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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. [Redistribution of 201 Tl after myocardial scintigraphy with dipyridamole: value in the detection of coronary stenosis and ventricular kinetic anomalies].

    PubMed

    Demangeat, J L; Wolff, F

    1985-12-01

    One hundred and eight-four patients suspected of having coronary artery disease underwent coronary and left ventricular angiography and Tl 201 myocardial scintigraphy with dipyridamole including images of redistribution after 3-4 hours. The results of scintigraphy were assessed visually in all cases and by quantitative analysis in 91 patients. Comparison of early (DIP) and late (REDIS) images showed three types of response: 1) no hypofixation on either (10 patients), 2) a constant defect (59 patients), 3) a reversible defect (115 patients, including 21 cases of "paradoxical" redistribution). The value of the redistribution images was assessed in the diagnosis of coronary stenosis and in the evaluation of ventricular wall function in post-stenotic zones. The following results were obtained: Visual analysis of the DIP scintigraphy alone gave 17 false positive and 8 false negative results (sens: 95%, spec: 41%). The false negative results were all observed in patients at high risk. The DIP/REDIS scintigraphy (considered normal if both images were normal) gave 20 false positive but only 1 false negative result (sens: 99%, spec: 32%). In addition, the negative predictivity increased from 60 to 90%. The considerable reduction in the number of false negative results was due to the detection of "paradoxical" redistribution. The finding indicates that late films must be taken systematically even if the early scintigraphy is normal. Quantitative analysis of DIP scintigraphy was less sensitive and more specific than visual analysis (sens: 82.7%, spec: 68.7%; NVP: 46%). The same was observed when the redistribution films were processed (DIP/REDIS): significantly increased sensitivity and negative predictive value at the cost of a lower specificity (sens: 96%, spec: 41%; NPV: 70%). No significant differences were observed between the type of scintigraphic defect (constant or reversible) and the probability of coronary stenosis (positive predictive value 93 and 86% respectively

  3. Abnormal 201Tl myocardial single photon emission computed tomography in energetic male patients with myocardial bridge.

    PubMed

    Huang, W S; Chang, H D; Yang, S P; Tsao, T P; Cheng, C Y; Cherng, S C

    2002-11-01

    Myocardial bridge is a relatively benign condition where a major coronary artery is bridged by a band of muscle and narrows during systole, particularly during rapid heart rates. Its clinical presentation and electrocardiogram (ECG) changes overlap with that of coronary artery disease. 201Tl myocardial perfusion imaging is thus frequently prescribed for further evaluation. This retrospective study was carried out to determine the 201Tl image patterns in patients with myocardial bridge. A total of 17 male patients (aged from 30 to 63 years) who had a positive exercise ECG and angiographic evidence of myocardial bridge in the mid-third of the left anterior descending coronary artery were recruited. Most of them were robust and received routine physical check-ups. They had no known heart disease or medication that affected cardiac function. The patients' clinical presentations, echocardiograph and exercise ECG findings were analysed. 201Tl single photon emission computed tomography (SPECT) was performed by intravenous injection of 201Tl (111 MBq) immediately following stress (treadmill or dipyridamole induced) and 4 h after stress, using a fixed, right angle camera equipped with a low energy, general purpose collimator. The images were interpreted independently by two experienced nuclear medicine physicians. Nine of the 17 patients had anterior chest pain during exercise. All patients had an abnormal ECG during exercise, including ST-T wave depression in leads II, III and aVF, and v4-6. Except for eight patients revealing reversible perfusion defect (R), 16 of the 17 patients also exhibited a partial reversible perfusion defect (PR) or a significant reverse redistribution (RR) scan pattern in the anterior or inferior walls of the left ventricle. Myocardial bridge should be taken into consideration in energetic male patients who had abnormal exercise ECGs and the corresponding patterns of Tl SPECT abnormalities including R, PR and RR.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Cold pressor /sup 201/Tl myocardial scintigraphy in the diagnosis of coronary artery disease

    SciTech Connect

    Ahmad, M.; Dubiel, J.P.; Haibach, H.

    1982-12-01

    /sup 201/Tl myocardial scintigraphy was performed during cold pressor stimulation in 36 patients aged 36 to 69 years. Thirty-one patients had coronary artery disease and 5 patients did not, as confirmed by coronary cineangiography. /sup 201/Tl (1.5 to 2 mCi) was injected at 30 seconds of the cold pressor stimulation. The product of systolic pressure X heart rate increased from a baseline of 77.4 +/- 16 (standard deviation (SD)) to 103.6 +/- 17 at 30 seconds of the cold pressor test (p less than 0.0005). Transient perfusion deficits developed in 24 of 31 patients with coronary artery disease (sensitivity 77%), and all 5 patients without coronary artery disease had normal scintigrams. The sensitivity in detecting coronary artery disease was 40% in patients with 1 vessel disease, 91% in patients with 2 vessel disease, and 100% in patients with 3 vessel disease. Exercise electrocardiograms (available in 29 of 36 patients) were positive for ischemia in 18 of 24 patients with coronary artery disease and in 1 of 5 patients without coronary artery disease (sensitivity 75% and specificity less than 80%). Exercise /sup 201/Tl scintigrams, obtained in 16 patients, were positive in 11 patients with coronary artery disease and positive cold pressor /sup 201/Tl scintigrams. Five patients without coronary artery disease and with normal cold pressor /sup 201/Tl scintigrams had normal exercise /sup 201/Tl scintigrams. Coronary cineangiography performed during cold pressor stimulation in 6 patients who had positive cold pressor and exercise /sup 201/Tl scintigrams did not show coronary spasm. Our data indicate that cold pressor thallium-201 scintigraphy offers promise as a noninvasive test in the diagnosis of coronary artery disease and may be used in patients in whom exercise testing is not feasible.

  9. 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.

  10. Accuracy of serial myocardial perfusion scintigraphy with /sup 201/Tl for prediction of graft patency early and late after coronary artery bypass surgery. A controlled prospective study

    SciTech Connect

    Pfisterer, M.; Emmenegger, H.; Schmitt, H.E.; Mueller-Brand, J.; Hasse, J.; Graedel, E.; Laver, M.B.; Burckhardt, D.; Burkart, F.

    1982-11-01

    To assess the accuracy of serial myocardial perfusion scintigraphy with /sup 201/Tl to predict graft patency early and late coronary artery bypass surgery, rest and exercise /sup 201/Tl and coronary arteriography were performed preoperatively and 2 weeks and 1 year after operation. The scintigraphic results were compared with graft patency, symptoms, left ventricular function and physical work capacity in a consecutive series of 55 patients with a total of 154 grafts. Serial /sup 201/Tl had an 80% sensitivity, 88% specificity and 86% overall accuracy in detecting or excluding graft occlusion, which was predicted by reversible ischemia as well as persistent new scar segments. Occluded grafts were correctly localized by /sup 201/Tl scintigraphy in 61%. Postoperative apical /sup 201/Tl defects were frequent (two-thirds of cases), and were the result of intraoperative transapical venting of the left ventricle. After coronary bypass graft surgery, ejection fraction at rest was unchanged. Left ventricular end-diastolic pressure and physical work capacity improved significantly. In the presence of new perfusion defects detected postoperatively, physical work capacity was reduced significantly. New /sup 201/Tl defects in addition to typical or atypical angina provided a high probability of graft occlusion, while in the absence of new /sup 201/Tl defects all grafts were patent in more than 90% of patients, all of whom had no or only atypical chest pain. We conclude that serial /sup 201/Tl imaging after coronary artery bypass surgery is an accurate noninvasive method that can be used routinely to assess graft function, to localize spatially occluded grafts and to identify patients with a high likelihood of graft occlusion who may need invasive studies.

  11. 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.

  12. 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)

  13. [The significance of 201Tl/123I MIBG (metaiodobenzylguanidine) mismatched myocardial regions for predicting ventricular tachycardia in patients with idiopathic dilated cardiomyopathy].

    PubMed

    Maeno, M; Ishida, Y; Shimonagata, T; Hayashida, K; Toyama, T; Hirose, Y; Nagata, M; Miyatake, K; Uehara, T; Nishimura, T

    1993-10-01

    123I-MIBG (MIBG) regional defects in myocardial regions with preserved 201Tl (Tl) uptake have been observed in patients with idiopathic dilated cardiomyopathy (DCM). To evaluate whether the presence of Tl/MIBG mismatched regions is related to the occurrence of ventricular tachycardia (VT), we performed myocardial dual SPECT imaging with Tl (111 MBq) and MIBG (111 MBq) in 17 patients with DCM, 11 (Gp A) with and 6 (Gp B) without VT. Myocardial dual SPECT imaging was performed at 15 minutes after and 4 hours after the tracer injection. The regional tracer uptake was scored visually in 6 segments of the basal, middle, and apical short-axial images and in 2 apical segments of the midventricular vertical long-axial image by a four-point scoring system (0 = normal, 1 = moderate, 2 = severe and 3 = complete defect). Then, the severity of tracer maldistributions was assessed by the difference between total defect scores (TDSs) of Tl and MIBG (delta TDS). TDS was not different between Gps A and B in both Tl and MIBG images. However, delta TDS was larger in Gp A than in Gp B (13.5 +/- 6.5 vs. 5.8 +/- 3.0, p < 0.05). Also, the number of segments with the mismatched tracer uptake was larger in Gp A than in Gp B (12.5 +/- 3.0 vs. 8.3 +/- 1.5, p < 0.01). In the electrophysiologic study, we found that the fractionated area corresponded to the mismatched region in 3 of 5 patients in Gp A. These results suggest that regional sympathetic denervation is a possible factor which provocates VT, and myocardial dual SPECT imaging with Tl and MIBG is a useful method for predicting VT in patients with DCM.

  14. 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).

  15. 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.

  16. Tomographic myocardial perfusion scintigraphy in children with Kawasaki disease

    SciTech Connect

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

    1987-12-01

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

  17. Thallium-201 scintigraphy perfusion defect with dipyridamole in a patient with a myocardial bridge

    SciTech Connect

    Bennett, J.M.; Blomerus, P.

    1988-04-01

    A patient with myocardial bridging and a thallium-201 scintigraphy perfusion defect after the administration of intravenous dipyridamole is presented. The same patient had a normal perfusion study on exercise stress testing. The effects of coronary vasodilators and dipyridamole on coronary artery flow patterns in patients with myocardial bridging are discussed. We suggest that coronary vasodilators may induce perfusion defects in patients with myocardial bridging and should be avoided in such patients.

  18. Thallium-201 myocardial imaging during coronary vasodilation induced by oral dipyridamole

    SciTech Connect

    Gould, K.L.; Sorenson, S.G.; Albro, P.; Caldwell, J.H.; Chaudhuri, T.; Hamilton, G.W.

    1986-01-01

    Myocardial perfusion imaging of /sup 201/TI injected during maximum exercise has been an important diagnostic tool for coronary artery disease. Pharmacologic coronary vasodilation by i.v. infusion of dipyridamole may be used in lieu of exercise stress for purposes of diagnostic perfusion imaging. However, i.v. dipyridamole is not currently available from commercial sources for widespread routine use. Accordingly, this study was carried out in order to determine whether high dose, oral dipyridamole would be useful as a coronary vasodilator for purposes of diagnostic perfusion imaging. Fifty-eight patients undergoing diagnostic coronary arteriography also had myocardial perfusion imaging with 201TI under conditions of rest, maximum exercise stress, and high dose oral dipyridamole. Of those patients who had a defect on exercise thallium images, 75% also had a perfusion defect on thallium images after high dose oral dipyridamole. These results indicate that oral dipyridamole causes sufficient coronary arteriolar vasodilation and increase of coronary flow in nonstenotic arteries to identify perfusion defects comparable to those seen on maximum exercise stress in at least 75% of cases. In 25% of patients with exercise defects, no perfusion defect was seen after oral dipyridamole. Thus, oral dipyridamole is a potent coronary vasodilator, comparable to exercise stress in most cases, but in a minority of patients may not be comparable to exercise stress.

  19. Two-dimensional echocardiographic evaluation of ventricular asynergy induced by dipyridamole: correlation with thallium scanning

    SciTech Connect

    Ferrara, N.; Bonaduce, D.; Leosco, D.; Longobardi, G.; Abete, P.; Morgano, G.; Salvatore, M.; Rengo, F.

    1986-09-01

    Myocardial asynergies detected by two-dimensional echocardiography during intravenous administration of Dipyridamole (0.75 mg/kg) were evaluated in 54 patients referred for angiographic evaluation of chest pain. Technically adequate two-dimensional echocardiograms suitable for analysis were recorded in 42 of 54 (77.7%) patients studied. Thallium-201 myocardial perfusion scintigraphy, during dipyridamole test was performed in the same patients. Thirty of the 42 patients studied showed significant coronary narrowing at cardiac catheterization. Dipyridamole-induced wall motion abnormalities and myocardial perfusion defects were detected, respectively, in 19 (63.3%) and 21 (70%) of 30 patients with significant coronary artery disease. Wall by wall comparison of the distribution of dipyridamole-induced echocardiographic asynergy with reversible thallium-201 (/sup 201/Tl) perfusion defects demonstrated complete correlation in 42 segments examined. Three segments with perfusion defects at thallium scanning did not show asynergy during the test while two segments showing wall motion abnormalities during dipyridamole infusion did not manifest perfusion defects. Our study demonstrates that two-dimensional echocardiography during dipyridamole testing is useful in detecting patients with coronary artery disease. Furthermore, ventricular asynergies detected during the test show a high correspondence with site of myocardial perfusion defects at thallium scanning.

  20. 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%.

  1. Transient mitral regurgitation: An adjunctive sign of myocardial ischemia during dipyridamole-thallium imaging

    SciTech Connect

    Lette, J.; Gagnon, A.; Lapointe, J.; Cerino, M.

    1989-07-01

    A patient developed transient exacerbation of a mitral insufficiency murmur and a reversible posterior wall perfusion defect during dipyridamole-thallium imaging. Coronary angiography showed significant stenoses of both the right and the circumflex coronary arteries that supply the posterior papillary muscle. Cardiac auscultation for transient mitral incompetence, a sign of reversible papillary muscle dysfunction, is a simple and practical adjunctive test for myocardial ischemia during dipyridamole-thallium imaging. It may confirm that an isolated reversible posterior wall myocardial perfusion defect is truly ischemic in nature as opposed to an artifact resulting from attenuation by the diaphragm.

  2. Thallium-201 myocardial imaging during pharmacologic coronary vasodilation: comparison of oral and intravenous administration of dipyridamole

    SciTech Connect

    Taillefer, R.; Lette, J.; Phaneuf, D.C.; Leveille, J.; Lemire, F.; Essiambre, R.

    1986-07-01

    Although the diagnostic utility of thallium-201 myocardial imaging after dipyridamole infusion is well established, the intravenous form of the drug is not yet commercially available in North America. Fifty patients referred for coronary angiography were prospectively studied. Within a 2 week period, each patient underwent cardiac catheterization and thallium-201 myocardial imaging after both oral and intravenous dipyridamole administration. For the oral protocol, patients were randomly assigned to treatment with either 200 or 400 mg of dipyridamole in tablet form. Coronary artery stenoses of 70% or greater were considered significant. For the 25 patients who received a 200 mg oral dose of dipyridamole, the scintigraphic study showed perfusion defects in 65% of patients with significant coronary artery disease after the oral dose and in 85% of patients after the intravenous dose. For the 25 patients who received a 400 mg oral dose, the sensitivity of the scintigram was 84% after the oral dose and 79% after the intravenous dose. Except for headache and nausea, side effects were less severe and less frequent with oral (either 200 or 400 mg) than with intravenous dipyridamole. Because of the delayed and variable absorption of dipyridamole tablets, the oral studies required a longer period of medical supervision (45 to 60 minutes), and aminophylline was empirically administered after completion of the first set of thallium-201 images. It is concluded from this study that thallium-201 myocardial imaging after coronary vasodilation with a 400 mg oral dose of dipyridamole is a safe, widely available and reliable alternative for the evaluation of coronary artery disease in patients unable to achieve an adequate exercise level on stress testing.

  3. /sup 201/Tl scintigraphy after surgical repair of hemodynamically significant primary coronary artery anomalies

    SciTech Connect

    Rajfer, S.I.; Oetgen, W.J.; Weeks, K.D. Jr.; Kaminski, R.J.; Rocchini, A.P.

    1982-06-01

    Nine patients with hemodynamically significant congenital coronary artery anomalies underwent surgical repair at our institution during the period 1960 to 1979. Four received diagnoses of anomalous left coronary artery arising from the pulmonary artery, while five patients had coronary artery fistulae. Stress /sup 201/Tl scintigraphy was performed on these patients 0.5 to 18 years after surgical correction as a means of assessing the adequacy of myocardial perfusion. No perfusion defects were visualized on any of the thallium studies. The surgical procedure used did not appear to influence the results of /sup 201/Tl stress imaging. Thus, these nine patients with surgically corrected primary coronary artery anomalies had no evidence of ischemia as assessed by stress thallium scintigraphy. Serial preoperative and postoperative thallium studies are now indicated to determine the role of this procedure in the management of hemodynamically significant congenital coronary artery anomalies.

  4. 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.

  5. Comparison of dipyridamole-echocardiography with dipyridamole-thallium scintigraphy for the diagnosis of myocardial ischemia

    SciTech Connect

    Perin, E.C.; Moore, W.; Blume, M.; Hernandez, G.; Dhekne, R.; DeCastro, C.M. )

    1991-06-01

    After an intravenous infusion of dipyridamole (0.56 mg/kg), the authors performed both echocardiography and thallium scintigraphy in 63 patients who were referred for known or suspected coronary artery disease. Of those patients, 25 returned for coronary arteriography within 1 month after the tests, thus forming the study group for this report. Sensitivity for detection of coronary artery disease, when analyzed region-by-region, was 80% for thallium scintigraphy and 57% for echocardiography, whereas specificity was 85% and 98%, respectively. When evaluating individual patients for the presence or absence of ischemia, they found a sensitivity of 95% for scintigraphy and 58% for echocardiography; corresponding specificities were 50% and 100%. By using arteriography as the gold standard for comparison, it appears that thallium scintigraphy has a significantly higher sensitivity but lower specificity for the detection of coronary artery disease than does echocardiography. Echocardiography may, however, be a useful adjunct to thallium scintigraphy in the evaluation of patients with coronary artery disease.

  6. Myocardial uptake and clearance of thallium-201 in normal subjects: comparison of dipyridamole-induced hyperemia with exercise stress

    SciTech Connect

    Ruddy, T.D.; Gill, J.B.; Finkelstein, D.M.; Strauss, H.W.; McKusick, K.A.; Okada, R.D.; Boucher, C.A.

    1987-09-01

    Thallium-201 uptake and clearance after dipyridamole infusion may differ from that after exercise stress because the hemodynamic effects of these two interventions are different. In this study of normal volunteers, thallium kinetics after dipyridamole (n = 13) were determined from three serial image sets (early, intermediate and delayed) and from serial blood samples and compared with thallium kinetics after exercise (n = 15). Absolute myocardial thallium uptake was greater after dipyridamole compared with exercise (p less than 0.0001), although the relative myocardial distribution was similar. The myocardial clearance (%/h) of thallium was slower after dipyridamole than it was after exercise. Comparing dipyridamole and exercise, the differences in clearance were large from the early to the intermediate image (anterior, -11 +/- 17 versus 24 +/- 5, p = 0.0005; 50 degrees left anterior oblique, -7 +/- 11 versus 15 +/- 8, p = 0.004; 70 degrees left anterior oblique, 3 +/- 9 versus 21 +/- 6, p = 0.001). In contrast, the differences in clearance were small from the intermediate to the delayed image (anterior, 15 +/- 4 versus 20 +/- 2, p = 0.025; 50 degrees left anterior oblique, 15 +/- 4 versus 19 +/- 3, p = 0.13; 70 degrees left anterior oblique, 15 +/- 3 versus 18 +/- 2, p = 0.047). Thallium uptake and clearance in the liver, splanchnic region and spleen were greater after dipyridamole (p less than 0.001). Blood thallium levels were greater after dipyridamole (p less than 0.05) and cleared more slowly (p = 0.07). Thus, myocardial thallium-201 uptake and clearance after dipyridamole infusion differ from thallium kinetics after exercise. This difference is, in part, related to associated differences in extracardiac and blood kinetics. Diagnostic criteria for the detection of abnormal thallium-201 clearance must be specific for the type of intervention.

  7. Cardiac imaging and myocardial kinetics of technetium-tertiary butyl-isonitrile during dipyridamole-induced hyperemia

    SciTech Connect

    Okada, R.D.; Williams, S.J.; Glover, D.K.; Dragatokis, D.

    1988-10-01

    To determine the myocardial kinetics of technetium-tertiary-butyl-isonitrile (Tc-TBI) during dipyridamole-induced hyperemia, the circumflex coronary arteries (LCX) of 15 dogs were partially occluded. Dipyridamole was then infused intravenously over 4 minutes, creating hyperemic flows in the anterior descending (LAD) coronary system. Tc-TBI was administered, then LAD and LCX regional myocardial Tc-TBI activities were continuously monitored with miniature detectors and gamma camera imaging over 3 hours. Microsphere-determined regional myocardial blood flows demonstrated an LCX/LAD flow ratio of 0.81 +/- 0.21 at rest and 0.45 +/- 0.24 (SD) during dipyridamole infusion. Three-hour fractional Tc-TBI clearance rates were minimal and were equal in the LAD (0.14 +/- 0.11) and LCX (0.13 +/- 0.12) zones (p = ns). Excellent gamma camera images, demonstrating the LCX defect, were obtained in all dogs. The correlation coefficient was 0.98 for regional myocardial blood flow vs initial Tc-TBI distribution. In conclusion: (1) Dipyridamole vasodilation unmasked coronary stenoses despite no flow disparities at rest. (2) The initial distribution of Tc-TBI is proportional to regional myocardial blood flow. (3) There is minimal washout and no redistribution into the initial defect over time, and thus image quality is stable over time. (4) Tc-TBI myocardial kinetics may be applicable to closely related agents currently being developed.

  8. 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.

  9. Relationship between gated myocardial perfusion SPECT findings and hemodynamic, electrocardiographic, and heart rate changes after Dipyridamole infusion.

    PubMed

    Gholoobi, Arash; Ayati, Narjess; Baghyari, Alireza; Mouhebati, Mohsen; Atar, Baharak; Dabbagh Kakhki, Vahid Reza

    2017-02-01

    After dipyridamole infusion, electrocardiographic (ECG), blood pressure and heart rate (HR) changes were seen. We tried to investigate whether there is a relationship between hemodynamic, ECG and HR changes after dipyridamole infusion and gated myocardial perfusion SPECT findings. We studied 206 consecutive patients which underwent a 2-day protocol Dipyridamole Stress/Rest Tc99m-Sestamibi gated myocardial perfusion SPECT. Systolic blood pressure (SBP), diastolic blood pressure (DBP), HR and ECG were recorded. HR was mildly increased while SBP and DBP were mildly decreased after Dipyridamole infusion. There was only statistically significant difference between ECG changes as well as transient ischemic dilation (TID) ratio between normal scans and scans with ischemia (P = 0.02 and P = 0.01 respectively). There was correlation between these variables and summed stress score (SSS) and summed difference score (SDS). Patients with ischemia in their scans, 44.3% had ST depression after Dipyridamole infusion. Also ST depression most frequently was seen in patients with left anterior descending artery disease. From patients with abnormal scan + ST depression after Dipyridamole infusion (33 patient), 27 patient (81.81%) had ischemia. There was an association between TID ratio as well as ECG changes after Dipyridamole infusion and SSS, SDS and coronary artery territory abnormality. Difference between calculated left ventricular ejection fraction using stress and rest images had significant correlation with SSS and SDS. ST depression after Dipyridamole infusion and TID ratio had association with ischemia, SSS and SDS. So in equivocal Gated SPECT findings, they could be very useful for interpretation.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. Serial right ventricle /sup 201/Tl imaging after exercise: relation to anatomy of the right coronary artery

    SciTech Connect

    Brown, K.A.; Boucher, C.A.; Okada, R.D.; Strauss, H.W.; McKusick, K.A.; Pohost, G.M.

    1982-12-01

    The relation of the appearance of the right ventricle on serium /sup 201/Tl myocardial imaging to coronary artery anatomy was examined in 88 consecutive patients undergoing exercise /sup 201/Tl testing and coronary angiography for the evaluation of chest pain. Transient defects in the right ventricle were found in 8 patients. All had high grade (greater than or equal to 90%) stenosis of the proximal right coronary artery. Nonvisualization of right ventricular (RV) activity occurred in 10 patients. Nine of the 10 (90%) had significant (greater than or equal to 50% stenosis) disease of the proximal right coronary artery and 7 (70%) had high grade stenosis. The right ventricle appeared normal in 70 patients. Twenty-nine (41%) of these patients had significant proximal right coronary artery disease. Right ventricular appearance was not affected by the presence or absence of disease of the left anterior descending or left circumflex artery or by the appearance of the left ventricle. Thus, with serial RV thallium-201 myocardial imaging after exercise, we found that (1) RV transient defects suggest the presence of high grade proximal right coronary artery stenosis, (2) non-visualization of RV activity also predicts significant proximal right coronary disease, and (3) the right ventricle frequently appears normal despite proximal right coronary artery disease and therefore this finding does not exclude such disease.

  15. Dipyridamole thallium imaging

    SciTech Connect

    Beer, S.G.; Heo, J.; Iskandrian, A.S. )

    1991-05-21

    Dipyridamole cardiac imaging is a useful alternative to exercise stress testing in the evaluation of patients with ischemic heart disease. Intravenous dipyridamole has been approved recently for clinical use. Oral dipyridamole is widely available. The hemodynamic effects of dipyridamole include an increase in coronary blood flow in excess of the increase in myocardial oxygen consumption and cardiac output. The quality of the thallium images is better or similar to that of exercise thallium images. The optimal dose of intravenous dipyridamole is 0.56 mg/kg and the optimal oral dose is 300-375 mg, although higher doses may be necessary in some patients. The sensitivity and specificity of dipyridamole-thallium imaging, whether intravenous or oral, have been shown in a number of studies to be quite adequate and comparable to that achieved during exercise thallium imaging. Dipyridamole-thallium imaging has also been useful in identifying high-risk patients undergoing major elective vascular surgery. The relative merits of dipyridamole imaging versus exercise testing after acute myocardial infarction require further studies.83 references.

  16. Failure of dipyridamole-thallium myocardial imaging to detect severe coronary disease

    SciTech Connect

    Chin, W.; Go, R.; Lenehan, S.; Underwood, D.A.

    1989-09-01

    Three patients referred for peripheral vascular surgery who died of coronary artery disease complications despite normal dipyridamole-thallium scans are discussed. Although recent literature has shown enthusiasm for this test in this clinical setting, the dipyridamole-thallium scans are not absolute and patients remain at risk for major coronary artery events. Careful clinical screening and awareness of the signs of left main coronary disease on thallium images are important in the evaluation of these patients.

  17. 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.

  18. Higher events rate in patients with a normal gated myocardial perfusion imaging with dipyridamole than exercise: “Run for reliability”

    PubMed Central

    Fatima, Nosheen; uz Zaman, Maseeh; Ishaq, Mohd; Rasheed, S Zahed; Baloch, Dad J; Wali, Asif; Bano, Javeria; Rehman, Kawish

    2012-01-01

    Objective: The aim of this is to evaluate the negative predictive value (NPV) of a normal gated myocardial perfusion imaging (NGMPI) with exercise and dipyridamole in a propensity matched population. Materials and Methods: This is a prospective study conducted at Nuclear Cardiology Department of Karachi Institute of Heart Diseases, Karachi from December 2008 until June 2010. A total of 809 patients with a NGMPI with adequate exercise (558/809) or dipyridamole (251/809) stress were included and followed-up for 12-30 months (mean 24 ± 3 months) for fatal or non-fatal myocardial infarctions (MI). Results: Mean ejection fraction (%), end diastolic volume (ml), and end systolic volume (ml) in exercise and dipyridamole cohorts were (72 ± 08, 66 ± 11), (68 ± 13, 81 ± 17), and (19 ± 11, 26 ± 12) respectively. On follow-up, in dipyridamole cohort 2 fatal and 6 non-fatal MIs were reported. While in exercise cohort only 2 non-fatal MIs were reported. The NPV of a NGMPI with exercise was 99.7% (95% confidence interval [CI] 98.93-99.96%) with an event rate of 0.3% (95% CI; 0.03-0.6%) and annualized event rate of 0.15%. The NPV of NGMPI with dipyridamole was 96.80% (95% CI; 2.2-4.3%) with an event rate of 3.2% (95% CI; 1.39-3.83%) and annualized event rate of approximately 1.6%. Event free survival for dipyridamole group was significantly lower than exercise analyzed by Log-rank test (14.509, P < 0.001). Conclusion: A NGMPI with dipyridamole stress has higher event rate (low-NPV) as compared with exercise and this raises concern over its credibility to label these patients into low-risk group. PMID:23919070

  19. Dipyridamole cardiac imaging

    SciTech Connect

    Iskandrian, A.S.; Heo, J.; Askenase, A.; Segal, B.L.; Auerbach, N.

    1988-02-01

    Dipyridamole cardiac imaging is a useful alternative technique to exercise stress testing in the evaluation of patients with ischemic heart disease. Intravenous dipyridamole is still in the investigational phase, while oral dipyridamole is widely available. The hemodynamic effects of dipyridamole include an increase in coronary blood flow (due to coronary vasodilation) which is in excess of the increase in myocardial oxygen consumption and cardiac output. The disparity in the increase in coronary blood flow relative to the cardiac output results in an increase in myocardial thallium activity and an increase in the myocardial/background activity ratio. The quality of the thallium images is better or similar to that of exercise thallium images. The optimal dose of intravenous dipyridamole is 0.56 mg/kg, and of the oral dose it is 300 to 400 mg, although higher doses may be necessary in some patients. Analysis of the thallium images has been to a large extent based on visual inspection of the planar images. Delayed images are helpful to establish the nature of the perfusion abnormalities (transient or fixed). The process of redistribution is based on disparate rates of washout from the normal and abnormal zones. The sensitivity and specificity of dipyridamole thallium imaging, whether intravenous or oral, have been shown in a number of studies to be quite adequate and comparable to that achieved during exercise thallium imaging. Dipyridamole two-dimensional echocardiography has also been used in the detection of coronary artery disease; transient (new or worsening of preexisting) wall motion abnormalities have been found to be a specific marker of coronary artery disease. Transmural as well as regional coronary steal phenomena have been postulated as the mechanism for dipyridamole-induced regional wall motion abnormalities. 65 references.

  20. Thallium-201 myocardial imaging after pharmacologic coronary vasodilation: Preliminary results of a comparison between oral and intravenous administration of dipyridamole

    SciTech Connect

    Taillefer, R.; Lette, J.; Phaneuf, D.C.; Lemire, F.; Leveille, J.

    1985-05-01

    Although the diagnostic utility of Tl-201 myocardial imaging after dipyridamole (DIP) infusion is well established, the intravenous form of the drug is not commercially available. The author prospectively studied 34 consecutive patients referred for coronary angiography. With in a 2 week period, each patient underwent cardiac catheterization and Tl-201 myocardial imaging following both oral and i.v. DIP. With the patient supine, DIP was infused at a rate of 0.56 mg/kg over 4 minutes. Tl-201 was injected 3 min. after the end of the infusion with the patient standing. Myocardial imaging was performed in 3 views at 3 min. and 4 hrs after Tl-201 injection. All patients were then randomized to either 200 mg or 400 mg of oral DIP. Imaging protocol was similar to the i.v. technique, except for a delay of 45-60 min. before Tl-201 injection. Myocardial regional perfusion was evaluated by 2 independent observers using original analog and background substracted digital images with segmental profile analysis. For the 17 patients who recieved DIP 400 mg, the sensitivity was 75%(9/12) with the infusion and 83% (10/12) with the oral dose. Side effects were minor and less frequent with the oral DIP. Despite the small number of patients studied, Tl-201 imaging following 400 mg oral DIP administration proved to be reliable alternative to the intravenously induced coronary vasodilation.

  1. 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.

  2. 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.

  3. Myocardial imaging using thallium 201 scintigraphy after dipyridamole infusion: A case history

    SciTech Connect

    Niemeyer, M.G.; van der Wall, E.E.; Leijtens, J.P.; Wever, J.; van der Pol, J.M.; Willekens, F.G. )

    1989-12-01

    Coronary artery disease frequently occurs in combination with peripheral vascular disorders and is an important cause of morbidity and mortality during or after peripheral vascular surgery. However, the detection of coronary artery disease in patients with peripheral vascular disease may be complicated, since most of these patients are unable to perform conventional exercise testing. The authors report a sixty-two-year-old man with an infrarenally located aneurysm of the abdominal aorta who underwent thallium 201 scintigraphy combined with dipyridamole infusion as an alternative exercise test. The subsequent thallium 201 images showed perfusion defects indicative of severe coronary artery disease. Coronary angiography showed an occluded right coronary artery and a significant proximal stenosis in the left anterior descending coronary artery. The patient underwent successful aortocoronary bypass surgery, and two months later, the aortic aneurysm was operated on without complications. As a result, dipyridamole thallium 201 scintigraphy should be considered as a valuable diagnostic test to detect coronary artery disease in patients with peripheral vascular disorders.

  4. 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.

  5. 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

  6. Assessment of the ability of myocardial contrast echocardiography with harmonic power Doppler imaging to identify perfusion abnormalities in patients with Kawasaki disease at rest and during dipyridamole stress.

    PubMed

    Ishii, M; Himeno, W; Sawa, M; Iemura, M; Furui, J; Muta, H; Sugahara, Y; Egami, K; Akagi, T; Ishibashi, M; Kato, H

    2002-01-01

    The aim of our study was to assess the ability of myocardial contrast echocardiography (MCE) with harmonic power Doppler imaging (HPDI) to identify perfusion abnormalities in patients with Kawasaki disease at rest and during pharmacological stress imaging with dipyridamole. Results were compared with those of 99mTc-tetrofosmin single-photon emission computed tomography (SPECT) imaging as the clinical reference standard. MCE with HPDI was performed on 20 patients with a history of Kawasaki disease. Images were obtained at baseline and during dipyridamole infusion (0.56 mg x kg(-1)) in the apical two- and four-chamber views. Myocardial opacification suitable for the analysis was obtained in all patients. Nine patients with stenotic lesions had a reversible defect after dipyridamole infusion detected by both MCE with HPDI and SPECT, and 3 patients with a history of myocardial infarction had a partially or completely irreversible defect detected by both methods. Three patients with coronary aneurysm without stenotic lesion, 4 patients with regressed coronary aneurysm, and 2 patients with normal coronary artery in acute phase also had normal perfusion at rest and after pharmacological stress by both methods. A 96% concordance (kappa = 0.87) was obtained when comparing the respective segmental perfusion scores using the two methods at baseline, and an 86% concordance (kappa = 0.81) was obtained at postdipyridamole infusion. After combining baseline and postdipyridamole images, each segment was labeled as having normal perfusion, irreversible defects, or reversible defects. Using these classifications, concordance for the two methods was 92% (kappa = 0.87). MCE with HPDI is a safe and feasible method by which to detect asymptomatic ischemia due to severe stenotic lesion, and it may be an important addition to the modalities used to identify patients at risk for myocardial infarction as a complication of Kawasaki disease.

  7. Dipyridamole-thallium-201 tomography documenting improved myocardial perfusion with therapy in Kawasaki disease

    SciTech Connect

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

    1988-12-01

    Thallium-201 tomographic perfusion studies after pharmacologic vasodilation were performed in seven children (aged 2 years 8 months to 8 years 7 months), 3 to 20 months after the acute stage of the disease. In all patients coronary aneurysms were seen on cross-sectional echocardiograms. The scintigrams of six children showed no significant regional reduction of myocardial thallium-201 uptake. These children had remained asymptomatic in the follow-up period after the acute inflammatory stage of Kawasaki disease. Persistent and transient thallium defects were present in one child with acute posterolateral myocardial infarction; obstruction of two coronary vessels supplying the defect zones was confirmed by contrast angiography. After 8 months of treatment a follow-up nuclear scan showed marked reduction in the size of the defect and almost complete abolishment of the ischemic reaction. Thus tomographic thallium-201 perfusion scintigraphy in conjunction with vasodilation stress is useful to assess myocardial perfusion in children with Kawasaki disease and demonstrates marked improvement in regional perfusion after adequate medical therapy.

  8. Prognostic importance of scintigraphic left ventricular cavity dilation during intravenous dipyridamole technetium-99m sestamibi myocardial tomographic imaging in predicting coronary events.

    PubMed

    McClellan, J R; Travin, M I; Herman, S D; Baron, J I; Golub, R J; Gallagher, J J; Waters, D; Heller, G V

    1997-03-01

    Left ventricular (LV) cavity dilation during stress myocardial perfusion imaging has been associated with multivessel disease, and may be an independent prognostic marker in addition to perfusion defects. The present study examines the predictive value for future cardiac events of transient or fixed LV dilation during dipyridamole technetium-99m (Tc-99m) sestamibi single-photon emission computed tomography (SPECT) imaging. The study included 512 consecutive patients who underwent SPECT imaging with Tc-99m sestamibi after dipyridamole infusion. Transient LV dilation was seen in 70 patients (14%) and 74 had fixed cavity dilation (14%); cavity size was normal in 368 patients (72%). Each perfusion scan was classified as normal or abnormal, and if abnormal, defects were categorized as transient or fixed, and as small, medium, or large (depending upon the number of abnormal vascular territories). Events during a mean follow-up of 12.8 +/- 6.8 months were tabulated by direct review of hospital charts and death certificates. The cardiac event rate (cardiac death or nonfatal infarction) was 1.9% in patients with normal cavity size, 11.4% with transient LV dilation, and 13.5% with fixed LV dilation (p < 0.01). Compared with patients with normal cavity size, those with transient LV dilation were more likely to sustain a myocardial infarction (p < 0.01) and those with fixed dilation more frequently suffered cardiac death (p < 0.01) and hospitalization for heart failure (p < 0.01). The group with the highest risk had both a large perfusion defect and cavity dilation. By Cox proportional hazard regression analysis, both transient and fixed LV dilation were strong independent predictors of cardiac events. Transient or fixed LV dilation are commonly seen during dipyridamole Tc-99m sestamibi SPECT imaging (14% incidence for each) and are useful predictors of cardiac events.

  9. 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.

  10. 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.

  11. Reproducibility of quantitative planar thallium-201 scintigraphy: quantitative criteria for reversibility of myocardial perfusion defects

    SciTech Connect

    Sigal, S.L.; Soufer, R.; Fetterman, R.C.; Mattera, J.A.; Wackers, F.J. )

    1991-05-01

    Fifty-two paired stress/delayed planar {sup 201}TI studies (27 exercise studies, 25 dipyridamole studies) were processed twice by seven technologists to assess inter- and intraobserver variability. The reproducibility was inversely related to the size of {sup 201}Tl perfusion abnormalities. Intraobserver variability was not different between exercise and dipyridamole studies for lesions of similar size. Based upon intraobserver variability, objective quantitative criteria for reversibility of perfusion abnormalities were defined. These objective criteria were tested prospectively in a separate group of 35 {sup 201}Tl studies and compared with the subjective interpretation of quantitative circumferential profiles. Overall, exact agreement existed in 78% of images (kappa statistic k = 0.66). We conclude that quantification of planar {sup 201}Tl scans is highly reproducible, with acceptable inter- and intraobserver variability. Objective criteria for lesion reversibility correlated well with analysis by experienced observers.

  12. Sex-specific criteria for interpretation of thallium-201 myocardial uptake and washout studies

    SciTech Connect

    Rabinovitch, M.; Suissa, S.; Elstein, J.; Staniloff, H.; Tang, A.; Rush, C.; Aldis, A.; Tannous, R.; Turek, M.; Addas, A.

    1986-12-01

    A study was undertaken to determine the effect of gender on criteria for the quantitative analysis of exercise-redistribution /sup 201/Tl myocardial scintigraphy. The studies of 26 normal females and 23 normal males were subjected to bilinear interpolative background subtraction and horizontal profile analysis. Significant sexual differences were found in both regional uptake ratios and washout rates. These differences primarily reflected a proportionately decreased anterior and upper septal uptake in females, and faster washout in females. Faster myocardial /sup 201/Tl washout rates in females could not be clearly ascribed to either a physiological or artifactual explanation. It is concluded that since important differences exist between males and females in the detected pattern of /sup 201/Tl myocardial uptake and washout, sex-specific criteria may enhance the predictive accuracy of exercise-redistribution /sup 201/Tl myocardial scintigraphy.

