived. This can fill many of the gaps in our knowledge with the potential to change thinking, disease classifications and definitions as well as patient care. Established techniques such as the late gadolinium enhancement technique are now embedded in clinical care. New techniques are coming through. Myocardial tissue characterisation techniques, particularly myocardial mapping can precisely measure tissue magnetisation-T1, T2, T2* and also the extracellular volume. These change in disease. Key biological pathways are now open for scrutiny including focal fibrosis (scar) and diffuse fibrosis, inflammation, metabolism and infiltration. Other new areas to engage in where major insights are growing include detailed assessments of myocardial mechanics and performance, spectroscopy and hyperpolarised CMR. In spite of the advances, challenges remain, particularly surrounding utilisation, technical development to improve accuracy, reproducibility and deliverability, and the role of multidisciplinary research to understand the detailed pathological basis of the MR signal changes. Collectively, these new developments are galvanising CMR uptake and having a major translational impact on healthcare globally and it is steadily becoming key imaging tool. PMID:27354273

  1. Systemic Atherosclerotic Inflammation Following Acute Myocardial Infarction: Myocardial Infarction Begets Myocardial Infarction

    PubMed Central

    Joshi, Nikhil V; Toor, Iqbal; Shah, Anoop S V; Carruthers, Kathryn; Vesey, Alex T; Alam, Shirjel R; Sills, Andrew; Hoo, Teng Y; Melville, Adam J; Langlands, Sarah P; Jenkins, William S A; Uren, Neal G; Mills, Nicholas L; Fletcher, Alison M; van Beek, Edwin J R; Rudd, James H F; Fox, Keith A A; Dweck, Marc R; Newby, David E

    2015-01-01

    Background Preclinical data suggest that an acute inflammatory response following myocardial infarction (MI) accelerates systemic atherosclerosis. Using combined positron emission and computed tomography, we investigated whether this phenomenon occurs in humans. Methods and Results Overall, 40 patients with MI and 40 with stable angina underwent thoracic 18F-fluorodeoxyglucose combined positron emission and computed tomography scan. Radiotracer uptake was measured in aortic atheroma and nonvascular tissue (paraspinal muscle). In 1003 patients enrolled in the Global Registry of Acute Coronary Events, we assessed whether infarct size predicted early (≤30 days) and late (>30 days) recurrent coronary events. Compared with patients with stable angina, patients with MI had higher aortic 18F-fluorodeoxyglucose uptake (tissue-to-background ratio 2.15±0.30 versus 1.84±0.18, P<0.0001) and plasma C-reactive protein concentrations (6.50 [2.00 to 12.75] versus 2.00 [0.50 to 4.00] mg/dL, P=0.0005) despite having similar aortic (P=0.12) and less coronary (P=0.006) atherosclerotic burden and similar paraspinal muscular 18F-fluorodeoxyglucose uptake (P=0.52). Patients with ST-segment elevation MI had larger infarcts (peak plasma troponin 32 300 [10 200 to >50 000] versus 3800 [1000 to 9200] ng/L, P<0.0001) and greater aortic 18F-fluorodeoxyglucose uptake (2.24±0.32 versus 2.02±0.21, P=0.03) than those with non–ST-segment elevation MI. Peak plasma troponin concentrations correlated with aortic 18F-fluorodeoxyglucose uptake (r=0.43, P=0.01) and, on multivariate analysis, independently predicted early (tertile 3 versus tertile 1: relative risk 4.40 [95% CI 1.90 to 10.19], P=0.001), but not late, recurrent MI. Conclusions The presence and extent of MI is associated with increased aortic atherosclerotic inflammation and early recurrent MI. This finding supports the hypothesis that acute MI exacerbates systemic atherosclerotic inflammation and remote plaque destabilization

  2. Type 2 myocardial infarction: the chimaera of cardiology?

    PubMed

    Collinson, Paul; Lindahl, Bertil

    2015-11-01

    The term type 2 myocardial infarction first appeared as part of the universal definition of myocardial infarction. It was introduced to cover a group of patients who had elevation of cardiac troponin but did not meet the traditional criteria for acute myocardial infarction although they were considered to have an underlying ischaemic aetiology for the myocardial damage observed. Since first inception, the term type 2 myocardial infarction has always been vague. Although attempts have been made to produce a systematic definition of what constitutes a type 2 myocardial infarction, it has been more often characterised by what it is not rather than what it is. Clinical studies that have used type 2 myocardial infarction as a diagnostic criterion have produced disparate incidence figures. The range of associated clinical conditions differs from study to study. Additionally, there are no agreed or evidence-based treatment strategies for type 2 myocardial infarction. The authors believe that the term type 2 myocardial infarction is confusing and not evidence-based. They consider that there is good reason to stop using this term and consider instead the concept of secondary myocardial injury that relates to the underlying pathophysiology of the primary clinical condition.

  3. Protective effect of taurine on myocardial antioxidant status in isoprenaline-induced myocardial infarction in rats.

    PubMed

    Shiny, K S; Kumar, S Hari Senthil; Farvin, K H Sabeena; Anandan, R; Devadasan, K

    2005-10-01

    We have examined the protective effect of taurine on the myocardial antioxidant defense system in isoprenaline (isoproterenol)-induced myocardial infarction in rats, an animal model of myocardial infarction in man. Levels of diagnostic marker enzymes in plasma, lipid peroxides and reduced glutathione, and the activity of glutathione-dependent antioxidant enzymes and anti-peroxidative enzymes in the heart tissue were determined. Intraperitoneal administration of taurine significantly prevented the isoprenaline-induced increases in the levels of alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and creatine phosphokinase in the plasma of rats. Taurine exerted an antioxidant effect against isoprenaline-induced myocardial infarction by preventing the accumulation of lipid peroxides and by maintaining the level of reduced glutathione and the activity of glutathione peroxidase, glutathione-S-transferase, catalase and superoxide dismutase at near normality. The results indicated that the cardioprotective potential of taurine was probably due to the increase of the activity of the free radical enzymes, or to a counteraction of free radicals by its antioxidant nature, or to a strengthening of myocardial membrane by its membrane stabilizing property.

  4. Regional left ventricular myocardial contractility and stress in a finite element model of posterobasal myocardial infarction.

    PubMed

    Wenk, Jonathan F; Sun, Kay; Zhang, Zhihong; Soleimani, Mehrdad; Ge, Liang; Saloner, David; Wallace, Arthur W; Ratcliffe, Mark B; Guccione, Julius M

    2011-04-01

    Recently, a noninvasive method for determining regional myocardial contractility, using an animal-specific finite element (FE) model-based optimization, was developed to study a sheep with anteroapical infarction (Sun et al., 2009, "A Computationally Efficient Formal Optimization of Regional Myocardial Contractility in a Sheep With Left Ventricular Aneurysm," ASME J. Biomech. Eng., 131(11), p. 111001). Using the methodology developed in the previous study (Sun et al., 2009, "A Computationally Efficient Formal Optimization of Regional Myocardial Contractility in a Sheep With Left Ventricular Aneurysm," ASME J. Biomech. Eng., 131(11), p. 111001), which incorporates tagged magnetic resonance images, three-dimensional myocardial strains, left ventricular (LV) volumes, and LV cardiac catheterization pressures, the regional myocardial contractility and stress distribution of a sheep with posterobasal infarction were investigated. Active material parameters in the noninfarcted border zone (BZ) myocardium adjacent to the infarct (T(max_B)), in the myocardium remote from the infarct (T(max_R)), and in the infarct (T(max_I)) were estimated by minimizing the errors between FE model-predicted and experimentally measured systolic strains and LV volumes using the previously developed optimization scheme. The optimized T(max_B) was found to be significantly depressed relative to T(max_R), while T(max_I) was found to be zero. The myofiber stress in the BZ was found to be elevated, relative to the remote region. This could cause further damage to the contracting myocytes, leading to heart failure.

  5. Myocarditis confirmed by biopsy presenting as acute myocardial infarction.

    PubMed Central

    Costanzo-Nordin, M R; O'Connell, J B; Subramanian, R; Robinson, J A; Scanlon, P J

    1985-01-01

    Two cases of acute myocardial infarction occurred in association with myocarditis, which was confirmed by biopsy. The first patient suffered an anteroseptal and the second patient an inferior wall myocardial infarction shortly after an acute viral illness. In both patients, coronary angiography showed normal coronary arteries, and right ventricular endomyocardial biopsy confirmed myocarditis. Histological abnormalities attributable to ischaemic heart disease were absent. The first patient's condition became stable after immunosuppressive treatment. Myocarditis resolved spontaneously within three months in the second patient. Coronary artery spasm and myocardial involvement with a systemic disease were unlikely. Endomyocardial biopsy in patients with acute myocardial infarction and normal coronary arteries may be useful in identifying myocarditis associated with myocardial necrosis. Myocarditis in acute myocardial infarction in the absence of coronary artery obstruction has not previously been documented during life. Images PMID:3966948

  6. [Myocardial viability, its importance for the therapeutic decision].

    PubMed

    Alexánderson, Erick; Ricalde, Alejandro; Meave, Aloha

    2005-01-01

    Myocardial viability detection is essential in patients with history of myocardial infarction whom develop ventricular dysfunction. Its detection influences the therapeutic decisions and the prognosis. Medical therapy in patients with ventricular dysfunction due to myocardial infarction and myocardial viability has been associated with higher morbidity and mortality rates than revascularization therapy, as well as improvements in the systolic function. Several imaging techniques used in the recognition of myocardial viability are available; these techniques are based on the assessment of the ventricular motion posterior to inotropic agents stimulation or on the demonstration of metabolic activity at the dysfunctional regions. In this study, some important aspects of each technique are reviewed, doing special emphasis in the utility of the Positron Emission Tomography (PET) which has been considered as the "gold standard" in the detection of myocardial viability. PMID:15909735

  7. Multimodality Imaging of Myocardial Injury and Remodeling

    PubMed Central

    Kramer, Christopher M.; Sinusas, Albert J.; Sosnovik, David E.; French, Brent A.; Bengel, Frank M.

    2011-01-01

    Advances in cardiovascular molecular imaging have come at a rapid pace over the last several years. Multiple approaches have been taken to better understand the structural, molecular, and cellular events that underlie the progression from myocardial injury to myocardial infarction (MI) and, ultimately, to congestive heart failure. Multimodality molecular imaging including SPECT, PET, cardiac MRI, and optical approaches is offering new insights into the pathophysiology of MI and left ventricular remodeling in small-animal models. Targets that are being probed include, among others, angiotensin receptors, matrix metalloproteinases, integrins, apoptosis, macrophages, and sympathetic innervation. It is only a matter of time before these advances are applied in the clinical setting to improve post-MI prognostication and identify appropriate therapies in patients to prevent the onset of congestive heart failure. PMID:20395347

  8. Matrix metalloproteinases: drug targets for myocardial infarction

    PubMed Central

    Yabluchanskiy, Andriy; Li, Yaojun; Chilton, Robert J.; Lindsey, Merry L.

    2013-01-01

    Myocardial infarction (MI) remains a major cause of morbidity and mortality worldwide. Rapid advances in the treatment of acute MI have significantly improved short-term outcomes in patient, due in large part to successes in preventing myocardial cell death and limiting infarct area during the time of ischemia and subsequent reperfusion. Matrix metalloproteases (MMPs) play key roles in post-MI cardiac remodeling and in the development of adverse outcomes. This review highlights the importance of MMPs in the injury and remodeling response of the left ventricle and also discusses their potential as therapeutic targets Additional pre-clinical and clinical research is needed to further investigate and understand the cardioprotective effects of MMPs inhibitors. PMID:23316962

  9. Amphetamine Abuse Related Acute Myocardial Infarction

    PubMed Central

    Lewis, O'Dene; Kumar, Rajan; Yeruva, Sri Lakshmi Hyndavi; Curry, Bryan H.

    2016-01-01

    Amphetamine abuse is a global problem. The cardiotoxic manifestations like acute myocardial infarction (AMI), heart failure, or arrhythmia related to misuse of amphetamine and its synthetic derivatives have been documented but are rather rare. Amphetamine-related AMI is even rarer. We report two cases of men who came to emergency department (ED) with chest pain, palpitation, or seizure and were subsequently found to have myocardial infarction associated with the use of amphetamines. It is crucial that, with increase in amphetamine abuse, clinicians are aware of this potentially dire complication. Patients with low to intermediate risk for coronary artery disease with atypical presentation may benefit from obtaining detailed substance abuse history and urine drug screen if deemed necessary. PMID:26998366

  10. Myocardial contractile function and intradialytic hypotension.

    PubMed

    Owen, Paul J; Priestman, William S; Sigrist, Mhairi K; Lambie, Stewart H; John, Stephen G; Chesterton, Lindsay J; McIntyre, Christopher W

    2009-07-01

    Dialysis-induced hypotension remains a significant problem in hemodialysis (HD) patients. Numerous factors result in dysregulation of blood pressure control and impaired myocardial reserve in response to HD-induced cardiovascular stress. Episodic intradialytic hypotension may be involved in the pathogenesis of evolving myocardial injury. We performed an initial pilot investigation of cardiovascular functional response to pharmacological cardiovascular stress in hypotension-resistant (HR) and hypotension-prone (HP) HD patients. We studied 10 matched chronic HD patients (5 HP, 5 HR). Dobutamine-atropine stress (DAS) was performed on a nondialysis short interval day, with noninvasive pulse-wave analysis using the Finometer to continuously measure hemodynamic variables. Baroreflex sensitivity was assessed at rest and during DAS. Baseline hemodynamic variables were not significantly different. The groups had differing hemodynamic responses to DAS. The Mean arterial pressure was unchanged in the HR group but decreased in HP patients (-13.6 +/- 3.5 mmHg; P<0.001). This was associated with failure to significantly increase cardiac output in the HP group (cf. increase in cardiac output in the HR group of +33.4 +/- 6%; P<0.05), and a reduced response in total peripheral resistance (HP -10.3 +/- 6.8%, HR -22.7 +/- 2.9%, P=NS). Baroreflex sensitivity was not significantly different between groups at baseline or within groups with increasing levels of DAS; however, the mean baroreflex sensitivity was higher in HR cf. HP subjects throughout pharmacological stress (P<0.05). Hypotension-prone patients appear to have an impaired cardiovascular response to DAS. The most significant abnormality is an impaired myocardial contractile reserve. Early identification of these patients would allow utilization of therapeutic strategies to improve intradialytic tolerability, potentially abrogating aggravation of myocardial injury.

  11. Myocardial infarction due to lightning strike.

    PubMed

    Karadas, Sevdegul; Vuruskan, Ertan; Dursun, Recep; Sincer, Isa; Gonullu, Hayriye; Akkaya, Emre

    2013-09-01

    Cardiac events due to lightning strike and their severity vary according to the strength of the electric current and the duration of exposure. The electrophysiological effects of lightning on the heart can result in ventricular fibrillation, asystole, QT prolongation, supraventricular tachycardia, and non-specific ST-T wave changes. In this report, a case of a patient who suffered myocardial infarction due to lightning strike is presented, which is a rare complication. PMID:24601203

  12. Acute Myocardial Infarction in Nephrotic Syndrome.

    PubMed

    Krishna, Kavita; Hiremath, Shirish; Lakade, Sachin; Davakhar, Sudarshan

    2015-11-01

    A 28 year old male, known case of nephrotic syndrome since 12 years, hypertensive presented with acute myocardial infarction (AMI) and accelerated hypertension. Coronary angiography revealed 100% thrombotic occlusion of mid left anterior descending artery, treated with thrombus aspiration and intracoronary tirofiban and nitroglycerine. He was stabilized within 24 hours. The pathogenesis of AMI in nephrotic syndrome has been discussed with this case report. PMID:27608787

  13. Transmural Myocardial Mechanics During Isovolumic Contraction

    PubMed Central

    Ashikaga, Hiroshi; van der Spoel, Tycho I. G.; Coppola, Benjamin A.; Omens, Jeffrey H.

    2010-01-01

    OBJECTIVES We sought to resolve the 3-dimensional transmural heterogeneity in myocardial mechanics observed during the isovolumic contraction (IC) phase. BACKGROUND Although myocardial deformation during IC is expected to be little, recent tissue Doppler imaging studies suggest dynamic myocardial motions during this phase with biphasic longitudinal tissue velocities in left ventricular (LV) long-axis views. A unifying understanding of myocardial mechanics that would account for these dynamic aspects of IC is lacking. METHODS We determined the time course of 3-dimensional finite strains in the anterior LV of 14 adult mongrel dogs in vivo during IC and ejection with biplane cineradiography of implanted transmural markers. Transmural fiber orientations were histologically measured in the heart tissue postmortem. The strain time course was determined in the subepicardial, midwall, and subendocardial layers referenced to the end-diastolic configuration. RESULTS During IC, there was circumferential stretch in the subepicardial layer, whereas circumferential shortening was observed in the midwall and the subendocardial layer. There was significant longitudinal shortening and wall thickening across the wall. Although longitudinal tissue velocity showed a biphasic profile; tissue deformation in the longitudinal as well as other directions was almost linear during IC. Subendocardial fibers shortened, whereas subepicardial fibers lengthened. During ejection, all strain components showed a significant change over time that was greater in magnitude than that of IC. Significant transmural gradient was observed in all normal strains. CONCLUSIONS IC is a dynamic phase characterized by deformation in circumferential, longitudinal, and radial directions. Tissue mechanics during IC, including fiber shortening, appear uninterrupted by rapid longitudinal motion created by mitral valve closure. This study is the first to report layer-dependent deformation of circumferential strain

  14. PICSO: from myocardial salvage to tissue regeneration.

    PubMed

    Mohl, Werner; Gangl, Clemens; Jusić, Alem; Aschacher, Thomas; De Jonge, Martin; Rattay, Frank

    2015-01-01

    Despite advances in primary percutaneous interventions (PPCI), management of microvascular obstructions in reperfused myocardial tissue remains challenging and is a high-risk procedure. This has led to renewed interest in the coronary venous system as an alternative route of access to the myocardium. This article reviews historical data describing therapeutic options via cardiac veins as well as discussing the clinical potential and limitations of a catheter intervention: pressure controlled intermittent coronary sinus occlusion (PICSO). Collected experimental and clinical information suggest that PICSO also offers the potential for tissue regeneration beyond myocardial salvage. A meta-analysis of observer controlled pICSO application in animal studies showed a dose dependent reduction in infarct size of 29.3% (p < 0.001). Additionally, a 4-fold increase of hemeoxygenase-1 gene expression (p < 0.001) in the center of infarction and a 2.5 fold increase of vascular endothelial growth factor (VEGF) (p < 0.002) in border zones suggest that molecular pathways are initiating structural maintenance. Early clinical evidence confirmed significant salvage and event free survival in patients with acute myocardial infarction and risk reduction for event free survival 5 years after the acute event (p < 0.0001). This experimental and clinical evidence was recently corroborated using modern PICSO technology in PPCI showing a significant reduction of infarct size, when compared to matched controls (p < 0.04). PICSO enhances redistribution of flow towards deprived zones, clearing microvascular obstruction and leading to myocardial protection. Beyond salvage, augmentation of molecular regenerative networks suggests a second mechanism of PICSO involving the activation of vascular cells in cardiac veins, thus enhancing structural integrity and recovery. PMID:25616738

  15. Thallium-201 myocardial imaging in children

    SciTech Connect

    Sty, J.R.; Starshak, R.J.

    1985-01-01

    The clinical applications of thallium-201 scintigraphy are less well defined in children than in adults. However, the published data indicate several potential applications including assessment of: 1) deficit in left ventricular myocardial perfusion, 2) early right ventricular volume or pressure overload, or both, and 3) the right ventricle in both cyanotic and acyanotic congenital heart disease. In this report, the applications of thallium imaging to pediatric diseases are described and the advantages and disadvantages of the procedure are enumerated.

  16. Myocardial infarction due to lightning strike.

    PubMed

    Karadas, Sevdegul; Vuruskan, Ertan; Dursun, Recep; Sincer, Isa; Gonullu, Hayriye; Akkaya, Emre

    2013-09-01

    Cardiac events due to lightning strike and their severity vary according to the strength of the electric current and the duration of exposure. The electrophysiological effects of lightning on the heart can result in ventricular fibrillation, asystole, QT prolongation, supraventricular tachycardia, and non-specific ST-T wave changes. In this report, a case of a patient who suffered myocardial infarction due to lightning strike is presented, which is a rare complication.

  17. Radioiodine therapy of hyperthyroidism precludes thallium-201 myocardial scintigraphy

    SciTech Connect

    Orzel, J.A.; Kruyer, W.B.; Borchert, R.D.

    1987-02-01

    The authors attempted to perform Tl-201 myocardial perfusion scintigraphy in a 42-year-old man 23 and 35 days after he received 9.8 mCi of oral I-131 for documented Graves' disease. Interference from primary and scattered photons from residual thyroid I-131 made Tl-201 myocardial scintigraphy technically impossible. A series of phantom and patient studies using I-131 and Tl-201 were performed, yielding guidelines for planning Tl-201 myocardial scintigraphy following radioiodine therapy.

  18. Myocardial infarction association with the Riley-Day syndrome.

    PubMed

    Reshef, R; Aderka, D; Suprun, H; Manelis, G; Manelis, J

    1977-10-01

    The "sudden death" of a 23-year-old Ashkenazy Jew, suffering from "familial dysautonomia" was probably caused by an arrhythmia accompanying a myocardial infarction. Such a report is unique. Diffuse coronary atherosclerosis and direct myocardial "catecholamine cardiomyopathy" seem responsible for the myocardial damage. However, diversion of the endocardial blood flow toward dpicardium and a "coronary steal" phenomenon, both the result of a sudden catecholamine discharge, could aggravate the ischemic injury.