  13. Delayed redistribution in thallium 201 SPECT myocardial perfusion studies

    SciTech Connect

    Ziessman, H.A.; Keyes, J.W. Jr.; Fox, L.M.; Green, C.E.; Fox, S.M. )

    1989-11-01

    Stress {sup 201}Tl myocardial perfusion studies are useful in differentiating viable, reversibly ischemic from infarcted myocardium. A perfusion defect that shows redistribution 2 to 4 h after {sup 201}Tl injection is diagnostic of ischemia, while a fixed defect suggests infarction. However, occasional patients with a fixed defect at 4 h have redistribution at 24 h. This study evaluates the frequency and significance of this delayed redistribution with SPECT {sup 201}Tl. Patients with either no or incomplete redistribution at 4 h had repeat imaging 18 to 48 h later. Delayed redistribution was seen in 8/26 (31 percent). Four had incomplete and four had no redistribution at 4 h. Delayed redistribution with SPECT {sup 201}Tl is more common than generally appreciated, and we recommend delayed images in patients with fixed perfusion defects or incomplete redistribution at 4-h imaging, particularly in patients with previous infarctions for whom a revascularization procedure is being considered.

  14. Wiener filtering improves quantification of regional myocardial perfusion with thallium-201 SPECT

    SciTech Connect

    Links, J.M.; Jeremy, R.W.; Dyer, S.M.; Frank, T.L.; Becker, L.C. )

    1990-07-01

    Quantitation of myocardial perfusion with thallium-201 (201Tl) SPECT is limited by finite resolution and image noise. This study examined whether Wiener filtering could improve quantitation of the severity of myocardial perfusion deficits. In 19 anesthetized dogs, adjustable stenoses were placed on the left anterior descending (LAD, n = 12) or circumflex (LCx, n = 7) arteries. Thallium-201 SPECT images were acquired during maximal coronary vasodilation with dipyridamole, and simultaneous measurements of myocardial blood flow were made with microspheres. The relationship between SPECT and microsphere flow deficits in the LAD region was significantly better (p less than 0.05) with Wiener filtering (Y = 0.90X + 0.03, r = 0.78) than with conventional Hanning filtering (Y = 0.66X + 0.34, r = 0.61). Similarly, in the LCx region the relationship between SPECT and microsphere perfusion deficits was better (p less than 0.01) with the Wiener filter (Y = 0.91X + 0.07, r = 0.66) than with the Hanning filter (Y = 0.36X + 0.50, r = 0.40). Wiener filtering improves quantitation of the severity of regional myocardial perfusion deficits, allowing better assessment of the functional significance of coronary artery stenoses.

  15. 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.

  16. Imaging considerations for a technetium-99m myocardial perfusion agent

    SciTech Connect

    English, R.J.; Jones, A.G.; Davison, A.; Lister-James, J.; Campbell, S.; Holman, B.L.

    1986-03-01

    Myocardial perfusion imaging with /sup 201/Tl chloride suffers from a number of physical, geometric, and dosimetric constraints that could be diminished if an agent labeled with /sup 99m/Tc were available. The cationic complex /sup 99m/Tc hexakis-(t-butylisonitrile)technetium(I) ((/sup 99m/Tc)TBI) has been shown to concentrate in the myocardial tissue of both animals and humans, with preliminary clinical studies demonstrating a number of technical attributes not possible with /sup 201/Tl. Technetium-99m-TBI is a promising myocardial imaging agent that may permit high quality planar, gated, and tomographic imaging of both myocardial ischemia and infarction with reduced imaging times and improved resolution.

  17. Dielectric properties and charge transfer in (TlInSe2)0.1(TlGaTe2)0.9 for the DC and AC current

    NASA Astrophysics Data System (ADS)

    Mustafaeva, S. N.; Asadov, M. M.; Dzhabbarov, A. I.

    2014-06-01

    The experimental results of studying the temperature and frequency dependences of dc and ac conductivity as well as the dispersion of dielectric coefficients of the grown single crystals of the (TlInSe2)0.1(TlGaTe2)0.9 solid solution are presented. The nature of dielectric losses and the hopping charge transfer mechanism have been established, and parameters of localized states, such as the density of states near the Fermi level and their spread, the average time and the hopping length of charge carriers, and the concentration of deep traps responsible for dc and ac conductivity, have been evaluated.

  18. 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.

  19. The additive value of transient left ventricular dilation using two-day dipyridamole 99mTc-MIBI SPET for screening coronary artery disease in patients with otherwise normal myocardial perfusion: a comparison between diabetic and non-diabetic cases.

    PubMed

    Fallahi, Babak; Beiki, Davood; Fard-Esfahani, Armaghan; Akbarpour, Saeed; Abolhassani, Arash; Kakhki, Vahid Reza Dabbagh; Eftekhari, Mohammad

    2010-01-01

    The prognostic value of transient ischemic dilation (TID) has been previously confirmed; however, its clinical significance for screening coronary artery disease (CAD) with balanced ischemia, as a cause of false negative myocardial perfusion imaging (MPI), is unclear. The goal of this study was to determine the additive diagnostic value of TID ratio for screening CAD in separate subgroups of diabetic and non-diabetics with normal perfusion. Eighty six patients with intermediate probability of CAD who had TID more than one in the presence of otherwise normal MPI using two-day technetium-99m methoxy isobutyl isonitrile ((99m)Tc-MIBI) single photon emission tomography (SPET) and dipyridamole stress (summed stress score<3 and left ventricular cavity<90 mL) were included in a prospective cohort study comprising two subgroups of diabetic and non- diabetic patients. An inclusive work-up with multiple noninvasive tests was performed for all patients from whom 38 cases subsequently underwent coronary angiography and 48 cases were categorized in the group with a very low likelihood (<5%) of CAD on the basis of clinical and paraclinical data over a minimum of 18 months follow up. The TID ratio was calculated using automated software. Gensini score (GS) as an indicator of severity/extent of stenosis and coronary artery index (CAI) as the number of arteries with more than 50% narrowing were calculated based on angiographic findings. Our results showed that only in diabetic patients with three-vessel disease, TID ratio (1.47 ± 0.23) differs significantly from the other groups of CAD. In diabetic patients subgroup, TID ratio correlated strongly with GS (r=0.957, P<0.0001) and CAI (r=0.659, P=0.001), while such correlations were not seen in the non-diabetic patients. On the basis of receiver operating characteristic curve analysis for screening CAD in diabetic patients with normal myocardial perfusion, 100% sensitivity and 77.8% normalcy rate were achieved when TID more than 1

  20. Use of thallium-201 redistribution scintigraphy in the preoperative differentiation of reversible and nonreversible myocardial asynergy.

    PubMed

    Rozanski, A; Berman, D S; Gray, R; Levy, R; Raymond, M; Maddahi, J; Pantaleo, N; Waxman, A D; Swan, H J; Matloff, J

    1981-11-01

    Thallium-201 (201Tl) redistribution scintigraphy might differentiate reversibly from nonreversibly asynergic myocardial segments and thus predict the response of these segments to coronary artery bypass grafting (CABG). To test this hypothesis, 25 consecutive patients undergoing CABG, preoperative stress-redistribution 201Tl scintigraphy, and both pre- and postoperative resting equilibrium radionuclide ventriculography were evaluated. For both types of scintigraphic study, each patient was imaged in the same three views. Because of the effects of CABG on septal motion, this region was considered separately. Postoperative improvement was noted in 54% of 72 preoperative asynergic segments. Improvement was common not only in hypokinetic but also in akinetic and dyskinetic segments, and occurred in a similar proportion of studies performed early (less than 2 weeks) or late (3-6 months) after CABG. Thallium-201 redistribution scintigraphy was highly predictive of the pattern of postoperative asynergy: The redistribution pattern was normal in 90% of segments with reversible asynergy and abnormal in 76% of segments with nonreversible asynergy. The presence or absence of pathologic Q waves was less sensitive in this differentiation. Septal segments, however, frequently demonstrated abnormal wall motion postoperatively, despite normal 201Tl redistribution scintigraphy. Resting left ventricular ejection fraction (LVEF) was generally unchanged postoperatively, but in some patients with multiple areas of reversible asynergy it did improve. Thus, 201Tl redistribution scintigraphy appears to reliably distinguish viable from nonviable asynergic myocardial zones, and predicts the response of these segments to CABG.

  1. 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.

  2. Dipyridamole-thallium imaging: The lazy man's stress test

    SciTech Connect

    Leppo, J.A.

    1989-03-01

    Dipyridamole-thallium imaging is a relatively safe and accurate method to evaluate myocardial perfusion and stress. It is independent of patient motivation, exercise capacity and antianginal medications. Overall it detects coronary artery disease as well as exercise thallium and has already shown utility in prognostic determinations. The continued use of this test on a wide scale appears warranted and additional large scale experience needs to be critically evaluated. 53 references.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Prognostic value of intravenous dipyridamole thallium imaging in patients with diabetes mellitus considered for renal transplantation

    SciTech Connect

    Camp, A.D.; Garvin, P.J.; Hoff, J.; Marsh, J.; Byers, S.L.; Chaitman, B.R. )

    1990-06-15

    Patients with diabetes and end-stage renal failure are known to have a high risk for cardiac morbidity and mortality associated with renal transplantation. The most efficient method to determine preoperative cardiac risk has not been established. To determine the effectiveness of intravenous dipyridamole thallium imaging in predicting cardiac events, 40 diabetic renal transplant candidates were studied preoperatively in a prospective trial. The study group consisted of 40 patients whose average age was 42 years (range 27 to 64); 34 (85%) were hypertensive and 21 (53%) were cigarette smokers. Cardiac history included chest pain in 6 patients and prior myocardial infarction in 3 patients. Dipyridamole thallium imaging showed reversible defects in 9 patients, fixed defects in 8 patients and normal scans in 23 patients. Dipyridamole thallium imaging was performed using 0.56 mg/kg of dipyridamole infused intravenously over 4 minutes. Cardiac events occurred only in patients with reversible thallium defects, of which there were 6. Of these 6 patients, 3 had cardiac events before transplantation and 3 had them in the early postoperative phase (within 6 weeks of surgery). Of 21 patients who underwent renal transplantation, 3 had cardiac events within 6 weeks of transplantation. The average duration of follow-up was 11 months (range 1 to 21). Thus, dipyridamole thallium imaging is an effective method of identifying renal transplant candidates likely to develop cardiac complications. Routine coronary angiography may not be necessary to screen all renal transplant candidates for coronary artery disease before surgery.

  8. Evaluation of the post-coronary artery bypass patient by myocardial perfusion scintigraphy and computed tomography

    SciTech Connect

    Engelstad, B.L.; Wagner, S.; Herfkens, R.; Botvinick, E.; Brundage, B.; Lipton, M.

    1983-09-01

    The clinical utility of /sup 201/Tl scintigraphy and of computed tomography for the noninvasive assessment of graft patency and regional myocardial perfusion was evaluated in 24 patients who had undergone aortocoronary bypass surgery. Perfusion defects on /sup 201/Tl scintigraphy (reversible or new, fixed) correlated (100% sensitivity, 78% specificity) with occlusion or stenosis of a graft or significant new native vessel disease. Graft occlusion was accurately demonstrated by dynamic computed tomography (100% sensitivity, 96% specificity) but did not uniformly correlate with regional perfusion. Perfusion defects in the distribution of patent grafts resulted from progressive native vessel disease or graft stenosis without complete occlusion. The absence of exercise-induced perfusion defects in regions of occluded grafts was attributed to suboptimal exercise, collateralization, or noncritical native vessel stenosis. The two studies provide complementary anatomic and physiologic information in the evaluation of the postbypass patient.

  9. 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.

  10. Dipyridamole-induced ST segment depression during thallium-201 imaging in patients with coronary artery disease: angiographic and hemodynamic determinants

    SciTech Connect

    Chambers, C.E.; Brown, K.A.

    1988-07-01

    To examine the angiographic and hemodynamic determinants of dipyridamole-induced ST segment depression in patients with coronary artery disease, 41 patients with angiographically documented coronary disease who underwent dipyridamole-thallium-201 myocardial scintigraphy were studied. Dipyridamole-induced ST depression occurred in 14 (34%) of the 41 patients. Stepwise multivariate logistic regression was performed to compare the predictive value of angiographic findings (good coronary collateral vessels, jeopardized collateral vessels, multivessel disease), hemodynamic changes (changes in heart rate, systolic pressure, diastolic pressure and rate-pressure product), thallium-201 results (perfusion defect, thallium-201 redistribution) and demographic data (age, gender, medications). Only the presence of good coronary collateral vessels (p less than 0.02) and increases in rate-pressure product after dipyridamole infusion (p less than 0.02) were significant multivariate predictors of dipyridamole-induced ST depression. Good collateral vessels were more common in the group with ST depression (11 (79%) of 14) than they were in the group without ST depression (6 (22%) of 27; p less than 0.001). Rate-pressure product increased 2,835 +/- 1,648 beats/min.mm Hg in the group with ST depression compared with 1,179 +/- 1,417 beats/min.mm Hg in patients without ST depression (p less than 0.005). In conclusion, dipyridamole-induced ST segment depression in patients with coronary artery disease appears to be related to 1) the presence of good coronary collateral vessels, which may act by facilitating coronary steal, and 2) increases in rate-pressure product, reflecting increased myocardial oxygen demand. These observations may explain the lack of prognostic value of dipyridamole-induced ST segment depression described in previous reports.

  11. Usefulness of dipyridamole-thallium-201 perfusion scanning for distinguishing ischemic from nonischemic cardiomyopathy

    SciTech Connect

    Eichhorn, E.J.; Kosinski, E.J.; Lewis, S.M.; Hill, T.C.; Emond, L.H.; Leland, O.S.

    1988-11-01

    To determine noninvasively the etiology of left ventricular (LV) dysfunction, 22 patients with a diagnosis of cardiomyopathy determined via cardiac catheterization and 5 normal control subjects underwent radionuclide ventriculography and intravenous dipyridamole-thallium-201 perfusion scanning. Both ischemically and nonischemically induced LV dysfunction had comparable global LV ejection fractions (24 +/- 6 vs 23 +/- 8%, respectively) and extent of segmental wall motion abnormalities. Right ventricular ejection fraction was significantly better in the group with an ischemic etiology of LV dysfunction (41 +/- 26 vs 13 +/- 10%, p less than 0.005) but significant group overlap was present. However, computer-assisted analysis of dipyridamole-thallium-201 myocardial perfusion scanning demonstrated more homogeneous myocardial perfusion in idiopathic cardiomyopathy (mean perfusion defect 25 +/- 11 vs 6 +/- 6%, p less than 0.001) and successfully predicted the correct etiology of LV dysfunction in 20 of 22 (91%) patients.

  12. Aspirin and Extended-Release Dipyridamole

    MedlinePlus

    ... dipyridamole is in a class of drugs called antiplatelet agents. It works by preventing excessive blood clotting. It ... Univasc), quinapril (Accupril), ramipril (Altace), and trandolapril (Mavik); anticoagulants ('blood thinners') such as warfarin (Coumadin) and heparin; ...

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. [Estimation of I-123 metaiodobenzylguanidine (MIBG) myocardial washout].

    PubMed

    Saito, T; Watanabe, N; Saitoh, T; Asakura, T; Kanke, M; Owada, K; Hoshi, K; Kimura, K; Maruyama, Y

    1990-11-01

    A crosstalk from I-123 to Tl-201 (Tl) window was 35 +/- 30% (mean +/- SD) and 30 +/- 10% in a myocardial phantom and the images of 6 patients respectively. However, the crosstalk from Tl to I-123 was approximately 1% in each. I-123 MIBG (MIBG) and Tl myocardial SPECT images were recorded in 3 normal volunteers (N), 10 patients with myocardial infarction (MI), and 4 with dilated cardiomyopathy (DCM). The MIBG and Tl imagings were performed on the other day to avoid the crosstalk. Myocardial washout rates (WR) of Tl and MIBG were derived from 15 min and 4 hour images. WR of Tl was approximately 36% in each group. On the other hand, WR of MIBG in DCM (52 +/- 7%) and MI (41 +/- 14%) groups were statistically higher than in N (24 +/- 7%) group. Thus WR of MIBG would be useful to detect abnormalities in adrenergic nervous system.

  19. 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.

  20. 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.

  1. 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.

  2. Detection of coronary artery disease using MR imaging with dipyridamole infusion

    SciTech Connect

    Pennell, D.J.; Underwood, S.R.; Longmore, D.B. )

    1990-03-01

    Exercise testing in the magnetic resonance (MR) scanner is difficult because of space restriction and movement artefact, which limit its use in the investigation of patients with suspected coronary artery disease. Pharmacological stress, however, can be used as a substitute for exercise. Therefore, a patient with angina underwent MR ventricular wall motion studies before and after intravenous dipyridamole. Reversible abnormal regional contraction of the myocardium was demonstrated and correlated with a reversible perfusion defect on subsequent thallium myocardial perfusion imaging and a blocked artery at coronary angiography. A clinically useful investigative procedure may be developed.

  3. Lack of pharmacokinetic interaction between dipyridamole and zalcitabine in rats.

    PubMed

    Abobo, C V; Xian, Y

    1997-11-01

    Resistance usually manifests following long-term dideoxynucleoside therapy of HIV-1 infection. This period appears to coincide with reduced dosage regimens. Resistance that is associated with long-term monotherapy may, in part, be due to decreased intracellular drug concentrations. It has been reported that intracellular uptake of the dideoxynucleosides is enhanced by dipyridamole. Hence, dipyridamole may potentially be used to optimize the effects of zalcitabine in HIV-1 antiretroviral "cocktail". The purpose of this study was to characterize the pharmacokinetics of zalcitabine when administered alone and concomitantly with dipyridamole. Also, we determined, indirectly, whether dipyridamole modulated the intracellular uptake of zalcitabine. Rats were intravenously administered either zalcitabine 100 mg/kg alone or with dipyridamole 15 mg/kg. Except renal clearance (CIR), there were no statistically significant differences in the pharmacokinetic parameters including the steady-state volume of distribution and distribution coefficient. Zalcitabine plasma concentrations declined rapidly in a bi-exponential fashion, with a terminal half-life of 1.03 +/- 0.18 hr. alone versus 1.08 +/- 0.22 hr. with dipyridamole. The area under the concentration-time curve was not significantly different with or without dipyridamole. ClR, was 1.42 +/- 0.37 l/hr./kg for zalcitabine alone versus 1.09 +/- 0.28 l/hr./kg with dipyridamole. Our single dose study show that zalcitabine disposition kinetics were not significantly modulated by dipyridamole.

  4. 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

  5. Peritoneal fluid causing inferior attenuation on SPECT thallium-201 myocardial imaging in women

    SciTech Connect

    Rab, S.T.; Alazraki, N.P.; Guertler-Krawczynska, E.

    1988-11-01

    On SPECT thallium images, myocardial left ventricular (LV) anterior wall attenuation due to breast tissue is common in women. In contrast, in men, inferior wall counts are normally decreased compared to anterior counts. The purpose of this report is to describe cases of inferior wall attenuation of counts in women caused by peritoneal fluid, not myocardial disease. Twelve consecutive SPECT thallium myocardial studies performed in women on peritoneal dialysis, being evaluated for kidney transplant, were included in this study. For all studies, 3.5 mCi 201Tl were injected intravenously. Thirty-two images were acquired over 180 degrees (45 degrees RAO progressing to 45 degrees LPO) at 40 sec per stop. SPECT images were reviewed in short axis, horizontal long and vertical long axes. Data were also displayed in bullseye format with quantitative comparison to gender-matched normal files. Ten of 12 female patients studied had inferior wall defects on images, confirmed by bullseye display. All patients had approximately 2 liters of peritoneal fluid. Review of planar rotational views showed diaphragm elevation and fluid margin attenuations affecting left ventricular inferior wall. Thus, peritoneal fluid is a cause of inferior attenuation on 201Tl cardiac imaging.

  6. Changes in coronary sinus pH during dipyridamole stress in patients with hypertrophic cardiomyopathy.

    PubMed Central

    Elliott, P. M.; Rosano, G. M.; Gill, J. S.; Poole-Wilson, P. A.; Kaski, J. C.; McKenna, W. J.

    1996-01-01

    OBJECTIVES: The presence of angina pectoris and myocardial scarring in patients with hypertrophic cardiomyopathy (HCM) suggests that myocardial ischemia is a factor in the pathophysiology of the disease. The clinical evaluation of ischaemia is problematic in HCM as baseline electrocardiographic abnormalities are frequent and thallium-201 perfusion abnormalities correlate poorly with anginal symptoms. Coronary sinus pH measurement using a catheter mounted pH electrode is a validated sensitive technique for the detection of myocardial ischaemia. METHODS AND RESULTS: 11 patients with HCM and chest pain (eight men; mean (SD) (range) age 36 (11) (19-53) years) and six controls (two men; mean (SD) (range) age 49 (11) (31-62) years) with atypical pain and normal coronary angiograms were studied. Eight patients with HCM had baseline ST segment depression of > or = 1 mm and four had reversible perfusion defects during stress 201TI scintigraphy. A catheter mounted hydrogen ion sensitive electrode was introduced into the coronary sinus and pH monitored continuously during dipyridamole infusion (0.56 mg/kg over four min). The maximal change in coronary sinus pH during dipyridamole stress was greater in patients with HCM than in controls (0.082 (0.083) (0 to -0.275) v 0.005 (0.006) (0 to -0.012), P = 0.02). In six patients (four men; mean (SD) (range) age 29 (9) (19-40 years) the development of chest pain was associated with a gradual decline in coronary sinus pH (mean 0.123 (0.089)), peaking at 442 (106) s. There were no relations among left ventricular dimensions, maximal wall thickness, and maximum pH change. In patients with HCM there was a correlation between maximum pH change and maximum heart rate during dipyridamole infusion (r = 0.70, P = 0.02). CONCLUSION: This study provides further evidence that chest pain in patients with HCM is caused by myocardial ischaemia. The role of myocardial ischaemia in the pathophysiology of the disease remains to be determined but

  7. 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.

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

    NASA Astrophysics Data System (ADS)

    Medich, David Christopher

    1997-09-01

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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Physiological assessment of sensitivity of noninvasive testing for coronary artery disease

    SciTech Connect

    Simonetti, I.; Rezai, K.; Rossen, J.D.; Winniford, M.D.; Talman, C.L.; Hollenberg, M.; Kirchner, P.T.; Marcus, M.L. )

    1991-05-01

    The sensitivity of three noninvasive tests for coronary artery disease was assessed by means of quantitative indexes of disease severity in three different groups of patients. The overall population consisted of 110 subjects with limited coronary artery disease and no myocardial infarction. Planar dipyridamole-{sup 201}Tl scintigraphy was evaluated in 31 patients, computer-assisted exercise treadmill in 28, and high-dose dipyridamole echocardiography testing in 51. Sensitivity was assessed by rigorous gold standards to define disease severity, such as measurement of minimum cross-sectional area and percent area of stenosis, by quantitative computerized coronary angiography (Brown/Dodge method). On the basis of the results of previous studies, the presence of physiologically significant coronary artery disease was indicated by a stenotic minimum cross-sectional area (MCSA) of less than 2.0 mm{sup 2} or a greater than 75% area of stenosis. With MCSA as the gold standard, dipyridamole-{sup 201}Tl scintigraphy, computerized exercise treadmill, and dipyridamole echocardiography testing showed sensitivities of 52%, 54%, and 61%, respectively, in the three different patient cohorts enrolled. With percent area of stenosis as the gold standard, the sensitivity figures obtained for dipyridamole-{sup 201}Tl, computerized exercise treadmill, and dipyridamole echocardiography testing were 64%, 54%, and 69%, respectively. For each of the three tests, sensitivity increased with increasing lesion severity. Sensitivity was also better in patients with left anterior descending coronary (LAD) disease when compared with patients with left circumflex or right coronary artery disease. Results of these studies demonstrate that in patients with limited coronary artery disease none of the tests evaluated is definitely superior in sensitivity.

  14. Sequential thallium-201 myocardial perfusion studies after successful percutaneous transluminal coronary artery angioplasty: delayed resolution of exercise-induced scintigraphic abnormalities

    SciTech Connect

    Manyari, D.E.; Knudtson, M.; Kloiber, R.; Roth, D.

    1988-01-01

    To characterize the sequential changes of myocardial perfusion scintigraphy in patients with coronary artery disease (CAD) after complete revascularization, 43 patients underwent exercise thallium-201 (/sup 201/Tl) myocardial perfusion scintigraphy before and at 9 +/- 5 days, 3.3 +/- 0.6, and 6.8 +/- 1.2 months after percutaneous transluminal coronary angioplasty (PTCA). Only patients with single-vessel CAD, without previous myocardial infarction, and without evidence of restenosis at 6 to 9 months after PTCA were included. Perfusion scans were analyzed blindly with the use of a new quantitative method to define regional myocardial perfusion in the topographic distribution of each coronary artery, which was shown to be reproducible (r = .94 or higher and SEE of 7% or less, between repeated measures by one and two operators). At 4 to 18 days after PTCA, the mean treadmill walking time increased by 123 +/- 42 sec, mean exercise-induced ST segment depression decreased by 0.6 +/- 0.3 mm, group maximal heart rate increased by 20 +/- 9 beats/min, and group systolic blood pressure at peak exercise increased by 24 +/- 10 mm Hg, compared with pre-PTCA values (p less than .001). However, no group differences were noted in these variables between the three post-PTCA stages. Myocardial perfusion in the distribution of the affected (dilated) coronary artery, on the other hand, improved progressively. In the 45 degree left anterior oblique view for instance, myocardial perfusion increased at 9 days after PTCA (from 68 +/- 24% before PTCA to 91 +/- 9%, p less than .001) and at 3.3 months after PTCA (101 +/- 8%, p less than .05 vs 9 days after PTCA), but no further significant changes were seen at 6.8 months after PTCA (102 +/- 8%). Similar changes were noted in the other two views. No relationship between minor complications during PTCA and delayed improvement on the /sup 201/Tl was observed.

  15. [Interest in myocardial scintigraphy following the arterial switch procedure for transposition of the great vessels].

    PubMed

    Acar, P; Maunoury, C; Bonnet, D; Sébahoun, S; Bonhoeffer, P; Hallaj, I; Aggoun, Y; Iserin, F; Sidi, D; Kachaner, J

    2001-05-01

    Coronary artery obstruction is the main late complication of the so-called arterial switch operation designed to repair transpositions of the great arteries in newborn infants by switching the great vessels and transferring the coronary ostia onto the posterior vessel. Our aim was to study the links between myocardial perfusion and coronary artery anatomy after the arterial switch operation. Forty-five patients (5.863 years) underwent a 201Tl myocardial SPECT and a selective coronary artery angiography. The latter was normal in 20 children: 13 had also a normal myocardial scan but 7 had myocardial perfusion defects including 2 with angina who had a very low coronary reserve at positron emission tomography. Twenty-five patients had severe coronary artery lesions: 5 with a normal myocardial scan and 20 with perfusion defects. Twelve out of these 20 underwent surgical revascularization and the SPECT images went back to normal in all within 6 months after surgery. Specificity and sensitivity of myocardial SPECT in detecting coronary artery lesions were 78% and 69% whereas positive and negative predictive values were 74 and 73%. We conclude that myocardial SPECT imaging is not the right way to detect late post arterial switch coronary artery lesions. It is helpful in decision making as to submit these children to surgical revascularization and in assessing its postoperative effectiveness.

  16. 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.

  17. Classical and pleiotropic actions of dipyridamole: Not enough light to illuminate the dark tunnel?

    PubMed

    Balakumar, Pitchai; Nyo, Ying Hui; Renushia, Raja; Raaginey, Devarajan; Oh, Ann Nah; Varatharajan, Rajavel; Dhanaraj, Sokkalingam A

    2014-09-01

    Dipyridamole is a platelet inhibitor indicated for the secondary prevention of transient ischemic attack. It inhibits the enzyme phosphodiesterase, elevates cAMP and cGMP levels and prevents platelet aggregation. Dipyridamole inhibits the cellular uptake of adenosine into red blood cells, platelets and endothelial cells that results in increased extracellular availability of adenosine, leading to modulation of cardiovascular function. The antiplatelet action of dipyridamole might offer therapeutic benefits in secondary stroke prevention in combination with aspirin. Inflammation and oxidative stress play an important role in atherosclerosis and thrombosis development, leading to stroke progression. Studies demonstrated anti-inflammatory, anti-oxidant and anti-proliferative actions of dipyridamole. These pleiotropic potentials of dipyridamole might contribute to improved therapeutic outcomes when used with aspirin in preventing secondary stroke. Dipyridamole was documented as a coronary vasodilator 5 decades ago. The therapeutic failure of dipyridamole as a coronary vasodilator is linked with induction of 'coronary steal' phenomenon in which by dilating resistance vessels in non-ischemic zone, dipyridamole diverts the already reduced blood flow away from the area of ischemic myocardium. Dipyridamole at high-dose could cause a marked 'coronary steal' effect. Dipyridamole, however, at low-dose could have a minimal hemodynamic effect. Low-dose dipyridamole treatment has a therapeutic potential in partially preventing diabetes mellitus-induced experimental vascular endothelial and renal abnormalities by enhancing endothelial nitric oxide signals and inducing renovascular reduction of oxidative stress. In spite of plenteous research on dipyridamole's use in clinics, its precise clinical application is still obscure. This review sheds lights on pleiotropic pharmacological actions and therapeutic potentials of dipyridamole.

  18. Tachycardic vs. pharmacologic stress myocardial perfusion imaging: differential implications in multi-vessel ischemia

    PubMed Central

    Nguyen, Thanh H; Horowitz, John D; Unger, Steven A

    2012-01-01

    Background In patients unable to exercise, potential methods of induction of reversible myocardial ischemia include physiological heart rate acceleration via pacing or dobutamine infusion and asymmetric coronary vasodilatation using dipyridamole. Although their bases for induction of ischemia are widely disparate, no direct comparison of these techniques has previously been reported. Methods We performed a randomised, paired comparison of dipyridamole and pacing myocardial perfusion imaging (MPI) in 28 patients in whom exercise stress imaging was precluded, comparing the detection, localisation and quantitation of ischemia. Results Reversible myocardial ischemia was detected in 21 patients, concordantly in 13 (p = 0.042). There was a high degree of concordance (p < 0.0001) regarding locations of sites of ischemia. While there was a good correlation (r = 0.74, p < 0.0001) between size of total ischemic zones with dipyridamole and pacing, the magnitude of ischemia tended to be greater with dipyridamole (mean percentage of left ventricular myocardium ± SD, 9.4 ± 11.0% vs. 7.0 ± 9.0%, p = 0.091). Furthermore, this difference resulted from accentuation of the primary ischemic zone with dipyridamole in patients with multi-vessel ischemia (mean ± SD, 28.1 ± 21.1% vs. 18.7 ± 16.1%, p = 0.046). Conclusions Despite major differences in mechanism(s) of induction of ischemia, dipyridamole and pacing produce similar results regarding detection, localisation and severity of ischemia. However, dipyridamole accentuates ischemia in primary (vs. secondary) ischemic zones, consistent with known induction of coronary “steal". This should be taken into account in interpretation of scan results. PMID:22254212

  19. 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.

  20. Quantitative thallium-201 single photon emission computed tomography after oral dipyridamole for assessing the presence, anatomic location and severity of coronary artery disease

    SciTech Connect

    Borges-Neto, S.; Mahmarian, J.J.; Jain, A.; Roberts, R.; Verani, M.S.

    1988-05-01

    The objective of this investigation was to determine whether analysis of thallium-201 images as detected by quantitative single photon emission computed tomography after a single high oral dose of dipyridamole (300 mg) would accurately detect the presence of coronary artery disease and the anatomic location of the individual stenosis. Analyses were performed on 100 patients who concomitantly underwent diagnostic coronary arteriography and myocardial imaging. Tomographic myocardial perfusion defects were quantified using computer-generated polar maps. Eighty-four patients had significant coronary artery disease defined as greater than 50% luminal diameter stenosis. The sensitivity for detecting patients with coronary disease was 92% overall, 89% in patients without previous myocardial infarction and 97% in those with prior infarction. The technique had a sensitivity of 80, 87 and 51% for localizing coronary artery stenosis of the left anterior descending, the right coronary and the left circumflex artery, respectively. The corresponding specificity was 84, 92 and 92%. Furthermore, the presence of severe (greater than or equal to 70%) multivessel disease was identified with a sensitivity of 79% and a specificity of 87%. In conclusion, quantitative thallium-201 single photon emission computed tomography after oral dipyridamole has high sensitivity and specificity for diagnosing the presence of coronary disease, ascertaining the location of stenosed vessels and identifying the presence of multivessel disease.

  1. 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.

  2. Effects of coronary angioplasty and reperfusion on distribution of myocardial flow

    SciTech Connect

    Wahr, D.W.; Ports, T.A.; Botvinick, E.H.; Dae, M.; Schechtmann, N.; Huberty, J.; Hattner, R.S.; O'Connell, J.W.; Turley, K.

    1985-08-01

    To assess the effects of angioplasty (PTCA) and intracoronary streptokinase (ICSK) on relative myocardial perfusion, the authors administered /sup 99m/Tc-macroaggregated albumin (MAA) to the uninvolved coronary artery before successful PTCA in 33 patients and before successful infusion of ICSK in eight patients and of /sup 111/In-MAA into the same vessel after the intervention. In 10 patients who underwent PTCA, MAA was injected into the involved, instrumented coronary artery. Computer-processed images were acquired in registry and compared. Similar scintigraphic studies were performed in six control patients and in 11 in whom planned interventions were not performed or were unsuccessful. Distribution of MAA was also compared with angiographic results and with the distribution of /sup 201/Tl on images obtained in patients at rest or on redistribution images obtained before and soon after intervention in 22 patients. In control patients and those studied after aborted or unsuccessful intervention, scintigraphic results showed excellent correlation with the angiographic anatomy and were without serial change. When MAA was injected into the uninvolved vessel, the scintigram revealed evidence of collateral perfusion with retraction of the perfusion zone from that of the involved coronary in 19 of 33 patients undergoing PTCA and in three of eight of those receiving ICSK. When MAA was injected into the involved artery, a relative increase in perfusion was seen in eight of 10 patients after PTCA. Although 30 patients demonstrated scintigraphic evidence of collateral vessels, only 10 patients had angiographic evidence of collateral circulation before intervention. The distribution of /sup 201/Tl demonstrated little change in its global pattern and regions previously supplied by collaterals were generally well perfused after intervention.

  3. 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

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

    PubMed

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

    2012-11-01

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

  5. Chest pain with myocardial ischemia in a child: should we think about coronary slow flow phenomenon?

    PubMed

    Kocabaş, Abdullah; Kardelen, Fırat; Akçurin, Gayaz; Ertuğ, Halil

    2013-10-01

    The coronary slow flow phenomenon (CSFP) is an angiographic finding characterized by delayed opacification of epicardial coronary arteries in the absence of stenotic lesion. Herein, we present a 13-year-old boy with recurrent chest pain who was diagnosed with acute ST-segment elevation myocardial infarction associated with CSFP, which has not been reported previously in the pediatric age group. Coronary angiography revealed only the presence of slow flow in the left anterior descending (LAD) coronary artery. Myocardial perfusion scintigraphy revealed a reversible perfusion defect in the LAD territory, which regressed partially at rest and showed complete improvement after dipyridamole infusion. All the symptoms, electrocardiogram abnormalities and cardiac markers returned to normal after dipyridamole treatment during the follow-up. We conclude that CSFP should be kept in mind in the differential diagnosis of chest pain with myocardial ischemia in the pediatric age group.

  6. Combined dipyridamole and aspirin pellet formulation for improved oral drug delivery. Part 1: Development pharmaceutics.

    PubMed

    Deasy, P B; Murtagh, P W

    1996-01-01

    The dissolution profile of various weight fractions of dipyridamole: hydropropylmethylcellulose acetate succinate (HPMC-AS) and dipyridamole: hydroxypropylmethylcellulose phthalate co-precipitates lead to the choice of 1:2 dipyridamole: HPMC-AS as the controlled-release component. It was deposited to form two-third of the total dose as an inner layer on inert sucrose cores by air suspension coating for release mainly in the small intestine. Further examination of this material by IR spectroscopy, differential scanning calorimetry and X-ray diffraction indicated some free drug, preferentially soluble under gastric pH conditions. One-third of the total dose was applied by pan coating as an outer layer of micronized dipyridamole around the inner enteric co-precipitate layer. Aspirin-loaded cores were prepared also by pan coating for use in the final product, which contained both anti-platelet drugs.

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

    PubMed

    Rogosnitzky, Moshe; Isakov, Itzhak; Wlassoff, Wjatschesslaw; Ingram, April; Barishak, Y Robert

    2016-03-01

    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.

  8. Protection of low density lipoprotein oxidation at chemical and cellular level by the antioxidant drug dipyridamole.

    PubMed Central

    Iuliano, L.; Colavita, A. R.; Camastra, C.; Bello, V.; Quintarelli, C.; Alessandroni, M.; Piovella, F.; Violi, F.

    1996-01-01

    1. The oxidative modification of low density lipoprotein (LDL) is thought to be an important factor in the initiation and development of atherosclerosis. Natural and synthetic antioxidants have been shown to protect LDL from oxidation and to inhibit atherosclerosis development in animals. Synthetic antioxidants are currently being tested, by they are not necessarily safe for human use. 2. We have previously reported that dipyridamole, currently used in clinical practice, is a potent scavenger of free radicals. Thus, we tested whether dipyridamole could affect LDL oxidation at chemical and cellular level. 3. Chemically induced LDL oxidation was made by Cu(II), Cu(II) plus hydrogen peroxide or peroxyl radicals generated by thermolysis of 2,2'-azo-bis(2-amidino propane). Dipyridamole, (1-10 microM), inhibited LDL oxidation as monitored by diene formation, evolution of hydroperoxides and thiobarbituric acid reactive substances, apoprotein modification and by the fluorescence of cis-parinaric acid. 4. The physiological relevance of the antioxidant activity was validated by experiments at the cellular level where dipyridamole inhibited endothelial cell-mediated LDL oxidation, their degradation by monocytes, and cytotoxicity. 5. In comparison with ascorbic acid, alpha-tocopherol and probucol, dipyridamole was the more efficient antioxidant with the following order of activity: dipyridamole > probucol > ascorbic acid > alpha-tocopherol. The present study shows that dipyridamole inhibits oxidation of LDL at pharmacologically relevant concentrations. The inhibition of LDL oxidation is unequivocally confirmed by use of three different methods of chemical oxidation, by several methods of oxidation monitoring, and the pharmacological relevance is demonstrated by the superiority of dipyridamole over the naturally occurring antioxidants, ascorbic acid and alpha-tocopherol and the synthetic antioxidant probucol. Images Figure 6 PMID:8968553

  9. 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.

  10. 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

  11. Reduced coronary flow and resistance reserve in primary scleroderma myocardial disease

    SciTech Connect

    Nitenberg, A.; Foult, J.M.; Kahan, A.; Perennec, J.; Devaux, J.Y.; Menkes, C.J.; Amor, B.

    1986-08-01

    The maximum coronary vasodilator capacity after intravenous dipyridamole (0.14 mg X kg-1 X min-1 X 4 minutes) was studied in seven patients with primary scleroderma myocardial disease and compared to that of seven control subjects. Hemodynamic data and left ventricular angiographic data were not different in the two groups. The coronary flow reserve was evaluated by the dipyridamole/basal coronary sinus blood flow ratio (D/B CSBF) and the coronary resistance reserve by the dipyridamole/basal coronary resistance ratio (D/B CR). Coronary reserve was greatly impaired in the group with primary scleroderma myocardial disease: D/B CSBF was lower than in the control group (2.54 +/- 1.37 vs 4.01 +/- 0.56, respectively; p less than 0.05) and D/B CR was higher than in the control group (0.47 +/- 0.25 vs 0.23 +/- 0.04, respectively; p less than 0.05). Such a decreased coronary flow and resistance reserve in patients with primary scleroderma myocardial disease was not explained by an alteration of left ventricular function. It may be an important contributing factor in the pathogenesis of primary scleroderma myocardial disease.

  12. Physical training of the patients with coronary heart disease: noninvasive strategies for the evaluation of its effects on the oxygentransport system and myocardial ischemia.

    PubMed

    Doba, N; Shukuya, M; Yoshida, H; Inagaki, M; Inaji, J; Hinohara, S

    1990-11-01

    To clarify the central effects of physical training on patients with coronary heart disease, 81 subjects were selected for the present study. Evaluations of the oxygen transport system function were performed according to the definition proposed by Bruce and others in terms of FAI (functional aerobic impairment), LVI (left ventricular impairment) or MRI (myocardial reserve impairment), CRI (chronotropic reserve impairment) and PCI (peripheral circulatory impairment). Remarkable improvement in left ventricular impairment was found in those patients with single vessel disease or those who experienced disappearance of chest pain after the completion of the program. In another series of study on myocardial perfusion performed on 11 patients with coronary heart disease, improvement in ischemia was also demonstrated in 7 of 8 patients who revealed redistribution pattern in 201TL exercise stress images specifying myocardial ischemia. In conclusion, exercise training could induce improvements not only the left ventricular functions characterized by increased maximal pressure rate product and maximal heart rate, but also in myocardial ischemia. Further studies are needed to specify its effects, since natural progression or regression of the disease process itself may influence the results.

  13. Photo-immobilization of dipyridamole (Persantin) at the surface of polyurethane biomaterials: reduction of in-vitro thrombogenicity.

    PubMed

    Aldenhoff, Y B; Blezer, R; Lindhout, T; Koole, L H

    1997-01-01

    Dipyridamole is a well-known vasodilator and a powerful inhibitor of activation and aggregation of blood platelets. Moreover, dipyridamole is essentially non-toxic. The drug is used extensively in clinical anti-coagulation regimes, for example pre- and post-coronary angioplasty procedures. Recently, we have found that photochemical, covalent coupling of dipyridamole to polyurethane surfaces leads to improved thromboresistance in vitro. This phenomenon is now studied in more detail. Both qualitative and more quantitative biochemical experiments were performed in order to characterize the in vitro blood compatibility of a set of polyurethane surfaces onto which dipyridamole was immobilized. First, scanning electron microscopy was used to examine the morphology of platelets which adhered during incubation with platelet-rich plasma. These experiments showed that immobilization of dipyridamole leads to a clearly decreased number of adherent platelets and to a largely diminished propensity of the surface to activate adherent platelets. Secondly, an in vitro thrombogenicity assay was run. These experiments showed that the thromboresistance increased with increasing surface density of immobilized dipyridamole. A short spacer chain separating dipyridamole from the polymer surface, was found to improve the thromboresistance further. Such a spacer chain apparently increases the efficacy of the immobilized drug. Collectively, the present results further substantiate the idea that dipyridamole retains its inhibitory activity with respect to activation and aggregation of blood platelets, when the compound is covalently attached to a polymer surface. The possible utility of these findings with respect to the development of an artificial blood vessel prosthesis is discussed briefly.

  14. 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.

  15. Distribution of dipyridamole in blood components among post-stroke patients treated with extended release formulation.

    PubMed

    Serebruany, Victor; Sabaeva, Elena; Booze, Christopher; Atar, Oliver D; Eisert, Christian; Hanley, Dan

    2009-09-01

    Extended release dipyridamole (ERD) is widely used in patients after ischaemic stroke; however, the ability of this antithrombotic agent to be stored in different blood cells has never been explored in post-stroke patients. We hypothesised that since ERD is known to be highly lipophilic, the drug may be present not only in plasma, but also accumulated in platelets, leukocytes, and erythrocytes. Fifteen patients after documented ischaemic stroke were treated with Aggrenox (ERD and low-dose aspirin combination) BID for 30 days, and 12 of them completed the study. ERD concentrations in blood cells and platelet-poor plasma were measured by spectrofluorimetry at Baseline, Day 14, and Day 30 after the initiation of therapy. The background level of spectrofluorometry readings differs slightly among the blood components (132-211 ng/ml) due to the differences in the preparation of samples and cell isolation techniques. As expected, two weeks of ERD therapy produced steady-state plasma concentration of dipyridamole already at Day 14 (1,680 +/- 542 ng/ ml), followed by a slight not significant decrease at one month (1,619 +/- 408 ng/ml). Two weeks of therapy was sufficient to achieve a consistent dipyridamole accumulation in erythrocytes (361 +/- 43 ng/ml), but not in platelets (244 +/- 78 ng/ml), or leukocytes (275 +/- 49 ng/ml). In fact, white blood cells continued dipyridamole intake beyond 14 days period, and this increase (398 +/- 66 ng/ml) was significant (p = 0.02) at 30 days. Treatment with ERD in post-stroke patients resulted not only in achievement of therapeutic plasma dipyridamole concentrations, but also deposition of the drug in erythrocytes and leukocytes, but not in platelets. If confirmed, these data will affect our better understanding of dipyridamole pleiotropy, and may explain long-term benefit of ERD formulation.

  16. 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.

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

    PubMed

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

    2005-01-04

    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).

  18. Effect of {beta}{sub 1} adrenergic receptor blockade on myocardial blood flow and vasodilatory capacity

    SciTech Connect

    Boettcher, M.; Czernin, J.; Sun, K.

    1997-03-01

    The {beta}{sub 1} receptor blockade reduces cardiac work and may thereby lower myocardial blood flow (MBF) at rest. The effect of {beta}{sub 1} receptor blockade on hyperemic MBF is unknown. To evaluate the effect of selective {beta}{sub 1} receptor blockade on MBF at rest and during dipyridamole induced hyperemia, 10 healthy volunteers (8 men, 2 women, mean age 24 {+-} 5 yr) were studied using {sup 13}N-ammonia PET (two-compartment model) under control conditions and again during metoprolol (50 mg orally 12 hr and 1 hr before the study). The resting rate pressure product (6628 {+-} 504 versus 5225 {+-} 807) and heart rate (63 {+-} 6-54 {plus_minus} 5 bpm) declined during metoprolol (p < 0.05). Similarly, heart rate and rate pressure product declined from the baseline dipyridamole study to dipyridamole plus metoprolol (p < 0.05). Resting MBF declined in proportion to cardiac work by approximately 20% from 0.61 {+-} 0.09-0.51 {+-} 0.10 ml/g/min (p < 0.05). In contrast, hyperemic MBF increased when metoprolol was added to dipyridamole (1.86 {plus_minus} 0.27 {+-} 0.45 ml/g/min; p<0.05). The decrease in resting MBF together with the increase in hyperemic MBF resulted in a significant increase in the myocardial flow reserve during metoprolol (3.14 {+-} 0.80-4.61 {+-} 0.68; p<0.01). The {beta}{sub 1} receptor blockade increases coronary vasodilatory capacity and myocardial flow reserve. However, the mechanisms accounting for this finding remain uncertain. 32 refs., 2 figs., 2 tabs.

  19. Long-term prognostic value of preoperative dipyridamole thallium imaging and clinical indexes in patients with diabetes mellitus undergoing peripheral vascular surgery.

    PubMed

    Cohen, M C; Curran, P J; L'Italien, G J; Mittleman, M A; Zarich, S W

    1999-04-01

    The objective of this study is to assess the prognostic impact of preoperative dipyridamole thallium imaging and clinical variables on the long-term outcome of diabetic patients undergoing peripheral vascular surgery. Complete follow-up was obtained in 101 consecutive patients with diabetes mellitus undergoing routine dipyridamole thallium scintigraphy before vascular surgery (mean 4.2 +/- 3.2 years, range 1 month to 11 years). Low risk was defined by diabetes alone with a normal resting electrocardiogram. High risk was defined as a history of angina, myocardial infarction, congestive heart failure, or resting electrocardiogram abnormalities. There were 71 deaths in 98 patients discharged alive from the hospital (median survival 4.4 years). Age, the presence of resting electrocardiogram abnormalities, and an abnormal thallium scan were independent predictors of late death. After adjusting for age >70 years and thallium abnormalities, high-risk patients had a death rate 4.8 times (95% confidence interval 1.7 to 13.4, p <0.002) greater than low-risk patients. The presence of >2 reversible thallium defects was useful in further risk stratification of both low- and high-risk patients. Low-risk patients with >2 reversible defects had a median survival of 4.0 years compared with 9.4 years in those with < or =2 reversible defects (p <0.001). Similarly, high-risk patients with < or =2 reversible defects had an intermediate median survival rate of 4.7 years compared with 1.8 years in the group with >2 reversible defects (p <0.001). Therefore, advanced age and the presence of resting electrocardiographic or thallium abnormalities identifies a subset of diabetic patients with a poor long-term outcome after vascular surgery. Combined clinical and thallium variables may identify a population in whom intensive medical or surgical interventions may be warranted to reduce both perioperative and late cardiac events.

  20. 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

  1. "ECG variability contour" method reveals amplitude changes in both ischemic patients and normal subjects during Dipyridamole stress: a preliminary report.

    PubMed

    Dori, Guy; Gershinsky, Michal; Ben-Haim, Simona; Lewis, Basil S; Bitterman, Haim

    2011-11-01

    To detect and quantify consistent ECG amplitude changes, the "ECG variability contour" (EVC) method was proposed. Using this method we investigated amplitude changes in subjects undergoing myocardial perfusion imaging (MPI) with Dipyridamole (Dp). Fifty-three patients having reversible perfusion defects and 19 normal subjects (NS) who were free of: perfusion defects on their MPI, standard ST-T changes during Dp stress, and a negative clinical follow up. Mean ∏¹(<∏¹>) was similar for the NS and patient group (6.2 ± 6.1 vs. 6.3 ± 6.2, P = 0.95). <∏¹> was 4.6 ± 3.0 in patients not having ST-T changes during Dp stress (n = 42), whereas in patients having ST-T changes (n = 11) it was 13.1 ± 10.2 (P < 0.001). For both groups <∏(QRS)> was smaller than <∏(ST)>, which in turn was smaller than <∏(T)>. The values of <∏(QRS)>, <∏(ST)>, and <∏(T)> for the NS, patients without and with ST-T changes were: 26.8 ± 28.6, 42.6 ± 41.8, 44.9 ± 36.5; 19.6 ± 20.8, 26.4 ± 31.4, 38.7 ± 27.3; 51.0 ± 30.0, 71.0 ± 36.8, 75.1 ± 20.9, respectively (P < 0.05 for all comparisons of patients with versus without ST-T changes). This study showed that Dp stress, with or without hypoperfusion, had a clear effect on myocyte electrophysiology, expressed by consistent ECG amplitude changes, detected by the EVC method. The EVC method did not distinguish between NS and patients in this clinical setting.

  2. 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.

  3. Adenosine thallium 201 myocardial perfusion scintigraphy

    SciTech Connect

    Verani, M.S. )

    1991-07-01

    Pharmacologic coronary vasodilation as an adjunct to myocardial perfusion imaging has become increasingly important in the evaluation of patients with coronary artery disease, in view of the large number of patients who cannot perform an adequate exercise test or in whom contraindications render exercise inappropriate. Adenosine is a very potent coronary vasodilator and when combined with thallium 201 scintigraphy produces images of high quality, with the added advantages of a very short half-life (less than 10 seconds) and the ability to adjust the dose during the infusion, which may enhance safety and curtail the duration of side effects. The reported sensitivity and specificity of adenosine thallium 201 scintigraphy for the detection of coronary artery disease are high and at least comparable with imaging after exercise or dipyridamole administration. 23 refs.

  4. 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.

  5. 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.

  6. 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.

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

    SciTech Connect

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

    1994-10-01

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

  8. 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%).

  9. Detection of moderate regional ischemia in pig hearts in vivo by near-infrared and thermal imaging: effects of dipyridamole.

    PubMed

    Kupriyanov, Valery V; Manley, Darren M; Xiang, Bo

    2008-01-01

    Effects of coronary vasodilator, dipyridamole, on epicardial oxygenation and flow were investigated under conditions of moderate coronary occlusion using near-infrared spectroscopic (NIRS) and thermal imaging. In anesthetized open chest pigs an inflatable occluder and flow probe were placed around the left anterior descending artery (LAD). In the ischemic group (n = 11) LAD occlusion (50% flow, 80 min) was followed by complete occlusion (10 min, n = 4), and reflow. Dipyridamole was infused (0.14 mg/min/kg/4 min) intravenously during 50% occlusion. In the control group (n = 6) LAD flow was temporarily increased (hyperemic response) by two 2-min periods of complete LAD occlusion applied 120 min apart, with a 4-min period of dipyridamole infusion between the two occlusions. NIRS and thermal images were acquired throughout the protocol. Maps of subepicardial oxygen saturation parameter (OSP), and epicardial temperature (T) were obtained. Partial occlusion reduced OSP and the temperature by 0.23 +/- 0.08 and 0.88 +/- 0.39 degrees C versus remote region, respectively. Dipyridamole decreased systolic blood pressure by 36%, which caused further decline in the LAD flow to 18% and OSP and T by 0.37 +/- 0.01 and 2.46 +/- 0.32 degrees C, respectively. Reflow restored OSP and T to their baseline levels. In control group dipyridamole and hyperemia increased LAD flow 2-4-fold associated with moderate increase in OSP and T. OSP and T showed linear dependence on the flow below 100%, which is leveled-off at flows above normal. Dipyridamole increases differences in the epicardial oxygenation and T between normal and moderately ischemic areas due to enhancement of disparity in perfusion of these areas.

  10. 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.

  11. Vasodilator myocardial perfusion imaging: demonstration of local electrophysiological changes of ischaemia

    PubMed Central

    John, Roy M; Taggart, Peter I; Sutton, Peter M; Costa, Durval C; Ell, Peter J; Swanton, Howard

    1992-01-01

    Objective—To examine the incidence and severity of myocardial ischaemia provoked in the course of perfusion scintigraphy by coronary vasodilators using endocardial recordings of steady state monophasic action potentials as an independent marker of early localised myocardial ischaemia. Patients—31 men undergoing routine cardiac catheterisation for investigation of chest pain were studied. Setting—A tertiary cardiac referral centre. Design—Single site monophasic action potentials were recorded from the left or right ventricle or both (50 recording sites) during intravenous infusion of dipyridamole (0·015 mg/kg/min) for four minutes. Heart rate was held constant with atrial pacing at 20% above the patient's resting rate. Technetium-99m hexakis-2-methoxy-2-methylpropyl-isonitrile (MIBI) was administered four minutes after dipyridamole, and single photon emission tomographic imaging was performed an hour later. Rest images were obtained the next day (two day, two dose protocol). Recordings were divided into three groups based on the scintigraphic perfusion characteristics and coronary anatomical data for the action potential recording site: group 1—recordings from areas with a normal perfusion pattern (n = 30), group 2—recordings from areas with a perfusion defect and subtended by significantly narrowed coronary arteries without obvious angiographic collateral supply (n = 10), and group 3—recordings from areas with a perfusion defect and subtended by occluded arteries with angiographically evident collaterals from adjacent vessels (n = 10). Results—There were changes in the duration of the monophasic action potential indicative of ischaemia—that is, shortening of duration of steady state action potential—in 18 of the 20 recordings from areas of abnormal perfusion. Peak changes were apparent eight minutes from the start of the dipyridamole infusion. Mean (SEM) values for duration of the action potential between control and peak effect at eight

  12. Reverse screening approach to identify potential anti-cancer targets of dipyridamole

    PubMed Central

    Ge, Shu-Min; Zhan, Dong-Ling; Zhang, Shu-Hua; Song, Li-Qiang; Han, Wei-Wei

    2016-01-01

    Dipyridamole (DIP) inhibits thrombus formation when given chronically, and causes vasodilation over a short time. To date, DIP can increase the anticancer drugs (5-fluorouracil, methotrexate, piperidine, vincristine) concentration in cancer cells and hence enhance the efficacy of treatment cancer. The inhibition of DIP may result in increased 5-fluorouracil efficacy and diminish the drug side effects. But the actual molecular targets remain unknown. In this study, reverse protein-ligands docking, and quantum mechanics were used to search for the potential molecular targets of DIP. The quantum mechanics calculation was performed by using Gaussian 03 program package. Reverse pharmacophore mapping was used to search for potential molecular target candidates for a given small molecule. The docking study was used for exploring the potential anti-cancer targets of dipyridamole. The two predicted binders with the statistically significant prediction are dihydropyrimidine dehydrogenase (DPD) (PDB Id: 1GTE) and human spindle checkpoint kinase Bub1 (PDB Id: 3E7E). Structure analysis suggests that electrostatic interaction and hydrogen bonding play an important role in their binding process. The strong functional linkage of DIP and 5FU supports our prediction. In conclusion, these results generate a tractable set of anticancer proteins. The exploration of polypharmacology will provide us new opportunities in treating systematic diseases, such as the cancers. The results would generate a tractable set of anticancer target proteins for future experimental validations. PMID:28077994

  13. Sensitive and simple determination of the vasodilator agent dipyridamole in pharmaceutical preparations by phosphorimetry.

    PubMed

    Salinas-Castillo, A; Carretero, A Segura; Fernández-Gutiérrez, A

    2003-08-01

    The applicability of heavy atom-induced room-temperature phosphorescence to pharmaceutical samples is demonstrated in this work. Thus a new, simple, rapid, and selective phosphorimetric method for dipyridamole determination is proposed. The phosphorescence signals are a consequence of intermolecular protection when analytes are exclusively in the presence of heavy atom salts and sodium sulfite as an oxygen scavenger to minimize RTP quenching. The determination was performed in 0.1 mol L(-1) thallium(I) nitrate and 8 mmol L(-1) sodium sulfite at a measurement temperature of 20 degrees C. The phosphorescence intensity was measured at 635 nm, with excitation at 305 nm. Phosphorescence was easily developed; a linear concentration range was obtained between 0 and 100 ng mL(-1) with a detection limit of 940 ng L(-1), an analytical sensitivity of 2.5 ng mL(-1), and a standard deviation of 2.7% at 60 ng mL(-1) concentration. The method has been successfully applied to the analysis of dipyridamole in a unique Spanish commercial formulation containing 100 ng mL(-1) per capsule. The recovery was 101.6% with 6.5% standard deviation of analytical measurement. The method using the standard addition methodology has been validated.

  14. Myocardial Ischemia

    MedlinePlus

    ... typically on the left side of the body (angina pectoris). Other signs and symptoms — which might be experienced ... ed. Philadelphia, Pa.: Saunders Elsevier; 2014. Podrid PJ. Angina pectoris: Chest pain caused by myocardial ischemia. www.uptodate. ...

  15. Myocardial viability.

    PubMed Central

    Birnbaum, Y; Kloner, R A

    1996-01-01

    Left ventricular function is a major predictor of outcome in patients with coronary artery disease. Acute ischemia, postischemic dysfunction (stunning), myocardial hibernation, or a combination of these 3 are among the reversible forms of myocardial dysfunction. In myocardial stunning, dysfunction occurs despite normal myocardial perfusion, and function recovers spontaneously over time. In acute ischemia and hibernation, there is regional hypoperfusion. Function improves only after revascularization. Evidence of myocardial viability usually relies on the demonstration of uptake of various metabolic tracers, such as thallium (thallous chloride TI 201) or fludeoxyglucose F 18, by dysfunctional myocardium or by the demonstration of contractile reserve in a dysfunctional region. This can be shown as an augmentation of function during the infusion of various sympathomimetic agents. The response of ventricular segments to increasing doses of dobutamine may indicate the underlying mechanism of dysfunction. Stunned segments that have normal perfusion show dose-dependent augmentation of function. If perfusion is reduced as in hibernating myocardium, however, a biphasic response usually occurs: function improves at low doses of dobutamine, whereas higher doses may induce ischemia and, hence, dysfunction. But in patients with severely impaired perfusion, even low doses may cause ischemia. Myocardial regions with subendocardial infarction or diffuse scarring may also have augmented contractility during catecholamine infusion due to stimulation of the subepicardial layers. In these cases, augmentation of function after revascularization is not expected. Because the underlying mechanism, prognosis, and therapy may differ among these conditions, it is crucial to differentiate among dysfunctional myocardial segments that are nonviable and have no potential to regain function, hibernating or ischemic segments in which recovery of function occurs only after revascularization, and

  16. Utilization of Gastrointestinal Simulator, an in Vivo Predictive Dissolution Methodology, Coupled with Computational Approach To Forecast Oral Absorption of Dipyridamole.

    PubMed

    Matsui, Kazuki; Tsume, Yasuhiro; Takeuchi, Susumu; Searls, Amanda; Amidon, Gordon L

    2017-03-03

    Weakly basic drugs exhibit a pH-dependent dissolution profile in the gastrointestinal (GI) tract, which makes it difficult to predict their oral absorption profile. The aim of this study was to investigate the utility of the gastrointestinal simulator (GIS), a novel in vivo predictive dissolution (iPD) methodology, in predicting the in vivo behavior of the weakly basic drug dipyridamole when coupled with in silico analysis. The GIS is a multicompartmental dissolution apparatus, which represents physiological gastric emptying in the fasted state. Kinetic parameters for drug dissolution and precipitation were optimized by fitting a curve to the dissolved drug amount-time profiles in the United States Pharmacopeia apparatus II and GIS. Optimized parameters were incorporated into mathematical equations to describe the mass transport kinetics of dipyridamole in the GI tract. By using this in silico model, intraluminal drug concentration-time profile was simulated. The predicted profile of dipyridamole in the duodenal compartment adequately captured observed data. In addition, the plasma concentration-time profile was also predicted using pharmacokinetic parameters following intravenous administration. On the basis of the comparison with observed data, the in silico approach coupled with the GIS successfully predicted in vivo pharmacokinetic profiles. Although further investigations are still required to generalize, these results indicated that incorporating GIS data into mathematical equations improves the predictability of in vivo behavior of weakly basic drugs like dipyridamole.

  17. 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.

  18. Transient left ventricular cavitary dilation during dipyridamole-thallium imaging as an indicator of severe coronary artery disease

    SciTech Connect

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

    1990-11-15

    Transient left ventricular (LV) cavitary dilation during dipyridamole-thallium imaging was reported in 45 of 510 (9%) consecutive patients referred for dipyridamole-thallium imaging. Clinical and hemodynamic effects observed during dipyridamole infusion were not predictive of transient cavitary dilation on the thallium images. Coronary angiography was performed in 32 of the 45 patients: 75% had either left main, 3-vessel or high-risk 2-vessel coronary artery disease. Although 25 of 45 patients (56%) with transient cavitary dilation were either asymptomatic or had only grade 1/4 effort angina, 16 of 25 patients (64%) not referred for coronary revascularization sustained a cardiac event during a mean follow-up of 12 months. Most events were cardiac deaths (75%) and 87% of events occurred within 4 months of the test. Noncardiac surgery was performed in 187 of the 510 patients. The postoperative cardiac event rate was 2% in the 101 patients with normal scans or fixed defects, 19% in 75 patients with reversible perfusion defects and 58% in 12 patients with reversible cavitary dilation (p less than 0.0001). Thus, transient LV dilation during dipyridamole-thallium imaging is a marker of severe underlying coronary artery disease, denotes a poor prognosis and predicts a high risk of postoperative cardiac complications in patients who undergo noncardiac surgery.

  19. 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.

  20. Effect of surfactants, gastric emptying, and dosage form on supersaturation of dipyridamole in an in vitro model simulating the stomach and duodenum.

    PubMed

    Mitra, A; Fadda, H M

    2014-08-04

    The purpose of this study was to investigate the influence of gastric emptying patterns, surfactants, and dosage form on the supersaturation of a poorly soluble weakly basic drug, dipyridamole, using an in vitro model mimicking the dynamic environment of the upper gastrointestinal tract, and, furthermore, to evaluate the usefulness of this model in establishing correlations to in vivo bioavailability for drugs with solubility/dissolution limited absorption. A simulated stomach duodenum model comprising four compartments was used to assess supersaturation and precipitation kinetics as a function of time. It integrates physiologically relevant fluid volumes, fluid transfer rates, and pH changes of the upper GI tract. Monoexponential gastric emptying patterns simulating the fasted state were compared to linear gastric emptying patterns simulating the fed state. The effect of different surfactants commonly used in oral preparations, specifically, sodium lauryl sulfate (SLS), poloxamer-188, and polysorbate-80, on dipyridamole supersaturation was investigated while maintaining surface tension of the simulated gastric fluids at physiological levels and without obtaining artificial micellar solubilization of the drug. The supersaturation behavior of different dose strengths of dipyridamole was explored. Significant levels of dipyridamole supersaturation were observed in the duodenal compartment under all the different in vivo relevant conditions explored. Dipyridamole supersaturation ratios of up to 11-fold have been observed, and supersaturation has been maintained for up to 120 min. Lower duodenal concentrations of dipyridamole were observed under linear gastric emptying patterns compared to mononexponential gastric emptying. The mean duodenal area under concentration-time curves (AUC60min) for the dipyridamole concentration profile in the duodenal compartment is significantly different for all the surfactants explored (P < 0.05). Our investigations with the different

  1. 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

    2015-07-06

    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.

  2. 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.

  3. Abnormal myocardial perfusion and risk of heart failure in patients with type 2 diabetes mellitus

    PubMed Central

    Utrera-Lagunas, Marcelo; Orea-Tejeda, Arturo; Castillo-Martínez, Lilia; Balderas-Muñoz, Karla; Keirns-Davis, Candace; Espinoza-Rosas, Sarahi; Sánchez-Ortíz, Néstor Alonso; Olvera-Mayorga, Gabriela

    2013-01-01

    BACKGROUND: Diabetes is a major risk factor for heart failure (HF), although the pathophysiological processes have not been clarified. OBJECTIVE: To determine the prevalence of HF and of abnormal myocardial perfusion in diabetic patients evaluated using technetium (99m) sestamibi single-photon emission computed tomography. METHODS: An observational cross-sectional study was conducted that included patients with type 2 diabetes mellitus who underwent echocardiography to diagnose HF and a pharmacological stress test with intravenous dipyridamole to examine cardiac scintigraphic perfusion abnormalities. Clinical and biochemical data were also collected. RESULTS: Of the 160 diabetic patients included, 92 (57.6%) were in HF and 68 (42.5%) were not. When patients were stratified according to the presence of abnormal myocardial perfusion, those with abnormal perfusion had a higher prevalence of HF (93%) than those with normal perfusion (44.4%) (P<0.0001). Patients with HF weighed more (P=0.03), used insulin less frequently (P=0.01), had lower total cholesterol (P=0.05) and high-density lipoprotein cholesterol concentrations (P=0.002), and a greater number of their myocardial segments showed abnormal perfusion (P≤0.001). More HF patients had a history of myocardial infarction (P<0.001) compared with those without HF. In a logistic regression analysis, the number of segments exhibiting abnormal myocardial perfusion was an independent risk factor for HF. CONCLUSIONS: The prevalence of HF in diabetic patients was high and HF predominantly occured in association with myocardial ischemia. PMID:24294048

  4. 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.

  5. 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).

  6. [Influence of dipyridamole on expression of PAC-1 and CD62p in patients with malignant lymphoma].

    PubMed

    Jiang, Ya-Jun; Li, Xiu-Mei; Wang, Hong-Xia; Kang, Li-Li; Zhu, Gui-Hua; Zhuang, Wan-Chuan

    2010-08-01

    This study was purposed to explore the expressions of platelet-activated markers PAC-1 and CD62p in peripheral blood of malignant lymphoma patients and the influence of dipyridamole on their expression. 32 lymphoma patients were divided into simple chemotherapy group (simple group) and chemotherapy plus dipyridamole group (combined group) randomly, and 15 healthy peoples were selected as control group. The dipyridamole of 100 mg/day was given to the patients in combined group. The expression levels of PAC-1, CD62p and fibrinogen (Fib) were detected by flow cytometry and magnetic bead method on day 0, 3, 7 and 14 of chemotherapy respectively. The results showed that the levels of PAC-1, CD62p and Fib in lymphoma patients were significantly higher than those in control group (p < 0.01, 0.05), moreover there was positive correlation between levels of PAC-1 and Fib (r = 0.549, p < 0.01). PAC-1 expression on day 0 and 3 of chemotherapy in simple group was higher than that on day 14 (p < 0.05, 0.01) and CD62p expression on day 3 of chemotherapy was higher than that on day 0, 7 and 14 (p < 0.05, 0.01). PAC-1 expression in combined group on day 14 of chemotherapy was lower than than on day 0 and 3 (p < 0.05, 0.01), and CD62p on day 14 was lower than that on day 3 of chemotherapy (p < 0.05); PAC-1 and CD62p expressions in combined group on day 3, 7 and 14 of chemotherapy were decreased than those in simple group, but Fib level was not changed significantly. It is concluded that the patients with malignant lymphoma usually accompany with platelet activation and hyperfibrinogenemia in peripheral blood. Applying dipyridamole routine dosage in chemotherapy can efficiently restrain platelet activation.

  7. Variability of insulin-stimulated myocardial glucose uptake in healthy elderly subjects.

    PubMed

    Kofoed, Klaus F; Hove, Jens D; Freiberg, Jacob; Høst, Ulla; Holm, Søren; Kelbaek, Henning

    2002-12-01

    The aim of this study was to assess regional and global variability of insulin-stimulated myocardial glucose uptake in healthy elderly subjects and to evaluate potentially responsible factors. Twenty men with a mean age of 64 years, no history of cardiovascular disease, and normal blood pressure, bicycle exercise test, electrocardiogram and echocardiography were studied [ P(coronary artery disease) <5%]. Whole-body insulin sensitivity and insulin-stimulated myocardial glucose uptake were measured during hyperinsulinaemic euglycaemic glucose clamp with fluorine-18 fluorodeoxyglucose, and myocardial rest and hyperaemic blood flow during dipyridamole infusion were measured with nitrogen-13 ammonia and positron emission tomography in 16 left ventricular myocardial segments. Intra-individual and inter-individual variability of insulin-stimulated myocardial glucose uptake [relative dispersion = (standard deviation/mean)] was 13% and 29% respectively. Although inter-individual variability of glucose uptake and blood flow at rest was of the same magnitude, no correlation was found between these measures. Regional and global insulin-stimulated myocardial glucose uptake correlated linearly with whole-body insulin sensitivity ( r=0.51, P<0.05 and r=0.56, P<0.01). The strongest independent association by multivariate linear regression analysis was found between myocardial glucose uptake and hyperaemic blood flow ( r=0.63, P<0.005). We conclude that in healthy elderly subjects, insulin-stimulated myocardial glucose uptake is homogeneous throughout the left ventricle, but has moderate inter-individual variability. Inter-individual variability of insulin-stimulated myocardial glucose uptake is primarily explained by variability in coronary vascular reactivity and tissue insulin sensitivity.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. New approach for quantitative analysis of myocardial perfusion with magnetic resonance first-pass bolus imaging

    NASA Astrophysics Data System (ADS)

    Oswald, Helmut; Schnackenburg, Bernd; Bornstedt, Axel; Gross, Michael; Al-Saadi, Nidal; Nagel, Eicke; Fleck, Eckart

    1999-05-01

    Myocardial perfusion reserve can be noninvasively assessed with cardiovascular magnetic resonance. With magnetic resonance (MR) multislice dynamic imaging techniques it is possible to acquire the complete heart during the first pass of a contrast agent bolus. For diagnostic reasons an important question is to obtain quantitative parameters of the perfusion of the myocardium. We developed a model for the analysis of the contrast agent bolus pass in the myocardium and established a process for the complete task, which will support a routine clinical use delivering these quantitative parameters in a reproducible way. To evaluate the analysis in a collective of patients with single vessel disease and without significant coronary artery disease the signal intensity curves of the first pass of a gadolinium-DTPA bolus injected via a central vein were estimated before and after dipyridamole infusion.

  14. 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.

  15. Myocardial Perfusion SPECT 2015 in Germany

    PubMed Central

    Burchert, Wolfgang; Schäfer, Wolfgang; Hacker, Marcus

    2016-01-01

    Summary Aim The working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine presents the results of the 7th survey of myocardial perfusion SPECT (MPS) of the reporting year 2015. Method 268 questionnaires (173 practices [PR], 67 hospitals [HO], 28 university hospitals [UH]) were evaluated. Results of the last survey from 2012 are set in squared brackets. Results MPS of 121 939 [105 941] patients were reported. 98 % [95 %] of all MPS were performed with Tc-99m radiopharmaceuticals and 2 % [5 %] with Tl-201. 78 % [79 %] of all patients were studied in PR, 14 % [15 %] in HO, and 8 % [6 %] in UH. A pharmacological stress test was performed in 43 % [39 %] (22 % [24 %] adenosine, 20 % [9 %] regadenoson, 1% [6 %] dipyridamole or dobutamine). Attenuation correction was applied in 25 % [2009: 10 %] of MPS. Gated SPECT was performed in 78 % [70 %] of all rest MPS, in 80 % [73 %] of all stress and in 76 % [67 %] of all stress and rest MPS. 53 % [33 %] of all nuclear medicine departments performed MPS scoring by default, whereas 24 % [41 %] did not apply any quantification. 31 % [26 %] of all departments noticed an increase in their counted MPS and 29 % [29 %] no changes. Data from 89 departments which participated in all surveys showed an increase in MPS count of 11.1 % (PR: 12.2 %, HO: 4.8 %, UH: 18.4 %). 70 % [60 %] of the MPS were requested by ambulatory care cardiologists. Conclusion The 2015 MPS survey reveals a high-grade adherence of routine MPS practice to current guidelines. The positive trend in MPS performance and number of MPS already observed in 2012 continues. Educational training remains necessary in the field of SPECT scoring. PMID:27909712

  16. 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.

  17. Necrobiosis lipoidica: a case with histopathological findings revealed asteroid bodies and was successfully treated with dipyridamole plus intralesional triamcinolone.

    PubMed

    Jiquan, Song; Khalaf, Ahmad T; Jinquan, Tan; Xiaoming, Liu

    2008-01-01

    The significance of necrobiosis lipoidica (NL) includes its relationship with insulin-dependent diabetes mellitus, its tendency to break down into painful ulcers, an albeit tenuous association with squamous cell carcinoma and, by no means least, its cosmetic impact, occurring as it does on the shins of young and middle-aged women. Necrobiosis (degeneration of collagen) and granulomous inflammation are well-documented histological findings in NL; however, to see an asteroid body in an area of NL is rare. To the best of our knowledge, there is only one such report of NL described so far. We report the case of a NL patient whose histopathological examination revealed asteroid bodies. The patient had suffered persistent NL for a period of more than 2 years. She was successfully treated with dipyridamole plus intralesional triamcinolone and the lesions healed completely after 2 months of therapy. The patient has remained free of lesions since discontinuing therapy.

  18. The neuron-astrocyte-microglia triad in a rat model of chronic cerebral hypoperfusion: protective effect of dipyridamole

    PubMed Central

    Lana, Daniele; Melani, Alessia; Pugliese, Anna Maria; Cipriani, Sara; Nosi, Daniele; Pedata, Felicita; Giovannini, Maria Grazia

    2014-01-01

    Chronic cerebral hypoperfusion during aging may cause progressive neurodegeneration as ischemic conditions persist. Proper functioning of the interplay between neurons and glia is fundamental for the functional organization of the brain. The aim of our research was to study the pathophysiological mechanisms, and particularly the derangement of the interplay between neurons and astrocytes-microglia with the formation of “triads,” in a model of chronic cerebral hypoperfusion induced by the two-vessel occlusion (2VO) in adult Wistar rats (n = 15). The protective effect of dipyridamole given during the early phases after 2VO (4 mg/kg/day i.v., the first 7 days after 2VO) was verified (n = 15). Sham-operated rats (n = 15) were used as controls. Immunofluorescent triple staining of neurons (NeuN), astrocytes (GFAP), and microglia (IBA1) was performed 90 days after 2VO. We found significantly higher amount of “ectopic” neurons, neuronal debris and apoptotic neurons in CA1 Str. Radiatum and Str. Pyramidale of 2VO rats. In CA1 Str. Radiatum of 2VO rats the amount of astrocytes (cells/mm2) did not increase. In some instances several astrocytes surrounded ectopic neurons and formed a “micro scar” around them. Astrocyte branches could infiltrate the cell body of ectopic neurons, and, together with activated microglia cells formed the “triads.” In the triad, significantly more numerous in CA1 Str. Radiatum of 2VO than in sham rats, astrocytes and microglia cooperated in the phagocytosis of ectopic neurons. These events might be common mechanisms underlying many neurodegenerative processes. The frequency to which they appear might depend upon, or might be the cause of, the burden and severity of neurodegeneration. Dypiridamole significantly reverted all the above described events. The protective effect of chronic administration of dipyridamole might be a consequence of its vasodilatory, antioxidant and anti-inflammatory role during the early phases after 2VO

  19. Fenofibrate and dipyridamole treatments in low-doses either alone or in combination blunted the development of nephropathy in diabetic rats.

    PubMed

    Balakumar, Pitchai; Varatharajan, Rajavel; Nyo, Ying Hui; Renushia, Raja; Raaginey, Devarajan; Oh, Ann Nah; Akhtar, Shaikh Sohrab; Rupeshkumar, Mani; Sundram, Karupiah; Dhanaraj, Sokkalingam A

    2014-12-01

    Low-doses of fenofibrate and dipyridamole have pleiotropic renoprotective actions in diabetic rats. This study investigated their combined effect relative to their individual treatments and lisinopril in rats with diabetic nephropathy. Streptozotocin (55mg/kg, i.p., once)-administered diabetic rats were allowed for 10 weeks to develop nephropathy. Diabetic rats after 10 weeks developed nephropathy with discernible renal structural and functional changes as assessed in terms of increase in kidney weight to body weight ratio (KW/BW), and elevations of serum creatinine, urea and uric acid, which accompanied with elevated serum triglycerides and decreased high-density lipoproteins. Hematoxylin-eosin, periodic acid Schiff and Masson trichrome staining confirmed renal pathological changes in diabetic rats that included glomerular capsular wall distortion, mesangial cell expansion, glomerular microvascular condensation, tubular damage and degeneration and fibrosis. Low-dose fenofibrate (30mg/kg, p.o., 4 weeks) and low-dose dipyridamole (20mg/kg, p.o., 4 weeks) treatment either alone or in combination considerably reduced renal structural and functional abnormalities in diabetic rats, but without affecting the elevated glucose level. Fenofibrate, but not dipyridamole, significantly prevented the lipid alteration and importantly the uric acid elevation in diabetic rats. Lisinopril (5mg/kg, p.o., 4 weeks, reference compound), prevented the hyperglycemia, lipid alteration and development of diabetic nephropathy. Lipid alteration and uric acid elevation, besides hyperglycemia, could play key roles in the development of nephropathy. Low-doses of fenofibrate and dipyridamole treatment either alone or in combination markedly prevented the diabetes-induced nephropathy. Their combination was as effective as to their individual treatment, but not superior in preventing the development of diabetic nephropathy.

  20. A flow-through optosensing device with fluorimetric transduction for rapid and sensitive determination of dipyridamole in pharmaceuticals and human plasma.

    PubMed

    Ruiz-Medina, A; Fernández-de Córdova, M L; Molina-Díaz, A

    2001-07-01

    A flow-through optosensor with fluorimetric transduction has been prepared for the sensitive and selective determination of dipyridamole in aqueous solutions and biological fluids. The method is based on a monochannel flow-injection analysis system using Sephadex QAE A-25 resin, placed into a Hellma 176-QS fluorimetric flow-through cell, as an active sorbing substrate. The native fluorescence of dipyridamole fixed on the solid sorbent is continuously monitored at wavelengths of 305 and 490 nm for excitation and emission, respectively. After obtaining the maximum fluorescence intensity, the eluent solution (KH(2)PO(4)/NaOH buffer solution, c(T)=0.05 mol l(-1), pH 6.0) is allowed to reach the flow cell, the analyte is removed, and the resin support is regenerated. When an NaOH (10(-4) mol l(-1))/NaCl (0.1 mol l(-1)) solution is used as carrier solution, at a flow-rate of 1.56 ml min(-1), the sensor responds linearly in the measuring range of 10-500 microg l(-1) with a detection limit of 0.94 microg l(-1) and a throughput of 22 samples per hour (300 microl of sample volume). The relative standard deviation for ten independent determinations (200 microg l(-1)) is less than 0.82%. The method was satisfactorily applied to the determination of dipyridamole in pharmaceutical preparations and human plasma.

  1. European Stroke Prevention Study 2: A study of low-dose acetylsalicylic acid and of high dose dipyridamole in secondary prevention of cerebro-vascular accidents.

    PubMed

    1995-11-01

    In spite of some data being added to our knowledge of the effect of antiplatelets in secondary prevention of brain ischemic lesion in recent years, the main reasons to perform a second European Stroke Prevention Study (ESPS 2), which started in 1987-1988, were: (a) clarify the relative roles of aspirin (ASA) and dipyridamole (DP) alone or in combination; (b) confirm the efficacy of small doses of ASA and, so doing, decrease the number of drop-outs due to ASA side effects; (c) join information to the effect of antiplatelets in complete stroke. General characteristics of the sample of 6602 patients are presented and compared with other major trials and series. The patients in the four treatment arms (aspirin, dipyridamole, aspirin + dipyridamole and placebo) are compared. The more relevant features and risk factors known to influence long term prognosis are described and discussed. The small proportion of patients included with TIA (23.7%) and the comparability among treatment groups are stressed. No relevant differences have been found, among groups, on the sex or age distribution, prevalence of hypertension, diabetes, previous vascular events or atrial fibrillation, nor in the characteristics of the accident leading to the inclusion in trial.

  2. 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.

  3. Usefulness of coronary flow reserve over regional wall motion when added to dual-imaging dipyridamole echocardiography.