  19. 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

  20. 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

  1. PARP inhibition and postinfarction myocardial remodeling.

    PubMed

    Halmosi, Robert; Deres, Laszlo; Gal, Roland; Eros, Krisztian; Sumegi, Balazs; Toth, Kalman

    2016-08-01

    Coronary artery disease accounts for the greatest proportion of cardiovascular diseases therefore it is the major cause of death worldwide. Its therapeutic importance is indicated by still high mortality of myocardial infarction, which is one of the most severe forms of CVDs. Moreover, the risk of developing heart failure is very high among survivors. Heart failure is accompanied by high morbidity and mortality rate, therefore this topic is in the focus of researchers' interest. After a myocardial infarct, at first ventricular hypertrophy develops as a compensatory mechanism to decrease wall stress but finally leads to left ventricular dilation. This phenomenon is termed as myocardial remodeling. The main characteristics of underlying mechanisms involve cardiomyocyte growth, vessel changes and increased collagen production, in all of which several mechanical stress induced neurohumoral agents, oxidative stress and signal transduction pathways are involved. The long term activation of these processes ultimately leads to left ventricular dilation and heart failure with decreased systolic function. Oxidative stress causes DNA breaks producing the activation of nuclear poly(ADP-ribose) polymerase-1 (PARP-1) enzyme that leads to energy depletion and unfavorable modulation of different kinase cascades (Akt-1/GSK-3β, MAPKs, various PKC isoforms) and thus it promotes the development of heart failure. Therefore inhibition of PARP enzyme could offer a promising new therapeutical approach to prevent the onset of heart failure among postinfarction patients. The purpose of this review is to give a comprehensive summary about the most significant experimental results and mechanisms in postinfarction remodeling. PMID:27392900

  2. Tomoscintigraphic assessment of myocardial metabolic heterogenity

    SciTech Connect

    Roesler, H.; Hess, T.; Weiss, M.; Noelpp, U.; Mueller, G.; Hoeflin, F.; Kinser, J.

    1983-04-01

    I-123-omega-heptadecanoic acid (HDA) was evaluated for myocardial scanning in 59 healthy volunteers and 133 patients, using a 7-pinhole collimator. Early (uptake) and late (retention) images were compared visually. Regional HDA elimination was also followed semiquantitatively based on the calculation of a retention-over-uptake ratio, R(phi), derived from the maximal counts/pixel in 60 midventricular slice sectors. The healthy heart concentrated HDA homogeneously in all segments with no difference between early and late images. The minimal R(phi), taken as representative of that myocardium with the best function, was unchanged after maximal ergometer stress and with dipyramidole-induced hyperperfusion. A circumscribed decreased HDA uptake is the clear-cut criterion for an abnormal finding. HDA tomography of the myocardium had an 86% sensitivity for myocardial infarcts (MIs) up to 4 wk old, and 83% for myocardial scars (MSs). Comparing early and late tomograms, we find a cool-warm sequence more often with acute and subacute MIs. A cool-cool or a cold-cold sequence dominated with MSs. HDA tomoscintigraphy cannot replace TI-201 for the evaluation of regional coronary reserve in coronary heart disease.

  3. Myocardial infarction: management of the subacute period.

    PubMed

    Mercado, Michael G; Smith, Dustin K; McConnon, Michael L

    2013-11-01

    Optimal management of myocardial infarction in the subacute period focuses on improving the discharge planning process, implementing therapies early to prevent recurrent myocardial infarction, and avoiding hospital readmission. Evidence-based guidelines for the care of patients with acute coronary syndrome are not followed up to 25% of the time. Antiplatelet therapy, renin-angiotensin-aldosterone system inhibitors, beta blockers, and statins constitute the foundation of medical therapy. Early noninvasive stress testing is an important risk assessment tool, especially in patients who do not undergo revascularization. Discharge preparation should include a review of medications, referral for exercise-based cardiac rehabilitation, activity recommendations, education about lifestyle modification and recognition of cardiac symptoms, and a clear follow-up plan. Because nonadherence to medications is common in patients after a myocardial infarction and is associated with increased mortality risk, modifiable factors associated with medication self-discontinuation should be addressed before discharge. Structured discharge processes should be used to enhance communication and facilitate the transition from the hospital to the family physician's care.

  4. Combretastatin A4 disodium phosphate-induced myocardial injury.

    PubMed

    Tochinai, Ryota; Nagata, Yuriko; Ando, Minoru; Hata, Chie; Suzuki, Tomo; Asakawa, Naoyuki; Yoshizawa, Kazuhiko; Uchida, Kazumi; Kado, Shoichi; Kobayashi, Toshihide; Kaneko, Kimiyuki; Kuwahara, Masayoshi

    2016-07-01

    Histopathological and electrocardiographic features of myocardial lesions induced by combretastatin A4 disodium phosphate (CA4DP) were evaluated, and the relation between myocardial lesions and vascular changes and the direct toxic effect of CA4DP on cardiomyocytes were discussed. We induced myocardial lesions by administration of CA4DP to rats and evaluated myocardial damage by histopathologic examination and electrocardiography. We evaluated blood pressure (BP) of CA4DP-treated rats and effects of CA4DP on cellular impedance-based contractility of human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs). The results revealed multifocal myocardial necrosis with a predilection for the interventricular septum and subendocardial regions of the apex of the left ventricular wall, injury of capillaries, morphological change of the ST junction, and QT interval prolongation. The histopathological profile of myocardial lesions suggested that CA4DP induced a lack of myocardial blood flow. CA4DP increased the diastolic BP and showed direct effects on hiPS-CMs. These results suggest that CA4DP induces dysfunction of small arteries and capillaries and has direct toxicity in cardiomyocytes. Therefore, it is thought that CA4DP induced capillary and myocardial injury due to collapse of the microcirculation in the myocardium. Moreover, the direct toxic effect of CA4DP on cardiomyocytes induced myocardial lesions in a coordinated manner. PMID:27559241

  5. Myocardial uptake of digoxin in chronically digitalized dogs.

    PubMed Central

    Steiness, E; Valentin, N

    1976-01-01

    1 The time course of myocardial uptake of digoxin, increase in contractility and changes in myocardial potassium concentration was studied for 90 min following an intravenous digoxin dose to long-term digitalized dogs. 2 Nineteen dogs were investigated by the use of a biopsy technique which allowed sampling before and after administration of digoxin. 3 Ten minutes after administration of digoxin the myocardial concentration increased from 60 to 306 nmol/kg tissue, the myocardial concentration of digoxin was significantly lower (250 nmol/kg tissue) after 30 min and then increased again. 4 The transmural myocardial distribution of digoxin was uniform before and 90 min after administration of digoxin in long-term digitalized dogs but at 10 min after administration, both the subepicardial and the subendocardial concentration of digoxin were significantly lower than that of the mesocardial layer. 5 During the first 10 min the dp/dtmax increased to 135% of the control level. The increase remained unchanged during the rest of the study. 6 Myocardial potassium decreased throughout the study. 7 The M-configuration of the myocardial uptake curve and the non-uniformity of myocardial distribution of digoxin observed at 10 min after administrating digoxin to long-term digitalized dogs indicate that the distribution of myocardial blood flow may be changed during chronic digitalization. PMID:1000132

  6. Reduced apoptosis after acute myocardial infarction by simvastatin.

    PubMed

    Luo, Ke-qin; Long, Hui-bao; Xu, Bing-can

    2015-03-01

    To observe the effect of simvastatin in patients with acute myocardial infarction in rabbits against myocardial apoptosis, and to explore its possible mechanism. Male New Zealand white rabbits were randomized into three groups, including the myocardial infarction group (12 rabbits), the simvastatin treatment group (15 rabbits), and the sham group (12 rabbits). In the simvastatin treatment and myocardial infarction groups, the rabbits received myocardial infarction surgeries. While in the sham group, loose knots were tied in the left anterior descending coronary artery branches. The simvastatin treatment group was given simvastatin by oral gavage 24 h after surgery. Parameters, which included left ventricular end-diastolic diameter, left ventricular end-systolic diameter, left ventricular ejection fraction, and left ventricular mass index, were recorded in these three groups. Edge myocardial infarction and myocardial cell apoptosis were analyzed using TUNEL assay, and Bcl-2, Bax, and Caspase-3 protein levels were detected by Western blot. Acute myocardial infarction model was successfully established in rabbits by ligation of the left anterior descending coronary artery. Compared with the myocardial infarction group, left ventricular end-diastolic diameter (LVEDD) and left ventricular end systolic diameter (LVESD) were significantly reduced and left ventricular ejection fraction (LVEF) increased in the simvastatin treatment group. Compared with the sham group, LVEDD and LVESD were significantly increased and LVEF decreased in the simvastatin treatment group. All the differences were statistically significant (P < 0.05). Left ventricular mass index in the simvastatin treatment group was statistically lower than the myocardial infarction group. Compared with the sham group, left ventricular mass index in both the simvastatin treatment and myocardial infarction groups was significantly increased. The differences of the above comparisons were statistically

  7. Depressive Symptoms Are Associated with Mental Stress-Induced Myocardial Ischemia after Acute Myocardial Infarction

    PubMed Central

    Wei, Jingkai; Pimple, Pratik; Shah, Amit J.; Rooks, Cherie; Bremner, J. Douglas; Nye, Jonathon A.; Ibeanu, Ijeoma; Murrah, Nancy; Shallenberger, Lucy; Raggi, Paolo; Vaccarino, Viola

    2014-01-01

    Objectives Depression is an adverse prognostic factor after an acute myocardial infarction (MI), and an increased propensity toward emotionally-driven myocardial ischemia may play a role. We aimed to examine the association between depressive symptoms and mental stress-induced myocardial ischemia in young survivors of an MI. Methods We studied 98 patients (49 women and 49 men) age 38–60 years who were hospitalized for acute MI in the previous 6 months. Patients underwent myocardial perfusion imaging at rest, after mental stress (speech task), and after exercise or pharmacological stress. A summed difference score (SDS), obtained with observer-independent software, was used to quantify myocardial ischemia under both stress conditions. The Beck Depression Inventory-II (BDI-II) was used to measure depressive symptoms, which were analyzed as overall score, and as separate somatic and cognitive depressive symptom scores. Results There was a significant positive association between depressive symptoms and SDS with mental stress, denoting more ischemia. After adjustment for demographic and lifestyle factors, disease severity and medications, each incremental depressive symptom was associated with 0.14 points higher SDS. When somatic and cognitive depressive symptoms were examined separately, both somatic [β = 0.17, 95% CI: (0.04, 0.30), p = 0.01] and cognitive symptoms [β = 0.31, 95% CI: (0.07, 0.56), p = 0.01] were significantly associated with mental stress-induced ischemia. Depressive symptoms were not associated with ischemia induced by exercise or pharmacological stress. Conclusion Among young post-MI patients, higher levels of both cognitive and somatic depressive symptoms are associated with a higher propensity to develop myocardial ischemia with mental stress, but not with physical (exercise or pharmacological) stress. PMID:25061993

  8. Internal countershock produces myocardial damage and lactate production without myocardial ischemia in anesthetized dogs

    SciTech Connect

    Gaba, D.M.; Maxwell, M.S.; Merlone, S.; Smith, C.

    1987-04-01

    The global myocardial extraction of lactate was measured in 13 halothane anesthetized dogs to assess the effect of electric countershock applied directly to the heart. Seven animals received two countershocks of 30 delivered joules each, while six animals were not shocked but were atrially paced to a rate of 190-200, both with and without occlusion of the vena cava to produce a mean arterial pressure of 40-50 mmHg. All animals had substantially positive lactate extraction in the baseline state (36 +/- 10% for countershock group vs. 41 +/- 3% for pacing group). Myocardial lactate extraction reached a markedly negative nadir 2.5 min after countershock (-19 +/- 15%), but returned toward normal by 6 min (10 +/- 6%). Lactate extraction was not significantly changed from baseline in the pacing group. The relationship between changes in regional myocardial blood flow (radiolabeled microspheres) and post-countershock myocardial damage (technetium pyrophosphate uptake) was assessed in six dogs shocked as above. Mean myocardial blood flow was increased minimally immediately after countershock (0.78 +/- 0.08 ml X min-1 X g-1 vs. 1.16 +/- 0.3), but there was no difference in blood flow between damaged and undamaged tissue at either time point. The epicardial-to-endocardial ratio of blood flow was unchanged after countershock (0.97 +/- 0.05 vs. 0.99 +/- 0.08). There was no relationship between myocardial damage and either the absolute amount of blood flow after countershock (r = -0.03) or the change in blood flow compared with the pre-shock period (r = 0.01).

  9. [Assessing myocardial perfusion with positron emission tomography].

    PubMed

    vom Dahl, J

    2001-11-01

    Positron emission tomography (PET) of the heart has gained widespread scientific and clinical acceptance with regard to two indications: 1) The detection of perfusion abnormalities by qualitative and semiquantitative analyses of perfusion images at rest and during physical or pharmacological stress using well-validated perfusion tracers, such as N-13 ammonia, Rb-82 rubidium chloride, or O-15 labeled water. 2) Viability imaging of myocardial regions with reduced contractility by combining perfusion measurements with substrate metabolism as assessed from F-18 deoxyglucose utilization. This overview summarizes the use of PET as a perfusion imaging method. With a sensitivity > 90% in combination with high specificity, PET is today the best-validated available nuclear imaging technique for the diagnosis of coronary artery disease (CAD). The short half-life of the perfusion tracers in combination with highly sophisticated hard- and software enables rapid PET studies with high patient throughput. The high diagnostic accuracy and the methological advantages as compared to conventional scintigraphy allows one to use PET perfusion imaging to detect subtle changes in the perfusion reserve for the detection of CAD in high risk but asymptomatic patients as well as in patients with proven CAD undergoing various treatment forms such as risk factor reduction or coronary revascularization. In patients following orthotopic heart transplantation, evolving transplant vasculopathy can be detected at an early stage. Quantitative PET imaging at rest allows for detection of myocardial viability since cellular survival is based on maintenance of a minimal perfusion and structural changes correlate to the degree of perfusion reduction. Furthermore, quantitative assessment of the myocardial perfusion reserve detects the magnitude and competence of collaterals in regions with occluded epicardial collaterals and, thus, imaging of several coronary distribution territories in one noninvasive

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

    PubMed Central

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

    2016-01-01

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

  11. Metabolic intervention in surgical patients. An assessment of the effect of somatostatin, ranitidine, naloxone, diclophenac, dipyridamole, or salbutamol infusion on energy and protein kinetics in surgical patients using stable and radioisotopes

    SciTech Connect

    Shaw, J.H.; Wolfe, R.R.

    1988-03-01

    We have assessed the effect of a variety of forms of metabolic intervention on both energy and protein metabolism in 44 severely ill surgical patients. The patients were studied either in the basal state or while receiving total parenteral nutrition (TPN), and the metabolic effects were assessed using the primed-constant infusion of a combination of stable isotopes and radioisotopes. Somatostatin infusion, either in the basal state or in the TPN, did not change glucose kinetics, but there was a significant decrease in the rate of net protein catabolism (NPC). In the basal studies the rate of NPC decreased from 3.4 +/- 0.7 g/kg/d to 2.9 +/- 0.7 g/kg/d (p less than 0.002), while in the TPN patients the corresponding values were 1.48 +/- 0.61 g/kg/d and 1.10 +/- 0.50 g/kg/d, respectively (p less than 0.005). Histamine type 2 blockade with ranitidine did not significantly alter glucose kinetics, but in both the TPN patients and in the basal state ranitidine was associated with a significant decrease in the rate of NPC. In the basal state rate of NPC was 2.44 +/- 0.53 g/kg/d and during ranitidine infusion the value was 2.08 +/- 0.42 g/kg/d (p less than 0.04). Naloxone infusion did not alter glucose kinetics, but there was a significant decrease in the rate of NPC from a basal value of 2.6 +/- 0.6 g/kg/d to 2.3 +/- 0.5 g/kg/d (p less than 0.04). The infusion of the prostaglandin antagonists diclofenac or dipyridamole resulted in increases in the plasma insulin level, and as a result glucose turnover decreased in both groups. In the diclofenac group the rate of glucose turnover decreased from 14.4 +/- 1.7 mumol/kg/min to 12.6 +/- 1.3 mumol/kg/min (p less than 0.02). Neither prostaglandin antagonist resulted in any significant change in the rate of NPC.

  12. Imaging the impact of cyclosporin A and dipyridamole on P-glycoprotein (ABCB1) function at the blood-brain barrier: A [(11)C]-N-desmethyl-loperamide PET study in nonhuman primates.

    PubMed

    Damont, Annelaure; Goutal, Sébastien; Auvity, Sylvain; Valette, Héric; Kuhnast, Bertrand; Saba, Wadad; Tournier, Nicolas

    2016-08-25

    Cyclosporin A (CsA) and dipyridamole (DPy) are potent inhibitors of the P-glycoprotein (P-gp; ABCB1) in vitro. Their efficacy at inhibiting P-gp at the blood-brain barrier (BBB) is difficult to predict. Efficient and readily available (i.e. marketed) P-gp inhibitors are needed as probes to investigate the role of P-gp at the human BBB. In this study, the P-gp inhibition potency at the BBB of therapeutic doses of CsA or DPy was evaluated in baboons using Positron Emission Tomography (PET) imaging with [(11)C]-N-desmethyl-loperamide ([(11)C]dLop), a radiolabeled P-gp substrate. The preparation of dLop as authentic standard and [(11)C]dLop as radiotracer were revisited so as to improve their production yields. [(11)C]dLop PET imaging was performed in the absence (n=3, baseline condition) and the presence of CsA (15mg/kg/h i.v., n=3). Three animals were injected with i.v. DPy at either 0.56 or 0.96 or 2mg/kg (n=1), corresponding to the usual, maximal and twice the maximal dose in patients, respectively, administered immediately before PET. [(11)C]dLop brain kinetics as well as [(11)C]dLop kinetics and radiometabolites in arterial plasma were measured to calculate [(11)C]dLop area-under the time-activity curve from 10 to 30min in the brain (AUCbrain) and in plasma (AUCplasma). [(11)C]dLop brain uptake was described by AUCR=AUCbrain/AUCplasma. CsA as well as DPy did not measurably influence [(11)C]dLop plasma kinetics and metabolism. Baseline AUCR (0.85±0.29) was significantly enhanced in the presence of CsA (AUCR=10.8±3.6). Injection of pharmacologic dose of DPy did not enhance [(11)C]dLop brain distribution with AUCR being 1.2, 0.9 and 1.1 after administration of 0.56, 0.96 and 2mg/kg DPy doses, respectively. We used [(11)C]dLop PET imaging in baboons, a relevant in vivo model of P-gp function at the BBB, to show the P-gp inhibition potency of therapeutic dose CsA. Despite in vitro P-gp inhibition potency, usual doses DPy are not likely to inhibit P-gp function at

  13. Low High-Density Lipoprotein and Risk of Myocardial Infarction

    PubMed Central

    Ramirez, A.; Hu, P. P.

    2015-01-01

    Low HDL is an independent risk factor for myocardial infarction. This paper reviews our current understanding of HDL, HDL structure and function, HDL subclasses, the relationship of low HDL with myocardial infarction, HDL targeted therapy, and clinical trials and studies. Furthermore potential new agents, such as alirocumab (praluent) and evolocumab (repatha) are discussed. PMID:26692765

  14. Low High-Density Lipoprotein and Risk of Myocardial Infarction.

    PubMed

    Ramirez, A; Hu, P P

    2015-01-01

    Low HDL is an independent risk factor for myocardial infarction. This paper reviews our current understanding of HDL, HDL structure and function, HDL subclasses, the relationship of low HDL with myocardial infarction, HDL targeted therapy, and clinical trials and studies. Furthermore potential new agents, such as alirocumab (praluent) and evolocumab (repatha) are discussed. PMID:26692765

  15. Prognostic value of radionuclide exercise testing after myocardial infarction

    SciTech Connect

    Schocken, D.D.

    1984-08-01

    Abnormal systolic ventricular function and persistent ischemia are sensitive indicators of poor prognosis following myocardial infarction. The use of exercise improves the utility of both radionuclide ventriculography and myocardial perfusion scintigraphy in the identification of postinfarction patients at high risk of subsequent cardiac events. 51 references.

  16. Predictors of Appraisal and Coping Dimensions in Myocardial Infarction Victims.

    ERIC Educational Resources Information Center

    Lee, Hyong Sil; Martin, Peter

    This study attempted to identify predictors of perception and coping after the occurrence of a myocardial infarction. Sixty males and 17 females who had suffered from a myocardial infarction within 3 months prior to the research were recruited from a hospital rehabilitation program. Subjects completed the Peri-Life Events Scale, the 16-PF…

  17. Clinical Application and Research Advances of CT Myocardial Perfusion Imaging.

    PubMed

    2016-06-10

    Computed tomography (CT)-based myocardial perfusion imaging (CTP)has been widely recognized as a one-station solution for the imaging of myocardial ischemia-related diseases. This article reviews the clinical scanning protocols,analytical methods,and research advances of CTP in recent years and briefly discusses its limitations and future development. PMID:27469926

  18. Acute myocardial infarction in a young woman on isotretinoin treatment.

    PubMed

    Lorenzo, Natalia; Antuña, Paula; Dominguez, Lourdes; Rivero, Fernando; Bastante, Teresa; Alfonso, Fernando

    2015-02-15

    The use of isotretinoin has been associated with mild changes in the metabolic profile of adolescents. In very rare cases, a possible association with myocardial infarction, stroke and thromboembolic events has been reported. In this report we describe the potential association of isotretinoin with the occurrence of an acute myocardial infarction in a very young girl. OCT provided unique visualization of the culprit lesion.

  19. An alternative method for neonatal cerebro-myocardial perfusion.

    PubMed

    Luciani, Giovanni Battista; De Rita, Fabrizio; Faggian, Giuseppe; Mazzucco, Alessandro

    2012-05-01

    Several techniques have already been described for selective cerebral perfusion during repair of aortic arch pathology in children. One method combining cerebral with myocardial perfusion has also been proposed. A novel technique is reported here for selective and independent cerebro-myocardial perfusion for neonatal and infant arch surgery. Technical aspects and potential advantages are discussed.

  20. Effect of hydroxy safflower yellow A on myocardial apoptosis after acute myocardial infarction in rats.

    PubMed

    Zhou, M X; Fu, J H; Zhang, Q; Wang, J Q

    2015-04-10

    This study aimed to investigate the effect of hydroxy safflower yellow A (HSYA) on myocardial apoptosis after acute myocardial infarction (AMI) in rats. We randomly divided 170 male Wistar rats into 6 groups (N = 23): normal control, sham, control, SY (90 mg/kg), HSYA high-dose (HSYA-H, 40 mg/kg), and HSYA low-dose groups (HSYA-L, 20 mg/kg). Myocardial ischemic injury was induced by ligating the anterior descending coronary artery, and the degree of myocardial ischemia was evaluated using electrocardiography and nitroblue tetrazolium staining. Bax and Bcl-2 expressions in the ischemic myocardium were determined using immunohistochemical analysis. Peroxisome proliferator-activated receptor-γ (PPAR-γ) expression in the myocardium of rats with AMI was determined using reverse transcription-polymerase chain reaction. Compared to rats in the control group, those in the HYSA-H, HSYA-L, and SY groups showed a decrease in the elevated ST segments and an increase in the infarct size. The rats in the drug-treated groups showed a significantly lower percentage of Bax-positive cells and a significantly higher percentage of Bcl-2-positive cells than those in the control group (P < 0.05). Moreover, mRNA expression of PPAR-γ in the ischemic myocardium of rats in the SY, HSYA-L, and HSYA-H groups was significantly lower than that in the control group (P < 0.05). Thus, HSYA and SY can attenuate myocardial ischemia in rats, possibly by increasing the level of Bcl-2/Bax, and PPAR-γ may be not a necessary link in this process.

  1. Complement component 3 is necessary to preserve myocardium and myocardial function in chronic myocardial infarction.

    PubMed

    Wysoczynski, Marcin; Solanki, Mitesh; Borkowska, Sylwia; van Hoose, Patrick; Brittian, Kenneth R; Prabhu, Sumanth D; Ratajczak, Mariusz Z; Rokosh, Gregg

    2014-09-01

    Activation of the complement cascade (CC) with myocardial infarction (MI) acutely initiates immune cell infiltration, membrane attack complex formation on injured myocytes, and exacerbates myocardial injury. Recent studies implicate the CC in mobilization of stem/progenitor cells and tissue regeneration. Its role in chronic MI is unknown. Here, we consider complement component C3, in the chronic response to MI. C3 knockout (KO) mice were studied after permanent coronary artery ligation. C3 deficiency exacerbated myocardial dysfunction 28 days after MI compared to WT with further impaired systolic function and LV dilation despite similar infarct size 24 hours post-MI. Morphometric analysis 28 days post-MI showed C3 KO mice had more scar tissue with less viable myocardium within the infarct zone which correlated with decreased c-kit(pos) cardiac stem/progenitor cells (CPSC), decreased proliferating Ki67(pos) CSPCs and decreased formation of new BrdU(pos) /α-sarcomeric actin(pos) myocytes, and increased apoptosis compared to WT. Decreased CSPCs and increased apoptosis were evident 7 days post-MI in C3 KO hearts. The inflammatory response with MI was attenuated in the C3 KO and was accompanied by attenuated hematopoietic, pluripotent, and cardiac stem/progenitor cell mobilization into the peripheral blood 72 hours post-MI. These results are the first to demonstrate that CC, through C3, contributes to myocardial preservation and regeneration in response to chronic MI. Responses in the C3 KO infer that C3 activation in response to MI expands the resident CSPC population, increases new myocyte formation, increases and preserves myocardium, inflammatory response, and bone marrow stem/progenitor cell mobilization to preserve myocardial function.

  2. Reducing myocardial infarct size: challenges and future opportunities.

    PubMed

    Bulluck, Heerajnarain; Yellon, Derek M; Hausenloy, Derek J

    2016-03-01

    Despite prompt reperfusion by primary percutaneous coronary intervention (PPCI), the mortality and morbidity of patients presenting with an acute ST-segment elevation myocardial infarction (STEMI) remain significant with 9% death and 10% heart failure at 1 year. In these patients, one important neglected therapeutic target is 'myocardial reperfusion injury', a term given to the cardiomyocyte death and microvascular dysfunction which occurs on reperfusing ischaemic myocardium. A number of cardioprotective therapies (both mechanical and pharmacological), which are known to target myocardial reperfusion injury, have been shown to reduce myocardial infarct (MI) size in small proof-of-concept clinical studies-however, being able to demonstrate improved clinical outcomes has been elusive. In this article, we review the challenges facing clinical cardioprotection research, and highlight future therapies for reducing MI size and preventing heart failure in patients presenting with STEMI at risk of myocardial reperfusion injury.

  3. Reducing myocardial infarct size: challenges and future opportunities

    PubMed Central

    Bulluck, Heerajnarain; Yellon, Derek M; Hausenloy, Derek J

    2016-01-01

    Despite prompt reperfusion by primary percutaneous coronary intervention (PPCI), the mortality and morbidity of patients presenting with an acute ST-segment elevation myocardial infarction (STEMI) remain significant with 9% death and 10% heart failure at 1 year. In these patients, one important neglected therapeutic target is ‘myocardial reperfusion injury’, a term given to the cardiomyocyte death and microvascular dysfunction which occurs on reperfusing ischaemic myocardium. A number of cardioprotective therapies (both mechanical and pharmacological), which are known to target myocardial reperfusion injury, have been shown to reduce myocardial infarct (MI) size in small proof-of-concept clinical studies—however, being able to demonstrate improved clinical outcomes has been elusive. In this article, we review the challenges facing clinical cardioprotection research, and highlight future therapies for reducing MI size and preventing heart failure in patients presenting with STEMI at risk of myocardial reperfusion injury. PMID:26674987

  4. Acute myocardial infarction complicating subarachnoid haemorrhage

    PubMed Central

    van der Velden, L.B.J.; Otterspoor, L.C.; Schultze Kool, L.J.; Biessels, G.J.; Verheugt, F.W.A.

    2009-01-01

    An acute myocardial infarction is a rare complication of a subarachnoid haemorrhage. The combination of these two conditions imposes important treatment dilemmas. We describe two patients with this combination of life-threatening conditions. Patient 1 was treated with emergency percutaneous coronary intervention followed by clipping of the anterior communicating artery aneurysm. Six months after discharge the patient's memory and orientation had almost completely recovered. Patient 2 was treated with aspirin until coiling of the aneurysm could be performed. After successful coiling low-molecular-weight heparin was added. One week later the patient died due to a free wall rupture. (Neth Heart J 2009;17:284-7.19789696) PMID:19789696

  5. Controversies in cardiovascular care: silent myocardial ischemia

    NASA Technical Reports Server (NTRS)

    Hollenberg, N. K.

    1987-01-01

    The objective evidence of silent myocardial ischemia--ischemia in the absence of classical chest pain--includes ST-segment shifts (usually depression), momentary left ventricular failure, and perfusion defects on scintigraphic studies. Assessment of angina patients with 24-hour ambulatory monitoring may uncover episodes of silent ischemia, the existence of which may give important information regarding prognosis and may help structure a more effective therapeutic regimen. The emerging recognition of silent ischemia as a significant clinical entity may eventually result in an expansion of current therapy--not only to ameliorate chest pain, but to minimize or eliminate ischemia in the absence of chest pain.

  6. Postmortem detection of inapparent myocardial infarction

    PubMed Central

    McVie, J. G.

    1970-01-01

    Two methods of detecting early inapparent myocardial infarcts have been studied and their value in diagnostic practice compared. The better method proved to be the determination of the potassium to sodium ratio (ionic ratio) which falls in infarcted tissue within minutes of the onset of anoxia. The second method was nitro blue tetrazolium staining of gross sections of myocardium which revealed any infarct older than three and a half hours. As staining is dependent upon enzyme activity, the latter method is disturbed by autolysis. It was shown, on the other hand, that the ionic ratio (K+/Na+) was not affected by autolysis and was therefore well suited to forensic practice. Sixteen non-infarcted control hearts, plus the nine from cases of sudden death due to causes other than myocardial infarction, all yielded high ionic ratios (K+/Na+), average 1·4, and stained normally with tetrazolium (the normal controls). Positive control was provided by 20 histologically proven infarcts of which the ionic ratios (K+/Na+) were all low (average 0·7). Histochemical staining with tetrazolium delineated infarcted areas in each case. In a series of 29 sudden deaths, a cause of death other than myocardial infarction was found at necropsy in nine, mentioned above as normal controls. The remaining 20 hearts were not infarcted histologically, but were shown to be infarcted by examination of the ionic ratios (K+/Na+). These ratios were low (average 0·8) including three borderline ratios. Confirmatory evidence of infarction included nitro blue tetrazolium staining which revealed infarcts in 10 of the 20 cases, and clinical and necropsy observations. The ionic ratio (K+/Na+) decreases as the age of the infarct increases for at least 24 hours. Thereafter as healing proceeds, the ratio gradually reverts to normal. Thus, previous infarction and replacement fibrosis do not significantly alter the ionic ratio (K+/Na+). Nor is it changed by left ventricular hypertrophy, the presence of

  7. Myocardial Na,K-ATPase: Clinical aspects

    PubMed Central

    Kjeldsen, Keld

    2003-01-01

    The specific binding of digitalis glycosides to Na,K-ATPase is used as a tool for Na,K-ATPase quantification with high accuracy and precision. In myocardial biopsies from patients with heart failure, total Na,K-ATPase concentration is decreased by around 40%; a correlation exists between a decrease in heart function and a decrease in Na,K-ATPase concentration. During digitalization, around 30% of remaining pumps are occupied by digoxin. Myocardial Na,K-ATPase is also influenced by other drugs used for the treatment of heart failure. Thus, potassium loss during diuretic therapy has been found to reduce myocardial Na,K-ATPase, whereas angiotensin-converting enzyme inhibitors may stimulate Na,K pump activity. Furthermore, hyperaldosteronism induced by heart failure has been found to decrease Na,K-ATPase activity. Accordingly, treatment with the aldosterone antagonist, spironolactone, may also influence Na,K-ATPase activity. The importance of Na,K pump modulation with heart disease, inhibition in digitalization and other effects of medication should be considered in the context of sodium, potassium and calcium regulation. It is recommended that digoxin be administered to heart failure patients who, after institution of mortality-reducing therapy, still have heart failure symptoms, and that the therapy be continued if symptoms are revealed or reduced. Digitalis glycosides are the only safe inotropic drugs for oral use that improve hemodynamics in heart failure. An important aspect of myocardial Na,K pump affection in heart disease is its influence on extracellular potassium (Ke) homeostasis. Two important aspects should be considered: potassium handling among myocytes, and effects of potassium entering the extracellular space of the heart via the bloodstream. It should be noted that both of these aspects of Ke homeostasis are affected by regulatory aspects, eg, regulation of the Na,K pump by physiological and pathophysiological conditions, as well as by medical

  8. Transcriptomic Analysis of Myocardial Ischemia Using the Blood of Rat.

    PubMed

    Hou, Jincai; Fu, Jianhua; Li, Dan; Han, Xiao; Li, Lei; Song, Wenting; Yao, Mingjiang; Liu, Jianxun

    2015-01-01

    Myocardial ischemia is a pathological state of heart with reduced blood flow to heart and abnormal myocardial energy metabolism. This disease occurs commonly in middle aged and elderly people. Several studies have indicated that the rat was an appropriate animal model used to study myocardial ischemia. In this study, in order to gain insights into the pathogenesis of myocardial ischemia, we sequenced the transcriptomes of three normal rats as control and the same number of myocardial ischemia rats. We sequenced the genomes of 6 rats, including 3 cases (myocardial ischemia) and 3 controls using Illumina HiSeq 2000. Then we calculated the gene expression values and identified differentially expressed genes based on reads per kilobase transcriptome per million (RPKM). Meanwhile we performed a GO enrichment analysis and predicted novel transcripts. In our study, we found that 707 genes were up-regulated and 21 genes were down-regulated in myocardial ischemia rats by at least 2-fold compared with controls. By the distribution of reads and the annotation of reference genes, we found 1,703 and 1,552 novel transcripts in cases and controls, respectively. At the same time, we refined the structure of 9,587 genes in controls and 10,301 in cases. According to the results of GO term and pathway analysis of differentially expressed genes, we found that the immune response, stimulus response, response to stress and some diseases may be associated with myocardial ischemia. Since many diseases, especially immune diseases, are associated with myocardial ischemia, we should pay more attention to the complications which might result from myocardial ischemia.

  9. Quantification of myocardial salvage by myocardial perfusion SPECT and cardiac magnetic resonance--reference standards for ECG development.

    PubMed

    Engblom, Henrik; Aletras, Anthony H; Heiberg, Einar; Arheden, Håkan; Carlsson, Marcus

    2014-01-01

    In order to determine the cardioprotective efficacy of acute reperfusion therapy, assessed as myocardial salvage, in patients with acute coronary occlusion, the final myocardial infarct (MI) size needs to be related to the amount of ischemic myocardium during coronary occlusion, referred to as the myocardium at risk (MaR). There are currently several imaging approaches available for quantification of both MI size and MaR in vivo of which some have been validated both in pre-clinical and clinical settings. These methods often involve the use of either myocardial perfusion SPECT or cardiac magnetic resonance (CMR). These imaging methods could potentially be used to further develop and validate ECG methods for determination of MI size and MaR. Therefore, the aim of the present review is to give an overview of myocardial perfusion SPECT and CMR methods available for assessment of myocardial salvage by determination of MI size and MaR.

  10. 5-Lipoxygenase facilitates healing after myocardial infarction.

    PubMed

    Blömer, Nadja; Pachel, Christina; Hofmann, Ulrich; Nordbeck, Peter; Bauer, Wolfgang; Mathes, Denise; Frey, Anna; Bayer, Barbara; Vogel, Benjamin; Ertl, Georg; Bauersachs, Johann; Frantz, Stefan

    2013-07-01

    Early healing after myocardial infarction (MI) is characterized by a strong inflammatory reaction. Most leukotrienes are pro-inflammatory and are therefore potential mediators of healing and remodeling after myocardial ischemia. The enzyme 5-lipoxygenase (5-LOX) has a key role in the transformation of arachidonic acid in leukotrienes. Thus, we tested the effect of 5-LOX on healing after MI. After chronic coronary artery ligation, early mortality was significantly increased in 5-LOX(-/-) when compared to matching wildtype (WT) mice due to left ventricular rupture. This effect could be reproduced in mice treated with the 5-LOX inhibitor Zileuton. A perfusion mismatch due to the vasoactive potential of leukotrienes is not responsible for left ventricular rupture since local blood flow assessed by magnetic resonance perfusion measurements was not different. However, after MI, there was an accentuation of the inflammatory reaction with an increase of pro-inflammatory macrophages. Yet, mortality was not changed in chimeric mice (WT vs. 5-LOX(-/-) bone marrow in 5-LOX(-/-) animals), indicating that an altered function of 5-LOX(-/-) inflammatory cells is not responsible for the phenotype. Collagen production and accumulation of fibroblasts were significantly reduced in 5-LOX(-/-) mice in vivo after MI. This might be due to an impaired migration of 5-LOX(-/-) fibroblasts, as shown in vitro to serum. In conclusion, a lack or inhibition of 5-LOX increases mortality after MI because of healing defects. This is not mediated by a change in local blood flow, but through an altered inflammation and/or fibroblast function.

  11. Cardiovascular gene therapy for myocardial infarction

    PubMed Central

    Scimia, Maria C; Gumpert, Anna M; Koch, Walter J

    2014-01-01

    Introduction Cardiovascular gene therapy is the third most popular application for gene therapy, representing 8.4% of all gene therapy trials as reported in 2012 estimates. Gene therapy in cardiovascular disease is aiming to treat heart failure from ischemic and non-ischemic causes, peripheral artery disease, venous ulcer, pulmonary hypertension, atherosclerosis and monogenic diseases, such as Fabry disease. Areas covered In this review, we will focus on elucidating current molecular targets for the treatment of ventricular dysfunction following myocardial infarction (MI). In particular, we will focus on the treatment of i) the clinical consequences of it, such as heart failure and residual myocardial ischemia and ii) etiological causes of MI (coronary vessels atherosclerosis, bypass venous graft disease, in-stent restenosis). Expert opinion We summarise the scheme of the review and the molecular targets either already at the gene therapy clinical trial phase or in the pipeline. These targets will be discussed below. Following this, we will focus on what we believe are the 4 prerequisites of success of any gene target therapy: safety, expression, specificity and efficacy (SESE). PMID:24328708

  12. Physiological Implications of Myocardial Scar Structure.

    PubMed

    Richardson, William J; Clarke, Samantha A; Quinn, T Alexander; Holmes, Jeffrey W

    2015-10-01

    Once myocardium dies during a heart attack, it is replaced by scar tissue over the course of several weeks. The size, location, composition, structure, and mechanical properties of the healing scar are all critical determinants of the fate of patients who survive the initial infarction. While the central importance of scar structure in determining pump function and remodeling has long been recognized, it has proven remarkably difficult to design therapies that improve heart function or limit remodeling by modifying scar structure. Many exciting new therapies are under development, but predicting their long-term effects requires a detailed understanding of how infarct scar forms, how its properties impact left ventricular function and remodeling, and how changes in scar structure and properties feed back to affect not only heart mechanics but also electrical conduction, reflex hemodynamic compensations, and the ongoing process of scar formation itself. In this article, we outline the scar formation process following a myocardial infarction, discuss interpretation of standard measures of heart function in the setting of a healing infarct, then present implications of infarct scar geometry and structure for both mechanical and electrical function of the heart and summarize experiences to date with therapeutic interventions that aim to modify scar geometry and structure. One important conclusion that emerges from the studies reviewed here is that computational modeling is an essential tool for integrating the wealth of information required to understand this complex system and predict the impact of novel therapies on scar healing, heart function, and remodeling following myocardial infarction. PMID:26426470

  13. Biomaterial strategies for alleviation of myocardial infarction

    PubMed Central

    Venugopal, Jayarama Reddy; Prabhakaran, Molamma P.; Mukherjee, Shayanti; Ravichandran, Rajeswari; Dan, Kai; Ramakrishna, Seeram

    2012-01-01

    World Health Organization estimated that heart failure initiated by coronary artery disease and myocardial infarction (MI) leads to 29 per cent of deaths worldwide. Heart failure is one of the leading causes of death in industrialized countries and is expected to become a global epidemic within the twenty-first century. MI, the main cause of heart failure, leads to a loss of cardiac tissue impairment of left ventricular function. The damaged left ventricle undergoes progressive ‘remodelling’ and chamber dilation, with myocyte slippage and fibroblast proliferation. Repair of diseased myocardium with in vitro-engineered cardiac muscle patch/injectable biopolymers with cells may become a viable option for heart failure patients. These events reflect an apparent lack of effective intrinsic mechanism for myocardial repair and regeneration. Motivated by the desire to develop minimally invasive procedures, the last 10 years observed growing efforts to develop injectable biomaterials with and without cells to treat cardiac failure. Biomaterials evaluated include alginate, fibrin, collagen, chitosan, self-assembling peptides, biopolymers and a range of synthetic hydrogels. The ultimate goal in therapeutic cardiac tissue engineering is to generate biocompatible, non-immunogenic heart muscle with morphological and functional properties similar to natural myocardium to repair MI. This review summarizes the properties of biomaterial substrates having sufficient mechanical stability, which stimulates the native collagen fibril structure for differentiating pluripotent stem cells and mesenchymal stem cells into cardiomyocytes for cardiac tissue engineering. PMID:21900319

  14. Association of urinary cadmium and myocardial infarction

    SciTech Connect

    Everett, Charles J. Frithsen, Ivar L.

    2008-02-15

    We conducted a cross-sectional analysis of individuals 45-79 years old in the National Health and Nutrition Examination Survey III (1988-1994) (NHANES III). Myocardial infarction was determined by electrocardiogram (ECG). Our sample included 4912 participants, which when weighted represented 52,234,055 Americans. We performed adjusted logistic regressions with the Framingham risk score, pack-years of smoking, race-ethnicity, and family history of heart attack, and diabetes as covariates. Urinary cadmium {>=}0.88 {mu}g/g creatinine had an odds ratio of 1.86 (95% CI 1.26-2.75) compared to urinary cadmium <0.43 {mu}g/g creatinine. This result supports the hypothesis that cadmium is associated with coronary heart disease. When logistic regressions were done by gender, women, but not men, showed a significant association of urinary cadmium with myocardial infarction. Women with urinary cadmium {>=}0.88 {mu}g/g creatinine had an odds ratio of 1.80 (95% CI 1.06-3.04) compared to urinary cadmium <0.43 {mu}g/g creatinine. When the analysis was restricted to never smokers (N=2187) urinary cadmium {>=}0.88 {mu}g/g creatinine had an odds ratio of 1.85 (95% CI 1.10-3.14) compared to urinary cadmium <0.43 {mu}g/g creatinine.

  15. Recurrent coronary stent thromboses and myocardial infarctions.

    PubMed

    Chen, Jack; Rajeev, Angampally

    2007-11-01

    Although stent thrombosis is a recognized complication of coronary intervention, recurrent stent thrombosis is rarely reported. We present a patient who suffered 3 ST-segment elevation myocardial infarctions associated with repeated stent thromboses within a month and a half. Although a potentially mechanical cause of thrombosis was identified in the only baremetal stent implanted in this case, no predisposing factors were seen for the 2 drug-eluting stents (DES). While recent worrisome data have suggested a slight increase in the incidence of late angiographic stent thrombosis (defined as occurring beyond 30 days) with drug-eluting stents (DES), their risk of subacute thrombosis (from 1 to 30 days) is reported to be equivalent to that of BMS. Therefore, this rare occurrence serves as a sobering reminder of the risks of subacute thrombosis with both BMS and DES. Marked neointimal inhibition, allergic reactions, as well as thienopyridine resistance, may all contribute to the pathophysiology of DES thrombosis. The Food and Drug Administration advisory panel has concluded that when these devices are used for "on-label" indications, the counterbalance of dramatic target lesion revascularization reduction versus rare incidence of late angiographic stent thrombosis results in no overall increase in DES myocardial infarction or mortality risk. Furthermore, a minimum of 1 year of dual antiplatelet therapy is recommended for all recipients of DES at low risk of bleeding.