    PubMed

    Rigo, Fausto; Richieri, Margherita; Pasanisi, Emilio; Cutaia, Valeria; Zanella, Carlo; Della Valentina, Patrizia; Di Pede, Francesco; Raviele, Antonio; Picano, Eugenio

    2003-02-01

    Vasodilator stress echocardiography allows semi-simultaneous imaging of left anterior descending (LAD) coronary flow and regional wall function. To assess the relative (and additive?) value of regional flow and function for noninvasive identification of angiographically assessed LAD disease in patients with chest pain syndrome, we studied 230 consecutive in-hospital patients (134 men, aged 63.5 +/- 11 years) with chest pain syndrome and normal regional and global left ventricular function. All patients underwent stress echocardiography with dipyridamole (up to 0.84 mg/kg over 10 minutes), including wall motion analysis by 2-dimensional echocardiography and coronary flow reserve (CFR) evaluation of the LAD artery by Doppler, with or without contrast injection. A new regional wall motion abnormality in >or=2 contiguous segments was required for 2-dimensional echocardiographic positivity. CFR was evaluated as the ratio of dipyridamole to peak diastolic coronary blood flow velocity at rest. All patients underwent coronary angiography within 60 days; a quantitatively assessed diameter reduction >50% of the LAD artery was considered significant. Of the 230 patients, 70 had LAD disease. A regional wall motion abnormality in LAD territory was present in 52 patients, and reduced CFR (<1.9) in 62 patients. Sensitivity for detecting LAD disease was 74% for 2-dimensional echocardiography (95% confidence interval [CI] 64% to 84%) and 81% for CFR <1.9 (95% CI 72% to 90%); specificity was 91% (95% CI 87% to 96%) for 2-dimensional echocardiography and 84% for CFR (95% CI 79% to 90%). Accuracy was 86% for 2-dimensional echocardiography (95% CI 82% to 91%) and 83.5% for CFR (95% CI 79% to 88%). When 2-dimensional echocardiography and CFR criteria were considered, sensitivity increased to 93% (95% CI 87% to 99%), with 80.6% specificity (95% CI 74.5% to 86.7%). CFR was assessed during vasodilator stress echocardiography. Its diagnostic accuracy for detecting LAD disease was comparable

  4. The influence of agent delivery mode on cardiomyocyte injury induced by myocardial contrast echocardiography in rats.

    PubMed

    Miller, Douglas L; Dou, Chunyan; Armstrong, William F

    2005-09-01

    Myocardial contrast echocardiography (MCE) can induce bioeffects in rat hearts by local activation of the contrast agent gas bodies. This study was designed to examine the influence of agent delivery mode on the magnitude of cardiomyocyte injury. A total of 69 hairless rats were anesthetized and mounted vertically in a water bath. Evans blue dye was injected as vital stain for cardiomyocyte injury. Definity contrast agent was diluted in saline and injected via tail vein at 20 or 80 microL/kg in bolus or infusion mode. In 12 rats, 0.57 mg/kg dipyridamole was given to simulate a stress test. MCE in a short axis view with 1:4 or 1:16 ECG triggering was performed at 1.5 MHz for 5 or 20 min. The peak rarefactional pressure amplitude was set to 1.1 or 2.0 MPa. Premature beats were counted from the ECG record. Evans blue fluorescent cells were counted on frozen sections from the center of the scan plane of heart samples obtained 24 h postMCE. Infusion of the contrast agent led to more cardiomyocyte injury than did bolus injection. Dipyridamole stress also increased the effect. Varying the infusion rate or trigger interval was less important than the overall dosage during scanning. Exposure at 1.1 MPa and 80 microL/kg yielded significant cell killing relative to shams. Premature beats generally followed the same trends as cell injury, except that lower infusion rates tended to increase this effect. Contrast agent delivery mode, as well as dose and peak rarefactional pressure amplitude, has a significant influence on the bioeffects potential of MCE.

  5. Periodontitis and myocardial hypertrophy.

    PubMed

    Suzuki, Jun-Ichi; Sato, Hiroki; Kaneko, Makoto; Yoshida, Asuka; Aoyama, Norio; Akimoto, Shouta; Wakayama, Kouji; Kumagai, Hidetoshi; Ikeda, Yuichi; Akazawa, Hiroshi; Izumi, Yuichi; Isobe, Mitsuaki; Komuro, Issei

    2017-04-01

    There is a deep relationship between cardiovascular disease and periodontitis. It has been reported that myocardial hypertrophy may be affected by periodontitis in clinical settings. Although these clinical observations had some study limitations, they strongly suggest a direct association between severity of periodontitis and left ventricular hypertrophy. However, the detailed mechanisms between myocardial hypertrophy and periodontitis have not yet been elucidated. Recently, we demonstrated that periodontal bacteria infection is closely related to myocardial hypertrophy. In murine transverse aortic constriction models, a periodontal pathogen, Aggregatibacter actinomycetemcomitans markedly enhanced cardiac hypertrophy with matrix metalloproteinase-2 activation, while another pathogen Porphyromonas gingivalis (P.g.) did not accelerate these pathological changes. In the isoproterenol-induced myocardial hypertrophy model, P.g. induced myocardial hypertrophy through Toll-like receptor-2 signaling. From our results and other reports, regulation of chronic inflammation induced by periodontitis may have a key role in the treatment of myocardial hypertrophy. In this article, we review the pathophysiological mechanism between myocardial hypertrophy and periodontitis.

  6. Preparation and characterization of dipyridamole solid dispersions for stabilization of supersaturation: effect of precipitation inhibitors type and molecular weight.

    PubMed

    Vora, Chintan; Patadia, Riddhish; Mittal, Karan; Mashru, Rajashree

    2016-11-01

    Dipyridamole (DPL) is a weakly basic BCS class II drug which precipitates upon entering into intestine leading to pH dependant and variable absorption. Thus, research envisaged focuses on developing formulations that maintain supersaturation following upon acid to neutral pH transition. In an endeavor to accomplish the objective, solid dispersion (SD) with hydroxypropylmethyl cellulose (HPMC) and polyvinylpyrrolidone (PVP) was prepared by a quench cooling method. The three molecular weight grades of HPMC (HPMC E5, HPMC E15 and HPMC E50) and two molecular weight grades of PVP (PVP K30 and PVP K90) were investigated to observe effect of increasing molecular weight on stabilizing DPL supersaturated solutions. Equilibrium solubility studies revealed increase in solubility with both HPMC and PVP with greater benefit from HPMC. In vitro supersaturated dissolution results demonstrated that HPMC formulations provided greater degree and extent of supersaturation as compared to PVP formulations. The formulation with HPMC E50 provided maximum stabilization to supersaturation upon acid to neutral pH transition. Moreover, the effect of increase in molecular weight was more pronounced in HPMC rather than PVP. Stronger interactions were observed for DPL with HPMC, while no interaction was observed with PVP which was evident from Fourier transform infra-red studies. Differential scanning calorimetry and powder X-ray diffraction studies revealed the amorphous state of DPL in SD.

  7. Leakage of potassium from red blood cells following gamma ray irradiation in the presence of dipyridamole, trolox, human plasma or mannitol.

    PubMed

    Hirayama, Junichi; Abe, Hideki; Azuma, Hiroshi; Ikeda, Hisami

    2005-07-01

    Transfusion-associated graft-versus-host disease (TA-GVHD) is a fatal complication of blood transfusion resulting from the contamination of blood products by leukocytes. In order to prevent this disease, gamma or X-ray irradiation of blood components,which can inactivate leukocytes, is currently used. However, the minimal doses needed to destroy lymphocytes promote the leakage of potassium from red blood cells (RBCs), which can induce other side effects, such as hyperpotassemia and cardiac arrest. The reactive oxygen species (ROS) generated by the irradiation of aqueous solutions may accelerate the leakage through oxidation of the RBC membrane. Here we studied the effect of dipyridamole, Trolox, human plasma or mannitol on the leakage of potassium from RBCs following irradiation. RBC preparations (hematocrit; 30%) containing antioxidants were irradiated at 30 Gy and stored at 4 degrees C for 7 d. The leakage of potassium from the RBCs caused by the irradiation was significantly suppressed by dipyridamole (more than 50 microM), Trolox (more than 5 mM) or human plasma (50%). Mannitol (80 mM) is used to inhibit hemolysis as a constituent of MAP solution, which is a solution used for the storage of RBC products in Japan. Here it was clarified that the leakage of potassium from not only irradiated but also non-irradiated RBCs was unexpectedly promoted by mannitol. The amount of mannitol in MAP solution may have to be reconsidered. The osmotic pressure of the RBC preparation increased in a manner dependent on the concentration of mannitol. The elevated osmotic pressure may promote the leakage. In conclusion, although antioxidants have the potential to suppress the leakage of potassium ascribed to the irradiation, the extent of the suppression (10-20%) by dipyridamole (DPM), Trolox or human plasma seems insufficient for the clinical use of these agents as an additive for MAP solution.

  8. Myocardial Noncompaction Presenting With Myocardial Bridge

    PubMed Central

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

    2015-01-01

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

  9. 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

  10. 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

  11. Dipyridamole attenuates ischemia reperfusion induced acute kidney injury through adenosinergic A1 and A2A receptor agonism in rats.

    PubMed

    Puri, Nikkita; Mohey, Vinita; Singh, Manjinder; Kaur, Tajpreet; Pathak, Devendra; Buttar, Harpal Singh; Singh, Amrit Pal

    2016-04-01

    Dipyridamole (DYP) is an anti-platelet agent with marked vasodilator, anti-oxidant, and anti-inflammatory activity. The present study investigated the role of adenosine receptors in DYP-mediated protection against ischemia reperfusion-induced acute kidney injury (AKI) in rats. The rats were subjected to bilateral renal ischemia for 40 min followed by reperfusion for 24 h. The renal damage induced by ischemia reperfusion injury (IRI) was assessed by measuring creatinine clearance, blood urea nitrogen, uric acid, plasma potassium, fractional excretion of sodium, and microproteinuria in rats. The oxidative stress in renal tissues was assessed by quantification of thiobarbituric acid-reactive substances, superoxide anion generation, and reduced glutathione level. The hematoxylin-eosin staining was carried out to observe histopathological changes in renal tissues. DYP (10 and 30 mg/kg, intraperitoneal, i.p.) was administered 30 min before subjecting the rats to renal IRI. In separate groups, caffeine (50 mg/kg, i.p.), an adenosinergic A1 and A2A receptor antagonist was administered with and without DYP treatment before subjecting the rats to renal IRI. The ischemia reperfusion-induced AKI was demonstrated by significant changes in serum as well as urinary parameters, enhanced oxidative stress, and histopathological changes in renal tissues. The administration of DYP demonstrated protection against AKI. The prior treatment with caffeine abolished DYP-mediated reno-protection suggesting role of A1 and A2A adenosine receptors in DYP-mediated reno-protection in rats. It is concluded that adenosine receptors find their definite involvement in DYP-mediated anti-oxidative and reno-protective effect against ischemia reperfusion-induced AKI.

  12. Quantitative myocardial perfusion SPECT.

    PubMed

    Tsui, B M; Frey, E C; LaCroix, K J; Lalush, D S; McCartney, W H; King, M A; Gullberg, G T

    1998-01-01

    In recent years, there has been much interest in the clinical application of attenuation compensation to myocardial perfusion single photon emission computed tomography (SPECT) with the promise that accurate quantitative images can be obtained to improve clinical diagnoses. The different attenuation compensation methods that are available create confusion and some misconceptions. Also, attenuation-compensated images reveal other image-degrading effects including collimator-detector blurring and scatter that are not apparent in uncompensated images. This article presents basic concepts of the major factors that degrade the quality and quantitative accuracy of myocardial perfusion SPECT images, and includes a discussion of the various image reconstruction and compensation methods and misconceptions and pitfalls in implementation. The differences between the various compensation methods and their performance are demonstrated. Particular emphasis is directed to an approach that promises to provide quantitative myocardial perfusion SPECT images by accurately compensating for the 3-dimensional (3-D) attenuation, collimator-detector response, and scatter effects. With advances in the computer hardware and optimized implementation techniques, quantitatively accurate and high-quality myocardial perfusion SPECT images can be obtained in clinically acceptable processing time. Examples from simulation, phantom, and patient studies are used to demonstrate the various aspects of the investigation. We conclude that quantitative myocardial perfusion SPECT, which holds great promise to improve clinical diagnosis, is an achievable goal in the near future.

  13. Myocardial Lineage Development

    PubMed Central

    Evans, Sylvia M.; Yelon, Deborah; Conlon, Frank L.; Kirby, Margaret L.

    2010-01-01

    The myocardium of the heart is composed of multiple highly specialized myocardial lineages, including those of the ventricular and atrial myocardium, and the specialized conduction system. Specification and maturation of each of these lineages during heart development is a highly ordered, ongoing process involving multiple signaling pathways and their intersection with transcriptional regulatory networks. Here, we attempt to summarize and compare much of what we know about specification and maturation of myocardial lineages from studies in several different vertebrate model systems. To date, most research has focused on early specification, and while there is still more to learn, less is known about factors that promote subsequent maturation of myocardial lineages required to build the functioning adult heart. PMID:21148449

  14. Simultaneous Determination of Aspirin, Dipyridamole and Two of Their Related Impurities in Capsules by Validated TLC-Densitometric and HPLC Methods.

    PubMed

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

    2016-08-01

    Aspirin (ASP) and dipyridamole (DIP) are widely used as a combination in pharmaceutical formulations for treatment of strokes. Many of these formulations are containing tartaric acid as an excipient (in DIP pellets formulation for sustained release), which increases the probability of formation of dipyridamole tartaric acid ester impurity (DIP-I). On the other hand, salicylic acid (SAL) is considered to be one of the synthesis impurities and a degradation product of ASP. In this work, two chromatographic methods, namely, TLC-densitometry and HPLC, have been established and validated for simultaneous determination of ASP, DIP, SAL and DIP-I. Good separation was achieved by using silica gel as stationary phase and toluene-methanol-ethyl acetate (2:3:5, by volume) as mobile phase in the case of TLC-densitometry and Zorbax ODS column with mobile phase consisting of phosphate buffer (pH 3.3)-acetonitrile-triethylamine (40:60:0.03, by volume) for HPLC. Influence of different organic solvents in mobile phase composition has been studied to optimize the separation efficiency in TLC densitometry. Moreover, factors affecting the efficiency of HPLC, like pH of the buffer used, organic solvent ratio in the mobile phase and flow rate, have been carefully studied using one variable at a time approach. Finally, the proposed methods were validated as per ICH guidelines.

  15. 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

  16. Single-photon agents for tumor imaging: 201Tl, 99mTc-MIBI, and 99mTc-tetrofosmin.

    PubMed

    Fukumoto, Mitsutaka

    2004-04-01

    This review aims at fostering comprehension and knowledge not only for expert physicians who can skillfully handle various techniques for tumor imaging but also for young practitioners in the field of nuclear medicine. As image processing software and hardware become smaller, faster and better, SPECT will adapt and incorporate these advances. A principal advantage of SPECT over PET is the more widespread availability of the equipment and lower cost for the introduction of the system in community-based facilities. Moreover, SPECT has become less dependent on a limited number of acknowledged experts for its interpretation owing to a variety of handy computer tools for imaging analyses. The increasing use of PET in tumor imaging is not necessarily proportional to the decline of SPECT. General physicians' attention to SPECT technology would also increase more by evoking their interest in "tracer imaging."

  17. Augmented myocardial perfusion reserve after coronary angioplasty quantified by positron emission tomography with H2(15)O

    SciTech Connect

    Walsh, M.N.; Geltman, E.M.; Steele, R.L.; Kenzora, J.L.; Ludbrook, P.A.; Sobel, B.E.; Bergmann, S.R. )

    1990-01-01

    Effects of coronary angioplasty on myocardial flow reserve have been difficult to characterize noninvasively because conventional imaging techniques cannot quantitate blood flow in absolute terms. The effects of coronary angioplasty on myocardial perfusion and perfusion reserve were delineated with positron emission tomography and oxygen-15-labeled water (H2(15)O) in 13 patients before and after single vessel angioplasty. In 11 patients, angioplasty was successful (minimal cross-sectional area increased from 0.60 +/- 0.59 to 3.45 +/- 1.09 mm2, p less than 0.001). In these patients, regional H2(15)O radioactivity (the ratio of nutritional perfusion in regions distal to the stenosis compared with regions supplied by angiographically normal arteries) at rest before angioplasty was 55 +/- 22% of peak myocardial radioactivity and did not increase significantly afterward (70 +/- 16%, p = NS). However, after administration of intravenous dipyridamole, hyperemic perfusion in regions distal to a stenosis averaged only 39 +/- 18% of peak myocardial counts before angioplasty, but increased to 66 +/- 22% after angioplasty (p less than 0.02). Perfusion reserve in the two patients in whom angioplasty was angiographically unsuccessful showed no change. Quantitative estimates of perfusion in absolute rather than relative terms were obtained with positron emission tomographic data from seven of the patients with successful angioplasty. At rest, perfusion in regions distal to a stenosis was not different from the values in regions supplied by normal coronary arteries (1.54 +/- 0.54 compared with 1.46 +/- 0.38 ml/g per min, p = NS).

  18. An adult case of Kawasaki disease with multiplex coronary aneurysms and myocardial infarction: the role of transesophageal echocardiography.

    PubMed

    Habon, T; Toth, K; Keltai, M; Lengyel, M; Palik, I

    1998-07-01

    Kawasaki disease (mucocutaneous lymph node syndrome) is an acute inflammatory disease that primarily affects infants and young children. In spite of proper therapy, coronary aneurysms develop in 10 to 25% of cases. Adult diagnosis of coronary aneurysm, presumably caused by Kawasaki disease, is rare. A 37-year-old male patient with previous inferior wall myocardial infarction (MI) was admitted with an acute anterior wall MI. Coronary angiography, performed 2 weeks after successful thrombolytic therapy, showed right coronary artery occlusion and multiplex (left main, left anterior descending, left circumflex, right coronary artery) giant coronary aneurysms. Transthoracic echocardiography was unable to detect the aneurysms. Transesophageal echocardiography (TEE) visualized a large left main coronary aneurysm with an occlusive thrombus and measured low flow velocity (0.2 m/s) in the proximal left anterior descending artery. At 4 weeks control, TEE showed marked regression of the thrombus, and it was not detectable after 6 months of oral anticoagulation with acenocumarol (International Normalized Ratio: 3-3.5) and standard postinfarction therapy. After 2 years of follow-up, the patient has no symptoms, and myocardial ischemia could not be provoked by stress tests [treadmill, dipyridamole single-photon emission computed tomography (SPECT)]. We conclude that, for diagnosis and follow-up of adult Kawasaki disease, transesophageal echocardiography is indicated. The importance and efficacy of long-term anticoagulant treatment should be emphasized in this disease.

  19. 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.

  20. The impact of supersaturation level for oral absorption of BCS class IIb drugs, dipyridamole and ketoconazole, using in vivo predictive dissolution system: Gastrointestinal Simulator (GIS).

    PubMed

    Tsume, Yasuhiro; Matsui, Kazuki; Searls, Amanda L; Takeuchi, Susumu; Amidon, Gregory E; Sun, Duxin; Amidon, Gordon L

    2017-03-03

    The development of formulations and the assessment of oral drug absorption for Biopharmaceutical Classification System (BCS) class IIb drugs is often a difficult issue due to the potential for supersaturation and precipitation in the gastrointestinal (GI) tract. The physiological environment in the GI tract largely influences in vivo drug dissolution rates of those drugs. Thus, those physiological factors should be incorporated into the in vitro system to better assess in vivo performance of BCS class IIb drugs. In order to predict oral bioperformance, an in vitro dissolution system with multiple compartments incorporating physiologically relevant factors would be expected to more accurately predict in vivo phenomena than a one-compartment dissolution system like USP Apparatus 2 because, for example, the pH change occurring in the human GI tract can be better replicated in a multi-compartmental platform. The Gastrointestinal Simulator (GIS) consists of three compartments, the gastric, duodenal and jejunal chambers, and is a practical in vitro dissolution apparatus to predict in vivo dissolution for oral dosage forms. This system can demonstrate supersaturation and precipitation and, therefore, has the potential to predict in vivo bioperformance of oral dosage forms where this phenomenon may occur. In this report, in vitro studies were performed with dipyridamole and ketoconazole to evaluate the precipitation rates and the relationship between the supersaturation levels and oral absorption of BCS class II weak base drugs. To evaluate the impact of observed supersaturation levels on oral absorption, a study utilizing the GIS in combination with mouse intestinal infusion was conducted. Supersaturation levels observed in the GIS enhanced dipyridamole and ketoconazole absorption in mouse, and a good correlation between their supersaturation levels and their concentration in plasma was observed. The GIS, therefore, appears to represent in vivo dissolution phenomena and

  1. 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.

  2. 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

  3. 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

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

    PubMed Central

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

    2017-01-01

    Purpose. Myocardial blood flow (MBF) quantification with 82Rb positron emission tomography (PET) is gaining clinical adoption, but improvements in precision are desired. This study aims to identify analysis variants producing the most repeatable MBF measures. Methods. 12 volunteers underwent same-day test-retest rest and dipyridamole stress imaging with dynamic 82Rb PET, from which MBF was quantified using 1-tissue-compartment kinetic model variants: (1) blood-pool versus uptake region sampled input function (Blood/Uptake-ROI), (2) dual spillover correction (SOC-On/Off), (3) right blood correction (RBC-On/Off), (4) arterial blood transit delay (Delay-On/Off), and (5) distribution volume (DV) constraint (Global/Regional-DV). Repeatability of MBF, stress/rest myocardial flow reserve (MFR), and stress/rest MBF difference (ΔMBF) was assessed using nonparametric reproducibility coefficients (RPCnp = 1.45 × interquartile range). Results. MBF using SOC-On, RVBC-Off, Blood-ROI, Global-DV, and Delay-Off was most repeatable for combined rest and stress: RPCnp = 0.21 mL/min/g (15.8%). Corresponding MFR and ΔMBF RPCnp were 0.42 (20.2%) and 0.24 mL/min/g (23.5%). MBF repeatability improved with SOC-On at stress (p < 0.001) and tended to improve with RBC-Off at both rest and stress (p < 0.08). DV and ROI did not significantly influence repeatability. The Delay-On model was overdetermined and did not reliably converge. Conclusion. MBF and MFR test-retest repeatability were the best with dual spillover correction, left atrium blood input function, and global DV. PMID:28293274

  5. Higher event rate in patients with known CAD despite a normal myocardial perfusion scan

    PubMed Central

    Fatima, Nosheen; Zaman, Unaiza; Zaman, Areeba; Balcoh, Dad J.; Rasheed, S Zahed

    2014-01-01

    Objective The negative predictive value of a normal single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is very high. However, prognostic implication of a normal SPECT MPI in patients with known coronary artery disease (CAD) is not clear. Objective of this study was to evaluate the cardiac event rate in patients with known CAD who had a normal stress SPECT MPI. Methods This prospective study accrued 428 consecutive patients with a history of CAD [revascularization or previous myocardial infarction (MI)] who had a normal stress (dynamic exercise or dipyridamole intervention) and rest Tc-99m-MIBI SPECT MPI. These patients were followed for 2-5 years (median: 3.1 years) for all-cause and cardiac mortality and non-fatal MI. Univariate and multivariate analyses were performed to identify predictors of outcome. Results During a follow-up period, all-cause mortality was found in 60 patients (14%) and 41 (10%) died of cardiac reasons. Non-fatal MI was found in 77 (18%) patients. Annualized cardiac mortality and non-fatal MI rates were 2% and 3.6% respectively. Smoking, congestive heart failure (CHF) and failure to achieve 85% age predicted heart rate were found to be predictors for all-cause and cardiac mortality. Diabetes, dyslipidemia, smoking and limited functional capacity (<7 METS) were found to be predictors for non-fatal MI. Conclusions Patients with known CAD had higher cardiac event rates despite a normal stress SPECT MPI. Diabetes, dyslipidemia, smoking and limited functional capacity were the predictors for fatal and non-fatal cardiac events. A cost effective but comprehensive surveillance strategy is warranted. PMID:25009792

  6. Diurnal variations in myocardial metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  7. Myocardial revascularisation after acute myocardial infarction.

    PubMed

    Bana, A; Yadava, O P; Ghadiok, R; Selot, N

    1999-05-15

    One hundred and twenty-three patients had coronary artery bypass grafting (CABG) within 30 days of acute myocardial infarction (AMI) from May 1992 to November 1997. Commonest infarct was anterior transmural (61.8%) and commonest indication of surgery was post-infarct persistent or recurrent angina (69.1%). Ten patients were operated within 48 h and 36 between 48 h to 2 weeks of having MI. Out of these, nine patients were having infarct extension and cardiogenic shock at the time of surgery. Pre-operatively fourteen patients were on inotropes of which six also had intra-aortic balloon pump (IABP) support. All patients had complete revascularisation with 3.8+/-1.2 distal anastomoses per patient. By multivariate analysis, we found that independent predictors of post-operative morbidity [inotropes >48 h, use of IABP, ventilation >24 h, ICU stay >5 days] and complications [re-exploration, arrhythmias, pulmonary complications, wound infection, cerebrovascular accident (CVA)] were left ventricular ejection fraction (LVEF) <30%, Q-wave MI, surgery <48 h after AMI, presence of pre-operative cardiogenic shock and age >60 years (P < or = 0.01). Mortality at 30 days was 3.3%. LVEF <30%, Q-wave MI, surgery <48 h after AMI, presence of pre-operative cardiogenic shock and age >60 years were found to be independent predictors of 30 days mortality (P < or = 0.01). Ninety patients were followed up for a mean duration of 33 months (1 to 65 months). There were three late deaths and five patients developed recurrence of angina. To conclude, CABG can be carried out with low risk following AMI in stable patients for post-infarct angina. Patients who undergo urgent or emergent surgery and who have pre-operative cardiogenic shock, IABP, poor left ventricular functions, age >60 years and Q-wave MI are at increased risk.

  8. 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.

  9. Bone regeneration in critical bone defects using three-dimensionally printed β-tricalcium phosphate/hydroxyapatite scaffolds is enhanced by coating scaffolds with either dipyridamole or BMP-2.

    PubMed

    Ishack, Stephanie; Mediero, Aranzazu; Wilder, Tuere; Ricci, John L; Cronstein, Bruce N

    2017-02-01

    Bone defects resulting from trauma or infection need timely and effective treatments to restore damaged bone. Using specialized three-dimensional (3D) printing technology we have created custom 3D scaffolds of hydroxyapatite (HA)/beta-tri-calcium phosphate (β-TCP) to promote bone repair. To further enhance bone regeneration we have coated the scaffolds with dipyridamole, an agent that increases local adenosine levels by blocking cellular uptake of adenosine. Nearly 15% HA:85% β-TCP scaffolds were designed using Robocad software, fabricated using a 3D Robocasting system, and sintered at 1100°C for 4 h. Scaffolds were coated with BMP-2 (200 ng mL(-1) ), dypiridamole 100 µM or saline and implanted in C57B6 and adenosine A2A receptor knockout (A2AKO) mice with 3 mm cranial critical bone defects for 2-8 weeks. Dipyridamole release from scaffold was assayed spectrophotometrically. MicroCT and histological analysis were performed. Micro-computed tomography (microCT) showed significant bone formation and remodeling in HA/β-TCP-dipyridamole and HA/β-TCP-BMP-2 scaffolds when compared to scaffolds immersed in vehicle at 2, 4, and 8 weeks (n = 5 per group; p ≤ 0.05, p ≤ 0.05, and p ≤ 0.01, respectively). Histological analysis showed increased bone formation and a trend toward increased remodeling in HA/β-TCP- dipyridamole and HA/β-TCP-BMP-2 scaffolds. Coating scaffolds with dipyridamole did not enhance bone regeneration in A2AKO mice. In conclusion, scaffolds printed with HA/β-TCP promote bone regeneration in critical bone defects and coating these scaffolds with agents that stimulate A2A receptors and growth factors can further enhance bone regeneration. These coated scaffolds may be very useful for treating critical bone defects due to trauma, infection or other causes. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 366-375, 2017.

  10. [Comparison of various parameters for determining an index of myocardial perfusion reserve in detecting coronary stenosis with cardiovascular magnetic resonance tomography].

    PubMed

    al-Saadi, N; Gross, M; Bornstedt, A; Schnackenburg, B; Klein, C; Fleck, E; Nagel, E

    2001-11-01

    For the assessment of myocardial perfusion with cardiac magnetic resonance imaging, different semiquantitative parameters of the first pass signal intensity time curves can be calculated and myocardial perfusion reserve indices can be determined. In this study we evaluated the feasibility of different perfusion parameters and their perfusion reserve indices for the detection of significant coronary artery stenosis. The signal intensity time curves of the first pass of a gadolinium-DTPA bolus injected via a central vein catheter before and after dipyridamole infusion were investigated in 15 patients with single vessel (stenosis > or = 75% area reduction) and five patients without significant coronary artery disease. For the distinction of ischemic and nonischemic myocardial segments, semiquantitative parameters, such as maximal signal intensity, contrast appearance time, time to maximal signal intensity and the steepness of the signal intensity curve's upslope determined by a linear fit, were assessed after correction for the input function. For each parameter a myocardial perfusion reserve index was calculated and cut off values for the detection of significant coronary stenosis were defined. The diagnostic accuracy of each parameter was then examined prospectively in 36 patients with coronary artery disease and compared with coronary angiography. Where as a distinction of ischemic and normal myocardium was possible with myocardial perfusion reserve indices, semiquantitative parameters at rest or after vasodilation alone did not allow such a distinction. The perfusion reserve index calculated from the upslope showed the most significant difference between ischemic and nonischemic myocardial segments (1.19 +/- 0.4 and 2.38 +/- 0.45, p < 0.001) followed by maximum signal intensity, time to maximum signal intensity and contrast apperance time. Sensitivity, specificity and diagnostic accuracy was 87, 82 and 85% for the detection of hypoperfusion induced by significant

  11. Wave propagation of myocardial stretch: correlation with myocardial stiffness.

    PubMed

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

    2014-01-01

    The mechanism of flow propagation during diastole in the left ventricle (LV) has been well described. Little is known about the associated waves propagating along the heart walls. These waves may have a mechanism similar to pulse wave propagation in arteries. The major goal of the study was to evaluate the effect of myocardial stiffness and preload on this wave transmission. Longitudinal late diastolic deformation and wave speed (Vp) of myocardial stretch in the anterior LV wall were measured using sonomicrometry in 16 pigs. Animals with normal and altered myocardial stiffness (acute myocardial infarction) were studied with and without preload alterations. Elastic modulus estimated from Vp (E VP; Moens-Korteweg equation) was compared to incremental elastic modulus obtained from exponential end-diastolic stress-strain relation (E SS). Myocardial distensibility and α- and β-coefficients of stress-strain relations were calculated. Vp was higher at reperfusion compared to baseline (2.6 ± 1.3 vs. 1.3 ± 0.4 m/s; p = 0.005) and best correlated with E SS (r2 = 0.80, p < 0.0001), β-coefficient (r2 = 0.78, p < 0.0001), distensibility (r2 = 0.47, p = 0.005), and wall thickness/diameter ratio (r2 = 0.42, p = 0.009). Elastic moduli (E VP and E SS) were strongly correlated (r2 = 0.83, p < 0.0001). Increasing preload increased Vp and E VP and decreased distensibility. At multivariate analysis, E SS, wall thickness, and end-diastolic and systolic LV pressures were independent predictors of Vp (r2 model = 0.83, p < 0.0001). In conclusion, the main determinants of wave propagation of longitudinal myocardial stretch were myocardial stiffness and LV geometry and pressure. This local wave speed could potentially be measured noninvasively by echocardiography.

  12. Optimization of myocardial function.

    PubMed

    Alpert, N R; Mulieri, L A; Hasenfuss, G; Holubarsch, C

    1993-01-01

    Under normal conditions the cardiac output is designed to meet the metabolic needs of the organism. Thus, the demands imposed on the heart muscle can range from low values at rest to an order of magnitude greater values during exercise. The heart uses a number of strategies to meet the short- and long-term changes in demand. These strategies are of general biological interest and employ similar mechanisms to those responsible for the differences in muscle performance seen between muscle from various species and diverse muscle types within a given animal. This review deals with the heart's utilization of these strategies to meet a broad range of requirements. Tortoise (TM) and rat soleus (RS) muscles are slow, have high economy and develop low power. In contrast (FM) and rat extensor digitorum longus (REDL) are fast, have low economy and have a high power output. These differences are explainable in terms of the characteristics of the myosin head cross-bridge cycle (Cross-bridge tension-time integral: FM/FT = 0.024; REDL/RS = 0.16. Myosin ATPase activity: FM/TM = 15; RDEL/RS = 2.3) and excitation contraction coupling system (time to peak tension: FM/TM = 0.2; REDL/RS = 0.4). Heart muscle employs similar strategies (cross-bridge cycle; excitation contraction coupling) to meet short (catecholamine) and long (hypertrophy secondary to pressure overload or thyrotoxicosis) term changes in demand. In the presence of catecholamine power is increased while economy is decreased. This difference between control (C) and isoproterenol treated hearts (I) is explainable in terms of the contractile and excitation contraction coupling systems (Cross-bridge tension-time integral: I/C = 0.4. Tension independent heat: I/C = 2.0. Tension independent heat rate: I/C = 2.5). A persistent increase in the demand on the heart results in myocardial hypertrophy that is associated with intracellular reorganization. Hyperthyroidism (T) and pressure overload (PO) were used to produce myocardial

  13. CAD of myocardial perfusion

    NASA Astrophysics Data System (ADS)

    Storm, Corstiaan J.; Slump, Cornelis H.

    2007-03-01

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

  14. 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.

  15. Alterations in myocardial thallium-201 distribution in patients with chronic systemic hypertension undergoing single-photon emission computed tomography

    SciTech Connect

    DePuey, E.G.; Guertler-Krawczynska, E.; Perkins, J.V.; Robbins, W.L.; Whelchel, J.D.; Clements, S.D.

    1988-08-01

    To characterize thallium-201 distribution in single-photon emission computed tomography (SPECT) cardiac images and polar bullseye maps, 100 patients with chronic systemic hypertension due to end-stage renal disease were studied and the results compared with those in 35 normotensive control subjects. Thallium-201 SPECT was performed after exercise in all control subjects and 70 hypertensive patients, and after intravenous dipyridamole in 30 patients. A frequent finding in hypertensive patients was a fixed decrease in the normal lateral-to-septal count density ratio in immediate thallium-201 SPECT images (1.02 +/- 0.10 vs 1.17 +/- 0.08 in control subjects, p less than 0.00001) and in 3-hour delayed images (1.02 +/- 0.11 vs 1.11 +/- 0.08 in control subjects, p less than 0.00001). No significant difference in count density ratio was present in patients undergoing treadmill versus diypridamole intervention. In 35 patients the count density ratio was greater than 2.0 standard deviations below the normal mean, creating the false impression of a fixed lateral defect (i.e., myocardial infarction). In 12 patients, myocardial wall thickness was measured at end-diastole by 2-dimensional echocardiography. Wall thickness was increased (greater than 11 mm) in all patients. The mean lateral-to-septal wall thickness ratio was 1.08 +/- 1.11; in no patient was the ratio less than 0.76 to indicate selective septal hypertrophy. The lateral-to-septal wall thickness and lateral-to-septal thallium-201 count density ratios correlated poorly (r = 0.43).

  16. 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.

  17. 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

  18. Clinical value and severity of myocardial perfusion defects in asymptomatic diabetic patients with negative or weakly positive exercise treadmill test

    PubMed Central

    Zakavi, Seyed Rasoul; Taherpour, Mehdi; Moossavi, Zohreh; Sadeghi, Ramin; Kakhki, Vahidreza Dabbagh; Rokni, Haleh

    2013-01-01

    Objective: Although coronary artery disease (CAD) is the leading cause of death in type 2 diabetic patients, it is frequently asymptomatic. Myocardial perfusion imaging (MPI) is reported to show ischemia in a significant number of asymptomatic diabetic patients. We studied the prevalence and severity of myocardial perfusion defects in asymptomatic diabetic patients and its clinical impact. Methods and patients: One hundred thirty consecutive asymptomatic patients, aged 35-65 years with type 2 diabetes mellitus and with no history of CAD and no cardiac symptoms were recruited in the study. Echocardiography, electrocardiography (ECG), routine laboratory tests and exercise treadmill test (ETT) were performed and patients with weakly positive or negative ETT underwent Dipyridamole MPI. Patients with positive ETT were referred to coronary angiography. Patients were followed for at least 17 months (mean 21.7 months) and any cardiac event was recorded. Results: We studied 81 female and 49 male patients with mean age of 51.8 years. Negative, weakly positive and positive ETT result was noted in 74.3%, 15% and 10.7% respectively. 75% of patients with positive ETT had coronary artery disease in angiography. Gated myocardial perfusion SPECT was done in 106 patients. MPI showed reversible defect in 26.9% of the patients with a mean summed stress score of 3.3±1.8. Follow up completed in 112 patients and only one patient with abnormal MPI underwent coronary angiography followed by PTCA. No cardiac death, MI, UA or hospital admission occurred among our patients during follow up (17-26 months). Mean stress end diastolic volume (EDV) was significantly higher in patients with reversible defect compared to patients without reversible defect based on MPI findings (62.0±31.6 Vs 48.5±18.4 ml, P=0.04). Blood glucose and HbA1c were significantly higher in patients with ischemia compared to patients without ischemia (P<0.05). Meanwhile the ratio of TG to HDL was 6.06±3.2 in ischemic

  19. 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

  20. 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.

  1. Paraganglioma causing a myocardial infarction

    PubMed Central

    DeMers, Gerard; Portouw, Steve

    2012-01-01

    Paragangliomas, extra-adrenal pheochromocytomas, are rare and classically associated with sustained or paroxysmal hypertension, headache, perspiration, palpitations, and anxiety. A 49-year-old male, parachute instructor, likely developed a hypertensive emergency when deploying his parachute leading to a myocardial infarction. A para-aortic tumor was incidentally discovered during the patient's emergency department work-up and was eventually surgically resected. He had no evidence of coronary disease during his evaluation. This case shows that a myocardial infarction may be the initial manifestation of these neuroendocrine tumors. Hypertensive emergency, much less elevated blood pressure may not be present at time of presentation. PMID:22787353

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

    SciTech Connect

    Wackers, F.J.

    1982-04-01

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

  3. Imaging techniques for myocardial inflammation

    SciTech Connect

    O'Connell, J.B.; Henkin, R.E.; Robinson, J.A.

    1986-03-01

    Dilated cardiomyopathy (DC) represents a heterogeneous group of disorders which results in morbidity and mortality in young individuals. Recent evidence suggests that a subset of these patients have histologic evidence of myocarditis which is potentially treatable with immunosuppression. The identification of myocardial inflammation may therefore lead to development of therapeutic regimens designed to treat the cause rather than the effect of the myocardial disease. Ultimately, this may result in improvement in the abysmal prognosis of DC. The currently accepted technique for identification of active myocardial inflammation is endomyocardial biopsy. This technique is not perfect, however, since pathologic standards for the diagnosis of myocarditis have not been established. Furthermore, focal inflammation may give rise to sampling error. The inflammation-avid radioisotope gallium-67 citrate has been used as an adjunct to biopsy improving the yield of myocarditis from 7 percent to 36 percent. Serial imaging correlates well to biopsy results. Future studies are designed to study the applicability of lymphocyte labelling techniques to myocardial inflammatory disease.

  4. 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…

  5. Severe Hypokalemia Masquerading Myocardial Ischemia

    PubMed Central

    Petrov, Daniel Bogdanov; Sardovski, Svetlozar Ivanov; Milanova, Maria Hristova

    2012-01-01

    An advanced degree of body potassium deficit may produce striking changes in the electrocardiogram (ECG). These changes can result in incidental findings on the 12-lead ECG or precipitate potentially life-threatening dysrhythmias. Although usually readily recognized, at times these abnormalities may be confused with myocardial ischemia. The object was to report a case of severe hypokalemia mimicking myocardial ischemia. A 33-year-old, previously healthy man, presented to the Emergency Department (ED) with a progressive weakness and chest discomfort. The electrocardiogram showed a marked ST-segment depression in leads II, III, aVF, V1-V6. The initial diagnosis was non ST-elevation myocardial infarction. Echocardiography was normal and troponin levels were within normal limits. A more detailed history revealed that the patient had an episode of acute gastroenteritis with diarrhea and vomiting. Serum chemistries were notable for a potassium concentration of 1,8 mmol per liter. With aggressive electrolyte correction, the ECG abnormalities reverted as potassium levels normalized. Hypokalemia induced ST-segment depression may simulate myocardial ischemia. The differential diagnosis might be difficult, especially in the cases when ST changes are accompanied with chest discomfort.