  16. Aortic valve replacement with combined myocardial revascularisation.

    PubMed Central

    Jones, M; Schofield, P M; Brooks, N H; Dark, J F; Moussalli, H; Deiraniya, A K; Lawson, R A; Rahman, A N

    1989-01-01

    Early and late outcome was studied in 630 patients who underwent aortic valve replacement between 1974 and 1982. Group 1 (506 patients) did not have important coronary artery disease, group 2 (69 patients) had coronary artery disease and underwent coronary artery bypass grafting, and group 3 (55 patients) had coronary artery disease but did not undergo myocardial revascularisation. Early mortality (within 30 days of operation) was significantly lower for group 1 (6%) than for group 2 (13%) and for group 3 (16%). Operative mortality in all three groups was lower in patients operated on more recently. The three year survival of patients in group 1 (83%) was significantly higher than that of patients in group 3 (62%) but not than that of patients in group 2 (76%). The findings of this study suggest that the presence of coronary artery disease increases the risk of aortic valve replacement whether or not coronary artery grafting is performed. Myocardial revascularisation, however, seems to return patients with aortic valve and coronary artery disease to a survival curve similar to that of patients with isolated aortic valve disease. PMID:2788003

  17. Myocardial tissue engineering using electrospun nanofiber composites

    PubMed Central

    Kim, Pyung-Hwan; Cho, Je-Yoel

    2016-01-01

    Emerging trends for cardiac tissue engineering are focused on increasing the biocompatibility and tissue regeneration ability of artificial heart tissue by incorporating various cell sources and bioactive molecules. Although primary cardiomyocytes can be successfully implanted, clinical applications are restricted due to their low survival rates and poor proliferation. To develop successful cardiovascular tissue regeneration systems, new technologies must be introduced to improve myocardial regeneration. Electrospinning is a simple, versatile technique for fabricating nanofibers. Here, we discuss various biodegradable polymers (natural, synthetic, and combinatorial polymers) that can be used for fiber fabrication. We also describe a series of fiber modification methods that can increase cell survival, proliferation, and migration and provide supporting mechanical properties by mimicking micro-environment structures, such as the extracellular matrix (ECM). In addition, the applications and types of nanofiber-based scaffolds for myocardial regeneration are described. Finally, fusion research methods combined with stem cells and scaffolds to improve biocompatibility are discussed. [BMB Reports 2016; 49(1): 26-36] PMID:26497579

  18. Incidence of myocardial infarction and weather

    NASA Astrophysics Data System (ADS)

    Staiger, Henning

    1982-08-01

    Extreme values of temperature and/or humidity in the temperate climate of Hamburg are not able to explain the influence of weather on day-to-day fluctuations of morbidity. Short term changes in weather are described by two objective classifications as deviation from the meteorological past: 1. the temperature-humidity-environment, derived from values of temperature and water vapour pressure at 07.00 h, 2. changes in the cyclonality, derived from the difference of 500 and 850 mbar vorticity values. Their suitability for human biometeorology is illustrated with a material of 1262 subjects who suffered from acute myocardial infarction. For these investigated cases it was known whether angina pectoris was already manifest before the infarction or not. The daily weather conditions have a significant effect on the incidence of acute myocardial infarction according to angina pectoris. Compared to subjects with angina pectoris those without angina pectoris show an increased susceptibility to infarction during changes in weather conditions to warmer/more humid and also during all strong changes in the cyclonality whereby the temperature-humidity-environment seems to leave only the role of an indicator too. Persons with a preceeding angina pectoris are more sensitive agains rapid changes in weather conditions.

  19. Cardioprotective Properties of Aerobic and Resistance Training Against Myocardial Infarction.

    PubMed

    Barboza, C A; Souza, G I H; Oliveira, J C M F; Silva, L M; Mostarda, C T; Dourado, P M M; Oyama, L M; Lira, F S; Irigoyen, M C; Rodrigues, B

    2016-06-01

    We evaluated the effects of aerobic and resistance exercise training on ventricular morphometry and function, physical capacity, autonomic function, as well as on ventricular inflammatory status in trained rats prior to myocardial infarction. Male Wistar rats were divided into the following groups: sedentary+Sham, sedentary+myocardial infarction, aerobic trained+myocardial infarction, and resistance trained+myocardial infarction. Sham and myocardial infarction were performed after training periods. In the days following the surgeries, evaluations were performed. Aerobic training prevents aerobic (to a greater extent) and resistance capacity impairments, ventricular dysfunction, baroreflex sensitivity and autonomic disorders (vagal tonus decrease and sympathetic tonus increase) triggered by myocardial infarction. Resistance training was able to prevent negative changes to aerobic and resistance capacity (to a greater extent) but not to ventricular dysfunction, and it prevented cardiovascular sympathetic increments. Additionally, both types of training reduced left ventricle inflammatory cytokine concentration. Our results suggest that aerobic and, for the first time, dynamic resistance training were able to reduce sympathetic tonus to the heart and vessels, as well as preventing the increase in pro-inflammatory cytokine concentrations in the left ventricle of trained groups. These data emphasizes the positive effects of aerobic and dynamic resistance training on the prevention of the negative changes triggered by myocardial infarction.

  20. Decellularized myocardial matrix hydrogels: In basic research and preclinical studies.

    PubMed

    Wang, Raymond M; Christman, Karen L

    2016-01-15

    A variety of decellularized materials have been developed that have demonstrated potential for treating cardiovascular diseases and improving our understanding of cardiac development. Of these biomaterials, decellularized myocardial matrix hydrogels have shown great promise for creating cellular microenvironments representative of the native cardiac tissue and treating the heart after a myocardial infarction. Decellularized myocardial matrix hydrogels derived from porcine cardiac tissue form a nanofibrous hydrogel once thermally induced at physiological temperatures. Use of isolated cardiac extracellular matrix in 2D and 3D in vitro platforms has demonstrated the capability to provide tissue specific cues for cardiac cell growth and differentiation. Testing of the myocardial matrix hydrogel as a therapy after myocardial infarction in both small and large animal models has demonstrated improved left ventricular function, increased cardiac muscle, and cellular recruitment into the treated infarct. Based on these results, steps are currently being taken to translate these hydrogels into a clinically used injectable biomaterial therapy. In this review, we will focus on the basic science and preclinical studies that have accelerated the development of decellularized myocardial matrix hydrogels into an emerging novel therapy for treating the heart after a myocardial infarction.

  1. Left ventricular pseudoaneurysm caused by coronary spasm, myocardial infarction, and myocardial rupture.

    PubMed

    Mahilmaran, Asha; Nayar, Pradeep G; Sheshadri, Mukundan; Sudarsana, Gurijala; Abraham, K A

    2002-01-01

    We report a very rare case of a 47-year-old man who had coronary spasm that resulted in a silent myocardial infarction, a ruptured myocardial wall, and a nonruptured left ventricular pseudoaneurysm. The patient presented with a 6-month history of dyspnea on exertion, without evidence of fixed coronary artery stenosis. Coronary angiography showed severe coronary spasm of the left anterior descending and left circumflex arteries; the spasm was relieved promptly by nitroglycerin. Echocardiography and left ventricular angiography revealed the large left ventricular pseudoaneurysm posterolateral to the left ventricle. We performed surgical resection of the pseudoaneurysm and patch repair of the ruptured left ventricular wall, with excellent results. We present this case because of the highly unusual sequence of events. Early surgical intervention resulted in the patient's recovery.

  2. Image-driven constitutive modeling of myocardial fibrosis

    NASA Astrophysics Data System (ADS)

    Wang, Vicky Y.; Niestrawska, Justyna A.; Wilson, Alexander J.; Sands, Gregory B.; Young, Alistair A.; LeGrice, Ian J.; Nash, Martyn P.

    2016-05-01

    Myocardial fibrosis is a pathological process that occurs during heart failure (HF). It involves microstructural remodeling of normal myocardial tissue, and consequent changes in both cardiac geometry and function. The role of myocardial structural remodeling in the progression of HF remains poorly understood. We propose a constitutive modeling framework, informed by high-resolution images of cardiac tissue structure, to model the mechanical response of normal and fibrotic myocardium. This image-driven constitutive modeling approach allows us to better reproduce and understand the relationship between structural and functional remodeling of ventricular myocardium during HF.

  3. Importance of magnesium chloride repletion after myocardial infarction.

    PubMed

    Sheehan, J

    1989-04-18

    Data pertinent to the role of magnesium deficits in coronary artery disease and myocardial infarction are reviewed. Results of clinical, laboratory and epidemiologic studies indicate an association between magnesium deficiency and a poor prognostic outcome in patients who have had myocardial infarction. It therefore appears to be a reasonable prophylactic measure to monitor closely magnesium status in patients with coronary heart disease and other patients at risk of acute myocardial infarction, and to supplement with magnesium chloride when clinically necessary. In addition, recent studies provide supportive evidence that supplementation of magnesium chloride may reduce the incidence of fatal and nonfatal arrhythmias after an infarct.

  4. 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.

  5. Myocardial tissue phase mapping reveals impaired myocardial tissue velocities in obesity.

    PubMed

    Rider, Oliver J; Ajufo, Ezimamaka; Ali, Mohammed K; Petersen, Steffen E; Nethononda, Richard; Francis, Jane M; Neubauer, Stefan

    2015-02-01

    Although obesity is linked to heart failure on a population level, not all obese subjects develop cardiac failure. As a result, identifying obese subjects with subclinical changes in myocardial velocities may enable earlier detection of those susceptible to developing overt heart failure. As echocardiography is limited in obesity due to limited acoustic window, we used phase contrast magnetic resonance imaging to assess myocardial velocities in obese and normal weight subjects. Normal weight (BMI 23 ± 3; n = 40) and obese subjects (BMI 37 ± 7; n = 59) without identifiable cardiovascular risk factors underwent MRI (1.5 Tesla) to determine left ventricular myocardial velocities using phase contrast tissue phase mapping. Systolic function was not different between normal and obese subjects (LVEF 67 ± 5 vs 68 ± 4, p = 0.22). However, obesity was associated with significantly impaired peak radial and longitudinal diastolic myocardial velocity (by 13 and 19 % respectively, both p < 0.001). In addition time-to-peak longitudinal diastolic velocity was delayed in obesity (by 39 ms, p < 0.001). In addition, peak longitudinal diastolic strain was 20 % lower in obesity (p = 0.015) and time-to-peak longitudinal diastolic strain rate significantly delayed in obesity (by 92 ms, p < 0.001).Although peak radial systolic velocity was similar between obese and normal weight subjects (p = 0.14) peak longitudinal systolic velocity was 7 % lower in the obese cohort (p = 0.02). In obesity without co-morbidities, tissue phase mapping has shown subclinical changes in systolic and diastolic function. Given the link between obesity and heart failure, early detection of changes may become clinically important to prevent disease progression.

  6. FGF21 attenuates pathological myocardial remodeling following myocardial infarction through the adiponectin-dependent mechanism.

    PubMed

    Joki, Yusuke; Ohashi, Koji; Yuasa, Daisuke; Shibata, Rei; Ito, Masanori; Matsuo, Kazuhiro; Kambara, Takahiro; Uemura, Yusuke; Hayakawa, Satoko; Hiramatsu-Ito, Mizuho; Kanemura, Noriyoshi; Ogawa, Hayato; Daida, Hiroyuki; Murohara, Toyoaki; Ouchi, Noriyuki

    2015-03-27

    Ischemic heart disease is one of the leading causes of death. Fibroblast growth factor 21 (FGF21) is a circulating factor with an anti-diabetic property. Skeletal muscle is an important source of FGF21 production. Here, we investigated whether skeletal muscle-derived FGF21 modulates cardiac remodeling in a murine model of myocardial infarction. Myocardial infarction was produced in C57BL/6J wild-type (WT) mice by the permanent ligation of the left anterior descending coronary artery (LAD). Adenoviral vectors expressing FGF21 (Ad-FGF21) or control β-galactosidase were intramuscularly injected into mice at 3 days before permanent LAD ligation. Intramuscular injection of Ad-FGF21 increased plasma FGF21 levels in WT mice compared with control. Treatment of WT mice with Ad-FGF21 led to improvement of left ventricular systolic dysfunction and dilatation at 2 weeks after LAD ligation. Ad-FGF21 administration to WT mice also led to enhancement of capillary density in the infarct border zone, and reduction of myocyte apoptosis in the remote zone, which were accompanied by decreased expression of pro-inflammatory cytokines. Furthermore, treatment of WT mice with Ad-FGF21 increased plasma levels of adiponectin, which is a cardioprotective adipokine. The beneficial effects of Ad-FGF21 on cardiac dysfunction and inflammatory response after myocardial infarction were diminished in adiponectin-knockout mice. These data suggest that muscle-derived FGF21 ameliorates adverse cardiac remodeling after myocardial infarction, at least in part, through an adiponectin-dependent mechanism.

  7. Lidocaine Enhances Contractile Function of Ischemic Myocardial Regions in Mouse Model of Sustained Myocardial Ischemia

    PubMed Central

    Kania, Gabriela; Osto, Elena; Jakob, Philipp; Krasniqi, Nazmi; Beck-Schimmer, Beatrice; Blyszczuk, Przemyslaw; Eriksson, Urs

    2016-01-01

    Rationale Perioperative myocardial ischemia is common in high-risk patients. The use of interventional revascularisation or even thrombolysis is limited in this patient subset due to exceedingly high bleeding risks. Blockade of voltage-gated sodium channels (VGSC) with lidocaine had been suggested to reduce infarct size and cardiomyocyte cell death in ischemia/reperfusion models. However, the impact of lidocaine on cardiac function during sustained ischemia still remains unclear. Methods Sustained myocardial ischemia was induced by ligation of the left anterior descending artery in 12–16 weeks old male BALB/c mice. Subcutaneous lidocaine (30 mg/kg) was used to block VGSC. Cardiac function was quantified at baseline and at 72h by conventional and speckle-tracking based echocardiography to allow high-sensitivity in vivo phenotyping. Infarct size and cardiomyocyte cell death were assessed post mortem histologically and indirectly using troponin measurements. Results Ischemia strongly impaired both, global systolic and diastolic function, which were partially rescued in lidocaine treated in mice. No differences regarding infarct size and cardiomyocyte cell death were observed. Mechanistically, and as shown with speckle-tracking analysis, lidocaine specifically improves residual contractility in the ischemic but not in the remote, non-ischemic myocardium. Conclusion VGSC blockade with lidocaine rescues function of ischemic myocardium as a potential bridging to revascularisation in the setting of perioperative myocardial ischemia. PMID:27140425

  8. Myocardial ischaemia and the inflammatory response: release of heat shock protein 70 after myocardial infarction

    PubMed Central

    Dybdahl, B; Slørdahl, S A; Waage, A; Kierulf, P; Espevik, T; Sundan, A

    2005-01-01

    Objectives: To test the hypothesis that heat shock protein (Hsp) 70 may be released into the circulation after acute myocardial infarction (AMI) by exploring the kinetics of Hsp70 release and the relations between Hsp70 and markers of inflammation and myocardial damage in AMI. Design: Blood samples from 24 patients were prospectively collected through to the first day after AMI. Hsp70, interleukin (IL) 6, IL-8, and IL-10 in serum were measured by enzyme linked immunosorbent assay (ELISA). Results: Median Hsp70 concentrations in AMI patients measured at arrival, six hours thereafter, and the following morning were 686, 868, and 607 pg/ml, respectively. These concentrations were all significantly different from those of the control patients with angina with a median serum Hsp70 concentration of 306 pg/ml. Peak Hsp70 correlated with creatine kinase (CK) MB (r  =  0.62, p < 0.01) and cardiac troponin T (r  =  0.58, p < 0.01). Furthermore, serum Hsp70 correlated with IL-6 and IL-8 at six hours (r  =  0.60, p < 0.01 and r  =  0.59, p < 0.01, respectively). Conclusions: In this study, Hsp70 was rapidly released into the circulation after AMI. Circulating Hsp70 is suggested as a marker of myocardial damage. In addition, Hsp70 may have a role in the inflammatory response after AMI. PMID:15710705

  9. Bone marrow mesenchymal stem cells improve myocardial function in a swine model of acute myocardial infarction.

    PubMed

    Zhao, Jing-Jie; Liu, Xiao-Cheng; Kong, Feng; Qi, Tong-Gang; Cheng, Guang-Hui; Wang, Jue; Sun, Chao; Luan, Yun

    2014-09-01

    The aim of the current study was to confirm the effect and elucidate the mechanism of bone marrow mesenchymal stem cells (BMSCs) in acute myocardial infarction (AMI). AMI was induced in mini‑swine by ligating the left anterior descending coronary artery, and BMSCs (1x107) were injected via a sterile microinjection into the ischemic area. Six months postoperatively, electrocardiograph‑gated single photon emission computed tomography revealed that the myocardial filling defect was reduced and the left ventricular ejection fraction was improved in the BMSC group compared with the control group (P<0.05). Histopathological examination indicated that, in the BMSC treatment group, the percentage of survived myocardial tissue and the vessel density were increased, and the percentage of apoptosis was decreased compared with controls (P<0.05). Reverse transcription‑polymerase chain reaction results indicated that the expression levels of multiple inflammatory factors were significantly upregulated in the BMSC group compared with levels in the control group (P<0.05). In conclusion, the present study demonstrated that BMSC injection significantly improved cardiac function and reduced infarct size in six months, indicating that this method may be valuable for future study in clinical trials.

  10. Acute myocardial infarction and myocardial ischemia-reperfusion injury: a comparison.

    PubMed

    Hashmi, Satwat; Al-Salam, Suhail

    2015-01-01

    Myocardial infarction (MI) denotes the death of cardiac myocytes due to extended ischemia. Myocardial reperfusion is the restoration of coronary blood flow after a period of coronary occlusion. Reperfusion has the potential to salvage ischemic myocardium but paradoxically can cause injury, a phenomenon called as 'reperfusion injury' (IR). Standard histologic, immunohistochemical and Elisa techniques were used to study the histopathologic, oxidative, apoptotic and inflammatory changes in MI and IR. The IL-6 levels in the LV of the MI group were significantly raised as compared to the IR group (P=0.0008). Plasma IL-6 was also significantly increased in the MI group as compared to the IR group (P=0.031). MI model was also associated with increase in the neutrophil polymorphs number in the infarction related myocardium as compared to the re-perfused myocardium. A significant increase in troponin I level in the MI group as compared to the IR group is also seen (P=0.0001). Our IR model showed enhanced pro-apoptotic mediators like cleaved caspase-3 (P=0.005) and cytochrome c in the myocardium as compared to the MI model. In conclusion, myocardial damage in MI is mainly due to ischemic necrosis and inflammatory mechanisms while apoptosis is the main mechanism of cell death in IR in addition to limited ischemic necrosis.

  11. 3D perfusion mapping in the intact mouse heart after myocardial infarction using myocardial contrast echocardiography

    NASA Astrophysics Data System (ADS)

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

    2005-04-01

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

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

    PubMed Central

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

    2016-01-01

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

  13. 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?"

  14. Lives of rural women after myocardial infarction.

    PubMed

    Caldwell, Patricia; Arthur, Heather M; Rideout, Elizabeth

    2005-03-01

    This study examines the influences of rurality on the lives of women post-myocardial infarction (MI). Using a critical ethnographic approach, the researchers analyze in-depth interviews with 12 women from southwestern Ontario, Canada, for the ways in which their experiences were related to social, political, and cultural forces associated with rurality. Data analysis revealed 4 themes: reticence, characterized by a tendency to minimize worry and accept one's life post-MI; referral games, or the challenges associated with accessing tertiary care; resourcefulness in managing one's recovery; and relationships, with rural health professionals and institutions being highly valued. The findings have relevance for nurses in both rural and urban settings who care for women post-MI and form a basis for supporting and building culturally specific post-MI care.

  15. Caffeine reduces myocardial blood flow during exercise.

    PubMed

    Higgins, John P; Babu, Kavita M

    2013-08-01

    Caffeine consumption has been receiving increased interest from both the medical and lay press, especially given the increased amounts now available in energy products. Acute ingestion of caffeine usually increases cardiac work; however, caffeine impairs the expected proportional increase in myocardial blood flow to match this increased work of the heart, most notably during exercise. This appears to be mainly due to caffeine's effect on blocking adenosine-induced vasodilatation in the coronary arteries in normal healthy subjects. This review summarizes the available medical literature specifically relating to pure caffeine tablet ingestion and reduced exercise coronary blood flow, and suggests possible mechanisms. Further studies are needed to evaluate this effect for other common caffeine-delivery systems, including coffee, energy beverages, and energy gels, which are often used for exercise performance enhancement, especially in teenagers and young athletes.

  16. Regenerating functional heart tissue for myocardial repair

    PubMed Central

    Alcon, Andre; Bozkulak, Esra Cagavi; Qyang, Yibing

    2012-01-01

    Heart disease is one of the leading causes of death worldwide and the number of patients with the disease is likely to grow with the continual decline in health for most of the developed world. Heart transplantation is one of the only treatment options for heart failure due to an acute myocardial infarction, but limited donor supply and organ rejection limit its widespread use. Cellular cardiomyoplasty, or cellular implantation, combined with various tissue-engineering methods aims to regenerate functional heart tissue. This review highlights the numerous cell sources that have been used to regenerate the heart as well as cover the wide range of tissue-engineering strategies that have been devised to optimize the delivery of these cells. It will probably be a long time before an effective regenerative therapy can make a serious impact at the bedside. PMID:22388688

  17. Mad honey poisoning mimicking acute myocardial infarction.

    PubMed

    Chen, Sammy P L; Lam, Y H; Ng, Vember C H; Lau, F L; Sze, Y C; Chan, W T; Mak, Tony W L

    2013-08-01

    We report a case of acute poisoning in a 48-year-old man who presented with chest pain, abdominal pain, dizziness, sweatiness, blurred vision, and severe hypotension after ingestion of honey. His electrocardiogram showed sinus bradycardia and transient ST elevation. He made a good recovery after treatment with atropine and close monitoring. Grayanotoxin was detected in his urine and the honey he ingested, which confirmed a diagnosis of mad honey poisoning. This is a condition prevalent in the Black Sea region around Turkey but rarely seen locally. Although mad honey poisoning is life-threatening, early use of atropine is life-saving. Such poisoning may present with ST elevation in the electrocardiogram and symptoms mimicking acute myocardial infarction. It is therefore essential for clinicians to recognise this unusual form of poisoning and avoid the disastrous use of thrombolytic therapy.

  18. Coronary microvascular obstruction in acute myocardial infarction.

    PubMed

    Niccoli, Giampaolo; Scalone, Giancarla; Lerman, Amir; Crea, Filippo

    2016-04-01

    The success of a primary percutaneous intervention (PCI) in the setting of ST elevation myocardial infarction depends on the functional and structural integrity of coronary microcirculation. Coronary microvascular dysfunction and obstruction (CMVO) occurs in up to half of patients submitted to apparently successful primary PCI and is associated to a much worse outcome. The current review summarizes the complex mechanisms responsible for CMVO, including pre-existing coronary microvascular dysfunction, and highlights the current limitations in the assessment of microvascular function. More importantly, at the light of the substantial failure of trials hitherto published on the treatment of CMVO, this review proposes a novel integrated therapeutic approach, which should overcome the limitations of previous studies.

  19. Acute myocardial infarction in the obstetric patient.

    PubMed

    Firoz, Tabassum; Magee, Laura A

    2012-06-01

    Acute myocardial infraction (AMI) in the obstetric patient is a rare event, although the incidence is rising due to advancing maternal age and pre-existing cardiac risk factors and medical co-morbidities. While atherosclerotic disease is the leading cause of AMI, coronary artery dissection is an important consideration in pregnancy and in the postpartum period. The physiological changes of pregnancy as well as pregnancy-specific risk factors can predispose the obstetric patient to AMI. Diagnosis of AMI can be challenging as symptoms may be atypical. Furthermore, diagnostic tests must be interpreted in the context of pregnancy. While the overall management of the obstetric patient with AMI is similar to that outside of pregnancy, drug therapy requires modification as some medications may be contraindicated in pregnancy and breastfeeding. There is limited information about prognosis and risk stratification but it is anticipated that future studies will address this issue.

  20. PPARs: Protectors or Opponents of Myocardial Function?

    PubMed Central

    Pol, Christine J.; Lieu, Melissa; Drosatos, Konstantinos

    2015-01-01

    Over 5 million people in the United States suffer from the complications of heart failure (HF), which is a rapidly expanding health complication. Disorders that contribute to HF include ischemic cardiac disease, cardiomyopathies, and hypertension. Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor family. There are three PPAR isoforms: PPARα, PPARγ, and PPARδ. They can be activated by endogenous ligands, such as fatty acids, as well as by pharmacologic agents. Activators of PPARs are used for treating several metabolic complications, such as diabetes and hyperlipidemia that are directly or indirectly associated with HF. However, some of these drugs have adverse effects that compromise cardiac function. This review article aims to summarize the current basic and clinical research findings of the beneficial or detrimental effects of PPAR biology on myocardial function. PMID:26713088

  1. Molecular Imaging of Healing After Myocardial Infarction

    PubMed Central

    Naresh, Nivedita K; Ben-Mordechai, Tamar; Leor, Jonathan

    2011-01-01

    The progression from acute myocardial infarction (MI) to heart failure continues to be a major cause of morbidity and mortality. Potential new therapies for improved infarct healing such as stem cells, gene therapy, and tissue engineering are being investigated. Noninvasive imaging plays a central role in the evaluation of MI and infarct healing, both clinically and in preclinical research. Traditionally, imaging has been used to assess cardiac structure, function, perfusion, and viability. However, new imaging methods can be used to assess biological processes at the cellular and molecular level. We review molecular imaging techniques for evaluating the biology of infarct healing and repair. Specifically, we cover recent advances in imaging the various phases of MI and infarct healing such as apoptosis, inflammation, angiogenesis, extracellular matrix deposition, and scar formation. Significant progress has been made in preclinical molecular imaging, and future challenges include translation of these methods to clinical practice. PMID:21869911

  2. Myocardial infarction among men below age 40.

    PubMed Central

    Bergstrand, R; Vedin, A; Wilhelmsson, C; Wallin, J; Wedel, H; Wilhelmsen, L

    1978-01-01

    Studies were made in Göteborg over a period of 6 years of all cases of acute myocardial infarction diagnosed among men below the age of 40. Thirty-six cases were registered and 8 of these died outside hospital. Three patients died early during the hospital stay. The remaining 25 patients were compared with a random sample from the general population in Göteborg with respect to conventional risk factors. Smoking, and high plasma cholesterol values were dominating findings among the patients, whereas there was no significant differences in blood pressure levels. Coronary angiography was performed in 18 patients of whom 2 showed normal coronary arteries and left ventricular angiograms. These 2 patients were the only ones free from risk factors. Of the remaining 16 patients, 10 had only one vessel affected. PMID:687475

  3. Caffeine reduces myocardial blood flow during exercise.

    PubMed

    Higgins, John P; Babu, Kavita M

    2013-08-01

    Caffeine consumption has been receiving increased interest from both the medical and lay press, especially given the increased amounts now available in energy products. Acute ingestion of caffeine usually increases cardiac work; however, caffeine impairs the expected proportional increase in myocardial blood flow to match this increased work of the heart, most notably during exercise. This appears to be mainly due to caffeine's effect on blocking adenosine-induced vasodilatation in the coronary arteries in normal healthy subjects. This review summarizes the available medical literature specifically relating to pure caffeine tablet ingestion and reduced exercise coronary blood flow, and suggests possible mechanisms. Further studies are needed to evaluate this effect for other common caffeine-delivery systems, including coffee, energy beverages, and energy gels, which are often used for exercise performance enhancement, especially in teenagers and young athletes. PMID:23764265

  4. Myocardial Salvaging Effects of Berberine in Experimental Diabetes Co-Existing with Myocardial Infarction

    PubMed Central

    Borde, Manjusha K.; Mohanty, Ipseeta Ray; Maheshwari, Ujwala; Deshmukh, Y.A.

    2016-01-01

    Introduction Berberine, an isoquinoline alkaloid isolated from the Berberis aristata, has been shown to display a wide array of pharmacological activities (hypoglycaemic and hypolipidemic). Aim The present study was designed to investigate whether these pharmacological properties translate into the cardioprotective effects of Berberine in the setting of diabetes mellitus. Materials and Methods Necessary approval from the Institutional Animal Ethics Committee was taken for the study. Experimental diabetes was produced with single dose of Streptozotocin (STZ): 45mg/kg ip and myocardial infarction was induced by administering Isoproterenol (ISP): 85mg/kg, sc to rats on 35th & 36th day. After the confirmation of diabetes on 7th day (>200mg/dl), Berberine (100 mg/kg) was administered orally to experimental rats from day 8 and continued for 30 days thereafter. Various anti-diabetic (Glucose, HbA1c), cardioprotective (CPK-MB), metabolic (lipid profile), safety {liver function (SGPT, kidney function (Creatinine)} and histopathological indices of injury were evaluated in Healthy Control, Diabetic Control and Berberine treated groups. Results Administration of STZ-ISP resulted in a significant decrease in body weight (p<0.001), diabetic changes (increase in blood glucose, HbA1c), cardiac injury (leakage of myocardial CPK-MB), altered lipid profile, SGPT, creatinine levels (p<0.001) in the diabetic control group rats as compared to healthy control. Berberine treatment demonstrated significant antidiabetic as well as myocardial salvaging effects as indicated by restoration of blood glucose, HbA1c and CPK-MB levels (p<0.001) compared to diabetic control group. In addition, Berberine favourably modulated the lipid parameters (total cholesterol, triglycerides, HDL, LDL). Subsequent to ISP challenge, histopathological assessment of heart, pancreas and biochemical indices of injury confirmed the cardioprotective effects of Berberine in setting of diabetes. In addition, Berberine

  5. (1) Coronary Events Caused by Myocardial Bridge

    PubMed Central

    Yoko, Kawawa; Ehiichi, Kohda; Toshiharu, Ishii

    2009-01-01

    Myocardial bridge (MB), which covers a part of the left anterior descending coronary artery (LAD), is a normal anatomical variant structure (45% in frequency by autopsy) in LAD. MB contraction plays the role of a “double-edged sword” on the coronary events, suppressing coronary atherosclerosis under the MB, yet generating abnormal blood flow associated with coronary heart diseases (CHDs). High shear stress driven by MB compression causes the suppression of vascular permeability and vasoactive protein expression such as e-NOS and endothelin-1, which leads to the suppression of atherosclerosis in the LAD segment under the MB. However, despite the prevalent view of MB as benignancy by conventional coronary angiography (5-6% in frequency), with advance of imaging technique such as multislice spiral computed tomography [(MSCT); 16% in frequency], cardiologists are now frequently aware of symptomatic MB occurring not only in hospitalized patients, but also in young athletes free from atherosclerosis. Moreover, the large mass volume of MB muscle induces atherosclerosis evolution at the settled site in LAD proximal to MB and contributes to the occurrence of myocardial infarction. These events upon the coronary events result from the different pathophysiological mechanisms induced by contractile force of MB, which is solely determined just by the integration of anatomical properties of MB, such as the location, length and thickness of MB in an individual LAD. A recent MSCT provides the objective quantification of the anatomical variables that correlate with the histopathological results in relation to the occurrence of CHD. In this review, we therefore discuss the necessity to explore MB as a inherent chance anatomical risk factor for CHD. PMID:23555365

  6. Myocardial Rotation and Torsion in Child Growth

    PubMed Central

    Kim, Chang Sin; Park, Sora

    2016-01-01

    Background The speckle tracking echocardiography can benefit to assess the regional myocardial deformations. Although, previous reports suggested no significant change in left ventricular (LV) torsion with aging, there are certain differences in LV rotation at the base and apex. The purpose of this study was to evaluate the change and relationship of LV rotation for torsion with aging in children. Methods Forty healthy children were recruited and divided into two groups of twenty based on whether the children were preschool-age (2–6 years of age) or school-age (7–12 years of age). After obtaining conventional echocardiographic data, apical and basal short axis rotation were assessed with speckle tracking echocardiography. LV rotation in the basal and apical short axis planes was determined using six myocardial segments along the central axis. Results Apical and basal LV rotation did not show the statistical difference with increased age between preschool- and school-age children. Apical radial strain showed significant higher values in preschool-age children, especially at the anterior (52.8 ± 17.4% vs. 34.7 ± 23.2%, p < 0.02), lateral (55.8 ± 20.4% vs. 36.1 ± 22.7%, p < 0.02), and posterior segments (57.1 ± 17.6% vs. 38.5 ± 21.7%, p < 0.01). The torsion values did not demonstrate the statistical difference between two groups. Conclusion This study revealed the tendency of higher rotation values in preschool-age children than in school-age children. The lesser values of rotation and torsion with increased age during childhood warrant further investigation. PMID:27721953

  7. Myocardial bioenergetic abnormalities in experimental uremia

    PubMed Central

    Chesser, Alistair MS; Harwood, Steven M; Raftery, Martin J; Yaqoob, Muhammad M

    2016-01-01

    Purpose Cardiac bioenergetics are known to be abnormal in experimental uremia as exemplified by a reduced phosphocreatine (PCr)/adenosine triphosphate (ATP) ratio. However, the progression of these bioenergetic changes during the development of uremia still requires further study and was therefore investigated at baseline, 4 weeks and 8 weeks after partial nephrectomy (PNx). Methods A two-stage PNx uremia model in male Wistar rats was used to explore in vivo cardiac and skeletal muscles’ bioenergetic changes over time. High-energy phosphate nucleotides were determined by phosphorus-31 nuclear magnetic resonance (31P-NMR) and capillary zone electrophoresis. Results 31P-NMR spectroscopy revealed lower PCr/ATP ratios in PNx hearts compared to sham (SH)-operated animals 4 weeks after PNx (median values given ± SD, 0.64±0.16 PNx, 1.13±0.31 SH, P<0.02). However, 8 weeks after PNx, the same ratio was more comparable between the two groups (0.84±0.15 PNx, 1.04±0.44 SH, P= not significant), suggestive of an adaptive mechanism. When 8-week hearts were prestressed with dobutamine, the PCr/ATP ratio was again lower in the PNx group (1.08±0.36 PNx, 1.55±0.38 SH, P<0.02), indicating a reduced energy reserve during the progression of uremic heart disease. 31P-NMR data were confirmed by capillary zone electrophoresis, and the changes in myocardial bioenergetics were replicated in the skeletal muscle. Conclusion This study provides evidence of the changes that occur in myocardial energetics in experimental uremia and highlights how skeletal muscle bioenergetics mirror those found in the cardiac tissue and so might potentially serve as a practical surrogate tissue during clinical cardiac NMR investigations. PMID:27307758

  8. EMPOWERING ADULT STEM CELLS FOR MYOCARDIAL REGENERATION

    PubMed Central

    Mohsin, Sadia; Siddiqi, Sailay; Collins, Brett; Sussman, Mark A.

    2012-01-01

    Treatment strategies for heart failure remain a high priority for ongoing research due to the profound unmet need in clinical disease coupled with lack of significant translational progress. The underlying issue is the same whether the cause is acute damage, chronic stress from disease, or aging: progressive loss of functional cardiomyocytes and diminished hemodynamic output. To stave off cardiomyocyte losses, a number of strategic approaches have been embraced in recent years involving both molecular and cellular approaches to augment myocardial structure and performance. Resultant excitement surrounding regenerative medicine in the heart has been tempered by realizations that reparative processes in the heart are insufficient to restore damaged myocardium to normal functional capacity and that cellular cardiomyoplasty is hampered by poor survival, proliferation, engraftment and differentiation of the donated population. To overcome these limitations, a combination of molecular and cellular approaches needs to be adopted involving use of genetic engineering to enhance resistance to cell death and increase regenerative capacity. This review will highlight biological properties of approached to potentiate stem cell-mediated regeneration to promote enhanced myocardial regeneration, persistence of donated cells, and long lasting tissue repair. Optimizing cell delivery and harnessing the power of survival signaling cascades for ex vivo genetic modification of stem cells prior to reintroduction into the patient will be critical to enhance the efficacy of cellular cardiomyoplasty. Once this goal is achieved, then cell-based therapy has great promise for treatment of heart failure to combat the loss of cardiac structure and function associated with acute damage, chronic disease or aging. PMID:22158649

  9. Severe Plasmodium falciparum infection mimicking acute myocardial infarction.

    PubMed

    Sulaiman, Helmi; Ismail, Muhammad Dzafir; Jalalonmuhali, Maisarah; Atiya, Nadia; Ponnampalavanar, Sasheela

    2014-08-30

    This case report describes a case of presumed acute myocardial infarction in a returned traveler who was later diagnosed to have severe malaria. Emergency coronary angiography was normal and subsequent peripheral blood film was positive for Plasmodium falciparum.

  10. Efforts to limit the size of myocardial infarcts.

    PubMed

    Rude, R E; Muller, J E; Braunwald, E

    1981-12-01

    Throughout the last decade, multiple interventions have been shown to decrease myocardial ischemic injury and limit infarct size in animal models of acute myocardial infarction. Results of pilot studies have suggested that some of these interventions may also have beneficial effects in humans with evolving myocardial infarction. This review focuses on the rationale for limiting infarct size, efficacy of methods for estimating size of infarcts, and current clinical data on specific intervention therapy. No intervention has yet been proved sufficiently efficacious to warrant its routine clinical use. However, treatment with beta-adrenergic blockers, intravenous nitroglycerin, and hyaluronidase has been shown to affect one or more indexes of infarct size in patients with acute myocardial infarction. Large, randomized clinical trials of these and other promising interventions are underway and will provide data on whether infarct size can be limited in humans and whether residual cardiac function and patient prognosis can thereby be improved.

  11. [Specifically adapted management of diabetics after myocardial infarct].

    PubMed

    Passa, P

    1998-06-13

    Approximately 20% of all patients hospitalized for myocardial infarction have diabetes. The percentage has been increasing constantly and mortality is significantly higher in these patients. The highest rate is observed in women. Despite continuing progress in patient management there has been no reduction in the overmortality after myocardial infarction in diabetic patients. The majority of these deaths are unwarranted and could be avoided if diabetic patients were given specifically adapted treatment after myocardial infarction. Unfortunately, as shown by the EURASPIRE study, there is a gap between intensive care unit discharge prescriptions and follow-up care. With the explosive "epidemic" of noninsulin-diabetes and population aging the number of patients with coronary artery disease and diabetes will rise in the future. Wouldn't it be reasonable to establish special cardiodiabetic units where such patients could benefit from close, and daily, cooperation between diabetologists and cardiologists? Such facilities could be expected to significantly reduce the overmortality in diabetic patients after myocardial infarction.

  12. Primary and Secondary Drug Treatment of Myocardial Infarction

    PubMed Central

    Warnica, J.W.

    1989-01-01

    The management of myocardial infarction has been revolutionized during the last few years. Based on a better understanding of the physiopathology of infarction, aggressive intervention with drug therapy has made great reductions in both mortality and morbidity possible. Early reperfusion of the infarct-related artery with such thrombolytic agents as streptokinase or recombinant tissue plasminogen activator may decrease acute mortality by up to 50%. New uses for older drugs, such as acetylsalicylic acid and nitroglycerin, give them a primary role in acute myocardial infarction. β-Blocking drugs, when given in the early and later phases of myocardial infarction, also clearly reduce mortality and morbidity. Combining early reperfusion and adjunctive therapy with ASA, nitrates, and β-blockers will surely become accepted as the most effective method of treating the pain, limiting the damage, and preventing the complications of myocardial infarction. PMID:21249088

  13. Management of cardiogenic shock complicating acute myocardial infarction.

    PubMed

    Van Herck, Jozef L; Claeys, Marc J; De Paep, Rudi; Van Herck, Paul L; Vrints, Christiaan J; Jorens, Philippe G

    2015-06-01

    Cardiogenic shock complicates approximately 5-10% of cases with acute myocardial infarction and carries a poor prognosis. Early revascularization remains the cornerstone treatment of cardiogenic shock complicating myocardial infarction. Inotropic and/or vasopressor agents can be used for haemodynamic stabilization, although this comes at the expense of increased myocardial oxygen consumption and extended myocardial ischaemia. In recent years, the use of mechanical circulatory support has significantly increased. However, there is only limited data available from randomized trials evaluating the different percutaneous support systems. This review summarizes the available literature concerning the management of cardiogenic shock and gives an overview of the recommendations of the European and German-Austrian guidelines on cardiogenic shock.

  14. Asymptomatic myocardial infarction in Kawasaki disease: Long-term prognosis

    SciTech Connect

    Shiraishi, I.; Onouchi, Z.; Hayano, T.; Hamaoka, K.; Kiyosawa, N. )

    1991-04-01

    Eight patients with Kawasaki disease who had sustained asymptomatic myocardial infarction 8-15 years ago (mean, 13.1 years) were reexamined by various noninvasive cardiac function tests to assess long-term prognosis. At present, electrocardiograms (ECGs) are normal in six patients. However, all eight patients had a prolonged preejection period (PEP) to left ventricular ejection time (LVET) ratio 30 s after amylnitrate (AN) inhalation. Six patients had perfusion defects by exercise thallium-201 myocardial scintigraphy, and two patients developed ST segment depression in treadmill exercise testing. These patients are symptom-free even though their physical activity has not been restricted. Yet they proved to have serious abnormalities suggesting sequelae of myocardial infarction or existing myocardial ischemia. Judging from the results of noninvasive cardiac function tests and recently performed coronary angiography, five of the eight patients require coronary bypass surgery.

  15. Copeptin Testing in Acute Myocardial Infarction: Ready for Routine Use?

    PubMed Central

    Reinstadler, Sebastian Johannes; Klug, Gert; Metzler, Bernhard; Mair, Johannes

    2015-01-01

    Suspected acute myocardial infarction is one of the leading causes of admission to emergency departments. In the last decade, biomarkers revolutionized the management of patients with suspected acute coronary syndromes. Besides their pivotal assistance in timely diagnosis, biomarkers provide additional information for risk stratification. Cardiac troponins I and T are the most sensitive and specific markers of acute myocardial injury. Nonetheless, in order to overcome the remaining limitations of these markers, novel candidate biomarkers sensitive to early stage of disease are being extensively investigated. Among them, copeptin, a stable peptide derived from the precursor of vasopressin, emerged as a promising biomarker for the evaluation of suspected acute myocardial infarction. In this review, we summarize the currently available evidence for the usefulness of copeptin in the diagnosis and risk stratification of patients with suspected acute myocardial infarction in comparison with routine biomarkers. PMID:25960596

  16. An Unusual Complication Following Transarterial Chemoembolization: Acute Myocardial Infarction

    SciTech Connect

    Lai Yiliang; Chang Weichou; Kuo Wuhsien; Huang Tienyu; Chu Hengcheng; Hsieh Tsaiyuan; Chang Weikuo

    2010-02-15

    Transarterial chemoembolization has been widely used to treat unresectable hepatocellular carcinoma. Various complications have been reported, but they have not included acute myocardial infarction. Acute myocardial infarction results mainly from coronary artery occlusion by plaques that are vulnerable to rupture or from coronary spasm, embolization, or dissection of the coronary artery. It is associated with significant morbidity and mortality. We present a case report that describes a patient with hepatocellular carcinoma who underwent transarterial chemoembolization and died subsequently of acute myocardial infarction. To our knowledge, there has been no previous report of this complication induced by transarterial chemoembolization for hepatocellular carcinoma. This case illustrates the need to be aware of acute myocardial infarction when transarterial chemoembolization is planned for the treatment of hepatocellular carcinoma, especially in patients with underlying coronary artery disease.

  17. Role of cardiomyocyte circadian clock in myocardial metabolic adaptation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Marked circadian rhythmicities in cardiovascular physiology and pathophysiology exist. The cardiomyocyte circadian clock has recently been linked to circadian rhythms in myocardial gene expression, metabolism, and contractile function. For instance, the cardiomyocyte circadian clock is essential f...