  6. 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

  7. Myocardial contractility in the stress echo lab: from pathophysiological toy to clinical tool

    PubMed Central

    2013-01-01

    Up-regulation of Ca2+ entry through Ca2+ channels by high rates of beating is involved in the frequency-dependent regulation of contractility: this process is crucial in adaptation to exercise and stress and is universally known as force-frequency relation (FFR). Disturbances in calcium handling play a central role in the disturbed contractile function in myocardial failure. Measurements of twitch tension in isolated left-ventricular strips from explanted cardiomyopathic hearts compared with non-failing hearts show flat or biphasic FFR, while it is up-sloping in normal hearts. Starting in 2003 we introduced the FFR measurement in the stress echo lab using the end-systolic pressure (ESP)/End-systolic volume index (ESVi) ratio (the Suga index) at increasing heart rates. We studied a total of 2,031 patients reported in peer-reviewed journals: 483 during exercise, 34 with pacing, 850 with dobutamine and 664 during dipyridamole stress echo. We demonstrated the feasibility of FFR in the stress echo lab, the clinical usefulness of FFR for diagnosing latent contractile dysfunction in apparently normal hearts, and residual contractile reserve in dilated idiopathic and ischemic cardiomyopathy. In 400 patients with left ventricular dysfunction (ejection fraction 30 ± 9%) with negative stress echocardiography results, event-free survival was higher (p < 0.001) in patients with ΔESPVR (the difference between peak and rest end-systolic pressure-volume ratio, ESPVR) ≥ 0.4 mmHg/mL/m2. The prognostic stratification of patients was better with FFR, beyond the standard LV ejection fraction evaluation, also in the particular settings of severe mitral regurgitation or diabetics without stress-induced ischemia. In the particular setting of selection of heart transplant donors, the stress echo FFR was able to correctly select 34 marginal donor hearts efficiently transplanted in emergency recipients. Starting in 2007, we introduced an operator-independent cutaneous sensor

  8. Myocardial contractility in the stress echo lab: from pathophysiological toy to clinical tool.

    PubMed

    Bombardini, Tonino; Zoppè, Monica; Ciampi, Quirino; Cortigiani, Lauro; Agricola, Eustachio; Salvadori, Stefano; Loni, Tiziana; Pratali, Lorenza; Picano, Eugenio

    2013-11-18

    Up-regulation of Ca2+ entry through Ca2+ channels by high rates of beating is involved in the frequency-dependent regulation of contractility: this process is crucial in adaptation to exercise and stress and is universally known as force-frequency relation (FFR). Disturbances in calcium handling play a central role in the disturbed contractile function in myocardial failure. Measurements of twitch tension in isolated left-ventricular strips from explanted cardiomyopathic hearts compared with non-failing hearts show flat or biphasic FFR, while it is up-sloping in normal hearts. Starting in 2003 we introduced the FFR measurement in the stress echo lab using the end-systolic pressure (ESP)/End-systolic volume index (ESVi) ratio (the Suga index) at increasing heart rates. We studied a total of 2,031 patients reported in peer-reviewed journals: 483 during exercise, 34 with pacing, 850 with dobutamine and 664 during dipyridamole stress echo. We demonstrated the feasibility of FFR in the stress echo lab, the clinical usefulness of FFR for diagnosing latent contractile dysfunction in apparently normal hearts, and residual contractile reserve in dilated idiopathic and ischemic cardiomyopathy. In 400 patients with left ventricular dysfunction (ejection fraction 30 ± 9%) with negative stress echocardiography results, event-free survival was higher (p < 0.001) in patients with ΔESPVR (the difference between peak and rest end-systolic pressure-volume ratio, ESPVR) ≥ 0.4 mmHg/mL/m2. The prognostic stratification of patients was better with FFR, beyond the standard LV ejection fraction evaluation, also in the particular settings of severe mitral regurgitation or diabetics without stress-induced ischemia. In the particular setting of selection of heart transplant donors, the stress echo FFR was able to correctly select 34 marginal donor hearts efficiently transplanted in emergency recipients. Starting in 2007, we introduced an operator-independent cutaneous sensor

  9. Criteria for definition of regional functional improvement on quantitative post-stress gated myocardial SPET after bypass surgery in patients with ischaemic cardiomyopathy.

    PubMed

    Lee, Dong Soo; Cheon, Gi Jeong; Paeng, Jin Chul; Kim, Ki Bong; Chung, June-Key; Lee, Myung Chul

    2002-08-01

    Myocardial viability can be defined as functional improvement of dysfunctional myocardium after revascularization. The purpose of this study was to define the optimal criteria for definition of regional functional improvement after coronary artery bypass graft (CABG) surgery on quantitative gated single-photon emission tomography (SPET). Thirty-two patients (26 men, 6 women; age 56 +/- 13 years) with coronary artery disease (three-vessel disease, 17; two-vessel disease, 15; previous history of myocardial infarction, 9) and severe left ventricular dysfunction (LVEF < or = 35%) underwent CABG. Rest thallium-201/dipyridamole stress technetium-99m methoxyisobutylisonitrile gated myocardial SPET was performed before and 3 months after CABG. Global LV functional improvement was defined as either an improvement in LVEF of 10% ( n = 15) or an improvement in LVEF of 5% combined with a decrease in end-systolic volume of 10 ml ( n = 2) after CABG on quantitative gated SPET. Postoperative regional wall thickening improvement (DeltaRWT), regional wall motion improvement (DeltaRWM) and regional resting (DeltaRP) and stress perfusion improvement (DeltaRstrP) were used to determine global functional improvement by ROC curve analysis, and the optimal criteria for definition of viable regional dysfunctional myocardium were defined on the ROC curves. Correlations were verified by determining the number of improved myocardial regions and LVEF improvement. LVEF was improved from 25% +/- 6% to 34% +/- 11% after CABG. A total of 229 segments were dysfunctional (wall motion < or = 2 mm, thickening < or = 20%) before CABG. On ROC curve analysis using global functional improvement as an indicator of viability, the areas under the ROC curves (AUCs) of DeltaRWT and DeltaRWM were 0.717 and 0.620, respectively. The AUC of DeltaRWT was significantly larger than that of DeltaRWM ( P = 0.009) and the optimal cut-off value of DeltaRWT was 15%. The AUCs of DeltaRP and DeltaRstrP were not significant

  10. Preparation and in vitro-in vivo evaluation of none gastric resident dipyridamole (DIP) sustained-release pellets with enhanced bioavailability.

    PubMed

    Xu, Lishuang; Luo, Yanfei; Feng, Jia; Xu, Ming; Tao, Xiaoguang; He, Haibing; Tang, Xing

    2012-01-17

    The objective of this study was to develop none gastric resident sustained-release pellets loaded with dipyridamole with a high bioavailability. Two different kinds of core pellets, one containing citric acid as a pH-modifier (CAP) and, the other without pH-modifier (NCAP) were prepared by extrusion-spheronization and then coated with mixtures of enteric soluble and insoluble polymers (referred to as CAP(1) and NCAP(1)) or insoluble polymer alone (referred to as CAP(2) and NCAP(2)). The relative bioavailability of the sustained-release pellets was studied in fasted beagle dogs after oral administration using a commercially available immediate release tablet (IRT) as a reference. The in vitro release, in vivo absorption and in vitro-in vivo correlation were also evaluated. Results revealed that the plasma drug concentrations after administration of CAP(2), NCAP(1) and NCAP(2) were undetectable, indicating that the drug release was almost zero from the preparations throughout the gastro-intestinal tract. The C(max), T(max) and AUC((0→24)) of CAP(1) were 0.78 ± 0.23 (μg/ml), 3.80 ± 0.30 (h), and 6.74 ± 0.47 (μg/mlh), respectively. While the corresponding values were 2.23 ± 0.32 (μg/ml), 3.00 ± 0.44 (h) and 9.42 ± 0.69 (μg/mlh) for IRT. The relative bioavailability of CAP(1) was 71.55% compared with IRT. By combined incorporation of a pH-modifier into the core of pellets to modify the inner micro-environment and employing mixtures of enteric soluble and insoluble polymers as a retarding layer, drugs with high solubility in stomach and limited solubility in small intestine, such as DIP, could be successfully formulated as sustained release preparations with no pH-dependence in drug release and enhanced bioavailability.

  11. Functional tests for myocardial ischemia

    SciTech Connect

    Levinson, J.R.; Guiney, T.E.; Boucher, C.A. )

    1991-01-01

    Functional tests for myocardial ischemia are numerous. Most depend upon a combination of either exercise or pharmacologic intervention with analysis of the electrocardiogram, of regional perfusion with radionuclide imaging, or of regional wall motion with radionuclide imaging or echocardiography. While each test has unique features, especially at the research level, they are generally quite similar in clinical practice, so the clinician is advised to concentrate on one or two in which local expertise is high.22 references.

  12. Tachyarrhythmias in acute myocardial infarction.

    PubMed

    McLean, K H; Bett, J N; Saltups, A

    1975-02-01

    In 1505 patients with acute myocardial infarction (MI) serious ventricular arrhythmias were commoner in those with transmural ECG changes, and were associated with an increase in mortality and in the incidence of left ventricular failure (LVF) as well as higher peak serum lactic dehydrogenase (LDH) levels. Atrial fibrillation (AF) occurred more often in older patients and in those with LVF and clinical evidence of pericarditis.

  13. Myocardial structure and matrix metalloproteinases.

    PubMed

    Aggeli, C; Pietri, P; Felekos, I; Rautopoulos, L; Toutouzas, K; Tsiamis, E; Stefanadis, C

    2012-01-01

    Metalloproteinases (MMPs) are enzymes which enhance proteolysis of extracellular matrix proteins. The pathophysiologic and prognostic role of MMPs has been demonstrated in numerous studies. The present review covers a wide a range of topics with regards to MMPs structural and functional properties, as well as their role in myocardial remodeling in several cardiovascular diseases. Moreover, the clinical and therapeutic implications from their assessment are highlighted.

  14. [Premonitory sign of myocardial rupture].

    PubMed

    Lauten, A; Dittrich, P

    1975-10-01

    It is reported on 14 cases in which a rupture of the myocardium occurred following a myocardial infarction. The moment of the appearance as well as anamnestic and clinical peculiarities are examined. As the only usable symptom of the rupture the symptomatology of the electromechanic dissociation must be taken into consideration. Finally it is referred to the on principle possible operative consequences of the rupture of the myocardium (oversewing or infarctetomy).

  15. 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

  16. 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

  17. Imaging of myocardial perfusion with magnetic resonance.

    PubMed

    Barkhausen, Jörg; Hunold, Peter; Jochims, Markus; Debatin, Jörg F

    2004-06-01

    Coronary artery disease (CAD) is currently the leading cause of death in developed nations. Reflecting the complexity of cardiac function and morphology, noninvasive diagnosis of CAD represents a major challenge for medical imaging. Although coronary artery stenoses can be depicted with magnetic resonance (MR) and computed tomography (CT) techniques, its functional or hemodynamic impact frequently remains elusive. Therefore, there is growing interest in other, target organ-specific parameters such as myocardial function at stress and first-pass myocardial perfusion imaging to assess myocardial blood flow. This review explores the pathophysiologic background, recent technical developments, and current clinical status of first-pass MR imaging (MRI) of myocardial perfusion.

  18. Myocardial perfusion scintigraphy: the evidence

    PubMed Central

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

    2003-01-01

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

  19. Technetium myocardial perfusion agents: an introduction

    SciTech Connect

    English, R.J.; Kozlowski, J.; Tumeh, S.S.; Holman, B.L.

    1987-09-01

    This is the third in a series of four Continuing Education articles on developing radiopharmaceuticals. After reading this article, the reader should be able to: 1) understand the basic concepts of myocardial perfusion imaging; and 2) discuss the advantages of the technetium myocardial perfusion complexes over thallium-201.

  20. 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

  1. Taxonomy of segmental myocardial systolic dysfunction

    PubMed Central

    McDiarmid, Adam K.; Pellicori, Pierpaolo; Cleland, John G.

    2017-01-01

    The terms used to describe different states of myocardial health and disease are poorly defined. Imprecision and inconsistency in nomenclature can lead to difficulty in interpreting and applying trial outcomes to clinical practice. In particular, the terms ‘viable’ and ‘hibernating’ are commonly applied interchangeably and incorrectly to myocardium that exhibits chronic contractile dysfunction in patients with ischaemic heart disease. The range of inherent differences amongst imaging modalities used to define myocardial health and disease add further challenges to consistent definitions. The results of several large trials have led to renewed discussion about the classification of dysfunctional myocardial segments. This article aims to describe the diverse myocardial pathologies that may affect the myocardium in ischaemic heart disease and cardiomyopathy, and how they may be assessed with non-invasive imaging techniques in order to provide a taxonomy of myocardial dysfunction. PMID:27147609

  2. [Cardiac rehabilitation after myocardial infarction].

    PubMed

    Ghannem, M; Ghannem, L; Ghannem, L

    2015-12-01

    Although the proofs of the benefits of cardiac rehabilitation accumulate, many patients are not sent to rehabilitation units, especially younger and very elderly patients. As the length of stay in acute care units decreases, rehabilitation offers more time to fully assess the patients' conditions and needs. Meta-analyses of randomised trials suggest that mortality can be improved by as much as 20-30%. In addition, rehabilitation helps managing risk factors, including hyperlipidemia, diabetes, smoking and sedentary behaviours. Physical training also helps improving exercise capacity. Because of all of these effects, cardiac rehabilitation for post-myocardial infarction patients has been given a class IA recommendation in current guidelines.

  3. 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.

  4. 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.

  5. 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.

  6. Parametric display of myocardial function.

    PubMed

    Eusemann, C D; Ritman, E L; Bellemann, M E; Robb, R A

    2001-01-01

    Quantitative assessment of regional heart motion has significant potential to provide more specific diagnosis of cardiac disease and cardiac malfunction than currently possible. Local heart motion may be captured from various medical imaging scanners. In this study, 3-D reconstructions of pre-infarct and post-infarct hearts were obtained from the Dynamic Spatial Reconstructor (DSR)[Ritman EL, Robb RA, Harris LD. Imaging physiological functions: experience with DSR. Philadelphia: Praeger, 1985; Robb RA, Lent AH, Gilbert BK, Chu A. The dynamic spatial reconstructor: a computed tomography system for high-speed simultaneous scanning of multiple cross sections of the heart. J Med Syst 1980;4(2):253-88; Jorgensen SM, Whitlock SV, Thomas PJ, Roessler RW, Ritman EL. The dynamic spatial reconstructor: a high speed, stop action, 3-D, digital radiographic imager of moving internal organs and blood. Proceedings of SPIE, Ultrahigh- and High-speed Photography, Videography, Photonics, and Velocimetry 1990;1346:180-91.] (DSR). Using functional parametric mapping of disturbances in regional contractility and relaxation, regional myocardial motion during a cardiac cycle is color mapped onto a deformable heart model to facilitate appreciation of the structure-to-function relationships in the myocardium, such as occurs in regional patterns of akinesis or dyskinesis associated with myocardial ischemia or infarction resulting from coronary artery occlusion.

  7. Relation between the kinetics of thallium-201 in myocardial scintigraphy and myocardial metabolism in patients with acute myocardial infarction

    PubMed Central

    Yamagishi, H; Akioka, K; Takagi, M; Tanaka, A; Takeuchi, K; Yoshikawa, J; Ochi, H

    1998-01-01

    Objective—To investigate the relations between myocardial metabolism and the kinetics of thallium-201 in myocardial scintigraphy.
Methods—46 patients within six weeks after the onset of acute myocardial infarction underwent resting myocardial dual isotope, single acquisition, single photon emission computed tomography (SPECT) using radioiodinated 15-iodophenyl 3-methyl pentadecaenoic acid (BMIPP) and thallium-201, exercise thallium-201 SPECT, and positron emission tomography (PET) using nitrogen-13 ammonia (NH3) and [F18]fluorodeoxyglucose (FDG) under fasting conditions. The left ventricle was divided into nine segments, and the severity of defects was assessed visually.
Results—In the resting SPECT, less BMIPP uptake than thallium-201 uptake was observed in all of 40 segments with reverse redistribution of thallium-201, and in 21 of 88 segments with a fixed defect of thallium-201 (p < 0.0001); and more FDG uptake than NH3 uptake (NH3-FDG mismatch) was observed in 35 of 40 segments with reverse redistribution and in 38 of 88 segments with fixed defect (p < 0.0001). Less BMIPP uptake in the resting SPECT was observed in 49 of 54 segments with slow stress redistribution in exercise SPECT, and in nine of 17 segments with rapid stress redistribution (p < 0.0005); NH3-FDG mismatch was observed in 42 of 54 segments with slow stress redistribution and in five of 17 segments with rapid stress redistribution (p < 0.0005).
Conclusions—Thallium-201 myocardial scintigraphy provides information about not only myocardial perfusion and viability but also about myocardial metabolism in patients with acute myocardial infarction.

 Keywords: thallium-201 SPECT;  BMIPP SPECT;  FDG PET;  myocardial infarction;  redistribution PMID:9764055

  8. Magnetic resonance imaging for characterizing myocardial diseases.

    PubMed

    Saeed, Maythem; Liu, Hui; Liang, Chang-Hong; Wilson, Mark W

    2017-03-31

    The National Institute of Health defined cardiomyopathy as diseases of the heart muscle. These myocardial diseases have different etiology, structure and treatment. This review highlights the key imaging features of different myocardial diseases. It provides information on myocardial structure/orientation, perfusion, function and viability in diseases related to cardiomyopathy. The standard cardiac magnetic resonance imaging (MRI) sequences can reveal insight on left ventricular (LV) mass, volumes and regional contractile function in all types of cardiomyopathy diseases. Contrast enhanced MRI sequences allow visualization of different infarct patterns and sizes. Enhancement of myocardial inflammation and infarct (location, transmurality and pattern) on contrast enhanced MRI have been used to highlight the key differences in myocardial diseases, predict recovery of function and healing. The common feature in many forms of cardiomyopathy is the presence of diffuse-fibrosis. Currently, imaging sequences generating the most interest in cardiomyopathy include myocardial strain analysis, tissue mapping (T1, T2, T2*) and extracellular volume (ECV) estimation techniques. MRI sequences have the potential to decode the etiology by showing various patterns of infarct and diffuse fibrosis in myocarditis, amyloidosis, sarcoidosis, hypertrophic cardiomyopathy due to aortic stenosis, restrictive cardiomyopathy, arrythmogenic right ventricular dysplasia and hypertension. Integrated PET/MRI system may add in the future more information for the diagnosis and progression of cardiomyopathy diseases. With the promise of high spatial/temporal resolution and 3D coverage, MRI will be an indispensible tool in diagnosis and monitoring the benefits of new therapies designed to treat myocardial diseases.

  9. 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.

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

    ClinicalTrials.gov

    2017-03-02

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

  11. [Percutaneous myocardial laser revascularization (PMR)].

    PubMed

    Lauer, B; Stahl, F; Bratanow, S; Schuler, G

    2000-09-01

    In patients with severe angina pectoris due to coronary artery disease, who are not candidates for either percutaneous coronary angioplasty or coronary artery bypass surgery, transmyocardial laser revascularization (TMR) often leads to improvement of clinical symptoms and increased exercise capacity. One drawback of TMR is the need for surgical thoracotomy in order to gain access to the epicardial surface of the heart. Therefore, a catheter-based system has been developed, which allows creation of laser channels into the myocardium from the left ventricular cavity. Between January 1997 and November 1999, this "percutaneous myocardial laser revascularization" (PMR) has been performed in 101 patients at the Herzzentrum Leipzig. In 63 patients, only 1 region of the heart (anterior, lateral, inferior or septal) was treated with PMR, in 38 patients 2 or 3 regions were treated in 1 session. There were 12.3 +/- 4.5 (range 4 to 22) channels/region created into the myocardium. After 3 months, the majority of patients reported significant improvement of clinical symptoms (CCS class at baseline: 3.3 +/- 0.4, after 6 months: 1.6 +/- 0.8) (p < 0.001) and an increased exercise capacity (baseline: 397 +/- 125 s, after 6 months: 540 +/- 190 s) (p < 0.05). After 2 years, the majority of patients had experienced sustained clinical benefit after PMR, the CCS class after 2 years was 1.3 +/- 0.7, exercise capacity was 500 +/- 193 s. However, thallium scintigraphy failed to show increased perfusion in the PMR treated regions. The pathophysiologic mechanisms of myocardial laser revascularization is not yet understood. Most of the laser channels are found occluded after various time intervals after intervention. Other possible mechanisms include myocardial denervation or angioneogenesis after laser revascularization, however, unequivocal evidence for these theories is not yet available. In conclusion, PMR seems to be a safe and feasible new therapeutic option for patients with refractory

  12. 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.

  13. Scintigraphic assessment of cardiac adrenergic innervation in patients with essential hypertension

    SciTech Connect

    Fujiwara, Y.; Hamada, M.; Shigematsu, Y.; Sumimoto, T.; Hamamoto, K.; Hiwada, K. )

    1991-01-01

    To assess the regional cardiac adrenergic innervation in patients with essential hypertension (EHT), simultaneous iodine-123 metaiodobenzylguanidine ((123I)MIBG) and thallium-201 (201Tl) myocardial imagings were performed in five patients with EHT, seven patients with hypertrophic cardiomyopathy (HCM), and seven normal subjects. Short axial images at rest were divided into five segments: anterior, septal, posterior, lateral, and apical segments. Percent regional uptake (%RU) of 201Tl except the septal segment in patients with EHT showed no significant difference. However, the %RU of (123I)MIBG at posterior, lateral, and apical segments was significantly lower than that at anterior and septal segments in EHT. This intraimage heterogeneity of (123I)MIBG was also observed in HCM. These results suggest that there is a difference in regional adrenergic innervation of the left ventricle with myocardial hypertrophy.

  14. Ethanol-induced myocardial ischemia: close relation between blood acetaldehyde level and myocardial ischemia.

    PubMed

    Ando, H; Abe, H; Hisanou, R

    1993-05-01

    A patient with vasospastic angina who developed myocardial ischemia following ethanol ingestion but not after exercise was described. Myocardial ischemia was evidenced by electrocardiograms (ECGs) and thallium-201 scintigrams. The blood acetaldehyde level after ethanol ingestion was abnormally high. The time course and severity of myocardial ischemia coincided with those of the blood ethanol and acetaldehyde level. Coronary arteriography showed ergonovine maleate-induced coronary vasospasm at the left anterior descending coronary artery. ECG changes similar to those induced by ethanol ingestion were observed at the same time. These findings suggest that the high blood acetaldehyde level might be responsible for the development of coronary vasospasm and myocardial ischemia in this patient.

  15. [Ventricular "remodeling" after myocardial infarction].

    PubMed

    Cohen-Solal, A; Himbert, D; Guéret, P; Gourgon, R

    1991-06-01

    Cardiac failure is the principal medium-term complication of myocardial infarction. Changes in left ventricular geometry are observed after infarction, called ventricular remodeling, which, though compensatory initially, cause ventricular failure in the long-term. Experimental and clinical studies suggest that early treatment by coronary recanalisation, trinitrin and angiotensin converting enzyme inhibitors may prevent or limit the expansion and left ventricular dilatation after infarction, so improving ventricular function, and, at least in the animal, reduce mortality. Large scale trials with converting enzyme inhibitors are currently under way to determine the effects of this new therapeutic option. It would seem possible at present, independently of any reduction in the size of the infarction, to reduce or delay left ventricular dysfunction by interfering with the natural process of dilatation and ventricular modeling after infarction.

  16. 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.

  17. [The new universal definition of myocardial infarction].

    PubMed

    Hod, Hanoch; Halon, David; Hammerman, Haim; Hasdai, David; Zahger, Doron; Lewis, Basil; Mosseri, Morris; Atar, Shaul

    2009-01-01

    Given the considerable advances in recent years in myocardial infarction diagnosis and management, the European Society of Cardiology (ESC), the American College of Cardiology (ACC), the American Heart Association (AHA), together with the World Heart Federation [WHF] recently published an expert consensus document to establish a universal definition for myocardial infarction. The consensus document recognizes five separate myocardial infarction categories based on the differences in pathophysiology, and whether percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery is involved. The new consensus document expands the criteria for defining myocardial infarction by adding new ECG criteria and imaging modalities, and also includes patients who present with sudden death. The Israel Heart Society has adopted the new universal definition and recommends its use by clinicians, researchers and epidemiologists. .

  18. Myocardial damage after inhalation of chloramines.

    PubMed

    Gonzalez-Castro, Alejandro; Holanda, Maria Soledad; Canas, Borja S; Morlote, Jesús G; Minambres, Eduardo; Prieto Solis, José A

    2006-04-01

    The objective of this case report was to document a rare case of myocardial damage, in the context of an accidental inhalation of chloramines, demonstrated by electrocardiogram and myocardium-specific enzymes.

  19. Bone marrow cells and myocardial regeneration.

    PubMed

    Wang, Fu-Sheng; Trester, Cathy

    2004-05-01

    Hematopoietic stem cell (HSC) plasticity and its clinical application have been studied profoundly in the past few years. Recent investigations indicate that HSC and other bone marrow stem cells can develop into other tissues. Because of the high morbidity and mortality of myocardial infarction and other heart disorders, myocardial regeneration is a good example of the clinical application of HSC plasticity in regenerative medicine. Preclinical studies in animals suggest that the use of this kind of treatment can reconstruct heart blood vessels, muscle, and function. Some clinical study results have been reported in the past 2 years. In 2003, reports of myocardial regeneration treatment increased significantly. Other studies include observations on the cell surface markers of transplanted cells and treatment efficacy. Some investigations, such as HSC testing, have focused on clinical applications using HSC plasticity and bone marrow transplantation to treat different types of disorders. In this review, we focus on the clinical application of bone marrow cells for myocardial regeneration.

  20. 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.

  1. [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.

  2. 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.

  3. 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

  4. Computational modeling of acute myocardial infarction

    PubMed Central

    Sáez, P.; Kuhl, E.

    2015-01-01

    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 towards 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

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. Biochemical assessment of acute myocardial ischaemia.

    PubMed Central

    Perez-Cárceles, M D; Osuna, E; Vieira, D N; Martínez, A; Luna, A

    1995-01-01

    AIMS--To evaluate the efficacy of biochemical parameters in different fluids in the diagnosis of myocardial infarction of different causes, analysed after death. METHODS--The myoglobin concentration and total creatine kinase (CK) and creatine kinase MB isoenzyme (CK-MB) activities were measured in serum, pericardial fluid, and vitreous humour from seven diagnostic groups of cadavers classified according to the severity of myocardial ischaemia and cause of death. Lactate dehydrogenase (LDH) and myosin were measured only in serum and pericardial fluid, and cathepsin D only in pericardial fluid. Routine haematoxylin and eosin and acridine orange staining were used for microscopy studies of heart tissue. RESULTS--In pericardial fluid there were substantial differences between the different groups with respect to CK, CK-MB, and LDH activities and myosin concentrations. The highest values were found in cases with morphological evidence of myocardial ischaemia. CONCLUSIONS--Biochemical parameters, which reach the pericardial fluid via passive diffusion and ultrafiltration due to a pressure gradient, were thus detectable in this fluid earlier than in serum in cases with myocardial ischaemia. These biochemical parameters may be of use for ruling out myocardial ischaemia in those controversial cases in which reliable morphological findings are lacking. PMID:7745110

  11. Myocardial factor revisited: The importance of myocardial fibrosis in adults with congenital heart disease.

    PubMed

    Broberg, Craig S; Burchill, Luke J

    2015-06-15

    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.

  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. 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

  15. Morphine Does Not Affect Myocardial Salvage in ST-Segment Elevation Myocardial Infarction

    PubMed Central

    Song, Young Bin; Kim, Eun Kyoung; Jang, Woo Jin; Yang, Jeong Hoon; Hahn, Joo-Yong; Choi, Seung-Hyuk; Choi, Jin-Ho; Lee, Sang Hoon; Choe, Yeon Hyeon; Ahn, Joonghyun; Carriere, Keumhee Chough; Gwon, Hyeon-Cheol

    2017-01-01

    Recent studies have proposed intravenous (IV) morphine is associated with delayed action of antiplatelet agents in acute myocardial infarction. However, it is unknown whether morphine results in increased myocardial damage in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI). We investigated myocardial salvage index (MSI) to determine whether IV morphine affects myocardial injury adversely in STEMI patients undergoing primary PCI. 299 STEMI patients underwent contrast-enhanced magnetic resonance imaging a median of 3 days after PCI. Infarct size was measured on delayed-enhancement imaging, and area at risk was quantified on T2-weighted imaging. MSI was calculated as ‘[area at risk–infarct size] X 100 / area at risk’. IV morphine was administrated in 32.1% of patients. Patients treated with morphine had shorter symptom to balloon time and higher prevalence of Thrombolysis in Myocardial Infarction flow grade 0 or 1. The morphine group showed a trend toward larger MSI and infarct size and significantly greater area at risk than the non-morphine group. After propensity score matching (90 pairs), MSI was similar between the morphine and non-morphine group (46.1% versus 43.5%, P = .11), and infarct size and area at risk showed no difference. In propensity score-matched analysis, IV morphine prior to primary PCI in STEMI patients did not cause adverse impacts on myocardial salvage. PMID:28081269

  16. 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.

  17. Neuroendocrine activation after acute myocardial infarction.

    PubMed Central

    McAlpine, H M; Morton, J J; Leckie, B; Rumley, A; Gillen, G; Dargie, H J

    1988-01-01

    The extent of neuroendocrine activation, its time course, and relation to left ventricular dysfunction and arrhythmias were investigated in 78 consecutive patients with suspected acute myocardial infarction. High concentrations of arginine vasopressin were found within six hours of symptoms, even in the absence of myocardial infarction (n = 18). Plasma catecholamine concentrations also were highest on admission, whereas renin and angiotensin II concentrations rose progressively over the first three days, not only in those with heart failure but also in patients with no clinical complications. Heart failure, ventricular tachycardia, and deaths were associated with extensive myocardial infarction, low left ventricular ejection fraction, and persistently high concentrations of catecholamines, renin, and angiotensin II up to 10 days after admission, whereas in uncomplicated cases concentrations had already returned to normal. PMID:3415870

  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 Ischemia Caused by Subepicardial Hematoma

    PubMed Central

    Grieshaber, Philippe; Nef, Holger; Böning, Andreas; Niemann, Bernd

    2017-01-01

    Background Bleeding from bypass anastomosis leakage occurs early after coronary artery bypass grafting. Later, once the anastomosis is covered by intima, spontaneous bleeding is unlikely. Case Description A 63-year-old male patient developed a pseudoaneurysm-like, subepicardial late-term bleeding resulting in a hematoma that compromised coronary artery flow by increasing extracoronary pressure. This resulted in severe angina pectoris (Canadian Cardiovascular Society IV) and myocardial ischemia within the affected area. After surgical removal of the hematoma and repair of the anastomosis, the patient's symptoms disappeared and no signs of myocardial ischemia were present. Conclusion Surgical removal is an efficient therapy for subepicardial hematoma inducing myocardial ischemia. PMID:28352501

  20. Disappearance of myocardial bridging of the left anterior descending coronary artery after inferior myocardial infarction.

    PubMed

    Yıldız, Bekir Serhat; Esin, Fatma; Alihanoğlu, Yusuf Izzettin; Kılıç, Ismail Doğu; Evrengül, Harun

    2014-06-01

    Myocardial bridging (MB) is defined as the intramural course of a major epicardial coronary artery, and is mostly confined to the left ventricle and the left anterior descending coronary artery (LAD). MB 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 MB may suffer from myocardial ischemia, myocardial infarction (MI), arrhythmias, and even sudden death. Therefore, the diagnosis and treatment of MB are both important. Since MB is congenital, its disappearance is unlikely. We here report a very rare case of disappearance of MB after inferior MI.

  1. 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.

  2. Thallium-201 myocardial perfusion imaging in myocarditis

    SciTech Connect

    Tamaki, N.; Yonekura, Y.; Kadota, K.; Kambara, H.; Torizuka, K.

    1985-08-01

    TI-201 myocardial perfusion imaging was performed in six patients with clinically documented myocarditis. Each case manifested electrocardiographic abnormalities with elevation of serum cardiac enzymes and no significant stenosis of the coronary arteries observed on angiogram. Resting TI-201 images were visually assessed by three observers. Focal perfusion defects were observed in three cases (50%), among which two showed multiple perfusion defects. Emission computed tomography using TI-201 clearly delineated multifocal lesions in the first case. On the other hand, no significant perfusion defects were noted in the remaining three cases. Thus, myocarditis should be considered as one of the disease entities that may produce perfusion defects on TI-201 myocardial imaging.

  3. Aspergillus coronary embolization causing acute myocardial infarction.

    PubMed

    Laszewski, M; Trigg, M; de Alarcon, P; Giller, R

    1988-05-01

    An increased frequency of disseminated aspergillosis has been observed in the last decade, mostly occurring in immunocompromised patients including the bone marrow transplant population. Cardiac involvement by Aspergillus remains rare. We report the clinical and postmortem findings of an unusual case of Aspergillus pancarditis in a 7-year-old bone marrow transplant patient with Aspergillus embolization to the coronary arteries leading to a massive acute myocardial infarction. This case suggests that myocardial injury secondary to disseminated aspergillosis should be included in the differential diagnosis of chest pain in the immunocompromised pediatric patient.

  4. Absolute quantification of myocardial blood flow.

    PubMed

    Yoshinaga, Keiichiro; Manabe, Osamu; Tamaki, Nagara

    2016-07-21

    With the increasing availability of positron emission tomography (PET) myocardial perfusion imaging, the absolute quantification of myocardial blood flow (MBF) has become popular in clinical settings. Quantitative MBF provides an important additional diagnostic or prognostic information over conventional visual assessment. The success of MBF quantification using PET/computed tomography (CT) has increased the demand for this quantitative diagnostic approach to be more accessible. In this regard, MBF quantification approaches have been developed using several other diagnostic imaging modalities including single-photon emission computed tomography, CT, and cardiac magnetic resonance. This review will address the clinical aspects of PET MBF quantification and the new approaches to MBF quantification.

  5. [Methylphenidate induced ST elevation acute myocardial infarction].

    PubMed

    Ruwald, Martin Huth; Ruwald, Anne-Christine Huth; Tønder, Niels

    2012-03-05

    Adult attention deficit and hyperkinetic disorder (ADHD) is increasingly diagnosed and treated with methylphenidate. We present the case of an 20 year-old man, who was diagnosed with ADHD and suffered a ST elevation acute myocardial infarction due to coronary vasospasm related to an overdose, and subsequent episodes of myocardial injury due to the use and misuse of methylphenidate over a period of two years. We recommend an increased attention to the subscription of methylphenidate to patients, who are at risk of misuse and patients, who have a cardiovascular history.

  6. Myocardial ischemia-reperfusion injury: a neglected therapeutic target

    PubMed Central

    Hausenloy, Derek J.; Yellon, Derek M.

    2013-01-01

    Acute myocardial infarction (MI) is a major cause of death and disability worldwide. In patients with MI, the treatment of choice for reducing acute myocardial ischemic injury and limiting MI size is timely and effective myocardial reperfusion using either thombolytic therapy or primary percutaneous coronary intervention (PPCI). However, the process of reperfusion can itself induce cardiomyocyte death, known as myocardial reperfusion injury, for which there is still no effective therapy. A number of new therapeutic strategies currently under investigation for preventing myocardial reperfusion injury have the potential to improve clinical outcomes in patients with acute MI treated with PPCI. PMID:23281415

  7. 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.

  8. 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.

  9. Protective approaches against myocardial ischemia reperfusion injury

    PubMed Central

    Li, Xianchi; Liu, Min; Sun, Rongrong; Zeng, Yi; Chen, Shuang; Zhang, Peiying

    2016-01-01

    Myocardial ischemia-reperfusion is the leading cause for the events of cardiovascular disease, and is considered as a major contributor to the morbidity and mortality associated with coronary occlusion. The myocardial damage caused by ischemia-reperfusion injury constitutes the primary pathological manifestation of coronary artery disease. It results from the interaction between the substances that accumulate during ischemia and those that are delivered on reperfusion. The level of this damage can range from a small insult resulting in limited myocardial damage to a large injury culminating in myocyte death. Importantly, major ischemia-reperfusion injury to the heart can result in permanent disability or death. Given the worldwide prevalence of coronary artery disease, developing a strategy to provide cardioprotection against ischemia-reperfusion-induced damage is of great importance. Currently, the treatment of reperfusion injury following ischemia is primarily supportive, since no specific target-oriented therapy has been validated thus far. Nevertheless, therapeutic approaches to protect against myocardial ischemia-reperfusion injury remain an active area of investigation given the detrimental effects of this phenomenon. PMID:28101167

  10. Myocardial ischemic protection in natural mammalian hibernation

    PubMed Central

    Yan, Lin; Kudej, Raymond K.; Vatner, Dorothy E.

    2015-01-01

    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

  11. Myocardial infarction. Considerations for geriatric patients.

    PubMed Central

    Sinclair, D.

    1994-01-01

    Myocardial infarction is common among the elderly. Presentation is often atypical, and symptoms include confusion, weakness, chest pain, dyspnea, and vomiting. Serial electrocardiograms and cardiac enzyme determination lead to diagnosis. Postmyocardial treatments include acetylsalicylic acid, beta-blockers, nitrates, and angiotensin-converting enzyme inhibitors. Thrombolytic agents are safe and useful. Angioplasty and cardiac surgery should be considered for certain patients. PMID:7912578

  12. [Myocardial depression in the burn patient].

    PubMed

    Carrillo-Esper, Raúl; Sánchez-Zúñiga, Martín de Jesús

    2006-01-01

    Myocardial depression and heart failure are frequent complications in critically ill burn patients. The physiopathology is complex and involves the activation of inflammatory pathways, ischemia-reperfusion, oxidative stress and endothelial lesion. Diagnosis should be made early by means of hemodynamic monitoring. Treatment is accomplished by inotropics that act on different pathways of the contractile function and immune response associated with antioxidants and allopurinol.

  13. 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...

  14. Perceived Neighborhood Social Cohesion and Myocardial Infarction

    PubMed Central

    Kim, Eric S.; Hawes, Armani M.; Smith, Jacqui

    2015-01-01

    Background The main strategy for alleviating heart disease has been to target individuals and encourage them to change their health behaviors. Though important, emphasis on individuals has diverted focus and responsibility away from neighborhood characteristics, which also strongly influence people’s behaviors. Although a growing body of research has repeatedly demonstrated strong associations between neighborhood characteristics and cardiovascular health, it has typically focused on negative neighborhood characteristics. Only a few studies have examined the potential health enhancing effects of positive neighborhood characteristics, such as perceived neighborhood social cohesion. Methods Using multiple logistic regression models, we tested whether higher perceived neighborhood social cohesion was associated with lower incidence of myocardial infarction. Prospective data from the Health and Retirement Study—a nationally representative panel study of American adults over the age of 50—were used to analyze 5,276 participants with no history of heart disease. Respondents were tracked for four years and analyses adjusted for relevant sociodemographic, behavioral, biological, and psychosocial factors. Results In a model that adjusted for age, gender, race, marital status, education, and total wealth, each standard deviation increase in perceived neighborhood social cohesion was associated with a 22% reduced odds of myocardial infarction (OR = 0.78, 95% CI, 0.63–0.94. The association between perceived neighborhood social cohesion and myocardial infarction remained even after adjusting for behavioral, biological, and psychosocial covariates. Conclusions Higher perceived neighborhood social cohesion may have a protective effect against myocardial infarction. PMID:25135074

  15. Steroid-induced recurrent myocardial ischemia.

    PubMed

    Yildirim, Ufuk; Gulel, Okan; Soylu, Korhan; Yuksel, Serkan; Sahin, Mahmut

    2014-01-01

    We report the case of a female patient under oral prednisolone therapy due to a diagnosis of idiopathic intracranial hypertension with papilledema. Unfortunately, short-term treatment with prednisolone caused an unusual complication in the patient, i.e., recurrent myocardial ischemia. Possible mechanisms leading to this complication were evaluated in the light of current knowledge.

  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. [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.

  19. 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

  20. 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.

  1. 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.

  2. Effect of Wenxin Granule on Ventricular Remodeling and Myocardial Apoptosis in Rats with Myocardial Infarction

    PubMed Central

    Wu, Aiming; Zhai, Jianying; Zhang, Dongmei; Lou, Lixia; Zhu, Haiyan; Gao, Yonghong; Chai, Limin; Xing, Yanwei; Lv, Xiying; Zhu, Lingqun; Zhao, Mingjing; Wang, Shuoren

    2013-01-01

    Aim. To determine the effect of a Chinese herbal compound named Wenxin Granule on ventricular remodeling and myocardial apoptosis in rats with myocardial infarction (MI). Methods. Male Sprague-Dawley (SD) rats were randomly divided into four groups: the control group, the model group, the metoprolol group, and the Wenxin Granule group (WXKL group) with sample size (n) of 7 rats in each group. An MI model was established in all rats by occlusion of the left anterior descending coronary artery (the control group was without occlusion). Wenxin Granule (1.35 g/kg/day), metoprolol (12 mg/kg/day), and distilled water (5 mL/kg/day for the control and model groups) were administered orally for 4 weeks. Ultrasonic echocardiography was used to examine cardiac structural and functional parameters. Myocardial histopathological changes were observed using haematoxylin and eosin (H&E) dyeing. Myocardial apoptosis was detected by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) staining. Serum angiotensin II (Ang II) concentration was measured using the enzyme-linked immunosorbent assay (ELISA). Results. It was found that Wenxin Granule could partially reverse ventricular remodeling, improve heart function, alleviate the histopathological damage, inhibit myocardial apoptosis, and reduce Ang II concentration in rats with MI. Conclusions. The results of the current study suggest that Wenxin Granule may be a potential alternative and complementary medicine for the treatment of MI. PMID:23997803

  3. Myocardial Tissue Characterization by Magnetic Resonance Imaging

    PubMed Central

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

    2014-01-01

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

  4. Myocardial tissue engineering using electrospun nanofiber composites.

    PubMed

    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.