  18. Inflammatory markers in ST-elevation acute myocardial infarction.

    PubMed

    Seropian, Ignacio M; Sonnino, Chiara; Van Tassell, Benjamin W; Biasucci, Luigi M; Abbate, Antonio

    2016-08-01

    After acute myocardial infarction, ventricular remodeling is characterized by changes at the molecular, structural, geometrical and functional level that determine progression to heart failure. Inflammation plays a key role in wound healing and scar formation, affecting ventricular remodeling. Several, rather different, components of the inflammatory response were studied as biomarkers in ST-elevation acute myocardial infarction. Widely available and inexpensive tests, such as leukocyte count at admission, as well as more sophisticated immunoassays provide powerful predictors of adverse outcome in patients with ST-elevation acute myocardial infarction. We review the value of inflammatory markers in ST-elevation acute myocardial infarction and their association with ventricular remodeling, heart failure and sudden death. In conclusion, the use of these biomarkers may identify subjects at greater risk of adverse events and perhaps provide an insight into the mechanisms of disease progression.

  19. Acute myocardial infarction and sudden death in Sioux Indians.

    PubMed Central

    Hrabovsky, S L; Welty, T K; Coulehan, J L

    1989-01-01

    While some Indian tribes have low rates of acute myocardial infarction, Northern Plains Indians, including the Sioux, have rates of morbidity and mortality from acute myocardial infarction higher than those reported for the United States population in general. In a review of diagnosed cases of acute myocardial infarction over a 3-year period in 2 hospitals serving predominantly Sioux Indians, 8% of cases were found misclassified, and 22% failed to meet rigorous diagnostic criteria, although the patients did indeed have ischemic heart disease. Patients had high frequencies of complications and risk factors and a fatality rate of 16% within a month of admission. Sudden deaths likely due to ischemic heart disease but in persons not diagnosed as having acute myocardial infarction by chart review occurred 3 times more frequently than deaths occurring within a month of clinical diagnosis. PMID:2735047

  20. The role of technetium-99m stannous pyrophosphate in myocardial imaging to recognize, localize and identify extension of acute myocardial infarction in patients

    NASA Technical Reports Server (NTRS)

    Willerson, J. T.; Parkey, R. W.; Bonte, F. J.; Stokely, E. M.; Buja, E. M.

    1975-01-01

    The ability of technetium-99m stannous pyrophosphate myocardial scintigrams to aid diagnostically in recognizing, localizing, and identifying extension of acute myocardial infarction in patients was evaluated. The present study is an extension of previous animal and patient evaluations that were recently performed utilizing this myocardial imaging agent.

  1. Impact of Gender on the Myocardial Metabolic Response to Obesity

    PubMed Central

    Peterson, Linda R.; Soto, Pablo F.; Herrero, Pilar; Mohammed, B. Selma; Avidan, Michael S.; Schechtman, Kenneth B.; Dence, Carmen; Gropler, Robert J.

    2010-01-01

    Objectives To determine the gender-specific effects of obesity on myocardial metabolism, work, and efficiency Background Myocardial metabolism abnormalities may contribute to the development of obesity-related heart failure. Increased myocardial oxygen consumption (MVO2) and fatty acid (FA) metabolism and decreased efficiency occur with obesity in women. It is unknown whether similar changes occur with obesity in men. Methods We quantified cardiac work, and efficiency, myocardial blood flow (MBF), MVO2, glucose, and FA metabolism, with echocardiography and positron emission tomography in nonobese and obese men and women (N=86). Results There were significant differences between the obese (N=35) and nonobese (N=51) in age, body composition, plasma lipids, and insulin resistance and differences between the men (N=30) and women (N=56) in body composition and plasma lipids. Female gender independently predicted increased cardiac work (p<.001). Female gender also related to lower efficiency (p<.05). Obesity and female gender independently predicted higher MBF (p<.01, p<.0005, respectively) and MVO2 (p<.0005, p<.0001). Myocardial glucose uptake was not different among the 4 subject groups, but obesity and gender interacted in predicting glucose uptake (p<.05). Lower myocardial glucose utilization was independently predicted by female gender (p<.05), and it independently predicted lower myocardial glucose utilization/plasma insulin (p<.05). Obesity and gender significantly interacted in the determination of glucose utilization/plasma insulin (p=.01). There were no differences in FA uptake among the 4 groups, and although increasing obesity correlated with higher myocardial FA utilization and oxidation; female gender (p<.005, <.01) and plasma triglycerides (p<.05, <.005) were their independent predictors. Conclusions Women’s and men’s myocardial metabolic response to obesity is not exactly the same. Obesity and gender modulate MBF and MVO2, are related to myocardial

  2. Inhalation of decomposed chlorodifluoromethane (freon-22) and myocardial infarction.

    PubMed

    Sjögren, Bengt; Gunnare, Sara; Sandler, Håkan

    2002-06-01

    After exposure to decomposed chlorodifluoromethane (freon-22), a 65-year-old man developed respiratory symptoms such as cough, blood-stained sputum, and increasing dyspnea. Three weeks later, his family doctor diagnosed infectious bronchitis. Another week later he died due to myocardial infarction. The discussion focuses on an inflammatory process caused by the inhalation of decomposed freon and its possible association with myocardial infarction.

  3. Systemic Effects of Electromagnetic Fields in Patients with Myocardial Infarction

    NASA Astrophysics Data System (ADS)

    Cañedo-Dorantes, L.; Valle, L.; Uruchurtu, E.; Medel, A.; García-Mayen, F.; Serrano-Luna, G.

    2003-09-01

    Healing of acute myocardial infarction (AMI) is associated with inflammatory response, which promotes healing and scar formation. Activation of a local inflammatory response in patients with sequel of AMI could have an important role to enhance angiogenesis and regeneration of hibernating myocardial tissue. Chronic arterial leg ulcers have a similar etiology, and healing has been promoted by exposure to extremely low frequency electromagnetic fields (ELF). We report the evolution of three AMI patients with sequel of AMI that were exposed to ELF.

  4. "My parents died of myocardial infarction: is that my destiny?".

    PubMed

    Narula, Nupoor; Rapezzi, Claudio; Tavazzi, Luigi; Arbustini, Eloisa

    2012-01-01

    This article presents an overview of clinical and molecular genetics of myocardial infarction (MI). Discussion includes the partial overlapping of risk factors for myocardial infarction and atherosclerosis, the impact of a positive family history on the risk of MI, the "familial" nongenetic, environmental factors, the inherited risk associated with the low-dose input of many genes, and a simple approach to stratify the individual risk in genetic counseling.

  5. Radionuclide imaging of myocardial infarction using Tc-99m TBI

    SciTech Connect

    Holman, B.L.; Campbell, S.; Kirshenbaum, J.M.; Lister-James, J.; Jones, A.G.; Davison, A.; Antman, E.

    1985-05-01

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

  6. Circulatory responses to hypoxia in experimental myocardial infarction.

    NASA Technical Reports Server (NTRS)

    Schroll, M.; Robison, S. C.; Harrison, D. C.

    1971-01-01

    Three levels of decreased arterial oxygen saturation elicited a graded circulatory response in dogs, manifested by stepwise increases in cardiac output, left ventricular dp/dt, and stroke volume, and decreases in systemic vascular resistance. Responses to similar hypoxia challenges after experimental myocardial infarction were qualitatively similar but quantitatively less. Although the circulatory compensation for hypoxia was less effective after myocardial infarction, no further deterioration of the haemodynamics was noted.

  7. Anaesthetic management of myocardial infarction in a parturient.

    PubMed

    Aglio, L S; Johnson, M D

    1990-08-01

    Myocardial infarction is encountered rarely during pregnancy, but when it occurs the event is life-threatening to both mother and fetus. Data on maternal and fetal outcome are limited, but overall maternal mortality approaches 35%, and 40% of deaths occur during the third trimester. We present a case of myocardial infarction occurring at 38 weeks gestation, and discuss the anaesthetic management of the problems encountered during labour and delivery. PMID:2121201

  8. Cardioprotection against experimental myocardial ischemic injury using cornin

    PubMed Central

    Xu, Y.; Xu, Y.; Luan, H.; Jiang, Y.; Tian, X.; Zhang, S.

    2016-01-01

    Phosphorylated-cyclic adenosine monophosphate response element-binding protein (Phospho-CREB) has an important role in the pathogenesis of myocardial ischemia. We isolated the iridoid glycoside cornin from the fruit of Verbena officinalis L, investigated its effects against myocardial ischemia and reperfusion (I/R) injury in vivo, and elucidated its potential mechanism in vitro. Effects of cornin on cell viability, as well as expression of phospho-CREB and phospho-Akt in hypoxic H9c2 cells in vitro, and myocardial I/R injury in vivo, were investigated. Cornin attenuated hypoxia-induced cytotoxicity significantly in H9c2 cells in a concentration-dependent manner. Treatment of H9c2 cells with cornin (10 µM) blocked the reduction of expression of phospho-CREB and phospho-Akt in a hypoxic condition. Treatment of rats with cornin (30 mg/kg, iv) protected them from myocardial I/R injury as indicated by a decrease in infarct volume, improvement in hemodynamics, and reduction of severity of myocardial damage. Cornin treatment also attenuated the reduction of expression of phospho-CREB and phospho-Akt in ischemic myocardial tissue. These data suggest that cornin exerts protective effects due to an increase in expression of phospho-CREB and phospho-Akt. PMID:26871971

  9. Cardioprotection against experimental myocardial ischemic injury using cornin.

    PubMed

    Xu, Y; Xu, Y; Luan, H; Jiang, Y; Tian, X; Zhang, S

    2016-02-01

    Phosphorylated-cyclic adenosine monophosphate response element-binding protein (Phospho-CREB) has an important role in the pathogenesis of myocardial ischemia. We isolated the iridoid glycoside cornin from the fruit of Verbena officinalis L, investigated its effects against myocardial ischemia and reperfusion (I/R) injury in vivo, and elucidated its potential mechanism in vitro. Effects of cornin on cell viability, as well as expression of phospho-CREB and phospho-Akt in hypoxic H9c2 cells in vitro, and myocardial I/R injury in vivo, were investigated. Cornin attenuated hypoxia-induced cytotoxicity significantly in H9c2 cells in a concentration-dependent manner. Treatment of H9c2 cells with cornin (10 µM) blocked the reduction of expression of phospho-CREB and phospho-Akt in a hypoxic condition. Treatment of rats with cornin (30 mg/kg, iv) protected them from myocardial I/R injury as indicated by a decrease in infarct volume, improvement in hemodynamics, and reduction of severity of myocardial damage. Cornin treatment also attenuated the reduction of expression of phospho-CREB and phospho-Akt in ischemic myocardial tissue. These data suggest that cornin exerts protective effects due to an increase in expression of phospho-CREB and phospho-Akt.

  10. [Myocardial serotonin metabolism after local ischemia and ischemic precondition].

    PubMed

    Naumenko, S E; Latysheva, T V; Gilinskiĭ, M A

    2014-07-01

    To determine the effect of ischemic preconditioning upon myocardial serotonin and 5-hydroxyindolacetic acid (5-HIAA) dynamic in myocardial ischemia and reperfusion. 28 male Wistar rats anesthetized with urethane were randomly divided into 2 groups. In the control group (n = 13) rats were subjected to 30 min coronary occlusion and subsequent 120 min reperfusion. In the ex- perimental group (n = 15) ischemic preconditioning (3 x 3 min ischemia + 3 x 3 min reperfusion) before prolonged ischemia was used. Myocardial interstitial serotonin and 5-HIAA were measured using a microdialysis technique. Myocardial serotonin and 5-HIAA significantly increased af- ter ischemic preconditioning (p = 0.00298; p = 0.00187). In prolonged ischemia interstitial serotonin level was lower in the experimental group vs. control up to 20 min of ischemia (p < 0.05). We conclude that ischemic preconditioning increases interstitial myocardial serotonin, but inhibit serotonin increase in subsequent prolonged myocardial ischemia. After 20 minutes of reperfusion the lack of correlation between serotonin and 5-HIAA levels appeared which may be the evidence of serotonin uptake activation.

  11. [Usefulness of attenuation correction with transmission source in myocardial SPECT].

    PubMed

    Murakawa, Keizo; Katafuchi, Tetsuro; Nishimura, Yoshihiro; Enomoto, Naoyuki; Sago, Masayoshi; Oka, Hisashi

    2006-01-20

    Attenuation correction in SPECT has been used for uniformly absorptive objects like the head. On the other hand, it has seldom been applied to nonuniform absorptive objects like the heart and surrounding lungs because of the difficulty and inaccuracy of data processing. However, since attenuation correction using a transmission source recently became practical, we were able to apply this method to a nonuniform absorptive object. Therefore, we evaluated the usefulness of this attenuation correction system with a transmission source in myocardial SPECT. The dose linearity, defect/normal ratio using a myocardial phantom, and myocardial count distribution in clinical cases was examined with and without the attenuation correction system. We found that all data processed with attenuation correction were better than those without attenuation correction. For example, in myocardial count distribution, while there was a difference between men and women without attenuation correction, which was considered to be caused by differences in body shape, after processing with attenuation correction, myocardial count distribution was almost the same in all cases. In conclusion, these results suggested that attenuation correction with a transmission source was useful in myocardial SPECT.

  12. Early-phase myocardial infarction: Evaluation by MR imaging

    SciTech Connect

    Tscholakoff, D.; Higgins, C.B.; McNamara, M.T.; Derugin, N.

    1986-06-01

    In vivo gated magnetic resonance (MR) imaging was performed in 12 dogs immediately after occlusion of the left anterior descending coronary artery and serially up to 5 hours and again between 4 and 14 days. This was done to evaluate the appearance of acute myocardial infarcts and to determine how soon after coronary artery occlusion MR imaging can demonstrate the site of acute myocardial ischemia. In nine dogs with postmortem evidence of myocardial infarction, regional increase of signal intensity of the myocardium was present by 3 hours after coronary occlusion and conformed to the site of myocardial infarct found at autopsy. The signal intensity on T2-weighted images of the infarcted on T2-weighted images of the infarcted myocardium was significantly greater than that of normal myocardium at 3, 4, and 5 hours after occlusion. The T2 (spin-spin) relaxation time was significantly prolonged in the region of myocardial infarct at 3, 4, and 5 hours post-occlusion compared with normal myocardium. Myocardial wall thinning and increased intracavitary flow signal were found in six dogs with comparable pre- and postocclusion images in late systole.

  13. Role of Endothelial Cells in Myocardial Ischemia-Reperfusion Injury

    PubMed Central

    Singhal, Arun K.; Symons, J. David; Boudina, Sihem; Jaishy, Bharat; Shiu, Yan-Ting

    2014-01-01

    Minimizing myocardial ischemia-reperfusion injury has broad clinical implications and is a critical mediator of cardiac surgical outcomes. “Ischemic injury” results from a restriction in blood supply leading to a mismatch between oxygen supply and demand of a sufficient intensity and/or duration that leads to cell necrosis, whereas ischemia-reperfusion injury occurs when blood supply is restored after a period of ischemia and is usually associated with apoptosis (i.e. programmed cell death). Compared to vascular endothelial cells, cardiac myocytes are more sensitive to ischemic injury and have received the most attention in preventing myocardial ischemia-reperfusion injury. Many comprehensive reviews exist on various aspects of myocardial ischemia-reperfusion injury. The purpose of this review is to examine the role of vascular endothelial cells in myocardial ischemia-reperfusion injury, and to stimulate further research in this exciting and clinically relevant area. Two specific areas that are addressed include: 1) data suggesting that coronary endothelial cells are critical mediators of myocardial dysfunction after ischemia-reperfusion injury; and 2) the involvement of the mitochondrial permeability transition pore in endothelial cell death as a result of an ischemia-reperfusion insult. Elucidating the cellular signaling pathway(s) that leads to endothelial cell injury and/or death in response to ischemia-reperfusion is a key component to developing clinically applicable strategies that might minimize myocardial ischemia-reperfusion injury. PMID:25558187

  14. Potential role of renin-angiotensin system blockade for preventing myocardial ischemia/reperfusion injury and remodeling after myocardial infarction.

    PubMed

    Dai, Wangde; Kloner, Robert A

    2011-03-01

    Experimental and clinical studies have demonstrated that myocardial ischemia induces activation of various components of the renin-angiotensin system (RAS), including angiotensinogen, renin, angiotensin-converting enzyme (ACE), angiotensins, and angiotensin receptors, in the acute phase of myocardial infarction and the postinfarction remodeling process. Pharmacological inhibition of the RAS by administration of renin inhibitors, ACE inhibitors, and angiotensin receptor blockers has shown beneficial effects on the pathological processes of myocardial infarction in both experimental animal studies and clinical trials. However, the potential mechanisms responsible for the cardioprotection of RAS inhibition remain unclear. In this review, we discuss roles of RAS blocking in the prevention of myocardial ischemia/reperfusion injury and postinfarction remodeling.

  15. Thallium-201 versus technetium-99m pyrophosphate myocardial imaging in detection and evaluation of patients with acute myocardial infarction

    SciTech Connect

    Pitt, B.; Thrall, J.H.

    1980-12-18

    Thallium-201 myocardial imaging is of value in the early detection and evaluation of patients with suspected acute infarction. Thallium imaging may have a special value in characterizing patients with cardiogenic shock and in detecting patients at risk for subsequent infarction or death or death or both, before hospital discharge. Approximately 95 percent of pateints with transmural or nontransmural myocardial infarction can be detected with technetium-99m pyrophosphate myocardial imaging if the imaging is performed 24 to 72 hours after the onset of symptoms. Pyrophosphate imaging may have an important role in the evaluation of patients during the early follow-up period after hospital discharge from an episode of acute infarction. The finding of a persistently positive pyrophosphate image suggests a poor prognosis and is associated with a relatively large incidence of subsequent myocardial infarction and death.

  16. Detecting Acute Myocardial Infarction by Diffusion-Weighted versus T2-Weighted Imaging and Myocardial Necrosis Markers

    PubMed Central

    Chen, Min; Li, Yongjun; Wang, YaLing; Zhang, Shijun; Wang, Zhen; Wang, Lin; Ju, Shenghong

    2016-01-01

    We used a porcine model of acute myocardial infarction to study the signal evolution of ischemic myocardium on diffusion-weighted magnetic resonance images (DWI). Eight Chinese miniature pigs underwent percutaneous left anterior descending or left circumflex coronary artery occlusion for 90 minutes followed by reperfusion, which induced acute myocardial infarction. We used DWI preprocedurally and hourly for 4 hours postprocedurally. We acquired turbo inversion recovery magnitude T2-weighted images (TIRM T2WI) and late gadolinium enhancement images from the DWI slices. We measured the serum myocardial necrosis markers myoglobin, creatine kinase-MB isoenzyme, and cardiac troponin I at the same time points as the magnetic resonance scanning. We used histochemical staining to confirm injury. All images were analyzed qualitatively. Contrast-to-noise ratio (the contrast between infarcted and healthy myocardium) and relative signal index were used in quantitative image analysis. We found that DWI identified myocardial signal abnormity early (<4 hr) after acute myocardial infarction and identified the infarct-related high signal more often than did TIRM T2WI: 7 of 8 pigs (87.5%) versus 3 of 8 (37.5%) (P=0.046). Quantitative image analysis yielded a significant difference in contrast-to-noise ratio and relative signal index between infarcted and normal myocardium on DWI. However, within 4 hours after infarction, the serologic myocardial injury markers were not significantly positive. We conclude that DWI can be used to detect myocardial signal abnormalities early after acute myocardial infarction—identifying the infarction earlier than TIRM T2WI and widely used clinical serologic biomarkers. PMID:27777517

  17. Improve Myocardial T1 Measurement in Rats with a New Regression Model: Application to Myocardial Infarction and Beyond

    PubMed Central

    Zhang, Haosen; Ye, Qing; Zheng, Jie; Schelbert, Erik B; Hitchens, T. Kevin; Ho, Chien

    2013-01-01

    Purpose To improve myocardial and blood T1 measurements with a multi-variable T1 fitting model specifically modified for a segmented multi-shot FLASH sequence. Methods The proposed method was first evaluated in a series of phantoms simulating realistic tissues, and then in healthy rats (n = 8) and rats with acute myocardial infarction (MI) induced by coronary artery ligation (n = 8). Results By accounting for the saturation effect caused by sampling α-train pulses, and the longitudinal magnetization recovery between readouts, our model provided more accurate T1 estimate than the conventional three-parameter fit in phantoms under realistic gating procedures (error of −0.42 ± 1.73% vs. −3.40 ± 1.46%, respectively, when using the measured inversion efficiency, β). The baseline myocardial T1 values in healthy rats was 1636.3 ± 23.4 ms at 7 T. One day post ligation, the T1 values in the remote and proximal myocardial areas were 1637.5 ± 62.6 ms and 1740.3 ± 70.5 ms, respectively. In rats with acute MI, regional differences in myocardial T1 values were observed both before and after the administration of gadolinium. Conclusion The proposed method has improved T1 estimate in phantoms and could advance applications utilizing quantitative myocardial T1 mapping in rodents. PMID:24142881

  18. Substrate stiffness-regulated matrix metalloproteinase output in myocardial cells and cardiac fibroblasts: implications for myocardial fibrosis.

    PubMed

    Xie, Jing; Zhang, Quanyou; Zhu, Ting; Zhang, Yanyan; Liu, Bailin; Xu, Jianwen; Zhao, Hucheng

    2014-06-01

    Cardiac fibrosis, an important pathological feature of structural remodeling, contributes to ventricular stiffness, diastolic dysfunction, arrhythmia and may even lead to sudden death. Matrix stiffness, one of the many mechanical factors acting on cells, is increasingly appreciated as an important mediator of myocardial cell behavior. Polydimethylsiloxane (PDMS) substrates were fabricated with different stiffnesses to mimic physiological and pathological heart tissues, and the way in which the elastic modulus of the substrate regulated matrix-degrading gelatinases in myocardial cells and cardiac fibroblasts was explored. Initially, an increase in cell spreading area was observed, concomitant with the increase in PDMS stiffness in both cells. Later, it was demonstrated that the MMP-2 gene expression and protein activity in myocardial cells and cardiac fibroblasts can be enhanced with an increase in PDMS substrate stiffness and, moreover, such gene- and protein-related increases had a significant linear correlation with the elastic modulus. In comparison, the MMP-9 gene and protein expressions were up-regulated in cardiac fibroblasts only, not in myocardial cells. These results implied that myocardial cells and cardiac fibroblasts in the myocardium could sense the stiffness in pathological fibrosis and showed a differential but positive response in the expression of matrix-degrading gelatinases when exposed to an increased stiffening of the matrix in the microenvironment. The phenomenon of cells sensing pathological matrix stiffness can help to increase understanding of the mechanism underlying myocardial fibrosis and may ultimately lead to planning cure strategies.