  5. 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

  6. Painless acute myocardial infarction on Mount Kilimanjaro.

    PubMed

    Jamal, Nasiruddin; Rajhy, Mubina; Bapumia, Mustaafa

    2016-03-17

    An individual experiencing dyspnoea or syncope at high altitude is commonly diagnosed to have high-altitude pulmonary edema or cerebral edema. Acute myocardial infarction (AMI) is generally not considered in the differential diagnosis. There have been very rare cases of AMI reported only from Mount Everest. We report a case of painless ST segment elevation myocardial infarction (STEMI) that occurred while climbing Mount Kilimanjaro. A 51-year-old man suffered dyspnoea and loss of consciousness near the mountain peak, at about 5600 m. At a nearby hospital, he was treated as a case of high-altitude pulmonary edema. ECG was not obtained. Two days after the incident, he presented to our institution with continued symptoms of dyspnoea, light-headedness and weakness, but no pain. He was found to have inferior wall and right ventricular STEMI complicated by complete heart block. He was successfully managed with coronary angioplasty, with good recovery.

  7. Myocardial fibrosis in an veteran endurance athlete

    PubMed Central

    Wilson, Mathew; O'Hanlon, Rory; Prasad, Sanjay; Basavarajaiah, Sandeep; Stephens, Nigel; Senior, Roxy; Shaw, Anthony; Sharma, Sanjay; Whyte, Gregory

    2009-01-01

    This study reports the cardiac structure and function of a lifelong male endurance athlete, who has run over 148 000 miles, who presented with symptoms of chest discomfort, dyspnoea and loss of competitive running performance. Importantly, the athlete documented several periods of regular intensive endurance activity while suffering with flu-like symptoms. Cardiovascular MRI demonstrated a pattern of late gadolinium enhancement, which indicated myocardial scarring as a result of previous myocarditis. Myocarditis is a non-ischaemic inflammatory disease of the myocardium associated with cardiac dysfunction and arrhythmogenic substrate. The clinical course of viral myocarditis is mostly insidious with limited cardiac inflammation and dysfunction. However, as in the present case, overwhelming inflammation may occur in a subset of patients leading to myocardial fibrosis due to recurrent inflammation. PMID:21847425

  8. Amphetamine Abuse Related Acute Myocardial Infarction.

    PubMed

    Sinha, Archana; 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.

  9. 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.

  10. Galectin-3 and post-myocardial infarction cardiac remodeling.

    PubMed

    Meijers, Wouter C; van der Velde, A Rogier; Pascual-Figal, Domingo A; de Boer, Rudolf A

    2015-09-15

    This review summarizes the current literature regarding the involvement and the putative role(s) of galectin-3 in post-myocardial infarction cardiac remodeling. Post-myocardial infarction remodeling is characterized by acute loss of myocardium, which leads to structural and biomechanical changes in order to preserve cardiac function. A hallmark herein is fibrosis formation, both in the early and late phase following acute myocardial infarction. Galectin-3, a β-galactoside-binding lectin, which is a shared factor in fibrosis formation in multiple organs, has an established role in cardiac fibrosis in the setting of pressure overload, neuro-endocrine activation and hypertension, but its role in post- myocardial infarction remodeling has received less attention. However, accumulative experimental studies have shown that myocardial galectin-3 expression is upregulated after myocardial infarction, both on mRNA and protein level. This already occurs shortly after myocardial infarction in the infarcted and border zone area, and also at a later stage in the spared myocardium, contributing to tissue repair and fibrosis. This is associated with typical aspects of fibrosis formation, such as apposition of matricellular proteins and increased factors of collagen turnover. Interestingly, myocardial fibrosis in experimental post-myocardial infarction cardiac remodeling could be attenuated by galectin-3 inhibition. In clinical studies, circulating galectin-3 levels have been shown to identify patients at risk for new-onset heart failure and atrial fibrillation. Circulating galectin-3 levels also predict progressive left ventricular dilatation after myocardial infarction. From literature we conclude that galectin-3 is an active player in cardiac remodeling after myocardial infarction. Future studies should focus on the dynamics of galectin-3 activation after myocardial infarction, and study the possibilities to target galectin-3.

  11. Concomitant aortic valve replacement and myocardial revascularization.

    PubMed Central

    Craver, J M; Jones, E L; Hatcher, C R; Farmer, J H

    1977-01-01

    Twenty-six consecutive patients underwent combined aortic valve replacement and myocardial revascularization at the Emory University Affiliated Hospitals between May, 1973 and March, 1976. Acute myocardial infarction resulted in two operative deaths (8%). There have been four late deaths, all Class IV preoperative. The age range was 37 to 79 years with an average age of 60. Preoperatively all patients were Class IV or late Class III. Twenty-three patients had symptoms of angina pectoris; congestive heart failure was evident in 56%. Postoperatively, 70% are now Class 1 or II. Single coronary bypass was performed in 16 patients, double in 6, and triple in three. Double bypass plus mitral valve replacement was required in two with aneurysmectomy in one. The rate of intraoperative infarction was 27% for the series but only 7% in the last year. The methods of intraoperative myocardial preservation and the technical approach for the operative procedures were variable. Results with each method are correlated, and currently preferred techniques are presented and discussed. Best results were obtained in patients who presented early in their symptomatic course with isolated proximal coronary lesions and good renoff vessels. Excellent results could be achieved despite advanced age of patients, requirement for multiple bypass grafts, and correction of other associated cardiac lesions. Poorest results were obtained when long-standing ventricular failure was combined with poor vessels distal to coronary stenoses. PMID:860881

  12. Mechanisms of cell survival in myocardial hibernation.

    PubMed

    Depre, Christophe; Vatner, Stephen F

    2005-04-01

    Myocardial hibernation represents a condition of regional ventricular dysfunction in patients with chronic coronary artery disease, which reverses gradually after revascularization. The precise mechanism mediating the regional dysfunction is still debated. One hypothesis suggests that chronic hypoperfusion results in a self-protecting downregulation in myocardial function and metabolism to match the decreased oxygen supply. An alternative hypothesis suggests that the myocardium is subject to repetitive episodes of ischemic dysfunction resulting from an imbalance between myocardial metabolic demand and supply that eventually creates a sustained depression of contractility. It is generally agreed that hibernating myocardium is submitted repeatedly to ischemic stress, and therefore one question persists: how do myocytes survive in the setting of chronic ischemia? The hallmark of hibernating myocardium is a maintained viability of the dysfunctional myocardium which relies on an increased uptake of glucose. We propose that, in addition to this metabolic adjustment, there must be molecular switches that confer resistance to ischemia in hibernating myocardium. Such mechanisms include the activation of a genomic program of cell survival as well as autophagy. These protective mechanisms are induced by ischemia and remain activated chronically as long as either sustained or intermittent ischemia persists.

  13. Coffee consumption and myocardial infarction in women.

    PubMed

    Palmer, J R; Rosenberg, L; Rao, R S; Shapiro, S

    1995-04-15

    Whether coffee consumption increases the risk of coronary heart disease has not yet been established. In a case-control study of nonfatal myocardial infarction among Massachusetts women aged 45-69 years in 1986-1990, 858 cases with first infarctions were compared with 858 community controls matched on age and town precinct. Detailed information on coffee drinking, cigarette smoking, and other factors was obtained by telephone interview. Relative risks (as estimated by odds ratios) and their 95% confidence intervals were computed from multiple logistic regression analyses that controlled for smoking and other risk factors. The risk of myocardial infarction increased with increasing number of cups per day among both drinkers of any type of coffee and drinkers of caffeine-containing coffee only: tests for trend, p = 0.002 and p = 0.0004, respectively. For consumption of caffeine-containing coffee alone, the relative risk estimates for 5-6 cups, 7-9 cups, and 10 or more cups per day relative to less than 1 cup per day were 1.4 (95% confidence interval (CI) 0.8-2.5), 2.1 (95% CI 0.9-4.9), and 2.5 (95% CI 1.0-6.5), respectively. No increase was observed for fewer than 5 cups per day. The positive association with heavy coffee drinking was present among nonsmokers as well as smokers. These findings and other recent studies suggest that heavy coffee consumption increases the risk of myocardial infarction.

  14. 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

  15. Usefulness of myocardial strain imaging in Duchenne muscular dystrophy.

    PubMed

    Fayssoil, A

    2010-04-01

    Duchenne muscular dystrophy is an X-linked recessive disorder caused by the absence of dystrophin. Heart involvement is a classical complication in this disease and leads progressively to heart failure. Detecting latent myocardial involvement is essential in this disease because early use of drugs like angiotensin-converting enzyme inhibitors may delay the progression of heart disease. Myocardial strain imaging is an application of the tissue Doppler imaging. By assessing regional myocardial function, this tool might help clinicians to detect latent myocardial involvement in DMD patients.

  16. Combretastatin A4 disodium phosphate-induced myocardial injury

    PubMed Central

    Tochinai, Ryota; Nagata, Yuriko; Ando, Minoru; Hata, Chie; Suzuki, Tomo; Asakawa, Naoyuki; Yoshizawa, Kazuhiko; Uchida, Kazumi; Kado, Shoichi; Kobayashi, Toshihide; Kaneko, Kimiyuki; Kuwahara, Masayoshi

    2016-01-01

    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

  17. Inferior ST-Elevation Myocardial Infarction Associated with Takotsubo Cardiomyopathy

    PubMed Central

    Koeth, Oliver; Zeymer, Uwe; Schiele, Rudolf; Zahn, Ralf

    2010-01-01

    Takotsubo cardiomyopathy (TCM) is usually characterized by transient left ventricular apical ballooning. Due to the clinical symptoms which include chest pain, electrocardiographic changes, and elevated myocardial markers, Takotsubo cardiomyopathy is frequently mimicking ST-elevation myocardial infarction in the absence of a significant coronary artery disease. Otherwise an acute occlusion of the left anterior descending coronary artery can produce a typical Takotsubo contraction pattern. ST-elevation myocardial infarction (STEMI) is frequently associated with emotional stress, but to date no cases of STEMI triggering TCM have been reported. We describe a case of a female patient with inferior ST-elevation myocardial infarction complicated by TCM. PMID:20811565

  18. Myocardial ischemia reperfusion injury: from basic science to clinical bedside.

    PubMed

    Frank, Anja; Bonney, Megan; Bonney, Stephanie; Weitzel, Lindsay; Koeppen, Michael; Eckle, Tobias

    2012-09-01

    Myocardial ischemia reperfusion injury contributes to adverse cardiovascular outcomes after myocardial ischemia, cardiac surgery or circulatory arrest. Primarily, no blood flow to the heart causes an imbalance between oxygen demand and supply, named ischemia (from the Greek isch, restriction; and haema, blood), resulting in damage or dysfunction of the cardiac tissue. Instinctively, early and fast restoration of blood flow has been established to be the treatment of choice to prevent further tissue injury. Indeed, the use of thrombolytic therapy or primary percutaneous coronary intervention is the most effective strategy for reducing the size of a myocardial infarct and improving the clinical outcome. Unfortunately, restoring blood flow to the ischemic myocardium, named reperfusion, can also induce injury. This phenomenon was therefore termed myocardial ischemia reperfusion injury. Subsequent studies in animal models of acute myocardial infarction suggest that myocardial ischemia reperfusion injury accounts for up to 50% of the final size of a myocardial infarct. Consequently, many researchers aim to understand the underlying molecular mechanism of myocardial ischemia reperfusion injury to find therapeutic strategies ultimately reducing the final infarct size. Despite the identification of numerous therapeutic strategies at the bench, many of them are just in the process of being translated to bedside. The current review discusses the most striking basic science findings made during the past decades that are currently under clinical evaluation, with the ultimate goal to treat patients who are suffering from myocardial ischemia reperfusion-associated tissue injury.

  19. Regional myocardial lidocaine concentration following continuous intravenous infusion early and later after myocardial infarction

    SciTech Connect

    Zito, R.A.; Caride, V.J.; Holford, T.; Zaret, B.L.

    1982-09-01

    The regional concentration of lidocaine using a double constant infusion technique (250 micrograms/kg/min x 15 minutes followed by 35 micrograms/kg/mg/min x 120 minutes) was studied immediately (2 hours) in seven dogs and 24 hours (six dogs) after myocardial infarction. Tissue levels were determined by gas chromatography and related to regional myocardial blood flow as determined by the radioactive microsphere technique in multiple samples. At 2 hours after infarction a significantly higher lidocaine concentration (4.1 +/- 0.42 micrograms/g) was found in zones with greatly reduced blood flow (regional myocardial blood flow less than 0.2 ml/min per g) when compared with that (2.6 +/- 0.19 micrograms/g) in zones with normal blood flow (regional myocardial blood flow greater than 0.8 ml/min per g) (p less than 0.01). In contrast, in the 24 hour model the opposite situation was observed. Although the concentration of lidocaine in the infarct zone was substantial, a significant decline in lidocaine tissue concentration was found in the zones of lowest blood flow (regional myocardial blood flow less than 0.2 ml/min per g) when compared with that in normal zones (1.76 +/- 0.21 versus 3.38 +/- 0.21 micrograms/g, p less than 0.001). In addition, no significant differences in lidocaine concentrations were found between endocardium and epicardium in any of the groups other than those related to regional myocardial blood flow. Thus, with the double constant infusion technique, lidocaine reached normal and ischemic myocardium in concentrations equivalent to therapeutic plasma concentrations, even in lower infarct blood flow zones, with no significant differences between endocardium and epicardium. Of perhaps greater significance, the age of the ischemic insult is an important determinant of lidocaine tissue distribution in infarcted myocardium.

  20. 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

  1. Ipratropium bromide-mediated myocardial injury in in vitro models of myocardial ischaemia/reperfusion.

    PubMed

    Harvey, Kate L; Hussain, Afthab; Maddock, Helen L

    2014-04-01

    Ipratropium bromide, a nonselective muscarinic antagonist, is widely prescribed for the treatment of chronic obstructive pulmonary disease (COPD). Analyses of COPD patients, with underlying ischaemic heart disease, receiving anticholinergics, have indicated increased risk of severity and occurrence of cardiovascular events (including myocardial infarction). The present study explored whether ipratropium bromide induces myocardial injury in nonclinical models of simulated myocardial ischaemia/reperfusion injury. Adult Sprague Dawley rat hearts/primary ventricular myocytes were exposed to simulated ischaemia/hypoxia prior to administration of ipratropium at the onset of reperfusion/reoxygenation. Infarct to risk ratio and cell viability was measured via triphenyl tetrazolium chloride staining and thiazolyl blue tetrazolium bromide (MTT) assay. The involvement of apoptosis and necrosis was evaluated by flow cytometry. Mitochondrial-associated responses were detected by tetramethylrhodamine methyl ester fluorescence and myocyte contracture. Ipratropium (1 × 10⁻¹¹ M - 1 × 10⁻⁴ M) significantly increased infarct/risk ratio and decreased cell viability in a dose-dependent manner. Increased levels of necrosis and apoptosis were observed via flow cytometry, accompanied by increased levels of cleaved caspase-3 following ipratropium treatment. Levels of endogenous myocardial acetylcholine were verified via use of an acetylcholine assay. In these experimental models, exogenous acetylcholine (1 × 10⁻⁷ M) showed protective properties, when administered alone, as well as abrogating the exacerbation of myocardial injury during ischaemia/reperfusion following ipratropium coadministration. In parallel experiments, under conditions of myocardial ischaemia/reperfusion, a similar injury was observed following atropine (1 × 10⁻⁷ M) administration. These data demonstrate for the first time in a nonclinical setting that ipratropium exacerbates ischaemia

  2. [Clinical significance of myocardial 123I-BMIPP imaging in patients with myocardial infarction].

    PubMed

    Narita, M; Kurihara, T; Shindoh, T; Honda, M

    1997-03-01

    In order to clarify the characteristics of fatty acid metabolism in patients with myocardial infarction (MI), we performed myocardial imaging with 123I-beta-methyl-p-iodophenylpentadecanoic acid (BMIPP) and we compared these findings with exercise stress (Ex) and resting myocardial perfusion imaging with 99mTc-methoxyisobutylisonitrile (MIBI) and left ventricular wall motion index (WMI) which were obtained by left ventriculography. We studied 55 patients with MI, 14 patients with recent MI (RMI) and 41 patients with old MI (OMI), and myocardial images were divided into 17 segments and myocardial uptake of the radionuclide was graded from 0 (normal) to 3 (maximal abnormality). In 28 patients we compared segmental defect score (SDS) with WMI which were obtained by centerline method at the corresponded segments. As a whole, the mean total defect scores (TDSs) of BMIPP and Ex were similar and they were greater than the mean TDS of resting perfusion. In 30 patient (55%) TDS of BMIPP was greater than that of TDS of resting perfusion. In 24 patients perfusion abnormality developed by Ex and the location of BMIPP abnormality coincided with the abnormality of Ex. But in the other 6 patients Ex did not induce any abnormality and they were all RMI and infarcted coronary artery was patent. However in the group with TDS of BMIPP identical to TDS of resting perfusion (25 patients), 92% did not show myocardial perfusion abnormality after Ex. In the comparison of SDS and WMI, myocardial segments were divided into 3 groups; both SDSs of BMIPP and resting perfusion were normal or borderline abnormality (Group 1, 82 segments), SDS of resting perfusion was normal or borderline and SDS of BMIPP was definitely abnormal (Group 2, 10 segments) and both SDSs of BMIPP and resting perfusion were definitely abnormal (Group 3, 48 segments). In Group 1, WMS (-0.41 +/- 0.77) was significantly (p < 0.001) greater than those of Group 2 (-2.14 +/- 0.50) and Group 3 (-2.32 +/- 0.67). But there was

  3. Visualization of myocardial perfusion after percutaneous myocardial septal ablation for hypertrophic cardiomyopathy using superharmonic imaging.

    PubMed

    Ten Cate, Folkert J; Bouakaz, Ayache; Krenning, Boudewijn; Vletter, Wim; de Jong, Nico

    2003-04-01

    Harmonic imaging is used for detection of ultrasound contrast agents in myocardial perfusion studies. However, harmonic imaging has limitations because of the presence of tissue harmonics, which results in less specificity and sensitivity, thus, lower contrast-to-tissue ratio. We describe a clinical example using superharmonic imaging. This technique detects the third, fourth, and fifth harmonics. These harmonics are not created in tissue, resulting, hence, in a high contrast-to-tissue ratio. After myocardial alcohol ablation for hypertrophic cardiomyopathy areas of nontreated and treated myocardium, normal and low flow could be visualized with superharmonic imaging.

  4. Combined assessment of reflow and collateral blood flow by myocardial contrast echocardiography after acute reperfused myocardial infarction

    PubMed Central

    Leclercq, F; Messner-Pellenc, P; Descours, Q; Daures, J; Pasquie, J; Hager, F; Davy, J; Grolleau-Raoux, R

    1999-01-01

    OBJECTIVE—To evaluate the combined assessment of reflow and collateral blood flow by myocardial contrast echocardiography after myocardial infarction.
DESIGN—Myocardial contrast echocardiography was performed in patients with acute myocardial infarction shortly after successful coronary reperfusion (TIMI 3 patency) by direct angioplasty. Collateral flow was assessed before coronary angioplasty, and contrast reflow was evaluated 15 minutes after reperfusion. The presence of contractile reserve was assessed by low dose dobutamine echocardiography (5 to 15 µg/kg/min) at (mean (SD)) 3 (2) days after myocardial infarction. Recovery of segmental function (myocardial viability) was evaluated by resting echocardiography at a two month follow up. The study was prospective.
PATIENTS—35 consecutive patients referred for acute transmural myocardial infarction.
RESULTS—Contrast reflow was observed in 20 patients (57%) and collateral flow in 14 (40%). Contrast reflow and collateral contrast flow were both correlated with reversible dysfunction on initial dobutamine echocardiography and at follow up (p < 0.05). The presence of reflow or collateral flow on myocardial contrast echocardiography was a highly sensitive (100%) but weakly specific (60%) indicator of segmental dysfunction recovery. Simultaneous presence of contrast reflow and collateral flow was more specific of reversible dysfunction than reflow alone (90% v 60%).
CONCLUSIONS—Combined assessment of reflow and collateral blood flow enhanced the sensitivity of myocardial contrast echocardiography in predicting myocardial viability after acute, reperfused myocardial infarction. The simultaneous presence of reflow and collateral blood flow was highly specific of recovery of segmental dysfunction.


Keywords: contrast echocardiography; coronary reflow; collateral blood flow; dobutamine echocardiography; myocardial dysfunction PMID:10377311

  5. 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.

  6. Acute Anterior Myocardial Infarction Accompanied by Acute Inferior Myocardial Infarction: A Very Rare Coronary Artery Anomaly.

    PubMed

    Alsancak, Y; Sezenöz, B; Duran, M; Unlu, S; Turkoglu, S; Yalcın, R

    2015-01-01

    Coronary artery anomalies are rare and mostly silent in clinical practice. First manifestation of this congenital abnormality can be devastating as syncope, acute coronary syndrome, and sudden cardiac death. Herein we report a case with coronary artery anomaly complicated with ST segment myocardial infarction in both inferior and anterior walls simultaneously diagnosed during primary percutaneous coronary intervention.

  7. Hydrogen Sulfide Inhibits High-Salt Diet-Induced Myocardial Oxidative Stress and Myocardial Hypertrophy in Dahl Rats

    PubMed Central

    Huang, Pan; Shen, Zhizhou; Yu, Wen; Huang, Yaqian; Tang, Chaoshu; Du, Junbao; Jin, Hongfang

    2017-01-01

    The study aimed to examine the protective effect of hydrogen sulfide (H2S) on high-salt-induced oxidative stress and myocardial hypertrophy in salt-sensitive (Dahl) rats. Thirty male Dahl rats and 40 SD rats were included in the study. They were randomly divided into Dahl control (Dahl + NS), Dahl high salt (Dahl + HS), Dahl + HS + NaHS, SD + NS, SD + HS, SD + HS + NaHS, and SD + HS + hydroxylamine (HA). Rats in Dahl + NS and SD + NS groups were given chow with 0.5% NaCl and 0.9% normal saline intraperitoneally daily. Myocardial structure, α-myosin heavy chain (α-MHC) and β-myosin heavy chain (β-MHC) expressions were determined. Endogenous myocardial H2S pathway and oxidative stress in myocardial tissues were tested. Myocardial H2S pathway was downregulated with myocardial hypertrophy featured by increased heart weight/body weight and cardiomyocytes cross-sectional area, decreased α-MHC and increased β-MHC expressions in Dahl rats with high-salt diet (all P < 0.01), and oxidative stress in myocardial tissues was significantly activated, demonstrated by the increased contents of hydroxyl radical, malondialdehyde and oxidized glutathione and decreased total antioxidant capacity, carbon monoxide, catalase, glutathione, glutathione peroxidase, superoxide dismutase (SOD) activities and decreased SOD1 and SOD2 protein expressions (P < 0.05, P < 0.01). However, H2S reduced myocardial hypertrophy with decreased heart weight/body weight and cardiomyocytes cross-sectional area, increased α-MHC, decreased β-MHC expressions and inhibited oxidative stress in myocardial tissues of Dahl rats with high-salt diet. However, no significant difference was found in H2S pathway, myocardial structure, α-MHC and β-MHC protein and oxidative status in myocardial tissues among SD + NS, SD + HS, and SD + HS + NaHS groups. HA, an inhibitor of cystathionine β-synthase, inhibited myocardial H2S pathway (P < 0.01), and stimulated myocardial hypertrophy and oxidative stress in SD rats

  8. Hydrogen Sulfide Inhibits High-Salt Diet-Induced Myocardial Oxidative Stress and Myocardial Hypertrophy in Dahl Rats.

    PubMed

    Huang, Pan; Shen, Zhizhou; Yu, Wen; Huang, Yaqian; Tang, Chaoshu; Du, Junbao; Jin, Hongfang

    2017-01-01

    The study aimed to examine the protective effect of hydrogen sulfide (H2S) on high-salt-induced oxidative stress and myocardial hypertrophy in salt-sensitive (Dahl) rats. Thirty male Dahl rats and 40 SD rats were included in the study. They were randomly divided into Dahl control (Dahl + NS), Dahl high salt (Dahl + HS), Dahl + HS + NaHS, SD + NS, SD + HS, SD + HS + NaHS, and SD + HS + hydroxylamine (HA). Rats in Dahl + NS and SD + NS groups were given chow with 0.5% NaCl and 0.9% normal saline intraperitoneally daily. Myocardial structure, α-myosin heavy chain (α-MHC) and β-myosin heavy chain (β-MHC) expressions were determined. Endogenous myocardial H2S pathway and oxidative stress in myocardial tissues were tested. Myocardial H2S pathway was downregulated with myocardial hypertrophy featured by increased heart weight/body weight and cardiomyocytes cross-sectional area, decreased α-MHC and increased β-MHC expressions in Dahl rats with high-salt diet (all P < 0.01), and oxidative stress in myocardial tissues was significantly activated, demonstrated by the increased contents of hydroxyl radical, malondialdehyde and oxidized glutathione and decreased total antioxidant capacity, carbon monoxide, catalase, glutathione, glutathione peroxidase, superoxide dismutase (SOD) activities and decreased SOD1 and SOD2 protein expressions (P < 0.05, P < 0.01). However, H2S reduced myocardial hypertrophy with decreased heart weight/body weight and cardiomyocytes cross-sectional area, increased α-MHC, decreased β-MHC expressions and inhibited oxidative stress in myocardial tissues of Dahl rats with high-salt diet. However, no significant difference was found in H2S pathway, myocardial structure, α-MHC and β-MHC protein and oxidative status in myocardial tissues among SD + NS, SD + HS, and SD + HS + NaHS groups. HA, an inhibitor of cystathionine β-synthase, inhibited myocardial H2S pathway (P < 0.01), and stimulated myocardial hypertrophy and oxidative stress in SD rats

  9. 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.

  10. [TIMI group study of thrombolysis in myocardial infarction].

    PubMed

    Braunwald, Eugene

    2009-01-01

    The article presents the history of development of various methods of reperfusion therapy in myocardial infarction. The method of intracoronary thrombolysis was developed and used in Russia in 1976. In 1984 the TIMI Study Group initiated large-scale long-term trial of thrombolytic therapy in myocardial infarction and unstable angina pectoris. Some basic results of the study are outlined.

  11. 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.

  12. 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…

  13. Disseminated intravascular coagulation and acute myocardial necrosis caused by lightning.

    PubMed

    Ekoé, J M; Cunningham, M; Jaques, O; Balague, F; Baumann, R P; Humair, L; de Torrenté, A

    1985-01-01

    A 24-year-old woman was struck by lightning and suffered 20% second degree burns. She was admitted after cardiac and respiratory arrest. Despite intensive supportive care she died 24 h later of cardiogenic shock complicated by disseminated intravascular coagulation. At autopsy there was myocardial necrosis. Disseminated intravascular coagulation and myocardial necrosis are only rarely described as complications of lightning.

  14. 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.

  15. Improved Quantitative Myocardial T2 Mapping

    PubMed Central

    Akçakaya, Mehmet; Basha, Tamer A.; Weingärtner, Sebastian; Roujol, Sébastien; Berg, Sophie; Nezafat, Reza

    2014-01-01

    Purpose To develop an improved T2 prepared (T2prep) balanced steady-state free-precession (bSSFP) sequence and signal relaxation curve fitting method for myocardial T2 mapping. Methods Myocardial T2 mapping is commonly performed by acquisition of multiple T2prep bSSFP images and estimating the voxel-wise T2 values using a 2-parameter fit for relaxation. However, a 2-parameter fit model does not take into account the effect of imaging pulses in a bSSFP sequence or other imperfections in T2prep RF pulses, which may decrease the robustness of T2 mapping. Therefore, we propose a novel T2 mapping sequence that incorporates an additional image acquired with saturation preparation, simulating a very long T2prep echo time. This enables the robust estimation of T2 maps using a 3-parameter fit model, which captures the effect of imaging pulses and other imperfections. Phantom imaging is performed to compare the T2 maps generated using the proposed 3-parameter model to the conventional 2-parameter model, as well as a spin echo reference. In-vivo imaging is performed on eight healthy subjects to compare the different fitting models. Results Phantom and in-vivo data show that the T2 values generated by the proposed 3-parameter model fitting do not change with different choices of the T2prep echo times, and are not statistically different than the reference values for the phantom (P = 0.10 with three T2prep echoes). The 2-parameter model exhibits dependence on the choice of T2prep echo times and are significantly different than the reference values (P = 0.01 with three T2prep echoes). Conclusion The proposed imaging sequence in combination with a 3-parameter model allows accurate measurement of myocardial T2 values, which is independent of number and duration of T2prep echo times. PMID:25103908

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. Atypical myocardial infarction on a cruise ship.

    PubMed

    Taylor, Christopher

    2015-01-01

    A previously asymptomatic 44-year-old male crewmember on a cruise ship experienced several brief episodes of acute chest pain within a short time frame. He was ultimately diagnosed with myocardial infarction; 5 h earlier he had been discharged from the ship's medical centre after almost 8 h of monitoring to rule-out infarction. Subsequent angiography ashore revealed a 99% occlusion of the right coronary artery. This case highlights the dangers of over-reliance on shipboard cardiac enzyme testing to clear a patient with chest pain.

  1. 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.

  2. Hypertrophic cardiomyopathy simulating an infiltrative myocardial disease.

    PubMed Central

    Frustaci, A; Loperfido, F; Pennestrì, F

    1985-01-01

    Congestive heart failure developed in a patient with low electrocardiographic QRS voltages, diffuse thickening of the septum and free cardiac wall, and a reduction in left ventricular internal diameter, which suggested an infiltrative heart muscle disease. Histological examination at necropsy showed hypertrophic cardiomyopathy with symmetrical left ventricular hypertrophy. Myocardial disarray of type 1A disorganisation was extensive and equally distributed in the ventricular septum and the left anterior and left posterior ventricular free walls. Severe fibrosis (40%) was also present and may have been a possible cause of the electrocardiographic abnormalities as well as of the lack of ventricular dilatation. Images PMID:4041302

  3. 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

  4. 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

  5. Infant acute myocarditis mimicking acute myocardial infarction

    PubMed Central

    Tilouche, Samia; Masmoudi, Tasnim; Sahnoun, Maha; Chkirbène, Youssef; Mestiri, Sarra; Boughamoura, Lamia; Ben Dhiab, Mohamed; Souguir, Mohamed Kamel

    2016-01-01

    Myocarditis is an inflammatory disease of the myocardium with heterogeneous clinical manifestations and progression. In clinical practice, although there are many methods of diagnosis of acute myocarditis, the diagnosis remains an embarrassing dilemma for clinicians. The authors report the case of 9-month-old infant who was brought to the Pediatric Emergency Department with sudden onset dyspnea. Examination disclosed heart failure and resuscitation was undertaken. The electrocardiogram showed an ST segment elevation in the anterolateral leads with a mirror image. Cardiac enzyme tests revealed a significant elevation of troponin and creatine phosphokinase levels. A diagnosis of acute myocardial infarction was made, and heparin therapy was prescribed. The infant died on the third day after admission with cardiogenic shock. The autopsy showed dilatation of the ventricles and massive edema of the lungs. Histological examinations of myocardium samples revealed the presence of a marked lymphocytic infiltrate dissociating myocardiocytes. Death was attributed to acute myocarditis. The authors call attention to the difficulties of differential diagnosis between acute myocarditis and acute myocardial infarction especially in children, and to the important therapeutic implications of a correct diagnosis. PMID:28210569

  6. 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

  7. Strategies and Challenges to Myocardial Replacement Therapy

    PubMed Central

    Feric, Nicole T.

    2016-01-01

    Summary Cardiovascular diseases account for the majority of deaths globally and are a significant drain on economic resources. Although heart transplants and left-ventricle assist devices are the solution for some, the best chance for many patients who suffer because of a myocardial infarction, heart failure, or a congenital heart disease may be cell-based regenerative therapies. Such therapies can be divided into two categories: the application of a cell suspension and the implantation of an in vitro engineered tissue construct to the damaged area of the heart. Both strategies have their advantages and challenges, and in this review, we discuss the current state of the art in myocardial regeneration, the challenges to success, and the future direction of the field. Significance This article outlines the advantages and limitations of the cell injection and patch approaches to cardiac regenerative therapy. If the field is to move forward, some fundamental questions require answers, including the limitations to the use of animal models for human cell-transplantation studies; the best way to measure success in terms of functional improvements, histological integration, electrical coupling, and arrhythmias; and where the cells should be applied for maximal benefit—the epicardium or the myocardium. PMID:26933042

  8. Physiological Implications of Myocardial Scar Structure.

    PubMed

    Richardson, William J; Clarke, Samantha A; Quinn, T Alexander; Holmes, Jeffrey W

    2015-09-20

    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.

  9. 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.

  10. [Myocardial ischemia-reperfusion injury and melatonin].

    PubMed

    Sahna, Engin; Deniz, Esra; Aksulu, Hakki Engin

    2006-06-01

    It is believed that myocardial ischemia-reperfusion injury is related to increased free radical generated and intracellular calcium overload especially during the period of reperfusion. The pineal secretory product, melatonin, is known to be a potent free radical scavenger, antioxidant and can inhibit the intracellular calcium overload. In this review, we have summarized the fundamental of cardiac ischemia-reperfusion injury and the effects of melatonin on myocardial damage that related to cardiac ischemia-reperfusion injury. The total antioxidant capacity of human serum is related to melatonin levels. Incidence of sudden cardiac death is high in the morning hours. It has been shown that melatonin levels are significantly low at these times and patients with coronary heart disease have lower than normal individuals. These findings thought that melatonin would be valuable to test in clinical trials for prevention of possible ischemia-reperfusion-induced injury, especially life threatening arrhythmias and infarct size, effecting life quality, associated with thrombolysis, angioplasty, coronary artery spasm or coronary bypass surgery.

  11. 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.

  12. 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

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

    PubMed

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

    2016-07-01

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

  14. [Environmental pollution with lead and myocardial infarction morbidity].

    PubMed

    Dulskiene, Virginija

    2003-01-01

    The aim of the study was to assess the effect of exposure to ambient lead and other environmental factors on first myocardial infarction incidence. Epidemiological case-control study comprised 579 male cases (25-64 year old) of myocardial infarction, treated in Kaunas hospitals and 1777 controls of the same age group without ischemic heart disease. Myocardial infarction incidence in the area of low exposure to lead was 2.34 per 1000, while in the high exposure area it was 2.61 per 1000. We determined the distribution of potential myocardial infarction risk factors among cases and controls and calculated corresponding crude odds ratios. Variables considered for inclusion in multivariate logistic regression model were those with higher prevalence among cases and values of odds ratios greater than 1.5. The analysis revealed that smoking, arterial hypertension and stress significantly increased the risk of first myocardial infarction among 25-64 year old men. Occupational exposure to chemical substances increased myocardial infarction risk by 26%, while residential exposure to ambient lead concentrations, exceeding 0.225 microg/m (3), tended to increase myocardial infarction risk by 12% (95% PI 0.94-1.34).

  15. Detection of silent myocardial ischemia in asymptomatic patients with diabetes: results of a randomized trial and meta-analysis assessing the effectiveness of systematic screening

    PubMed Central

    2011-01-01

    Background Most guidelines recommend a systematic screening of asymptomatic high risk patients with diabetes for silent ischemia, but the clinical benefit of this strategy has not been demonstrated compared with the simple control of cardiovascular risk factors. We sought to determine whether referring asymptomatic diabetic patients for screening of silent ischemia decreases the risk of cardiovascular events compared with usual care. Methods DYNAMIT was a prospective, randomized, open, blinded end-point multicenter trial run between 2000 and 2005, with a 3.5 year mean follow-up in ambulatory care in 45 French hospitals. The study included 631 male and female with diabetes aged 63.9 ± 5.1 years, with no evidence of coronary artery disease and at least 2 additional cardiovascular risk factors, receiving appropriate medical treatment. The patients were randomized centrally to either screening for silent ischemia using a bicycle exercise test or Dipyridamole Single Photon Emission Computed Tomography (N = 316), or follow-up without screening (N = 315). The main study end point was time to death from all causes, non-fatal myocardial infarction, non-fatal stroke, or heart failure requiring hospitalization or emergency service intervention. The results of a meta-analysis of DYNAMIT and DIAD, a similar study, are also presented. Results The study was discontinued prematurely because of difficulties in recruitment and a lower-than expected event rate. Follow-up was complete for 98.9% patients regarding mortality and for 97.5% regarding the main study end point. Silent ischemia detection procedure was positive or uncertain in 68 (21.5%) patients of the screening group. There was no significant difference between the screening and the usual care group for the main outcome (hazard ratio = 1.00 95%CI 0.59 to 1.71). The meta-analysis of these and DIAD results gave similar results, with narrower confidence intervals for each endpoint. Conclusions These results suggest that the

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

    PubMed

    Lobo, Reema Orison; Shenoy, Chandrakala K

    2015-07-01

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

  17. Compensatory mechanisms for cardiac dysfunction in myocardial infarction.

    PubMed

    Ertl, G; Gaudron, P; Eilles, C; Schorb, W; Kochsiek, K

    1991-01-01

    Loss of contractile myocardial tissue by myocardial infarction would result in depressed cardiac output if compensatory mechanisms would not be operative. Frank-Straub-Starling-mechanism and increased heart rate and contractility due to sympathetic stimulation are unlikely to chronically compensate for cardiac dysfunction. Structural left ventricular dilatation may be compensatory, but results in increased wall stress and, ultimately, in progressive dilatation and heart failure. In patients with myocardial infarction, we have shown left-ventricular dilatation in dependence of infarct size and time after infarction. Dilatation is compensatory first and normalizes stroke volume. However, left ventricular dilatation progresses without further hemodynamic profit and, thus, may participate in development of heart failure.

  18. 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.

  19. Disseminated mucormycosis with myocardial involvement in a renal transplant recipient.

    PubMed

    Nam, Y; Jung, J; Park, S S; Kim, S J; Shin, S J; Choi, J H; Kim, M; Yoon, H E

    2015-12-01

    We report the case of a renal transplant recipient with pulmonary and splenic mucormycosis whose demise was accelerated by a myocardial abscess. Once pulmonary and splenic mucormycosis was diagnosed, liposomal amphotericin B was started and immunosuppressant treatments were discontinued. The pulmonary cavities regressed during treatment, but new myocardial and peri-allograft abscesses developed. The myocardial abscess diffusely infiltrated the left ventricular wall and was associated with akinesia, which led to sudden cardiac arrest. This case demonstrates a rare manifestation of mucormycosis and highlights the fatality and invasiveness of this infection.

  20. 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.

  1. 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

  2. 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

  3. 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

  4. 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

  5. [Compromized myocardial perfusion in arrhythmias (author's transl)].

    PubMed

    Simon, H; Neumann, G; Felix, R; Hedde, H; Schaede, A; Thurn, P; Winkler, C

    1977-09-15

    In 7 patients with arrhythmias of various origin the myocardial scintigram displayed either a diffuse or circumscript defect of the perfusion. The coronary arteriogram was normal in all patients. The localized defect of the perfusion in 2 patients was in the region of the upper part of the interventricular septum. Both had a left bundle brunch block. A correlation between the perfusion defect and the electrophysiological abnormality seems probable. The perfusion defect in one of the patients is most probably caused by a previous myocarditis followed by fibrous changes. In the other 6 patients the cause for the perfusion defect is not obvious. A history of myocarditis is missing. The presence of "small vessel disease" in those patients has however to be considered. Our results point to the relation between an abnormality of the microcirculation and arrhythmias in younger patients.

  6. Acute prolongation of myocardial refractoriness by sotalol.

    PubMed Central

    Bennett, D H

    1982-01-01

    Sotalol, a beta adrenoceptor antagonist, was given intravenously to 15 patients with accessory atrioventricular pathways during intracardiac electrophysiological studies. Eleven patients had the Wolff-Parkinson-White syndrome and four patients had concealed left sided accessory pathways. Four patients were restudied while receiving oral sotalol. In contrast to the actions typical of beta blocking agents, intravenous sotalol prolonged the effective refractory periods of the ventricles and accessory pathways and reduced the ventricular response to atrial fibrillation in the patients with the Wolff-Parkinson-White syndrome. Similar results were obtained with oral administration. These findings support the observation that sotalol, unlike other beta blocking agents. causes acute prolongation of the myocardial action potential and suggest that this action might be of therapeutic use. PMID:7082500

  7. Recovery of midlife women from myocardial infarction.

    PubMed

    Stevens, Sherri; Thomas, Sandra P

    2012-01-01

    We conducted this qualitative study to elicit the experiences of midlife women who survived myocardial infarctions (MIs) and returned home to recover. We selected a phenomenological research method based on the philosophy of Merleau-Ponty. The researcher interviewed eight women ranging in age from 45 to 65. The interviews were transcribed and analyzed using the approach of Thomas and Pollio. For the women in this study, figural themes of the experience of the MI and recovery must be understood within the existential grounds of the body and others. Themes included the following: (a) interference, (b) freedom/unfreedom, (c) knowing/not knowing, and (d) living in fear. Based on the findings of this study, we suggest that women need to be better educated before leaving the hospital. Returning home post MI was a difficult time, and the women in this study felt a support group for female MI survivors was needed.