  19. Myocardial protection of early extracorporeal membrane oxygenation (ECMO) support for acute myocardial infarction with cardiogenic shock in pigs.

    PubMed

    Zhu, Gang-jie; Sun, Li-na; Li, Xing-hai; Wang, Ning-fu; Wu, Hong-hai; Yuan, Chen-xing; Li, Qiao-qiao; Xu, Peng; Ren, Ya-qi; Mao, Bao-gen

    2015-09-01

    The aim of this study was to explore myocardial protection of early extracorporeal membrane oxygenation (ECMO) support for acute myocardial infarction with cardiogenic shock in pigs. 24 male pigs (34.6 ± 1.3 kg) were randomly divided into three groups-control group, drug therapy group, and ECMO group. Myocardial infarction model was created in drug therapy group and ECMO group by ligating coronary artery. When cardiogenic shock occurred, drugs were given in drug therapy group and ECMO began to work in ECMO group. The pigs were killed 24 h after cardiogenic shock. Compared with in drug therapy group, left ventricular end-diastolic pressure in ECMO group decreased significantly 6 h after ligation (P < 0.05). At the end of the experiments, LV - dp/dt among three groups was significantly different, drug therapy group < ECMO group < control group. There was no difference in LV + dp/dt between drug therapy group and ECMO group. Compared with drug group, myocardial infarct size of ECMO group did not reduce significantly, but myocardial enzyme and troponin-I decreased significantly. Compared with drug therapy, ECMO improves left ventricular diastolic function, and may improve systolic function. ECMO cannot reduce myocardial infarct size without revascularization, but may have positive effects on ischemic areas by avoiding further injuring.

  20. Myocardial failure with altered response to adrenaline in endotoxin shock

    PubMed Central

    Archer, L.T.; Black, M.R.; Hinshaw, L.B.

    1975-01-01

    1 There is a growing concensus that myocardial performance in the early stages of experimental endotoxic and septic shock is relatively normal; however, recent reports have identified an intermediate phase of shock when myocardial dysfunction is clearly apparent. 2 The mechanism of dysfunction has become a subject of intense investigation. A current view is that altered myocardial responsiveness to circulating catecholamines may play an important role in the dysfunction observed after endotoxin administration. The present studies, in which an isolated working heart preparation of the dog was used, were designed to test this hypothesis. This particular experimental preparation was selected to provide an adequate interpretation of results; cardiac output, afterload, and concentrations of adrenaline reaching the coronary vascular bed were controlled in all experiments. Responses to infusions of adrenaline were recorded in the `steady-state' condition. Control (non-shocked) heart responses to adrenaline were highly reproducible in terms of inotropic, chronotropic and coronary vascular behaviour. 3 Results from the study document myocardial dysfunction within 4-6 h following an LD70 endotoxin administration on the basis of increased left ventricular end diastolic pressure (LVEDP), decreased cardiac power and myocardial efficiency, and depressed negative and positive dP/dt parameters. 4 Findings suggest significantly altered responsiveness of the myocardium to infused adrenaline at rates of 1, 2, and 5 μg/min with concentrations between 10 and 1 ng/ml blood. LVEDP was elevated while calculated power and efficiency parameters remained significantly below control values during infusion of adrenaline in endotoxin-treated hearts. Depressions of responsiveness were interpreted to occur on the basis of failure to restore positive and negative dP/dt to normal values and depressed coronary blood flow responses during adrenaline administration. Increases in coronary flow were

  1. Early myocardial damage assessment in dystrophinopathies using 99Tcm-MIBI gated myocardial perfusion imaging

    PubMed Central

    Zhang, Li; Liu, Zhe; Hu, Ke-You; Tian, Qing-Bao; Wei, Ling-Ge; Zhao, Zhe; Shen, Hong-Rui; Hu, Jing

    2015-01-01

    Background Early detection of muscular dystrophy (MD)-associated cardiomyopathy is important because early medical treatment may slow cardiac remodeling and attenuate symptoms of cardiac dysfunction; however, no sensitive and standard diagnostic method for MD at an earlier stage has been well-recognized. Thus, the aim of this study was to test the early diagnostic value of technetium 99m-methoxyisobutylisonitrile (99Tcm-MIBI) gated myocardial perfusion imaging (G-MPI) for MD. Methods and results Ninety-one patients underwent 99Tcm-MIBI G-MPI examinations when they were diagnosed with Duchenne muscular dystrophy (DMD) (n=77) or Becker muscular dystrophy (BMD; n=14). 99Tcm-MIBI G-MPI examinations were repeated in 43 DMD patients who received steroid treatments for 2 years as a follow-up examination. Myocardial defects were observed in nearly every segment of the left ventricular wall in both DMD and BMD patients compared with controls, especially in the inferior walls and the apices by using 99Tcm-MIBI G-MPI. Cardiac wall movement impairment significantly correlated with age in the DMD and BMD groups (rs=0.534 [P<0.05] and rs=0.784 [P<0.05], respectively). Intermittent intravenous doses of glucocorticoids and continuation with oral steroid treatments significantly improved myocardial function in DMD patients (P<0.05), but not in BMD patients. Conclusion 99Tcm-MIBI G-MPI is a sensitive and safe approach for early evaluation of cardiomyopathy in patients with DMD or BMD, and can serve as a candidate method for the evaluation of progression, prognosis, and assessment of the effect of glucocorticoid treatment in these patients. PMID:26677332

  2. Myocardial Connective Tissue Growth Factor (CCN2/CTGF) Attenuates Left Ventricular Remodeling after Myocardial Infarction

    PubMed Central

    Gravning, Jørgen; Ørn, Stein; Kaasbøll, Ole Jørgen; Martinov, Vladimir N.; Manhenke, Cord; Dickstein, Kenneth; Edvardsen, Thor; Attramadal, Håvard; Ahmed, Mohammed Shakil

    2012-01-01

    Aims Myocardial CCN2/CTGF is induced in heart failure of various etiologies. However, its role in the pathophysiology of left ventricular (LV) remodeling after myocardial infarction (MI) remains unresolved. The current study explores the role of CTGF in infarct healing and LV remodeling in an animal model and in patients admitted for acute ST-elevation MI. Methods and Results Transgenic mice with cardiac-restricted overexpression of CTGF (Tg-CTGF) and non-transgenic littermate controls (NLC) were subjected to permanent ligation of the left anterior descending coronary artery. Despite similar infarct size (area of infarction relative to area at risk) 24 hours after ligation of the coronary artery in Tg-CTGF and NLC mice, Tg-CTGF mice disclosed smaller area of scar tissue, smaller increase of cardiac hypertrophy, and less LV dilatation and deterioration of LV function 4 weeks after MI. Tg-CTGF mice also revealed substantially reduced mortality after MI. Remote/peri-infarct tissue of Tg-CTGF mice contained reduced numbers of leucocytes, macrophages, and cells undergoing apoptosis as compared with NLC mice. In a cohort of patients with acute ST-elevation MI (n = 42) admitted to hospital for percutaneous coronary intervention (PCI) serum-CTGF levels (s-CTGF) were monitored and related to infarct size and LV function assessed by cardiac MRI. Increase in s-CTGF levels after MI was associated with reduced infarct size and improved LV ejection fraction one year after MI, as well as attenuated levels of CRP and GDF-15. Conclusion Increased myocardial CTGF activities after MI are associated with attenuation of LV remodeling and improved LV function mediated by attenuation of inflammatory responses and inhibition of apoptosis. PMID:23284892

  3. Cardiac restricted overexpression of membrane type-1 matrix metalloproteinase causes adverse myocardial remodeling following myocardial infarction.

    PubMed

    Spinale, Francis G; Mukherjee, Rupak; Zavadzkas, Juozas A; Koval, Christine N; Bouges, Shenikqua; Stroud, Robert E; Dobrucki, Lawrence W; Sinusas, Albert J

    2010-09-24

    The membrane type-1 matrix metalloproteinase (MT1-MMP) is a unique member of the MMP family, but induction patterns and consequences of MT1-MMP overexpression (MT1-MMPexp), in a left ventricular (LV) remodeling process such as myocardial infarction (MI), have not been explored. MT1-MMP promoter activity (murine luciferase reporter) increased 20-fold at 3 days and 50-fold at 14 days post-MI. MI was then induced in mice with cardiac restricted MT1-MMPexp (n = 58) and wild type (WT, n = 60). Post-MI survival was reduced (67% versus 46%, p < 0.05), and LV ejection fraction was lower in the post-MI MT1-MMPexp mice compared with WT (41 ± 2 versus 32 ± 2%,p < 0.05). In the post-MI MT1-MMPexp mice, LV myocardial MMP activity, as assessed by radiotracer uptake, and MT1-MMP-specific proteolytic activity using a specific fluorogenic assay were both increased by 2-fold. LV collagen content was increased by nearly 2-fold in the post-MI MT1-MMPexp compared with WT. Using a validated fluorogenic construct, it was discovered that MT1-MMP proteolytically processed the pro-fibrotic molecule, latency-associated transforming growth factor-1 binding protein (LTBP-1), and MT1-MMP-specific LTBP-1 proteolytic activity was increased by 4-fold in the post-MI MT1-MMPexp group. Early and persistent MT1-MMP promoter activity occurred post-MI, and increased myocardial MT1-MMP levels resulted in poor survival, worsening of LV function, and significant fibrosis. A molecular mechanism for the adverse LV matrix remodeling with MT1-MMP induction is increased processing of pro-fibrotic signaling molecules. Thus, a proteolytically diverse portfolio exists for MT1-MMP within the myocardium and likely plays a mechanistic role in adverse LV remodeling.

  4. Intracoronary Levosimendan during Ischemia Prevents Myocardial Apoptosis

    PubMed Central

    Malmberg, Markus; Vähäsilta, Tommi; Saraste, Antti; Koskenvuo, Juha W.; Pärkkä, Jussi P.; Leino, Kari; Laitio, Timo; Stark, Christoffer; Heikkilä, Aira; Saukko, Pekka; Savunen, Timo

    2012-01-01

    Background: Levosimendan is a calcium sensitizer that has been shown to prevent myocardial contractile depression in patients post cardiac surgery. This drug exhibits an anti-apoptotic property; however, the underlying mechanism remains elusive. In this report, we characterized the myocardial protective of levosimendan in preventing cardiomyocyte apoptosis and post-operative stunning in an experimental ischemia–reperfusion model. Methods: Three groups of pigs (n = 8 per group) were subjected to 40 min of global, cardioplegic ischemia followed by 240 min of reperfusion. Levosimendan (65 μg/kg body weight) was given to pigs by intravenous infusion (L-IV) before ischemia or intracoronary administration during ischemia (L-IC). The Control group did not receive any levosimendan. Echocardiography was used to monitor cardiac function in all groups. Apoptosis levels were assessed from the left ventricle using the terminal transferase mediated dUTP nick end labeling (TUNEL) assay and immunocytochemical detection of Caspase-3. Results: Pigs after ischemia–reperfusion had a much higher TUNEL%, suggesting that our treatment protocol was effective. Levels of apoptosis were significantly increased in Control pigs that did not receive any levosimendan (0.062 ± 0.044%) relative to those received levosimendan either before (0.02 ± 0.017%, p = 0.03) or during (0.02 ± 0.017%, p = 0.03) the ischemia phase. Longitudinal left ventricular contraction in pigs that received levosimendan before ischemia (0.75 ± 0.12 mm) was significantly higher than those received levosimendan during ischemia (0.53 ± 0.11 mm, p = 0.003) or Control pigs (0.54 ± 0.11 mm, p = 0.01). Conclusion: Our results suggested that pigs received levosimendan displayed a markedly improved cell survival post I–R. The effect on cardiac contractility was only significant in our perfusion heart model when levosimendan was delivered intravenously before

  5. Significance of U wave polarities in previous anterior myocardial infarction

    SciTech Connect

    Kanemoto, N.; Imaoka, C.; Suzuki, Y. )

    1991-04-01

    The significance of the polarity of U waves in left precordial leads was evaluated in relation to myocardial perfusion (T1 201 myocardial scintigraphy) and left ventricular function (99m Tc radionuclide ventriculography) in 63 patients with clinical and electrocardiographic evidence of a previous anterior myocardial infarction. Patients were divided into three groups according to the polarity of the U waves: positive U waves, flat U waves, and negative U waves. Twelve matched patients served as normal controls. The following parameters were analyzed: (1) total number of abnormal Q waves; (2) total myocardial perfusion index and regional myocardial perfusion index; (3) global ejection fraction; (4) regional ejection fraction; and (5) number of diseased coronary arteries. The total myocardial perfusion index values were 43.9 {plus minus} 1.0 in controls, 40.8 {plus minus} 3.4 in the positive U wave group, 33.4 {plus minus} 3.5 in the flat U wave group, and 30.3 {plus minus} 4.4 in the patients with negative U waves. Global ejection fractions in these groups were, respectively, 63.9 {plus minus} 8.6%, 65.0 {plus minus} 11.8%, 53.6 {plus minus} 8.1%, and 36.5 {plus minus} 13.6%. The sensitivity of negative U waves suggesting a global ejection fraction of less than 45% was 91.6%, and the specificity was 82.1%. Therefore the size of myocardial infarction increased and left ventricular function decreased, in order, from patients with positive U waves, to those with flat U waves, to those with negative U waves, with statistically significant differences.

  6. Myocardial regeneration potential of adipose tissue-derived stem cells

    SciTech Connect

    Bai, Xiaowen; Alt, Eckhard

    2010-10-22

    Research highlights: {yields} Various tissue resident stem cells are receiving tremendous attention from basic scientists and clinicians and hold great promise for myocardial regeneration. {yields} For practical reasons, human adipose tissue-derived stem cells are attractive stem cells for future clinical application in repairing damaged myocardium. {yields} This review summarizes the characteristics of cultured and freshly isolated stem cells obtained from adipose tissue, their myocardial regeneration potential and the, underlying mechanisms, and safety issues. -- Abstract: Various tissue resident stem cells are receiving attention from basic scientists and clinicians as they hold promise for myocardial regeneration. For practical reasons, adipose tissue-derived stem cells (ASCs) are attractive cells for clinical application in repairing damaged myocardium based on the following advantages: abundant adipose tissue in most patients and easy accessibility with minimally invasive lipoaspiration procedure. Several recent studies have demonstrated that both cultured and freshly isolated ASCs could improve cardiac function in animal model of myocardial infarction. The mechanisms underlying the beneficial effect of ASCs on myocardial regeneration are not fully understood. Growing evidence indicates that transplantation of ASCs improve cardiac function via the differentiation into cardiomyocytes and vascular cells, and through paracrine pathways. Paracrine factors secreted by injected ASCs enhance angiogenesis, reduce cell apoptosis rates, and promote neuron sprouts in damaged myocardium. In addition, Injection of ASCs increases electrical stability of the injured heart. Furthermore, there are no reported cases of arrhythmia or tumorigenesis in any studies regarding myocardial regeneration with ASCs. This review summarizes the characteristics of both cultured and freshly isolated stem cells obtained from adipose tissue, their myocardial regeneration potential, and the

  7. 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

  8. 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

  9. Spirituality in survivors of myocardial infarction

    PubMed Central

    Momennasab, Marzieh; Moattari, Marzieh; Abbaszade, Abbas; Shamshiri, Babak

    2012-01-01

    Background: Life-threatening and stressful events, such as myocardial infarction (MI) can lead to an actual crisis, which affects the patients spiritually as well as physically, psychologically, and socially. However, the focus of health care providers is on physical needs. Furthermore, the spirituality of the patients experiencing heart attack in the light of our cultural context is not well addressed in the literature. This study is aimed at exploring the spiritual experiences of the survivors of the MI. Materials and Methods: In this qualitative research a grounded theory approach was used. Key informants were 9 MI patients hospitalized in the coronary care units of 3 hospitals in Shiraz. In addition, 7 nurses participated in the study. In-depth interviews and a focus group were used to generate data. Data analysis was done based on Strauss and Corbin method. Constant comparison analysis was performed until data saturation. Results: Five main categories emerged from the data, including perceived threat, seeking spiritual support, referring to religious values, increasing faith, and realization. The latter with its 3 subcategories was recognized as core category and represents a deep understanding beyond knowing. At the time of encountering MI, spirituality provided hope, strength, and peace for the participants. Conclusion: Based on the results we can conclude that connecting to God, religious values, and interconnectedness to others are the essential components of the participants’ spiritual experience during the occurrence of MI. Spirituality helps patients to overcome this stressful life-threatening situation. PMID:23853646

  10. Role of risk stratification after myocardial infarction.

    PubMed

    Kuriachan, Vikas; Exner, Derek V

    2009-02-01

    Despite advances in medical and surgical therapy for patients with heart disease, sudden cardiac death remains an important public health problem that prematurely ends the lives of more than 300,000 persons each year in North America. Many of these deaths occur in patients with a history of myocardial infarction (MI). Although severe left ventricular (LV) systolic dysfunction is used to identify patients at risk of sudden death after MI, most cardiac arrests occur in those with only mild LV dysfunction. Further, severe LV dysfunction is not a specific indicator for cardiac arrest. Risk stratification, to identify patients most likely to benefit from implantable defibrillator therapy after MI, is an essential area of investigation. Because the development of cardiac arrest is complex and likely requires the confluence of several factors, using a single test to predict the risk of sudden death or to guide implantable defibrillator therapy is unlikely to be successful. Tests that assess cardiac structure, including repolarization, and those that evaluate autonomic modulation and other factors have been developed with the goal of identifying patients at highest risk of cardiac arrest after MI. These tests, particularly in combination, appear to identify patients who may benefit from implantable defibrillator therapy after MI. Ongoing and planned randomized controlled trials will assess whether these tests can be used to guide implantable defibrillator therapy. Until the data from these studies are available, severe LV dysfunction remains the only proven approach to guide implantable defibrillator therapy after MI. PMID:19141257

  11. Mitochondria, myocardial remodeling, and cardiovascular disease.

    PubMed

    Verdejo, Hugo E; del Campo, Andrea; Troncoso, Rodrigo; Gutierrez, Tomás; Toro, Barbra; Quiroga, Clara; Pedrozo, Zully; Munoz, Juan Pablo; Garcia, Lorena; Castro, Pablo F; Lavandero, Sergio

    2012-12-01

    The process of muscle remodeling lies at the core of most cardiovascular diseases. Cardiac adaptation to pressure or volume overload is associated with a complex molecular change in cardiomyocytes which leads to anatomic remodeling of the heart muscle. Although adaptive at its beginnings, the sustained cardiac hypertrophic remodeling almost unavoidably ends in progressive muscle dysfunction, heart failure and ultimately death. One of the features of cardiac remodeling is a progressive impairment in mitochondrial function. The heart has the highest oxygen uptake in the human body and accordingly it has a large number of mitochondria, which form a complex network under constant remodeling in order to sustain the high metabolic rate of cardiac cells and serve as Ca(2+) buffers acting together with the endoplasmic reticulum (ER). However, this high dependence on mitochondrial metabolism has its costs: when oxygen supply is threatened, high leak of electrons from the electron transport chain leads to oxidative stress and mitochondrial failure. These three aspects of mitochondrial function (Reactive oxygen species signaling, Ca(2+) handling and mitochondrial dynamics) are critical for normal muscle homeostasis. In this article, we will review the latest evidence linking mitochondrial morphology and function with the process of myocardial remodeling and cardiovascular disease.

  12. New Trends in Radionuclide Myocardial Perfusion Imaging

    PubMed Central

    Hung, Guang-Uei; Wang, Yuh-Feng; Su, Hung-Yi; Hsieh, Te-Chun; Ko, Chi-Lun; Yen, Ruoh-Fang

    2016-01-01

    Radionuclide myocardial perfusion imaging (MPI) with single photon emission computed tomography (SPECT) has been widely used clinically as one of the major functional imaging modalities for patients with coronary artery disease (CAD) for decades. Ample evidence has supported the use of MPI as a useful and important tool in the diagnosis, risk stratification and treatment planning for CAD. Although popular in the United States, MPI has become the most frequently used imaging modality among all nuclear medicine tests in Taiwan. However, it should be acknowledged that MPI SPECT does have its limitations. These include false-positive results due to certain artifacts, false-negative due to balanced ischemia, complexity and adverse reaction arising from current pharmacological stressors, time consuming nature of the imaging procedure, no blood flow quantitation and relatively high radiation exposure. The purpose of this article was to review the recent trends in nuclear cardiology, including the utilization of positron emission tomography (PET) for MPI, new stressor, new SPECT camera with higher resolution and higher sensitivity, dynamic SPECT protocol for blood flow quantitation, new software of phase analysis for evaluation of LV dyssynchrony, and measures utilized for reducing radiation exposure of MPI. PMID:27122946

  13. Myocardial effects of flavonoids from Crataegus species.

    PubMed

    Schüssler, M; Hölzl, J; Fricke, U

    1995-08-01

    The influence of the main flavonoids from Crataegus species (hawthorn, Rosaceae) on coronary flow, heart rate and left ventricular pressure as well as on the velocity of contraction and relaxation was investigated in Langendorff perfused isolated guinea pig hearts at a constant pressure of 70 cmH2O. Drug action was evaluated in a concentration range of 10(-7) to 5 x 10(-4) mol/l. An increase of coronary flow caused by the O-glycosides luteolin-7-glucoside (186%), hyperoside (66%) and rutin (66%) as well as an increase of the relaxation velocity (positive lusitropism) by luteolin-7-glucoside (104%), hyperoside (62%) and rutin (73%) were the major effects observed at a maximum concentration of 0.5 mmol/l. Furthermore, slight positive inotropic effects and a rise in heart rate were seen. Similar but less intensive actions were found with the C-glycosides vitexin, vitexin-rhamnoside and monoacetyl-vitexin-rhamnoside. Possible beta-adrenergic activities of the flavonoids could be excluded by the addition of propranolol in fixed concentrations of 10(-8) to 10(-5) mol/l. Moreover, pretreatment of the animals with reserpine (7 mg/kg) did not influence myocardial activity of hyperoside (10(-4) mol/l). As previous experiments showed an inhibition of the 3',5'-cyclic adenosine monophosphate phosphodiesterase, the results suggest an inhibition of this enzyme as the possible underlying mechanism of cardiac action of flavonoids from Crataegus species.

  14. Effects of hemodialysis on myocardial performance index.

    PubMed

    Ulucam, Melek; Yildirir, Aylin; Muderrisoglu, Haldun; Yakupoglu, Ulkem; Korkmaz, Mehmet Emin; Ozdemir, Nurhan; Ozin, Bulent; Tayfun, Egemen

    2004-01-01

    The myocardial performance index (MPI) reflects global ventricular function. Chronic hypervolemia and uremia may negatively affect the myocardium of both ventricles. The aims of this study were to investigate how chronic renal failure (CRF) affects biventricular MPI and to determine whether preload reduction by hemodialysis (HD) affects left ventricular MPI (LVMPI) and right ventricular MPI (RVMPI) in CRF. Twenty-one patients with CRF (group 1) were examined 1 hour before and 1 hour after an HD session and 17 healthy control patients (group 2) were examined once by echocardiography. The MPI for each ventricle was calculated as the sum of isovolumic time intervals divided by the ejection time. Before HD, the LVMPI of group 1 was similar to that in group 2 (P>.05), but the RVMPI of group 1 was significantly higher (P=.007). After the HD session, LVMPI and RVMPI remained unchanged (P>.05 for both). The LVMPI and RVMPI were not correlated either before or after HD in group 1 (P>.05 for both), whereas they were correlated in group 2 (r=0.671, P=.003). Chronic renal failure causes isolated RV dysfunction, as reflected by increased RVMPI values. Preload reduction by HD does not affect LVMPI or RVMPI. Patients with CRF also do not exhibit the correlation of LVMPI and RVMPI that is observed in healthy individuals. PMID:15310083

  15. Physiological Implications of Myocardial Scar Structure

    PubMed Central

    Richardson, WJ; Clarke, SA; Quinn, TA; Holmes, JW

    2016-01-01

    Once myocardium dies during a heart attack, it is replaced by scar tissue over the course of several weeks. The size, location, composition, structure and mechanical properties of the healing scar are all critical determinants of the fate of patients who survive the initial infarction. While the central importance of scar structure in determining pump function and remodeling has long been recognized, it has proven remarkably difficult to design therapies that improve heart function or limit remodeling by modifying scar structure. Many exciting new therapies are under development, but predicting their long-term effects requires a detailed understanding of how infarct scar forms, how its properties impact left ventricular function and remodeling, and how changes in scar structure and properties feed back to affect not only heart mechanics but also electrical conduction, reflex hemodynamic compensations, and the ongoing process of scar formation itself. In this article, we outline the scar formation process following an MI, discuss interpretation of standard measures of heart function in the setting of a healing infarct, then present implications of infarct scar geometry and structure for both mechanical and electrical function of the heart and summarize experiences to date with therapeutic interventions that aim to modify scar geometry and structure. One important conclusion that emerges from the studies reviewed here is that computational modeling is an essential tool for integrating the wealth of information required to understand this complex system and predict the impact of novel therapies on scar healing, heart function, and remodeling following myocardial infarction. PMID:26426470

  16. [On the actual nomenclature of myocardial infarcts].

    PubMed

    Medrano, Gustavo A; Aranda, Alberto; Meléndez, Gabriela; de Micheli, Alfredo

    2010-01-01

    Certain criteria are examined for infarctions currents defined as inferior or inferolateral. To do this, certain considerations on the anatomical aspects of isolated and in situ heart are laid out. The topographical relationship of the in situ heart with other adjacent thoracic organs is described. The heart is schematically represented as a pyramid with a triangular base and its walls and borders are related to walls of the thorax. The spatial orientation of the main resulting vectors from ventricular depolarization and repolarization are summarized also. Usefulness of registering the unipolar thoracic leads V7, V8, V9 or a complete electrocardiographic thoracic circle, is underlined. This method allows to detect for of the existence of an acute myocardial infarction in the inferior and inferolateral segments in as third basal and mid cardiac regions previously denominated posterolateral. On the base of previous electroanatomical comparisons, it is concluded that the thoracic posterior leads V7 - V9, as well as the magnetic resonance images, explore the same heart regions. Therefore, these two methods: electrocardiography which is an essentially functional method and magnetic resonance that especially focus on structural changes are not contradictory but rather complementary tests." PMID:21147577

  17. 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

  18. Myocardial effects of flavonoids from Crataegus species.

    PubMed

    Schüssler, M; Hölzl, J; Fricke, U

    1995-08-01

    The influence of the main flavonoids from Crataegus species (hawthorn, Rosaceae) on coronary flow, heart rate and left ventricular pressure as well as on the velocity of contraction and relaxation was investigated in Langendorff perfused isolated guinea pig hearts at a constant pressure of 70 cmH2O. Drug action was evaluated in a concentration range of 10(-7) to 5 x 10(-4) mol/l. An increase of coronary flow caused by the O-glycosides luteolin-7-glucoside (186%), hyperoside (66%) and rutin (66%) as well as an increase of the relaxation velocity (positive lusitropism) by luteolin-7-glucoside (104%), hyperoside (62%) and rutin (73%) were the major effects observed at a maximum concentration of 0.5 mmol/l. Furthermore, slight positive inotropic effects and a rise in heart rate were seen. Similar but less intensive actions were found with the C-glycosides vitexin, vitexin-rhamnoside and monoacetyl-vitexin-rhamnoside. Possible beta-adrenergic activities of the flavonoids could be excluded by the addition of propranolol in fixed concentrations of 10(-8) to 10(-5) mol/l. Moreover, pretreatment of the animals with reserpine (7 mg/kg) did not influence myocardial activity of hyperoside (10(-4) mol/l). As previous experiments showed an inhibition of the 3',5'-cyclic adenosine monophosphate phosphodiesterase, the results suggest an inhibition of this enzyme as the possible underlying mechanism of cardiac action of flavonoids from Crataegus species. PMID:7575743

  19. Effects of carbon monoxide on myocardial ischemia

    SciTech Connect

    Allred, E.N.; Pagano, M. ); Bleecker, E.R.; Walden, S.M. ); Chaitman, B.R.; Dahms, T.E. ); Hackney, J.D.; Selvester, R.H. ); Warren, J. ); Gottlieb, S.O.

    1991-02-01

    The purpose of this study was to determine whether low doses of carbon monoxide (CO) exacerbate myocardial ischemia during a progressive exercise test. The effect of CO exposure was evaluated using the objective measure of time to development of electrocardiographic changes indicative of ischemia and the subjective measure of time to onset of angina. Sixty-three male subjects (41-75 years) with well-documented coronary artery disease, who had exertional angina pectoris and ischemic ST-segment changes in their electrocardiograms, were studied. Results from three randomized, double-blind test visits (room air, low and high CO) were compared. The effect of CO exposure was determined from the percent difference in the end points obtained on exercise tests performed before and after a 1-hr exposure to room air or CO. A significant dose-response relationship was found for the individual differences in the time to ST end point and angina for the pre-versus postexposure exercise test at the three carboxyhemoglobin levels. These findings demonstrate that low doses of CO produce significant effects on cardiac function during exercise in subjects with coronary artery disease.

  20. Mitochondria, myocardial remodeling, and cardiovascular disease.

    PubMed

    Verdejo, Hugo E; del Campo, Andrea; Troncoso, Rodrigo; Gutierrez, Tomás; Toro, Barbra; Quiroga, Clara; Pedrozo, Zully; Munoz, Juan Pablo; Garcia, Lorena; Castro, Pablo F; Lavandero, Sergio

    2012-12-01

    The process of muscle remodeling lies at the core of most cardiovascular diseases. Cardiac adaptation to pressure or volume overload is associated with a complex molecular change in cardiomyocytes which leads to anatomic remodeling of the heart muscle. Although adaptive at its beginnings, the sustained cardiac hypertrophic remodeling almost unavoidably ends in progressive muscle dysfunction, heart failure and ultimately death. One of the features of cardiac remodeling is a progressive impairment in mitochondrial function. The heart has the highest oxygen uptake in the human body and accordingly it has a large number of mitochondria, which form a complex network under constant remodeling in order to sustain the high metabolic rate of cardiac cells and serve as Ca(2+) buffers acting together with the endoplasmic reticulum (ER). However, this high dependence on mitochondrial metabolism has its costs: when oxygen supply is threatened, high leak of electrons from the electron transport chain leads to oxidative stress and mitochondrial failure. These three aspects of mitochondrial function (Reactive oxygen species signaling, Ca(2+) handling and mitochondrial dynamics) are critical for normal muscle homeostasis. In this article, we will review the latest evidence linking mitochondrial morphology and function with the process of myocardial remodeling and cardiovascular disease. PMID:22972531

  1. Natural and unnatural triggers of myocardial infarction.

    PubMed

    Kloner, Robert A

    2006-01-01

    Previous analyses have suggested that factors that stimulate the sympathetic nervous system and catecholamine release can trigger acute myocardial infarction. The wake-up time, Mondays, winter season, physical exertion, emotional upset, overeating, lack of sleep, cocaine, marijuana, anger, and sexual activity are some of the more common triggers. Certain natural disasters such as earthquakes and blizzards have also been associated with an increase in cardiac events. Certain unnatural triggers may play a role including the Holiday season. Holiday season cardiac events peak on Christmas and New Year. A number of hypotheses have been raised to explain the increase in cardiac events during the holidays, including overeating, excessive use of salt and alcohol, exposure to particulates, from fireplaces, a delay in seeking medical help, anxiety or depression related to the holidays, and poorer staffing of health care facilities at this time. War has been associated with an increase in cardiac events. Data regarding an increase in cardiac events during the 9/11 terrorist attack have been mixed. Understanding the cause of cardiovascular triggers will help in developing potential therapies.

  2. Clinical studies on diabetic myocardial disease using exercise testing with myocardial scintigraphy and endomyocardial biopsy

    SciTech Connect

    Genda, A.; Mizuno, S.; Nunoda, S.; Nakayama, A.; Igarashi, Y.; Sugihara, N.; Namura, M.; Takeda, R.; Bunko, H.; Hisada, K.

    1986-08-01

    Nine diabetics without significant coronary stenosis participated in an exercise testing protocol with thallium-201 myocardial scintigraphy. Endomyocardial biopsy of right ventricle was also obtained. There were 4 patients with abnormal perfusion (positive group) and 5 patients with normal perfusion (negative group). All cases of the positive group were familial diabetics and there was only one case of dietary treatment, whereas in the negative group, there were only 2 cases of familial diabetics and 3 cases receiving dietary treatment. No statistical differences between the positive and negative groups were observed for the data of exercise performance and hemodynamic parameters in cardiac catheterization at rest. However, the mean ejection fraction in the positive group (62 +/- 13%) was significantly lower than in the negative group (77 +/- 4%). In both groups, the mean diameter of myocardial cells and the mean percent fibrosis of biopsy specimens showed significant increases compared with the control group. The mean percent fibrosis in the positive group (24.1 +/- 8.5%) compared with that in the negative group (16.5 +/- 5.9%) showed a tendency to increase. It is suggested that the abnormal perfusion of thallium-201 in the positive group indicates subclinically a pathological change of microcirculation caused by diabetes mellitus.

  3. Myocardial protection by ischemic preconditioning: the influence of the composition of myocardial phospholipids.

    PubMed

    al Makdessi, S; Brändle, M; Ehrt, M; Sweidan, H; Jacob, R

    1995-04-12

    It was the aim of this study to investigate (1) whether preconditioning modifies the fatty acid (FA) composition of myocardial phospholipids (PL), (2) whether a previous modification of membrane PL composition by the administration of coconut oil or fish oil influences the preconditioning, and (3) to compare the protective effects of preconditioning to those of dietary fish oil. To this end, three groups of rats were given during 10 weeks either a standard diet, or a standard diet + 10% coconut oil, or a standard diet + 10% fish oil. The preconditioning was performed in situ in the anesthetized open-chest rats by 2 cycles of 3 min left anterior descending coronary artery occlusion and 10 min reperfusion. It was followed by a 40 min ischemia and a 60 min reperfusion. ECG was recorded and used for the continuous count of the salves of extrasystoles, ventricular flutter and fibrillation. These rhythm disturbances were subsequently added and evaluated as total arrhythmias. The FA of tissue PL were analyzed in a sample of the ischemic zone the size of which was determined by means of malachite green. Coconut oil diet (rich in saturated FA) modified slightly the myocardial PL by increasing oleic acid and decreasing linoleic acid and resulted in the highest incidence of arrhythmias. Fish oil diet had the opposite effect in modifying drastically the PLFA (replacement of the n-6 FA by the n-3 FA) and minimizing significantly the arrhythmias in comparison with the standard diet group.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. B lymphocytes trigger monocyte mobilization and impair heart function after acute myocardial infarction.

    PubMed

    Zouggari, Yasmine; Ait-Oufella, Hafid; Bonnin, Philippe; Simon, Tabassome; Sage, Andrew P; Guérin, Coralie; Vilar, José; Caligiuri, Giuseppina; Tsiantoulas, Dimitrios; Laurans, Ludivine; Dumeau, Edouard; Kotti, Salma; Bruneval, Patrick; Charo, Israel F; Binder, Christoph J; Danchin, Nicolas; Tedgui, Alain; Tedder, Thomas F; Silvestre, Jean-Sébastien; Mallat, Ziad

    2013-10-01

    Acute myocardial infarction is a severe ischemic disease responsible for heart failure and sudden death. Here, we show that after acute myocardial infarction in mice, mature B lymphocytes selectively produce Ccl7 and induce Ly6C(hi) monocyte mobilization and recruitment to the heart, leading to enhanced tissue injury and deterioration of myocardial function. Genetic (Baff receptor deficiency) or antibody-mediated (CD20- or Baff-specific antibody) depletion of mature B lymphocytes impeded Ccl7 production and monocyte mobilization, limited myocardial injury and improved heart function. These effects were recapitulated in mice with B cell-selective Ccl7 deficiency. We also show that high circulating concentrations of CCL7 and BAFF in patients with acute myocardial infarction predict increased risk of death or recurrent myocardial infarction. This work identifies a crucial interaction between mature B lymphocytes and monocytes after acute myocardial ischemia and identifies new therapeutic targets for acute myocardial infarction. PMID:24037091

  5. B lymphocytes trigger monocyte mobilization and impair heart function after acute myocardial infarction

    PubMed Central

    Zouggari, Yasmine; Ait-Oufella, Hafid; Bonnin, Philippe; Simon, Tabassome; Sage, Andrew P; Guérin, Coralie; Vilar, José; Caligiuri, Giuseppina; Tsiantoulas, Dimitrios; Laurans, Ludivine; Dumeau, Edouard; Kotti, Salma; Bruneval, Patrick; Charo, Israel F; Binder, Christoph J; Danchin, Nicolas; Tedgui, Alain; Tedder, Thomas F; Silvestre, Jean-Sébastien; Mallat, Ziad

    2014-01-01

    Acute myocardial infarction is a severe ischemic disease responsible for heart failure and sudden death. Here, we show that after acute myocardial infarction in mice, mature B lymphocytes selectively produce Ccl7 and induce Ly6Chi monocyte mobilization and recruitment to the heart, leading to enhanced tissue injury and deterioration of myocardial function. Genetic (Baff receptor deficiency) or antibody-mediated (CD20- or Baff-specific antibody) depletion of mature B lymphocytes impeded Ccl7 production and monocyte mobilization, limited myocardial injury and improved heart function. These effects were recapitulated in mice with B cell–selective Ccl7 deficiency. We also show that high circulating concentrations of CCL7 and BAFF in patients with acute myocardial infarction predict increased risk of death or recurrent myocardial infarction. This work identifies a crucial interaction between mature B lymphocytes and monocytes after acute myocardial ischemia and identifies new therapeutic targets for acute myocardial infarction. PMID:24037091

  6. Regional Longitudinal Myocardial Deformation Provides Incremental Prognostic Information in Patients with ST-Segment Elevation Myocardial Infarction

    PubMed Central

    Jensen, Jan Skov; Pedersen, Sune H.; Galatius, Søren; Fritz-Hansen, Thomas; Bech, Jan; Olsen, Flemming Javier; Mogelvang, Rasmus

    2016-01-01

    Background Global longitudinal systolic strain (GLS) has recently been demonstrated to be a superior prognosticator to conventional echocardiographic measures in patients after myocardial infarction (MI). The aim of this study was to evaluate the prognostic value of regional longitudinal myocardial deformation in comparison to GLS, conventional echocardiography and clinical information. Method In total 391 patients were admitted with ST-Segment elevation myocardial infarction (STEMI), treated with primary percutaneous coronary intervention and subsequently examined by echocardiography. All patients were examined by tissue Doppler imaging (TDI) and two-dimensional strain echocardiography (2DSE). Results During a median-follow-up of 5.3 (IQR 2.5–6.1) years the primary endpoint (death, heart failure or a new MI) was reached by 145 (38.9%) patients. After adjustment for significant confounders (including conventional echocardiographic parameters) and culprit lesion, reduced longitudinal performance in the anterior septal and inferior myocardial regions (but not GLS) remained independent predictors of the combined outcome. Furthermore, inferior myocardial longitudinal deformation provided incremental prognostic information to clinical and conventional echocardiographic information (Harrell's c-statistics: 0.63 vs. 0.67, p = 0.032). In addition, impaired longitudinal deformation outside the culprit lesion perfusion region was significantly associated with an adverse outcome (p<0.05 for all deformation parameters). Conclusion Regional longitudinal myocardial deformation measures, regardless if determined by TDI or 2DSE, are superior prognosticators to GLS. In addition, impaired longitudinal deformation in the inferior myocardial segment provides prognostic information over and above clinical and conventional echocardiographic risk factors. Furthermore, impaired longitudinal deformation outside the culprit lesion perfusion region seems to be a paramount marker of adverse

  7. Nuclear cardiac imaging for the assessment of myocardial viability

    PubMed Central

    Slart, R.H.J.A.; Bax, J.J.; van der Wall, E.E.; van Veldhuisen, D.J.; Jager, P.L.; Dierckx, R.A.

    2005-01-01

    An important aspect of the diagnostic and prognostic work-up of patients with ischaemic cardiomyopathy is the assessment of myocardial viability. Patients with left ventricular dysfunction who have viable myocardium are the patients at highest risk because of the potential for ischaemia but at the same time benefit most from revascularisation. 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 (SPECT), whether using 201thallium, 99mTc-sestamibi, or 99mTc- 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 and perfusion 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 revascularisation. New techniques in the nuclear cardiology field, such as attenuation corrected SPECT, dual isotope simultaneous acquisition (DISA) SPECT and gated FDG PET are promising and will further improve the detection of myocardial viability. Also the combination of multislice computed tomography scanners with PET opens possibilities of adding coronary calcium scoring and noninvasive coronary angiography to myocardial perfusion imaging and quantification. ImagesFigure 1Figure 2Figure 3 PMID:25696432

  8. Isolated myocardial bridging and exercise-related cardiac events.

    PubMed

    Gowd, B M P; Thompson, P D

    2014-12-01

    Myocardial bridging, which is defined as cardiac muscle overlying a part of a coronary artery, is the most common congenital coronary artery anomaly. Myocardial bridging is usually benign, but has been associated with exercise-related cardiac events. Guidelines for athletic participation in these patients are primarily based on reports from the general population with myocardial bridging. We performed a systematic literature search of PubMed, Ovid and Google Scholar for articles addressing exercise-related cardiac events associated with myocardial bridging. We identified 69 cases of which only 35 were well defined. We conclude that there are insufficient data to form definitive guidelines as to how physically active individuals with myocardial bridging should be managed. Prudence suggests that management should be individualized for those with possible symptoms. Beta adrenergic blockade is recommended as initial medical therapy. Surgery should be restricted to those with continued symptoms despite beta blocker therapy. There is no evidence that asymptomatic individuals without clinical evidence of ischemia should be restricted from vigorous activity. PMID:25144435

  9. Myocardial perfusion imaging study of CO(2)-induced panic attack.

    PubMed

    Soares-Filho, Gastão L F; Machado, Sergio; Arias-Carrión, Oscar; Santulli, Gaetano; Mesquita, Claudio T; Cosci, Fiammetta; Silva, Adriana C; Nardi, Antonio E

    2014-01-15

    Chest pain is often seen alongside with panic attacks. Moreover, panic disorder has been suggested as a risk factor for cardiovascular disease and even a trigger for acute coronary syndrome. Patients with coronary artery disease may have myocardial ischemia in response to mental stress, in which panic attack is a strong component, by an increase in coronary vasomotor tone or sympathetic hyperactivity setting off an increase in myocardial oxygen consumption. Indeed, coronary artery spasm was presumed to be present in cases of cardiac ischemia linked to panic disorder. These findings correlating panic disorder with coronary artery disease lead us to raise questions about the favorable prognosis of chest pain in panic attack. To investigate whether myocardial ischemia is the genesis of chest pain in panic attacks, we developed a myocardial perfusion study through research by myocardial scintigraphy in patients with panic attacks induced in the laboratory by inhalation of 35% carbon dioxide. In conclusion, from the data obtained, some hypotheses are discussed from the viewpoint of endothelial dysfunction and microvascular disease present in mental stress response. PMID:24188891

  10. Nitroglycerin Use in Myocardial Infarction Patients: Risks and Benefits

    PubMed Central

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

    2012-01-01

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

  11. 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.

  12. Stem cell therapy after myocardial infarction: ready for clinical application?

    PubMed

    Engelmann, Markus G; Franz, Wolfgang M

    2006-10-01

    The discovery of stem cells capable of generating angiogenic or contractile cells and structures might offer new treatment options for patients suffering from heart disease. In particular, embryonic stem cells are considered to have great potential for regenerative medicine and tissue engineering. Studies suggest that deliv