  8. Closed-chest myocardial ischaemia in dog.

    PubMed

    Birkui, P J; Georgiopoulos, G; Riche, M C; Perrault, M; Puisieux, F; Merland, J J; Saumont, R

    1981-01-01

    Myocardial ischaemia in dog was induced with releasable material in the distal segment of the anterior descending branch of the left coronary artery. Three releasable materials were tested: gel foam, wax microspheres (120-200 micron) and latex balloons, using different methods of introduction. The left carotid route was selected for introduction of a preformed catheter. The gel foam and wax microspheres caused transitory ischaemia, which was proximal for the foam and distal for the microspheres. The balloons made it possible to standardize the ischaemia as its localization and duration could be selected. This material therefore provided a model for stable chronic ischaemia. Nine dogs were observed by means of precordial mapping (36 electrodes) during the phase following ischaemia or for a period of 4 weeks. The results of these experiments are analysed and correlated with histological results for the post-mortem phase.

  9. [Sexuality in acute myocardial infarction patients].

    PubMed

    Casado Dones, Ma J; de Andrés Gimeno, B; Moreno González, C; Fernández Balcones, C; Cruz Martín, R Ma; Colmenar García, C

    2002-01-01

    We as nurses in the Coronary Unit we do not see the sexuality of the patients sufficiently addressed neither by us nor by the patients themselves. In this article we are trying to analize the reasons and to emphasize the need to include this subject in our Nursing Problem List. In it we explaine the fears and the wrong ideas that we have identified in our patients. The sexual function is not affected by a myocardial infarction but psychological factors, age, drugs and other associated diseases might be a reason. A quiet enviroment, a fit training plan and looking for personalise proper alternatives may help the patient to start a satisfactory sexual life again.

  10. 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

  11. Computing myocardial motion in 4-dimensional echocardiography.

    PubMed

    Mukherjee, Ryan; Sprouse, Chad; Pinheiro, Aurélio; Abraham, Theodore; Burlina, Philippe

    2012-07-01

    We describe a novel method for computing dense 3D myocardial motion with high accuracy in four-dimensional (4D) echocardiography (3 dimensions spatial plus time). The method is based on a classic variational optical flow technique but exploits modern developments in optical flow research to utilize the full capabilities of 4D echocardiography. Using a variety of metrics, we present an in-depth performance evaluation of the method on synthetic, phantom, and intraoperative 4D transesophageal echocardiographic data. When compared with state-of-the-art optical flow and speckle tracking techniques currently found in 4D echocardiography, the method we present shows notable improvements in error rates. We believe the performance improvements shown can have a positive impact when the method is used as input for various applications, such as strain computation, biomechanical modeling, and automated diagnostics.

  12. 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.

  13. 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

  14. Adaptation to cardiac dysfunction after myocardial infarction.

    PubMed

    Gaudron, P; Eilles, C; Ertl, G; Kochsiek, K

    1993-05-01

    Survival after myocardial infarction decreases with left ventricular dilatation, although dilatation at 4 weeks was found to be compensatory. To study this apparent discrepancy, prospective simultaneous volume and hemodynamic measurements at rest were extended in 39 patients with small and 37 with large myocardial infarctions from 4 days (range, 2-6 days) and 4 weeks (range, 3-5 weeks) to 6 months (range, 5-8 months) after infarction and were repeated during supine bicycle exercise at 50 W. In patients with small infarction, end-diastolic volume (mL/m2) decreased from 4 days to 6 months; ejection fraction (%), stroke volume (mL/m2), and end-systolic volume (mL/m2) remained unchanged. Stroke index rose during exercise at 4 weeks and 6 months. In patients after large infarction (n = 37), left ventricular end-systolic volume index (4 days, 38 +/- 3; 4 weeks, 47 +/- 3*; 6 months, 52 +/- 3*; *p < 0.05 versus 4 days) and end-diastolic volume indexes (4 days, 72 +/- 3; 4 weeks, 86 +/- 5*; 6 months, 92 +/- 5*; *p < 0.05 versus 4 days, +p < 0.05 versus 4 weeks) increased at constant wedge pressure. Stroke index remained restored beyond 4 weeks after infarction (4 days, 35 +/- 2; 4 weeks, 42 +/- 2*; 6 months, 42 +/- 2*; p < 0.05 versus 4 days) and rose during exercise at 4 weeks (rest, 45 +/- 2; exercise, 55 +/- 3; p < 0.05) but not at 6 months (rest, 42 +/- 3; exercise, 45 +/- 3; p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Mineralocorticoid excess, dietary sodium, and myocardial fibrosis.

    PubMed

    Brilla, C G; Weber, K T

    1992-12-01

    Unlike the non-renin-dependent hypertension associated with infrarenal aorta banding, an abnormal accumulation of fibrillar collagen occurs within the adventitia of intramural coronary arteries and neighboring interstitial space of the left and right ventricles in arterial hypertension associated with primary or secondary hyperaldosteronism. Based on these findings it was suggested that this interstitial and perivascular fibrosis was mediated by mineralocorticoid excess (i.e., elevated plasma aldosterone relative to dietary sodium) and not ventricular loading. To further address the importance of mineralocorticoid excess, we examined the fibrous tissue response after 8 weeks in the following uninephrectomized rat groups receiving a high-sodium diet: D-aldosterone (ALDO) infusion (0.75 micrograms/hr sc, n = 16); deoxycorticosterone acetate (DOCA) administration (100 mg/kg/wk sc, n = 8); and administration of a mineralocorticoid-like substance, glycyrrhizic acid (GA; 1 gm kg/wk sc, n = 8). Compared with ALDO infusion and sodium deprivation (n = 9), untreated controls (n = 14), and uninephrectomized rats with high dietary sodium and no mineralocorticoid administration (n = 15), we found (1) hypertension and left ventricular hypertrophy with all forms of mineralocorticoid excess; (2) a rise in collagen volume fraction with ALDO, and an increase in perivascular collagen with DOCA; and (3) no observance of myocardial fibrosis with GA or experimental controls, including ALDO infusion and sodium deprivation. Thus, in the presence of enhanced sodium intake, chronic administration of ALDO or DOCA are associated with collagen accumulation in the myocardium, whereas with the mineralocorticoid-like compound GA, myocardial fibrosis was not seen.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. [Myocardial perfusion imaging by digital subtraction angiography].

    PubMed

    Kadowaki, H; Ishikawa, K; Ogai, T; Katori, R

    1986-03-01

    Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; at the R wave of the electrocardiogram, 100 msec before the R wave, and 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. 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

  18. 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

  19. Increased Sensitivity to Heparin Following Acute Myocardial Infarction

    PubMed Central

    Dufault, C.

    1965-01-01

    In vivo increased sensitivity to heparin has been demonstrated in patients following an acute myocardial infarction. An intravenous injection of 10,000 units of heparin was given to each of 18 patients with recent myocardial infarction in order to compare them with 17 patients who were not suffering from any acute illness. The changes in whole blood clotting time, recalcified plasma clotting time and prothrombin time were greater and more prolonged in the patients with recent myocardial infarction. Of the three tests, the one-stage prothrombin time provided the simplest and the most precise measurement of heparin sensitivity. The reason for this was not clear: it is possible that it is related to shock and congestive heart failure which were complications of the clinical course following myocardial infarction. PMID:14216140

  20. Contractile analysis with kriging based on MR myocardial velocity imaging.

    PubMed

    Lee, Su-Lin; Huntbatch, Andrew; Yang, Guang-Zhong

    2008-01-01

    Diagnosis and treatment of coronary artery disease requires a full understanding of the intrinsic contractile mechanics of the heart. MR myocardial velocity imaging is a promising technique for revealing intramural cardiac motion but its ability to depict 3D strain tensor distribution is constrained by anisotropic voxel coverage of velocity imaging due to limited imaging slices and the achievable SNR in patient studies. This paper introduces a novel Kriging estimator for simultaneously improving the tracking and dense inter-slice estimation of the myocardial velocity data. A harmonic embedding technique is employed to determine point correspondence between left ventricle models between subjects, allowing for a statistical shape model to be reconstructed. The use of different semivariograms is investigated for optimal deformation reconstruction. Results from in vivo data demonstrate a marked improvement in tracking myocardial deformation, thus enhancing the potential clinical value of MR myocardial velocity imaging.

  1. Reduced myocardial blood flow in acute and chronic digitalization.

    PubMed

    Steiness, E; Bille-Brahe, N E; Hansen, J F; Lomholt, N; Ring-Larsen, H

    1978-07-01

    The myocardial blood flow was measured by the 133Xenon disappearance curve from the left ventricular wall following an injection of 133Xenon in the left coronary artery in 8 dogs without digoxin pretreatment and in 8 chronically digitalized dogs. The myocardial blood flow was significantly less (30%) in the digitalized dogs than in the dogs without pretreatment. In the digitalized dogs as well as in those without pretreatment an intravenous injection of digoxin resulted in a further significant decrease of the myocardial blood flow of about 20% and a significant increase of the coronary vascular resistance. The reduced myocardial blood flow both during acute and chronic digitalization is beleived to be of clinical importance.

  2. 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.

  3. 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.

  4. 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...

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Myocardial uptake of a bone tracer associated with hypercalcemia

    SciTech Connect

    Atkins, H.L.; Oster, Z.H.

    1984-11-01

    A patient with end-stage renal disease and hypercalcemia was referred for a radionuclide bone imaging study. Deposition of Tc-99m hydroxymethylenediphosphonate was apparent in the lungs and myocardium as well as in the skeleton. Renal uptake was also noted, despite anuria. Computed tomography demonstrated nephrocalcinosis but no myocardial calcification. The cause of myocardial uptake of tracer is unknown. Amyloidosis is suggested as a possibility but is not validated in this case.

  10. Ventricular Septal Dissection Complicating Inferior Wall Myocardial Infarction

    PubMed Central

    Kalvin, Lindsey; Yousefzai, Rayan; Khandheria, Bijoy K.; Paterick, Timothy E.

    2017-01-01

    Postmyocardial infarction ventricular septal defect is an increasingly rare mechanical complication of acute myocardial infarction. We present a case of acute myocardial infarction from right coronary artery occlusion that developed hypotension and systolic murmur 12 hours after successful percutaneous coronary intervention. Although preoperative imaging suggested a large ventricular septal defect and a pseudoaneurysm, intraoperative findings concluded a serpiginous dissection of the ventricular septum. The imaging technicalities are discussed.

  11. Hospital mortality of acute myocardial infarction in the thrombolytic era

    PubMed Central

    Mahon, N; O'Rorke, C; Codd, M; McCann, H; McGarry, K; Sugrue, D

    1999-01-01

    OBJECTIVE—To examine the management and outcome of an unselected consecutive series of patients admitted with acute myocardial infarction to a tertiary referral centre.
DESIGN—A historical cohort study over a three year period (1992-94) of consecutive unselected admissions with acute myocardial infarction identified using the HIPE (hospital inpatient enquiry) database and validated according to MONICA criteria for definite or probable acute myocardial infarction.
SETTING—University teaching hospital and cardiac tertiary referral centre.
RESULTS—1059 patients were included. Mean age was 67 years; 60% were male and 40% female. Rates of coronary care unit (CCU) admission, thrombolysis, and predischarge angiography were 70%, 28%, and 32%, respectively. Overall in-hospital mortality was 18%. Independent predictors of hospital mortality by multivariate analysis were age, left ventricular failure, ventricular arrhythmias, cardiogenic shock, management outside CCU, and reinfarction. Hospital mortality in a small cohort from a non-tertiary referral centre was 14%, a difference largely explained by the lower mean age of these patients (64 years). Five year survival in the cohort was 50%. Only age and left ventricular failure were independent predictors of mortality at follow up.
CONCLUSIONS—In unselected consecutive patients the hospital mortality of acute myocardial infarction remains high (18%). Age and the occurrence of left ventricular failure are major determinants of short and long term mortality after acute myocardial infarction.


Keywords: myocardial infarction; mortality; thrombolysis PMID:10212164

  12. Myocardial ischemia and ventricular fibrillation: pathophysiology and clinical implications.

    PubMed

    Luqman, Nazar; Sung, Ruey J; Wang, Chun-Li; Kuo, Chi-Tai

    2007-07-31

    Ventricular fibrillation (VF) and myocardial ischemia are inseparable. The first clinical manifestation of myocardial ischemia or infarction may be sudden cardiac death in 20-25% of patients. The occurrence of potentially lethal arrhythmia is the end result of a cascade of pathophysiological abnormalities that result from complex interactions between coronary vascular events, myocardial injury, and changes in autonomic tone, metabolic conditions and ionic state of the myocardium. It is also related to the time from the onset of ischemia. Within the first few minutes there is abundant ventricular arrhythmogenesis usually lasting for 30 min. Triggers for ischemic VF occur at the border zone or regionally ischemic heart. The border zone of ischemia is the predominant site of fragmentation. Acute ischemia opens K(ATP) channels and causes acidosis and hypoxia of myocardial cells leading to a large dispersion in repolarization across the border zone. Abnormalities of intracellular Ca2+ handling also occur in the first few minutes of acute myocardial ischemia and may be an important cause of arrhythmias in human coronary artery disease. Substrate on the other hand transforms triggers into VF and serves to maintain it through fragmentation of waves in the ischemic zone. Thrombin levels, stretch, catecholamine, genetic predisposition, etc. are some of these factors. Reentry models described are spiral wave reentry, 3 dimensional rotors, reentry around 'M' cells and figure-of-eight reentry. Continuing efforts to better understand these arrhythmias will help identify patients of myocardial ischemia prone to arrhythmias.

  13. Stem cell therapy for the treatment of myocardial infarction.

    PubMed

    Dauwe, D F; Janssens, S P

    2011-10-01

    Despite timely reperfusion and subsequent optimal postinfarct pharmacotherapy and device-based treatment, the outcome in patients with severe myocardial infarction remains unfavourable. Myocardial salvage is incomplete, resulting in adverse left ventricular remodeling with concomitant morbidity and mortality. The combined risk of recurrent myocardial infarction, death or readmission for heart failure amounts to 25 % within the first year, highlighting the need for additional treatment strategies. Recent and rapidly evolving insights in cardiac biology, recognizing endogenous repair capabilities of the adult human heart, paved the path towards progenitor or stem cell based cardiac protection and repair strategies following ischemic injury. We critically report on the major randomized controlled clinical trials published so far concerning intracoronary transfer of autologous bone marrow cells in the setting of acute myocardial infarction. Moreover, underlying mechanisms, practical aspects, remaining questions and future challenges are highlighted. Taken together, these trials confirm the safety and feasibility of intracoronary progenitor cell transfer in the setting of myocardial infarction. Efficacy data suggests its potential to improve left ventricular function recovery beyond current state of the art therapy, but results are mixed, modest at best and do not support true cardiomyogenesis. Hence, due to its complexity, costs and remaining uncertainties, it is still too early to implement progenitor cell therapy in its current form in standard treatment strategies for ischemic heart disease. Future studies on strategies for cardiomyocyte regeneration in combination with myocardial protection are needed.

  14. 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.

  15. Heroin-associated myocardial damages--conventional and immunohistochemical investigations.

    PubMed

    Dettmeyer, R; Friedrich, K; Schmidt, P; Madea, B

    2009-05-30

    Well-known complications related to drug abuse are myocardial insufficiency, myocardial infarction, endocarditis, myocarditis, aortic dissection, neurologic damages, ischemic colitis, thrombotic phenomenons, renal infarction and acute liver failure. Furthermore, microfocal fibrosis of the myocardium is found in stimulant abuse. The origin of myocardial fibrosis associated with opiate abuse (endocarditis, myocarditis, embolism) is still unclear. This question shall be investigated using immunohistochemical staining for early diagnosis of myocarditis. A quantification of myocardial interstitial leucocytic infiltrates was accomplished in 21 chronic drug abusers who died of heroin/morphine intoxication and compared to 15 normal subjects who died suddenly due to non-cardiac causes of death without intoxication (e.g. traffic accidents, head trauma). Toxicological investigations were performed and in addition, blood samples were checked to clarify the status of HIV, hepatitis A, B and C in both groups. To verify signs of inflammation, myocardial specimen from different locations were investigated with conventional histological stainings and immunohistochemical techniques for characterization and quantification of interstitial myocardial leucocytes, T-lymphocytes and macrophages. The number of cells were found up to fivefold increased in heroin addicts compared to the control group without reaching the cut-off values for immunohistochemically based diagnosis of myocarditis.

  16. 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.

  17. Detecting Acute Myocardial Infarction by Diffusion-Weighted versus T2-Weighted Imaging and Myocardial Necrosis Markers.

    PubMed

    Jin, Jiyang; Chen, Min; Li, Yongjun; Wang, YaLing; Zhang, Shijun; Wang, Zhen; Wang, Lin; Ju, Shenghong

    2016-10-01

    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.

  18. 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

  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. The allometric model in chronic myocardial infarction

    PubMed Central

    2012-01-01

    Background An allometric relationship between different electrocardiogram (ECG) parameters and infarcted ventricular mass was assessed in a myocardial infarction (MI) model in New Zealand rabbits. Methods A total of fifteen animals were used, out of which ten underwent left anterior descending coronary artery ligation to induce infarction (7–35% area). Myocardial infarction (MI) evolved and stabilized during a three month-period, after which, rabbits were sacrificed and the injured area was histologically confirmed. Right before sacrifice, ECGs were obtained to correlate several of its parameters to the infarcted mass. The latter was normalized after combining data from planimetry measurements and heart weight. The following ECG parameters were studied: RR and PR intervals, P-wave duration (PD), QRS duration (QRSD) and amplitude (QRSA), Q-wave (QA), R-wave (RA) and S-wave (SA) amplitudes, T-wave peak amplitude (TA), the interval from the peak to the end of the T-wave (TPE), ST-segment deviation (STA), QT interval (QT), corrected QT and JT intervals. Corrected QT was analyzed with different correction formulae, i.e., Bazett (QTB), Framingham (QTFRA), Fridericia (QTFRI), Hodge (QTHO) and Matsunaga (QTMA) and compared thereafter. The former variables and infarcted ventricular mass were then fitted to the allometric equation in terms of deviation from normality, in turn derived after ECGs in 5 healthy rabbits. Results Six variables (JT, QTB, QA, SA, TA and STA) presented statistical differences among leads. QT showed the best allometric fit (r = 0.78), followed by TA (r = 0.77), STA (r = 0.75), QTFRA (r = 0.72), TPE (r = 0.69), QTFRI (r = 0.68) and QTMA (r = 0.68). Corrected QT’s (QTFRA, QTFRI and QTMA) performed worse than the uncorrected counterpart (QT), the former scaling allometrically with similar goodness of fits. Conclusions QT, TA, STA and TPE could possibly be used to assess infarction extent in an old MI event through the

  1. Effect of initial temperature changes on myocardial enzyme levels and cardiac function in acute myocardial infarction.

    PubMed

    Qian, Yuanyu; Liu, Jie; Ma, Jinling; Meng, Qingyi; Peng, Chaoying

    2014-07-01

    In the present study, the effect of initial body temperature changes on myocardial enzyme levels and cardiac function in acute myocardial infarction (AMI) patients was investigated. A total of 315 AMI patients were enrolled and the mean temperature was calculated based on their body temperature within 24 h of admission to hospital. The patients were divided into four groups according to their normal body temperature: Group A, <36.5°C; group B, ≥36.5°C and <37.0°C; group C, ≥37.0°C and <37.5°C and group D, ≥37.5°C. The levels of percutaneous coronary intervention, myocardial enzymes and troponin T (TNT), as well as cardiac ultrasound images, were analyzed. Statistically significant differences in the quantity of creatine kinase at 12 and 24 h following admission were identified between group A and groups C and D (P<0.01). A significant difference in TNT at 12 h following admission was observed between groups A and D (P<0.05), however, this difference was not observed with groups B and C. The difference in TNT between the groups at 24 h following admission was not statistically significant (P>0.05). Significant differences in lactate dehydrogenase at 12 and 24 h following admission were observed between groups A and D (P<0.05), however, differences were not observed with groups B and C (P>0.05). Significant differences in glutamic-oxaloacetic transaminase at 12 and 24 h following admission were observed between groups A and D (P<0.05), however, differences were not observed in groups B and C (P>0.05). However, no significant differences were identified in cardiac function index between all the groups. Therefore, the results of the present study indicated that AMI patients with low initial body temperatures exhibited decreased levels of myocardial enzymes and TNT. Thus, the observation of an initially low body temperature may be used as a protective factor for AMI and may improve the existing clinical program.

  2. Left ventricular remodeling after experimental myocardial cryoinjury in rats.

    PubMed

    Ciulla, Michele M; Paliotti, Roberta; Ferrero, Stefano; Braidotti, Paola; Esposito, Arturo; Gianelli, Umberto; Busca, Giuseppe; Cioffi, Ugo; Bulfamante, Gaetano; Magrini, Fabio

    2004-01-01

    The standard coronary ligation, the most studied model of experimental myocardial infarction in rats, is limited by high mortality and produces unpredictable areas of necrosis. To standardize the location and size of the infarct and to elucidate the mechanisms of myocardial remodeling and its progression to heart failure, we studied the functional, structural, and ultrastructural changes of myocardial infarction produced by experimental myocardial cryoinjury. The cryoinjury was successful in 24 (80%) of 30 male adult CD rats. A subepicardial infarct was documented on echocardiograms, with an average size of about 21%. Macroscopic examination reflected closely the stamp of the instrument used, without transition zones to viable myocardium. Histological examination, during the acute setting, revealed an extensive area of coagulation necrosis and hemorrhage in the subepicardium. An inflammatory infiltrate was evident since the 7th hour, whereas the reparative phase started within the first week, with proliferation of fibroblasts, endothelial cells, and myocytes. From the 7th day, deposition of collagen fibers was reported with a reparative scar completed at the 30th day. Ultrastructural study revealed vascular capillary damage and irreversible alterations of the myocytes in the acute setting and confirmed the histological findings of the later phases. The damage was associated with a progressive left ventricular (LV) remodeling, including thinning of the infarcted area, hypertrophy of the noninfarcted myocardium, and significant LV dilation. This process started from the 60th day and progressed over the subsequent 120 days period; at 180 days, a significant increase in LV filling pressure, indicative of heart failure, was found. In conclusion, myocardial cryodamage, although different in respect to ischemic damage, causes a standardized injury reproducing the cellular patterns of coagulation necrosis, early microvascular reperfusion, hemorrhage, inflammation

  3. 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

  4. 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.

  5. Assessment and classification of patients with myocardial injury and infarction in clinical practice

    PubMed Central

    Chapman, Andrew R; Adamson, Philip D

    2017-01-01

    Myocardial injury is common in patients without acute coronary syndrome, and international guidelines recommend patients with myocardial infarction are classified by aetiology. The universal definition differentiates patients with myocardial infarction due to plaque rupture (type 1) from those due to myocardial oxygen supply-demand imbalance (type 2) secondary to other acute illnesses. Patients with myocardial necrosis, but no symptoms or signs of myocardial ischaemia, are classified as acute or chronic myocardial injury. This classification has not been widely adopted in practice, because the diagnostic criteria for type 2 myocardial infarction encompass a wide range of presentations, and the implications of the diagnosis are uncertain. However, both myocardial injury and type 2 myocardial infarction are common, occurring in more than one-third of all hospitalised patients. These patients have poor short-term and long-term outcomes with two-thirds dead in 5 years. The classification of patients with myocardial infarction continues to evolve, and future guidelines are likely to recognise the importance of identifying coronary artery disease in type 2 myocardial infarction. Clinicians should consider whether coronary artery disease has contributed to myocardial injury, as selected patients are likely to benefit from further investigation and in these patients targeted secondary prevention has the potential to improve outcomes. PMID:27806987

  6. 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

  7. Myocardial Bridge and Acute Plaque Rupture

    PubMed Central

    Perl, Leor; Daniels, David; Schwartz, Jonathan; Tanaka, Shige; Yeung, Alan; Tremmel, Jennifer A.; Schnittger, Ingela

    2016-01-01

    A myocardial bridge (MB) is a common anatomic variant, most frequently located in the left anterior descending coronary artery, where a portion of the coronary artery is covered by myocardium. Importantly, MBs are known to result in a proximal atherosclerotic lesion. It has recently been postulated that these lesions predispose patients to acute coronary events, even in cases of otherwise low-risk patients. One such mechanism may involve acute plaque rupture. In this article, we report 2 cases of patients with MBs who presented with acute coronary syndromes despite having low cardiovascular risk. Their presentation was life-risking and both were treated urgently and studied with coronary angiographies and intravascular ultrasound. This latter modality confirmed a rupture of an atherosclerotic plaque proximal to the MB as a likely cause of the acute events. These cases, of unexplained acute coronary syndrome in low-risk patients, raise the question of alternative processes leading to the event and the role MB play as an underlying cause of ruptured plaques. In some cases, an active investigation for this entity may be warranted, due to the prognostic implications of the different therapeutic modalities, should an MB be discovered. PMID:28251167

  8. Guidelines for management of acute myocardial infarction.

    PubMed

    Banerjee, Amal Kumar; Kumar, Soumitra

    2011-12-01

    These Guidelines summarize and evaluate all currently available evidence on Acute Myocardial Infarction (AMI) with the aim of assisting physicians in selecting the best management strategies for a typical patient, suffering from AMI, taking into account the impact on outcome, as well as the risk/benefit ratio of particular diagnostic or therapeutic means. Rapid diagnosis and early risk stratification of patients presenting with AMI are important to identify patients in whom early interventions can improve outcome. AMI can be defined from a number of different perspectives related to clinical, electrocardiographic (ECG), biochemical, and pathological characteristics. Quantitative assessment of risk is useful for clinical decision making. For patients with the clinical presentation of AMI within 12 h after symptom onset, early mechanical (PCI) or pharmacological reperfusion should be performed. Platelet activation and subsequent aggregation play a dominant role in the propagation of arterial thrombosis and consequently are the key therapeutic targets in the management of AMI. Adjunctive therapy with antiplatelets and antithrombotics is essential. A recommendation for routine urgent PCI (within 24 h) following successful fibrinolysis seems to be most practical option. In India, pharmacoinvasive therapy is the best option.

  9. [Thrombolytic therapy of acute myocardial infarct].

    PubMed

    Murín, J; Kasper, J; Bulas, J; Uhliar, R

    1993-08-01

    In the period of two years the authors treated at the coronary care unit 146 patients inflicted by the acute myocardial infarction (AMI). In 15 of them (13 men, 2 women, 13 times Q and twice non-Q, 5 times anterior, 10 times inferior) they performed intravenous thrombolytic treatment by use of streptokinase. The success rate of the thrombolytic therapy was evaluated by noninvasive markers: 1.) rapid withdrawal of chest pain, 2.) rapid (in 6 hours) and essential improvement of ST segment elevation and 3.) presence of reperfusion arrhythmias (in 6 hours). The authors detected insufficient medicinal conciousness among their health district population as regard to their response after the AMI origin (absolute majority of patients delayed their arrival). Minor complications due to therapy (allergy and minor local hemorrhage) occurred in 4 patients. Nobody died. Only those cases were considered as being successful, in which all three success rate markers were present. This condition was fulfilled in 8 patients (i.e. in 53% of cases) and with minor insufficiencies in further two patients (which would increase the percentage of the success rate to 67%). This success rate of the thrombolytic therapy ranges within the limits given by literature. In five patients the authors evaluated the behaviour of the left ventricular asynergy (its range and index) prior to and following the thrombolytic therapy and this examination they consider to be appropriate for observance of the thrombolytic therapy success rate in patients with AMI. (Tab. 3, Ref. 20.).

  10. 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.

  11. Vitamin D and acute myocardial infarction

    PubMed Central

    Milazzo, Valentina; De Metrio, Monica; Cosentino, Nicola; Marenzi, Giancarlo; Tremoli, Elena

    2017-01-01

    Vitamin D deficiency is a prevalent condition, cutting across all ethnicities and among all age groups, and occurring in about 30%-50% of the population. Besides vitamin D established role in calcium homeostasis, its deficiency is emerging as a new risk factor for coronary artery disease. Notably, clinical investigations have suggested that there is an association between hypovitaminosis D and acute myocardial infarction (AMI). Not only has it been linked to incident AMI, but also to increased morbidity and mortality in this clinical setting. Moreover, vitamin D deficiency seems to predispose to recurrent adverse cardiovascular events, as it is associated with post-infarction complications and cardiac remodeling in patients with AMI. Several mechanisms underlying the association between vitamin D and AMI risk can be involved. Despite these observational and mechanistic data, interventional trials with supplementation of vitamin D are controversial. In this review, we will discuss the evidence on the association between vitamin D deficiency and AMI, in terms of prevalence and prognostic impact, and the possible mechanisms mediating it. Further research in this direction is warranted and it is likely to open up new avenues for reducing the risk of AMI. PMID:28163832

  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. 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

  14. 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

  15. Regulation of myocardial amino acid balance in the conscious dog.

    PubMed Central

    Schwartz, R G; Barrett, E J; Francis, C K; Jacob, R; Zaret, B L

    1985-01-01

    The effects in vivo of physiologic increases in insulin and amino acids on myocardial amino acid balance were evaluated in conscious dogs. Arterial and coronary sinus concentrations of amino acids and coronary blood flow were measured during a 30-min basal and a 100-min experimental period employing three protocols: euglycemic insulin clamp (plasma insulin equaled 70 +/- 11 microU/ml, n = 6); euglycemic insulin clamp during amino acid infusion (plasma insulin equaled 89 +/- 12 microU/ml, n = 6); and suppression of insulin with somatostatin during amino acid infusion (plasma insulin equaled 15 +/- 4 microU/ml, n = 6). Basally, only leucine and isoleucine were removed significantly by myocardium (net branched chain amino acid [BCAA] uptake equaled 0.5 +/- 0.2 mumol/min), while glycine, alanine, and glutamine were released. Glutamine demonstrated the highest net myocardial production (1.6 +/- 0.2 mumol/min). No net exchange was seen for valine, phenylalanine, tyrosine, cysteine, methionine, glutamate, asparagine, serine, threonine, taurine, and aspartate. In group I, hyperinsulinemia caused a decline of all plasma amino acids except alanine; alanine balance switched from release to an uptake of 0.6 +/- 0.4 mumol/min (P less than 0.05), while the myocardial balance of other amino acids was unchanged. In group II, amino acid concentrations rose, and were accompanied by a marked rise in myocardial BCAA uptake (0.4 +/- 0.1-2.6 +/- 0.3 mumol/min, P less than 0.001). Uptake of alanine was again stimulated (0.9 +/- 0.3 mumol/min, P less than 0.01), while glutamine production was unchanged (1.3 +/- 0.4 vs. 1.6 +/- 0.3 mumol/min). In group III, there was a 4-5-fold increase in the plasma concentration of the infused amino acids, accompanied by marked stimulation in uptake of only BCAA (6.8 +/- 0.7 mumol/min). Myocardial glutamine production was unchanged (1.9 +/- 0.4-1.3 +/- 0.7 mumol/min). Within the three experimental groups there were highly significant linear correlations

  16. Myocardial aging as a T-cell–mediated phenomenon

    PubMed Central

    Ramos, Gustavo Campos; van den Berg, Anne; Nunes-Silva, Vânia; Weirather, Johannes; Peters, Laura; Burkard, Matthias; Friedrich, Mike; Pinnecker, Jürgen; Abeßer, Marco; Heinze, Katrin G.; Schuh, Kai; Beyersdorf, Niklas; Kerkau, Thomas; Demengeot, Jocelyne; Frantz, Stefan; Hofmann, Ulrich

    2017-01-01

    In recent years, the myocardium has been rediscovered under the lenses of immunology, and lymphocytes have been implicated in the pathogenesis of cardiomyopathies with different etiologies. Aging is an important risk factor for heart diseases, and it also has impact on the immune system. Thus, we sought to determine whether immunological activity would influence myocardial structure and function in elderly mice. Morphological, functional, and molecular analyses revealed that the age-related myocardial impairment occurs in parallel with shifts in the composition of tissue-resident leukocytes and with an accumulation of activated CD4+ Foxp3− (forkhead box P3) IFN-γ+ T cells in the heart-draining lymph nodes. A comprehensive characterization of different aged immune-deficient mouse strains revealed that T cells significantly contribute to age-related myocardial inflammation and functional decline. Upon adoptive cell transfer, the T cells isolated from the mediastinal lymph node (med-LN) of aged animals exhibited increased cardiotropism, compared with cells purified from young donors or from other irrelevant sites. Nevertheless, these cells caused rather mild effects on cardiac functionality, indicating that myocardial aging might stem from a combination of intrinsic and extrinsic (immunological) factors. Taken together, the data herein presented indicate that heart-directed immune responses may spontaneously arise in the elderly, even in the absence of a clear tissue damage or concomitant infection. These observations might shed new light on the emerging role of T cells in myocardial diseases, which primarily affect the elderly population. PMID:28255084

  17. Histopathological study on myocardial hypertrophy associated with ischemic heart disease.

    PubMed

    Ishijima, M

    1990-06-01

    The mode and causes of myocardial hypertrophy occurring in association with ischemic heart disease were studied. The investigation involved autopsied hearts (15 cases of subendocardial infarction, 27 of transmural infarction, 20 of non-infarcted three vessel disease and 17 controls) and biopsied materials obtained during coronary-aorta bypass graft surgery (23 patients with angina pectoris and 46 with myocardial infarction). The subendocardial infarction group showed most marked myocardial hypertrophy that reflected extensive infarction and fibrosis, dilatation of the left ventricular cavity and the loss of myocytes. Despite a marked decrease in the number of myocyte layers, the residual myocardium of the left ventricle was uniformly hypertrophic, accompanied by an increase in the heart weight. The larger the area of fibrosis, the more marked was myocardial hypertrophy irrespective of the luminal diameter of the responsible coronary artery. These findings indicate that myocardial hypertrophy associated with ischemic heart disease is enhanced by the compensatory mechanisms for a decrease in the contractile myocardium due to fibrosis.

  18. Helicobacter pylori seropositivity in subjects with acute myocardial infarction.

    PubMed Central

    Rathbone, B.; Martin, D.; Stephens, J.; Thompson, J. R.; Samani, N. J.

    1996-01-01

    OBJECTIVE: To determine whether Helicobacter pylori infection increases the risk of myocardial infarction. DESIGN: Case-control study. SETTING: University teaching hospital. METHODS: Serological evidence of H pylori infection was determined in 342 consecutive patients with acute myocardial infarction admitted into the coronary care unit and in 236 population-based controls recruited from visitors to patients on medical and surgical wards. RESULTS: 206/342 (60.2%) of cases were H pylori positive compared with 132/236 (55.9%) of controls (P = 0.30). Age and sex stratified odds ratio for myocardial infarction associated with H pylori seropositivity was 1.05 (95% CI 0.7 to 1.53, P = 0.87) and this remained non-significant (P = 0.46) when other risk factors for ischaemic heart disease were taken into account using logistic regression analysis. H pylori seropositivity was not associated with several coronary risk factors in either cases or controls. CONCLUSION: No increase was found in H pylori seropositivity in subjects with acute myocardial infarction. This suggests that previous H pylori infection is not a major risk factor for acute myocardial infarction. Images PMID:8983674

  19. Human Umbilical Cord Blood for Transplantation Therapy in Myocardial Infarction

    PubMed Central

    Acosta, Sandra A; Franzese, Nick; Staples, Meaghan; Weinbren, Nathan L.; Babilonia, Monica; Patel, Jason; Merchant, Neil; Simancas, Alejandra Jacotte; Slakter, Adam; Caputo, Mathew; Patel, Milan; Franyuti, Giorgio; Franzblau, Max H.; Suarez, Lyanne; Gonzales-Portillo, Chiara; Diamandis, Theo; Shinozuka, Kazutaka; Tajiri, Naoki; Sanberg, Paul R.; Kaneko, Yuji; Miller, Leslie W.; Borlongan, Cesar V.

    2013-01-01

    Cell-based therapy is a promising therapy for myocardial infarction. Endogenous repair of the heart muscle after myocardial infarction is a challenge because adult cardiomyocytes have a limited capacity to proliferate and replace damaged cells. Pre-clinical and clinical evidence has shown that cell based therapy may promote revascularization and replacement of damaged myocytes after myocardial infarction. Adult stem cells can be harvested from different sources including bone marrow, skeletal myoblast, and human umbilical cord blood cells. The use of these cells for the repair of myocardial infarction presents various advantages over other sources of stem cells. Among these are easy harvesting, unlimited differentiation capability, and robust angiogenic potential. In this review, we discuss the milestone findings and the most recent evidence demonstrating the therapeutic efficacy and safety of the transplantation of human umbilical cord blood cells as a stand-alone therapy or in combination with gene therapy, highlighting the importance of optimizing the timing, dose and delivery methods, and a better understanding of the mechanisms of action that will guide the clinical entry of this innovative treatment for ischemic disorders, specifically myocardial infarction. PMID:24307973

  20. Human Umbilical Cord Blood for Transplantation Therapy in Myocardial Infarction.

    PubMed

    Acosta, Sandra A; Franzese, Nick; Staples, Meaghan; Weinbren, Nathan L; Babilonia, Monica; Patel, Jason; Merchant, Neil; Simancas, Alejandra Jacotte; Slakter, Adam; Caputo, Mathew; Patel, Milan; Franyuti, Giorgio; Franzblau, Max H; Suarez, Lyanne; Gonzales-Portillo, Chiara; Diamandis, Theo; Shinozuka, Kazutaka; Tajiri, Naoki; Sanberg, Paul R; Kaneko, Yuji; Miller, Leslie W; Borlongan, Cesar V

    2013-07-01

    Cell-based therapy is a promising therapy for myocardial infarction. Endogenous repair of the heart muscle after myocardial infarction is a challenge because adult cardiomyocytes have a limited capacity to proliferate and replace damaged cells. Pre-clinical and clinical evidence has shown that cell based therapy may promote revascularization and replacement of damaged myocytes after myocardial infarction. Adult stem cells can be harvested from different sources including bone marrow, skeletal myoblast, and human umbilical cord blood cells. The use of these cells for the repair of myocardial infarction presents various advantages over other sources of stem cells. Among these are easy harvesting, unlimited differentiation capability, and robust angiogenic potential. In this review, we discuss the milestone findings and the most recent evidence demonstrating the therapeutic efficacy and safety of the transplantation of human umbilical cord blood cells as a stand-alone therapy or in combination with gene therapy, highlighting the importance of optimizing the timing, dose and delivery methods, and a better understanding of the mechanisms of action that will guide the clinical entry of this innovative treatment for ischemic disorders, specifically myocardial infarction.

  1. Myocardial apoptosis in heart disease: does the emperor have clothes?

    PubMed

    Jose Corbalan, J; Vatner, Dorothy E; Vatner, Stephen F

    2016-05-01

    Since the discovery of a novel mechanism of cell death that differs from traditional necrosis, i.e., apoptosis, there have been numerous studies concluding that increased apoptosis augments myocardial infarction and heart failure and that limiting apoptosis protects the heart. Importantly, the vast majority of cells in the heart are non-myocytes with only roughly 30 % myocytes, yet almost the entire field studying apoptosis in the heart has disregarded non-myocyte apoptosis, e.g., only 4.7 % of 423 studies on myocardial apoptosis in the past 3 years quantified non-myocyte apoptosis. Accordingly, we reviewed the history of apoptosis in the heart focusing first on myocyte apoptosis, followed by the history of non-myocyte apoptosis in myocardial infarction and heart failure. Apoptosis of several of the major non-myocyte cell types in the heart (cardiac fibroblasts, endothelial cells, vascular smooth muscle cells, macrophages and leukocytes) may actually be responsible for affecting the severity of myocardial infarction and heart failure. In summary, even though it is now known that the majority of apoptosis in the heart occurs in non-myocytes, very little work has been done to elucidate the mechanisms by which non-myocyte apoptosis might be responsible for the adverse effects of apoptosis in myocardial infarction and heart failure. The goal of this review is to provide an impetus for future work in this field on non-myocyte apoptosis that will be required for a better understanding of the role of apoptosis in the heart.

  2. 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

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

    SciTech Connect

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

    1989-01-01

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

  4. 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.

  5. 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

  6. The influence of hypertonic mannitol on regional myocardial blood flow during acute and chronic myocardial ischemia in anesthetized and awake intact dogs.

    PubMed Central

    Willerson, J T; Watson, J T; Hutton, I; Fixler, D E; Curry, G C; Templeton, G H

    1975-01-01

    The influence of hypertonic mannitol on regional myocardial blood flow and ventricular performance was studied during acute myocardial ischemia in awake, unsedated and in anesthesized dogs and after myocardial infarction in awake unsedated dogs. Regional myocardial blood flow was measured with radioactive microspheres. Generalized increases in regional myocardial blood flow occurred after mannitol in all of the different animal models studied. The increases in coronary blood flow after mannitol were just as impressive in the nonischemic regions as in the ischemic portion of the left ventricle in all of the different models that were examined in this study. Improvement in regional myocardial blood flow to the ischemic area of the left ventricle after mannitol was associated with a reduction in ST segment elevation during acute myocardial ischemia in anesthetized dogs. The increases in regional myocardial flow after mannitol were also associated with increases in contractility, but the increases in flow appeared to be more impressive than the changes in contractility. The data obtained demonstrate that mannitol increases regional coronary blood flow to both ischemic and nonischemic myocardium in both anesthetized and awake, unsedated, intact dogs with acute and chronic myocardial ischemia and that mannitol reduces ST segment elevation during acute myocardial ischemia in anesthetized dogs. Thus the results suggest that under these circumstances the increases in regional myocardial blood flow after mannitol are of physiological importance in reducing the extent of myocardial injury. Since coronary blood flow increased to nonischemic regions the increases in regional myocardial flow demonstrated in this study after mannitol cannot be entirely explained by the mechanism of reduction in ischemic cell swelling. PMID:1123427

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

    SciTech Connect

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

    1989-11-01

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

  8. The Association between Diffuse Myocardial Fibrosis on Cardiac Magnetic Resonance T1 Mapping and Myocardial Dysfunction in Diabetic Rabbits

    PubMed Central

    Zeng, Mu; Qiao, Yingyan; Wen, Zhaoying; Liu, Jun; Xiao, Enhua; Tan, Changlian; Xie, Yibin; An, Jing; Zhang, Zishu; Fan, Zhanming; Li, Debiao

    2017-01-01

    The objective of this study was to assess the relationship between imaging surrogates for diffuse fibrosis and myocardial dysfunction. Thirty-six New Zealand white rabbits were classified into two groups: a control group (n = 18) and an alloxan-induced diabetes mellitus (DM) group (n = 18). For all rabbits, conventional ultrasonography, two-dimensional speckle tracking, and cardiac magnetic resonance (CMR) T1 mapping were performed; all of the rabbits were then sacrificed for Masson’s staining. The extracellular volume (ECV) was calculated from pre- and post-contrast T1 values and compared with myocardial function measured by echocardiography using Pearson’s correlation. In the DM group, ECV increased as the duration of diabetes increased, consistent with the changes in myocardial fibrosis verified by pathology. Moreover, ECV was strongly correlated with the early diastolic strain rate (r = −0.782, p < 0.001) and moderately correlated with the radial systolic peak strain (r = 0.478, p = 0.045). Thus, ECV is an effective surrogate for myocardial diffuse fibrosis on CMR imaging, and higher ECV values are associated with an increased impairment of myocardial diastolic function. PMID:28338005

  9. Formation of binucleated myocardial cells in the neonatal rat. An index for growth hypertrophy

    SciTech Connect

    Clubb, F.J. Jr.; Bishop, S.P.

    1984-05-01

    The purposes of this study were to characterize myocardial cell growth in neonatal rats and investigate the mechanism of binucleation in myocardial cells. To test the hypothesis that binucleated myocardial cells result from karyokinesis without cytokinesis, experiments were designed to measure the rate of DNA synthesis and the percentage of binucleated myocardial cells in neonatal rats during growth. Estimates of myocardial cell nuclear divisions were obtained from rats pulsed with tritiated thymidine at 17 days of gestation. Autoradiograms were prepared from isolated myocardial cells of rats killed at various ages postpartum, and the number of developed silver halide grains over myocardial cell nuclei was calculated. This estimated the mitotic activity of nuclei. To determine myocardial cell DNA synthesis postpartum, another set of rats were injected at various time periods with 4 hourly doses of tritiated thymidine, and hearts were fixed by perfusion 1 hour later. Labeling index of myocardial cells was calculated (labeled/total myocardial cells) from autoradiograms. Results indicated that the growth of myocardial cells in period can be divided into three phases: (a) a hyperplastic phase, (b) a transitional phase, and (c) a hypertrophic phase. Binucleation of myocardial cells was not due to fusion of mononucleated cells.

  10. Myocardial Ischemic Memory Imaging With Molecular Echocardiography

    PubMed Central

    Villanueva, Flordeliza S.; Lu, Erxiong; Bowry, Shivani; Kilic, Sevgi; Tom, Eric; Wang, Jianjun; Gretton, Joan; Pacella, John J.; Wagner, William R.

    2014-01-01

    Background Diagnosing acute coronary syndrome in patients presenting with chest discomfort is a challenge. Because acute myocardial ischemia/reperfusion is associated with endothelial upregulation of leukocyte adhesion molecules, which persist even after ischemia has resolved, we hypothesized that microbubbles designed to adhere to endothelial selectins would permit echocardiographic identification of recently ischemic myocardium. Methods and Results Lipid microbubbles (diameter, 3.3±1.7 μm) were synthesized. The selectin ligand sialyl Lewisx was conjugated to the microbubble surface (MBsLex). Control bubbles (MBCTL) bore surface Lewisx or sialyl Lewisc. Intravital microscopy of mouse cremaster muscle was performed after intravenous injection of MBsLex (n=11) or MBCTL (n=9) with or without prior intrascrotal tumor necrosis factor–α. There was greater adhesion of MBsLex to inflamed versus noninflamed endothelium (P=0.0081). Rats (n=12) underwent 15 minutes of anterior descending coronary artery occlusion. After 30 minutes and 1 hour of reperfusion, high-mechanical-index nonlinear echocardiographic imaging was performed in which single frames were acquired at 3.5 and 4 minutes after intravenous injection of MBsLex or MBCTL. Video intensity at 4 minutes was subtracted from that at 3.5 minutes to derive target-specific acoustic signal. MBsLex caused greater opacification in postischemic versus nonischemic myocardium at both time points (P≤0.002). Immunostaining confirmed endothelial P-selectin expression in the ischemic bed. Conclusions Echocardiographic identification of recently ischemic myocardium is possible using ultrasound contrast agents targeted to selectins. This may offer a new approach to the more timely and precise diagnosis of acute coronary syndrome in patients presenting with chest pain of uncertain cardiac origin. PMID:17210843

  11. Animal models of primary myocardial diseases.

    PubMed Central

    Liu, S. K.; Tilley, L. P.

    1980-01-01

    Feline and canine cardiomyopathies (primary myocardial diseases) were reviewed and divided into three groups based on the clinical, hemodynamic, angiocardiographic, and pathologic findings: (1) feline and canine hypertrophic cardiomyopathy, (2) feline and canine congestive (dilated) cardiomyopathy, and (3) feline restrictive cardiomyopathy. All three groups consisted predominantly of mature adult male cats and dogs. Cardiomyopathy in the hamster and turkey was also reviewed. The most common presenting signs were dyspnea and/or thromboembolism in the cat, systolic murmurs with gallop rhythms on auscultation, cardiomegaly with (groups 1 and 3) or without (group 2) pulmonary edema, abnormal electrocardiograms, elevated left ventricular end-diastolic pressures, and angiocardiographic evidence of mitral regurgitation with left ventricular concentric hypertrophy (group 1), left ventricular dilatation (group 2), or midventricular stenosis (group 3). Some cats in groups 1 and 3 also had evidence of left ventricular outflow obstruction. The principal pathologic findings in all of the cats and dogs were left atrial dilation, hypertrophy, increased septal:left ventricular free wall thickness ratio with disorganization of cardiac muscle cells (group 1); dilatation of the four chambers with degeneration of cardiac muscle cells (group 2); and extensive endocardial fibrosis and adhesion of the left ventricle (group 3). Aortic thromboembolism was commonly observed in the cats of all three groups. These clinical and pathologic findings indicate that cardiomyopathy in the cat or dog is similar to the three forms of cardiomyopathy in humans (hypertrophic, congestive, and restrictive). Images FIG. 2 FIG. 3 FIG. 5 FIG. 6 FIG. 7 FIG. 8 FIG. 9 FIG. 11 FIG. 12 FIG. 13 FIG. 15 FIG. 16 FIG. 17 FIG. 20 FIG. 21 FIG. 22 FIG. 24 FIG. 25 PMID:6447412

  12. Virtual electrode effects in myocardial fibers.

    PubMed Central

    Knisley, S B; Hill, B C; Ideker, R E

    1994-01-01

    The changes in transmembrane potential during a stimulation pulse in the heart are not known. We have used transmembrane potential sensitive dye fluorescence to measure changes in transmembrane potential along fibers in an anisotropic arterially perfused rabbit epicardial layer. Cathodal or anodal extracellular point stimulation produced changes in transmembrane potential within 60 microns of the electrode that were positive or negative, respectively. The changes in transmembrane potential did not simply decrease to zero with increasing distance, as would occur with a theoretical fiber space constant, but instead became reversed beyond approximately 1 mm from the electrode consistent with a virtual electrode effect. Even stimulation from a line of terminals perpendicular to the fibers produced negative changes in transmembrane potential for cathodal stimulation with the largest negative changes during a 50-ms pulse at 3-4 mm from the electrode terminals. Negative changes as large as the amplitude of the action potential rising phase occurred during a 50-ms pulse for 20-volt cathodal stimulation. Switching to anodal stimulation reversed the directions of changes in transmembrane potential at most recording spots, however for stimulation during the refractory period negative changes in transmembrane potential were significantly larger than positive changes in transmembrane potential. Anodal stimulation during diastole with 3-ms pulses produced excitation in the region of depolarization that accelerated when the stimulation strength was increased to > 3 times the anodal threshold strength. Thus, virtual electrode effects of unipolar stimulation occur in myocardial fibers, and for sufficiently strong stimuli the virtual electrode effects may influence electrical behavior of the myocardium. PMID:8011903

  13. Myocardial regeneration of the failing heart.

    PubMed

    Akhmedov, Alexander T; Marín-García, José

    2013-11-01

    Human heart failure (HF) is one of the leading causes of morbidity and mortality worldwide. Currently, heart transplantation and implantation of mechanical devices represent the only available treatments for advanced HF. Two alternative strategies have emerged to treat patients with HF. One approach relies on transplantation of exogenous stem cells (SCs) of non-cardiac or cardiac origin to induce cardiac regeneration and improve ventricular function. Another complementary strategy relies on stimulation of the endogenous regenerative capacity of uninjured cardiac progenitor cells to rebuild cardiac muscle and restore ventricular function. Various SC types and delivery strategies have been examined in the experimental and clinical settings; however, neither the ideal cell type nor the cell delivery method for cardiac cell therapy has yet emerged. Although the use of bone marrow (BM)-derived cells, most frequently exploited in clinical trials, appears to be safe, the results are controversial. Two recent randomized trials have failed to document any beneficial effects of intracardiac delivery of autologous BM mononuclear cells on cardiac function of patients with HF. The remarkable discovery that various populations of cardiac progenitor cells (CPCs) are present in the adult human heart and that it possesses limited regeneration capacity has opened a new era in cardiac repair. Importantly, unlike BM-derived SCs, autologous CPCs from myocardial biopsies cultured and subsequently delivered by coronary injection to patients have given positive results. Although these data are promising, a better understanding of how to control proliferation and differentiation of CPCs, to enhance their recruitment and survival, is required before CPCs become clinically applicable therapeutics.

  14. Myocardial Performance Index in Neurocardiogenic Syncope Patients

    PubMed Central

    Yilmaz Coskun, Fatma; Sucu, Murat; Uku, Okkes; Yuce, Murat; Ozer, Orhan; Ercan, Suleyman; Davutoglu, Vedat

    2014-01-01

    Background Many syncopes resulting from neural reflexes in various conditions are called neurocardiogenic syncope (NCS). We aimed to investigate the presence of left ventricular (LV) myocardial performance index (MPI) in patients with NCS, which was diagnosed with head-up tilt table test (HUTT), and the accurateness of the test in order to use it as a method in patients with NCS. Assuming the MPI as a potential cause of syncope, we assessed the Tei index with non-invasive tissue Doppler echocardiography method. Methods Consecutive outpatients with a history of recurrent unexplained syncope underwent HUTT. Twenty-nine HUTT (+) patients (24 female and five male, mean age: 30 ± 15 years) as the study group and HUTT (-) 23 healthy patients (six female and 17 male, mean age: 34 ± 16 years) as the control group were included into the study. Conventional and tissue Doppler echocardiography was performed to both groups. The MPI was determined by using PW Doppler. Measurements of Doppler time intervals, according to Tei index ((isovolumic contraction time + isovolumic relaxation time)/ejection time) is calculated as (a - b/b), where “a” is the interval between cessation and onset of the mitral inflow, and “b” is the ejection time (ET) at the LV outflow. Results When comparing the groups in terms of MPI and ET, there was significant difference between groups. Patients with NCS had significantly longer ET and lower MPI value than control group (284 ± 24 ms vs. 260 ± 24 ms, P < 0.001, respectively and 0.44 ± 0.7 vs. 0.52 ± 0.8, P < 0.001, respectively). There was no significant difference in ejection fraction between groups. Conclusion In the present study, LV MPI value decreases in patients with NCS.

  15. Myocardial toxicity in a group of greyhounds administered ractopamine.

    PubMed

    Yaeger, M J; Mullin, K; Ensley, S M; Ware, W A; Slavin, R E

    2012-05-01

    Ractopamine, a synthetic β(2)-adrenoceptor agonist, is widely used as a feed additive in the United States to promote a reduction in body fat and enhance muscle growth in cattle, pigs, and turkeys. It has the potential for illegal use in show and racing animals because it may affect performance via its β-adrenergic agonist properties or anabolic activities. Nine greyhounds were orally administered 1 mg/kg of ractopamine to investigate the ability to detect the drug in urine. Postdosing, 7 of 9 dogs developed cardiac arrhythmias and had elevated troponin levels indicating myocardial damage. One dog necropsied 4 days postdosing had massive myocardial necrosis, mild to focally moderate skeletal muscle necrosis, and widespread segmental arterial mediolysis. A second dog necropsied 17 days postdosing had mild myocardial necrosis and fibrosis. Scattered arteries exhibited segmental medial and perimedial fibromuscular dysplasia. This is the first reported case of arterial, cardiac, and skeletal muscle damage associated with ractopamine.

  16. Effects of methylphenidate (Ritalin) on mammalian myocardial ultrastructure.

    PubMed

    Henderson, T A; Fischer, V W

    1995-01-01

    Previous observations have indicated lamellated ultrastructural lesions in the myocardium of a patient treated with methylphenidate (Ritalin) hydrochloride (MPH). A causal relationship between MPH exposure and these membranous changes was tested in the myocardium of rats and mice. Following injection of varying doses of MPH for different periods, myocardial ultrastructure was examined and lesions were quantified by stereological techniques. Myocardial tissue also was stained using techniques selective for acid phosphatase and for sarcoplasmic reticulum to identify possible pathogenetic mechanisms. MPH induced membrane accumulations and lamellations which were not membrane-bound and did not react for acid phosphatase, but stained positively for sarcoplasmic reticulum. Both lesions were highly focal, surrounded by normal appearing myocardial tissue. Lamellations were evident at the earliest timepoints examined and appeared to occur without lysosomal involvement. Lesions were still apparent 12 weeks after terminating MPH. These data suggest that MPH may have persistent, cumulative effects on the myocardium.

  17. Amphetamine Containing Dietary Supplements and Acute Myocardial Infarction

    PubMed Central

    Hritani, Abdulwahab; Antoun, Patrick

    2016-01-01

    Weight loss is one of the most researched and marketed topics in American society. Dietary regimens, medications that claim to boost the metabolism, and the constant pressure to fit into society all play a role in our patient's choices regarding new dietary products. One of the products that are well known to suppress appetite and cause weight loss is amphetamines. While these medications suppress appetite, most people are not aware of the detrimental side effects of amphetamines, including hypertension, tachycardia, arrhythmias, and in certain instances acute myocardial infarction. Here we present the uncommon entity of an acute myocardial infarction due to chronic use of an amphetamine containing dietary supplement in conjunction with an exercise regimen. Our case brings to light further awareness regarding use of amphetamines. Clinicians should have a high index of suspicion of use of these substances when young patients with no risk factors for coronary artery disease present with acute arrhythmias, heart failure, and myocardial infarctions. PMID:27516911

  18. [Lay theories regarding myocardial infarction in a transcultural comparison].

    PubMed

    Bermejo, Isaac; Bursch, Stephanie; Muthny, Fritz A

    2006-08-01

    Culturally influenced lay theories about myocardial infarction which exist in healthy individuals have an impact on treatment compliance. However, empirical data on the subject is rare. Using healthy subjects, a transcultural survey comparing three different ethnic groups was conducted. The groups were: Germans in Germany, Spaniards in Spain, and 1st generation Spaniards in Germany. Subjects were paralleled according to age, sex, and education. The groups were compared regarding cultural differences in casual attributions and locus of control with respect to myocardial infarction. While all three groups show a psycho-social understanding of myocardial infarction, it is most predominate in the German group. The results show both common factors as well as some significant differences between Germans and Spaniards, the Spaniards reporting more external attributions. Consequences for prevention concepts and medical care in a multicultural society were derived from the results.

  19. [General features of myocardial protection in heart surgery].

    PubMed

    González Vergara, B

    2001-01-01

    Cardioplegia solutions commonly used in cardiac surgery, without doubt, have decreased the damage to the myocardium during these procedures; nonetheless, optimal cardioplegia composition is still under investigation, one of the most important factors to date is the use of hypothermia. Intermittent cold cardioplegia has been adopted as the choice for myocardial protection by surgeons. An alternative method, based on the principles of electromechanic asystole and normothermic aerobic perfusion, is the use of blood cardioplegia. As Follete et al. demonstrated, blood cardioplegia protects more than asanguineous cardioplegia, this conclusion is based on abnormal electrocardiographic tracings and enzyme activity in the postoperative period when both methods are compared. In this review we make a brief introduction on the physiologic and ischemic conditions of the myocardial cell, as well as on the principles of myocardial protection and techniques designed to avoid ischemic damage.

  20. Cardiovascular collapse after myocardial infarction due to centipede bite.

    PubMed

    Üreyen, Çağin Mustafa; Arslan, Şakir; Baş, Cem Yunus

    2015-07-01

    Centipede bites have been reported to cause localized and/or systemic symptoms including local pain, erythema and edema, nausea and vomiting, palpitations, headache, lymphadenopathy, and rhabdomyolysis. However, acute myocardial infarction due to centipede envenomation is reported in only three cases in English medical literature.We present a case of 31-year-old male bitten by a golden colored centipede leading to myocardial infarction and cardiopulmonary arrest which is seen very rarely. The patient was admitted to emergency department with a swollen and painful right foot. However, typical chest pain became the major complaint and cardiopulmonary arrest developed while electrocardiography was being obtained. The patient was resuscitated successfully for 5 min and acute infero-posterolateral myocardial infarction was detected on electrocardiography.

  1. Endogenous S-nitrosothiols protect against myocardial injury.

    PubMed

    Lima, Brian; Lam, Gregory K W; Xie, Liang; Diesen, Diana L; Villamizar, Nestor; Nienaber, Jeffrey; Messina, Emily; Bowles, Dawn; Kontos, Christopher D; Hare, Joshua M; Stamler, Jonathan S; Rockman, Howard A

    2009-04-14

    Despite substantial evidence that nitric oxide (NO) and/or endogenous S-nitrosothiols (SNOs) exert protective effects in a variety of cardiovascular diseases, the molecular details are largely unknown. Here we show that following left coronary artery ligation, mice with a targeted deletion of the S-nitrosoglutathione reductase gene (GSNOR(-/-)) have reduced myocardial infarct size, preserved ventricular systolic and diastolic function, and maintained tissue oxygenation. These profound physiological effects are associated with increases in myocardial capillary density and S-nitrosylation of the transcription factor hypoxia inducible factor-1alpha (HIF-1alpha) under normoxic conditions. We further show that S-nitrosylated HIF-1alpha binds to the vascular endothelial growth factor (VEGF) gene, thus identifying a role for GSNO in angiogenesis and myocardial protection. These results suggest innovative approaches to modulate angiogenesis and preserve cardiac function.

  2. [Cardiogenic shock in acute myocardial infarct. Its coronary angioplasty treatment].

    PubMed

    Fernández Valadez, E; García y Otero, J M; Escobar, G P; Frutos Rangel, E; Zúñiga Sedano, J; García García, R; Verduzco Bazavilvazo, S; López Aranda, J; López Ruiz, J

    1993-01-01

    Ventricular dysfunction is the most common cause of in-hospital death in patients with acute myocardial infarction. When cardiogenic shock is manifested the mortality is very high. Seven patients with cardiogenic shock complicating acute myocardial infarction were treated with emergency coronary angioplasty. Four patients required cardiopulmonary resuscitation (CPR), 2 intraaortic balloon pump support and one femoro-femoral bypass pump support during the coronary angioplasty. The angiography success rate was 86%. Two patients died, one in the catheterization laboratory and the other one 24 hours later. The hospital mortality was 29%. Of the patients who survived 4 are in functional class I and one in functional class II (NYHA). Coronary angioplasty therapy in patients with cardiogenic shock complicating acute myocardial infarction plays a decisive role in the reduction of mortality.

  3. Effect of beam hardening on transmural myocardial perfusion quantification in myocardial CT imaging

    NASA Astrophysics Data System (ADS)

    Fahmi, Rachid; Eck, Brendan L.; Levi, Jacob; Fares, Anas; Wu, Hao; Vembar, Mani; Dhanantwari, Amar; Bezerra, Hiram G.; Wilson, David L.

    2016-03-01

    The detection of subendocardial ischemia exhibiting an abnormal transmural perfusion gradient (TPG) may help identify ischemic conditions due to micro-vascular dysfunction. We evaluated the effect of beam hardening (BH) artifacts on TPG quantification using myocardial CT perfusion (CTP). We used a prototype spectral detector CT scanner (Philips Healthcare) to acquire dynamic myocardial CTP scans in a porcine ischemia model with partial occlusion of the left anterior descending (LAD) coronary artery guided by pressure wire-derived fractional flow reserve (FFR) measurements. Conventional 120 kVp and 70 keV projection-based mono-energetic images were reconstructed from the same projection data and used to compute myocardial blood flow (MBF) using the Johnson-Wilson model. Under moderate LAD occlusion (FFR~0.7), we used three 5 mm short axis slices and divided the myocardium into three LAD segments and three remote segments. For each slice and each segment, we characterized TPG as the mean "endo-to-epi" transmural flow ratio (TFR). BH-induced hypoenhancement on the ischemic anterior wall at 120 kVp resulted in significantly lower mean TFR value as compared to the 70 keV TFR value (0.29+/-0.01 vs. 0.55+/-0.01 p<1e-05). No significant difference was measured between 120 kVp and 70 keV mean TFR values on segments moderately affected or unaffected by BH. In the entire ischemic LAD territory, 120 kVp mean endocardial flow was significantly reduced as compared to mean epicardial flow (15.80+/-10.98 vs. 40.85+/-23.44 ml/min/100g; p<1e-04). At 70 keV, BH was effectively minimized resulting in mean endocardial MBF of 40.85+/-15.3407 ml/min/100g vs. 74.09+/-5.07 ml/min/100g (p=0.0054) in the epicardium. We also found that BH artifact in the conventional 120 kVp images resulted in falsely reduced MBF measurements even under non-ischemic conditions.

  4. Comparison of radiological and morphologic assessments of myocardial bridges.

    PubMed

    Ercakmak, Burcu; Bulut, Elif; Hayran, Mutlu; Kaymaz, Figen; Bilgin, Selma; Hazirolan, Tuncay; Bayramoglu, Alp; Erbil, Mine

    2015-09-01

    In this study we aimed to compare the findings of coronary dual-source computed tomography angiography of myocardial bridges with cadaveric dissections. Forty-one isolated, non-damaged fresh sheep hearts were used in this study. Myocardial bridges of the anterior interventricular branch of the left coronary artery were demonstrated and analyzed by a coronary dual-source computed tomography angiography. Dissections along the left anterior interventricular branch of the left coronary artery were performed by using Zeiss OPMI pico microscope and the length of the bridges were measured. The depths of the myocardial bridges were measured from the stained sections by using the light microscope (Leica DM 6000B). MBs were found in all 41 hearts (100%) during dissections. Dual-source computed tomography angiography successfully detected 87.8% (36 of the 41 hearts) of the myocardial bridges measured on left anterior interventricular branch of left coronary artery. The lengths of the myocardial bridges were found 5-40 and 8-50 mm with dissection and dual-source computed tomography angiography, respectively. And the depths were found 0.7-4.5 mm by dual-source computed tomography angiography and 0.745-4.632 mm morphologically. Comparison of the mean values of the lengths showed statistically significantly higher values (22.0 ± 8.5, 17.7 ± 7.7 mm, p = 0.003) for the dissections. Radiological assessment also effectively discriminated complete bridges from incomplete ones. Our study showed that coronary computed tomography angiography is reliable in evaluating the presence and depth of myocardial bridges.

  5. Myocardial matrix-polyethylene glycol hybrid hydrogels for tissue engineering

    NASA Astrophysics Data System (ADS)

    Grover, Gregory N.; Rao, Nikhil; Christman, Karen L.

    2014-01-01

    Similar to other protein-based hydrogels, extracellular matrix (ECM) based hydrogels, derived from decellularized tissues, have a narrow range of mechanical properties and are rapidly degraded. These hydrogels contain natural cellular adhesion sites, form nanofibrous networks similar to native ECM, and are biodegradable. In this study, we expand the properties of these types of materials by incorporating poly(ethylene glycol) (PEG) into the ECM network. We use decellularized myocardial matrix as an example of a tissue specific ECM derived hydrogel. Myocardial matrix-PEG hybrids were synthesized by two different methods, cross-linking the proteins with an amine-reactive PEG-star and photo-induced radical polymerization of two different multi-armed PEG-acrylates. We show that both methods allow for conjugation of PEG to the myocardial matrix by gel electrophoresis and infrared spectroscopy. Scanning electron microscopy demonstrated that the hybrid materials still contain a nanofibrous network similar to unmodified myocardial matrix and that the fiber diameter is changed by the method of PEG incorporation and PEG molecular weight. PEG conjugation also decreased the rate of enzymatic degradation in vitro, and increased material stiffness. Hybrids synthesized with amine-reactive PEG had gelation rates of 30 min, similar to the unmodified myocardial matrix, and incorporation of PEG did not prevent cell adhesion and migration through the hydrogels, thus offering the possibility to have an injectable ECM hydrogel that degrades more slowly in vivo. The photo-polymerized radical systems gelled in 4 min upon irradiation, allowing 3D encapsulation and culture of cells, unlike the soft unmodified myocardial matrix. This work demonstrates that PEG incorporation into ECM-based hydrogels can expand material properties, thereby opening up new possibilities for in vitro and in vivo applications.

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

    PubMed Central

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

    1994-01-01

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

  7. Dense motion field estimation from myocardial boundary displacements.

    PubMed

    Morais, Pedro; Queirós, Sandro; Ferreira, Adriano; Rodrigues, Nuno F; Baptista, Maria J; D'hooge, Jan; Vilaça, João L; Barbosa, Daniel

    2016-09-01

    Minimally invasive cardiovascular interventions guided by multiple imaging modalities are rapidly gaining clinical acceptance for the treatment of several cardiovascular diseases. These images are typically fused with richly detailed pre-operative scans through registration techniques, enhancing the intra-operative clinical data and easing the image-guided procedures. Nonetheless, rigid models have been used to align the different modalities, not taking into account the anatomical variations of the cardiac muscle throughout the cardiac cycle. In the current study, we present a novel strategy to compensate the beat-to-beat physiological adaptation of the myocardium. Hereto, we intend to prove that a complete myocardial motion field can be quickly recovered from the displacement field at the myocardial boundaries, therefore being an efficient strategy to locally deform the cardiac muscle. We address this hypothesis by comparing three different strategies to recover a dense myocardial motion field from a sparse one, namely, a diffusion-based approach, thin-plate splines, and multiquadric radial basis functions. Two experimental setups were used to validate the proposed strategy. First, an in silico validation was carried out on synthetic motion fields obtained from two realistic simulated ultrasound sequences. Then, 45 mid-ventricular 2D sequences of cine magnetic resonance imaging were processed to further evaluate the different approaches. The results showed that accurate boundary tracking combined with dense myocardial recovery via interpolation/diffusion is a potentially viable solution to speed up dense myocardial motion field estimation and, consequently, to deform/compensate the myocardial wall throughout the cardiac cycle. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Cardiac Trauma: Clinical and Experimental Correlations of Myocardial Contusion

    PubMed Central

    Doty, Donald B.; Anderson, Alan E.; Rose, Earl F.; Go, Raymundo T.; Chiu, Chiang L.; Ehrenhaft, J. L.

    1974-01-01

    Clinical and experimental observations in myocardial contusion have been correlated. Cardiac arrhythmia is always an important consequence and may be fatal. Reduction in cardiac output often accompanies significant cardiac injury. The coronary arterial circulation is not interrupted and is generally enhanced to the area of injury. Healing of the injury under these circulatory conditions may result in patchy scarring and peculiar adynamic areas of myocardium. Early diagnosis of myocardial contusion may be aided using radionuclide imaging with 99mTc-Sn-polyphosphate. ImagesFig. 1.Fig. 2.Fig. 3.Fig. 4.Fig. 5.Fig. 6.Fig. 7.Fig. 8. PMID:4412327

  9. Myocardial Infarction after Endoscopic Removal of Foreign Body

    PubMed Central

    Lupercio, Florentino; Piña, Ileana L.

    2017-01-01

    The development of cardiac complications during or after endoscopic procedures is rare. However, mortality from myocardial ischemia, particularly in the elderly population, is elevated. We illustrate the rare case of a 79-year-old man with multiple cardiovascular risk factors who developed a non-ST elevation myocardial infarction (NSTEMI) after endoscopic removal of a foreign body. This case report summarizes a rare complication of a low-risk procedure and highlights the importance of considering this potential adverse event, particularly in patients with significant cardiovascular risk factors, to promote early diagnosis and proper treatment. PMID:28337347

  10. Myocardial T1 mapping: modalities and clinical applications

    PubMed Central

    Jellis, Christine L.

    2014-01-01

    Myocardial fibrosis appears to be linked to myocardial dysfunction in a multitude of non-ischemic cardiomyopathies. Accurate non-invasive quantitation of this extra-cellular matrix has the potential for widespread clinical benefit in both diagnosis and guiding therapeutic intervention. T1 mapping is a cardiac magnetic resonance (CMR) imaging technique, which shows early clinical promise particularly in the setting of diffuse fibrosis. This review will outline the evolution of T1 mapping and the various techniques available with their inherent advantages and limitations. Histological validation of this technique remains somewhat limited, however clinical application in a range of pathologies suggests strong potential for future development. PMID:24834410

  11. Risk stratification after acute myocardial infarction: which studies are best?

    PubMed

    Figueredo, V M

    1996-04-01

    The prognosis for a patient who has survived an acute myocardial infarction depends on three general prognostic factors: (1) residual left ventricular function, (2) remaining viable myocardium at risk (residual ischemia), and (3) presence of substrate for the development of malignant arrhythmias. Multiple clinical and historical factors predict the presence of one or more of these prognostic indicators. Electrocardiographic exercise treadmill testing needs to be done in all patients with uncomplicated infarctions. Guidelines of the American College of Cardiology/American Heart Association Task Force are recommended for risk stratification in most patients after acute myocardial infarction.

  12. [Is secondary myocardial hypertrophy a physiological or pathological adaptive mechanism?].

    PubMed

    Krayenbühl, H P

    1982-08-01

    Physiological hypertrophy is present when the increase in myocardial mass resulting from chronic mechanical loading is associated with normal or enhanced myocardial function and myosin ATPase activity. Morphological alterations occurring during the formation of hypertrophy are fully reversible in physiological hypertrophy. In pathological hypertrophy myocardial function and myosin ATPase activity are depressed and morphological changes do not or only incompletely regress following the elimination of the stimulus of hypertrophy. In the experimental animal myocardial hypertrophy resulting from exercise conditioning or slight to moderate ventricular pressure overload fulfills the criteria of physiological hypertrophy. More severe sudden pressure overload is accompanied by depression of contractile function. These pressure overload models have however, little analogy to the more progressive development of pressure loading in humans. In young dogs and in cats with a gradually increasing pressure load, in vivo ventricular ejection fraction remained within normal limits 37 to 60 weeks after banding of the ventricular outflow vessel. In vitro myocardial function evaluated in the hypertrophied papillary muscle was, however, at least in part depressed, notably when hydroxyproline concentration was augmented. Following debanding in rats with aortic constriction hydroxyproline content did not regress suggesting that fibrosis once established is not reversible. In man myocardial hypertrophy from exercise conditioning is associated with normal ventricular function except in older athletes, who may show a subtle reduction in ventricular shortening. Patients with chronic pressure overload from aortic stenosis or volume overload from aortic insufficiency in whom the angiographic muscle mass is severely increased (greater than or equal to 180 g/m2) elicit a depressed left ventricular contractile function. Preserved left ventricular ejection performance in aortic valve disease is

  13. ST-elevation acute myocardial infarction in pregnancy: 2016 update.

    PubMed

    Ismail, Sahar; Wong, Cynthia; Rajan, Priya; Vidovich, Mladen I

    2017-02-13

    Acute myocardial infarction (AMI) during pregnancy or the early postpartum period is rare, but can be devastating for both the mother and the fetus. There have been major advances in the diagnosis and treatment of acute coronary syndromes in the general population, but there is little consensus on the approach to diagnosis and treatment of pregnant women. This article reviews the literature relating to the pathophysiology of AMI in pregnant patients and the challenges in diagnosis and treatment of ST-elevation myocardial infarction (STEMI) in this unique population. From a cardiologist, maternal-fetal medicine specialist, and anesthesiologist's perspective, we provide recommendations for the diagnosis and management of STEMI occurring during pregnancy.

  14. Myocardial perfusion scintigraphy: techniques, interpretation, indications and reporting.

    PubMed

    Fathala, Ahmed

    2011-01-01

    Myocardial perfusion single photon emission-computed tomography (MPS) has been one of the most important and common non-invasive diagnostic cardiac test. Gated MPS provides simultaneous assessment of myocardial perfusion and function with only one study. With appropriate attention to the MPS techniques, appropriate clinical utilization and effective reporting, gated MPS will remain a useful diagnostic test for many years to come. The aim of this article is to review the basic techniques of MPS, a simplified systematic approach for study interpretation, current clinical indications and reporting. After reading this article the reader should develop an understanding of the techniques, interpretation, current clinical indications and reporting of MPS studies.

  15. Pathological observation of acute myocardial infarction in Chinese miniswine

    PubMed Central

    Wang, Chuang; Wang, Shao-Xin; Dong, Ping-Shuan; Wang, Li-Ping; Duan, Na-Na; Wang, Yan-Yu; Wang, Ke; Li, Zhuan-Zhen; Wei, Li-Juan; Meng, Ya-Li; Cheng, Jian-Xin

    2015-01-01

    The acute myocardial infarction (AMI) model in Chinese miniswine was built by percutaneous coronary artery occlusion. Pathological observation of AMI was performed, and the expression of tumor necrosis factor alpha (TNF-α) in the infarct sites was detected at different days after modeling in Chinese miniswine. The experimental findings may be used as the basis for blood flow reconstruction and intervention after AMI. Seven experimental Chinese miniswine were subjected to general anesthesia and Seldinger right femoral artery puncture. After coronary angiography, the gelfoam was injected via the microtube to occlude the obtuse marginal branch (OM branch). At 1 d, 3 d, 5 d, 7 d, 10 d, 14 d and 17 d after modeling, hetatoxylin-eosin (HE) staining was performed to observe the pathological changes and to detect the expression of TNF-α in the myocardial tissues. Cytoplasmic acidophilia of the necrotic myocardial tissues at 1 d after modeling was enhanced, and cytoplasmic granules were formed; at 3 d, the margins of the necrotic myocardial tissues were infiltrated by a large number of inflammatory cells; at 5 d, the nuclei of the necrotic myocardial cells were fragmented; at 7 d, extensive granulation tissues were formed at the margin of the necrotic myocardial tissues; at 10 d, part of the granulation tissues were replaced by fibrous scar tissues; at 14-17 d, all granulation tissues were replaced by fibrous scar tissues. Immunohistochemical detection indicated that no TNF-α expression in normal myocardial tissues. The TNF-α expression was first detected at 3 d in the necrotic myocardial tissues and then increased at 5 d and 7 d. After reaching the peak at 10 d, the expression began to decrease at 14 d and the decrease continued at 17 d. Coronary angiography showed the disappearance of blood flow at the distal end of OM branch occluded by gelfoam, indicating that AMI model was constructed successfully. The repair of the infarcted myocardium began at 10-17 d after

  16. Myocardial Infarction after Endoscopic Removal of Foreign Body.

    PubMed

    Maraboto, Carola; Lupercio, Florentino; Piña, Ileana L

    2017-01-01

    The development of cardiac complications during or after endoscopic procedures is rare. However, mortality from myocardial ischemia, particularly in the elderly population, is elevated. We illustrate the rare case of a 79-year-old man with multiple cardiovascular risk factors who developed a non-ST elevation myocardial infarction (NSTEMI) after endoscopic removal of a foreign body. This case report summarizes a rare complication of a low-risk procedure and highlights the importance of considering this potential adverse event, particularly in patients with significant cardiovascular risk factors, to promote early diagnosis and proper treatment.

  17. Percutaneous transluminal septal myocardial ablation in hypertrophic cardiomyopathy

    PubMed Central

    van der Lee, C.; Foley, D.P.; Vletter, W.B.; ten Cate, F.J.; Kofflard, M.J.M.

    2001-01-01

    Background Percutaneous transluminal septal myocardial ablation (PTSMA) is a new interventional technique to treat patients with hypertrophic cardiomyopathy. Methods Small doses of ethanol 96% were injected into a targeted septal artery causing a chemical myocardial infarction. Three patients were evaluated, including a follow-up of three months. Results There were no complications during the procedure LVOT gradient was reduced from 120±140 mmHg. At follow-up, all three patients showed improvement in validity. Conclusion The method requires an echocardiographic contrast determination of the myocardium at risk for ethanol treatment, in addition to haemodynamic monitoring. ImagesFigure 1Figure 2Figure 3A PMID:25696698

  18. Echocardiography in the Assessment of Complications of Myocardial Infarction

    PubMed Central

    Wilansky, Susan

    1991-01-01

    The value of echocardiography as a tool for evaluating the prognosis of patients after myocardial infarction lies in its ability to define the region and extent of ischemic damage. Additionally, echocardiography is useful in assessing and predicting postinfarction complications. Wall motion abnormalities, pericardial effusion, left ventricular thrombi, and left ventricular aneurysms and pseudoaneurysms can be detected using echocardiography. The severity of mitral regurgitation and the location of interventricular septal repture can also be assessed using echocardiography. This diagnostic tool can provide vital information regarding the appropriate clinical management of patients after myocardial infarction. (Texas Heart Institute Journal 1991; 18:237-42) Images PMID:15227405

  19. Imaging Macrophage Development and Fate in Atherosclerosis and Myocardial Infarction

    PubMed Central

    Swirski, Filip K.; Nahrendorf, Matthias

    2013-01-01

    Macrophages are central regulators of disease progression in both atherosclerosis and myocardial infarction. In atherosclerosis, macrophages are the dominant leukocyte population that influences lesional development. In myocardial infarction, which is caused by atherosclerosis, macrophages accumulate readily and play important roles in inflammation and healing. Molecular imaging has grown considerably as a field and can reveal biological process at the molecular, cellular, and tissue levels. Here we explore how various imaging modalities, from intravital microscopy in mice to organ-level imaging in patients, are contributing to our understanding of macrophages and their progenitors in cardiovascular disease. PMID:23207281

  20. Hair zinc and copper concentration in survivors of myocardial infarction.

    PubMed

    Białkowska, M; Hoser, A; Szostak, W B; Dybczyński, R; Sterliński, S; Nowicka, G; Majchrzak, J; Kaczorowski, J; Danko, B

    1987-01-01

    Increased Zn/Cu ratio in the diet, and consequently in the body, was suggested to be of importance in the pathogenesis of atherosclerosis. Head hair of 29 male survivors of myocardial infarction and of 23 control males was studied for the concentration of Zn and Cu. The Zn hair concentration and Zn/Cu ratio in survivors of myocardial infarction was significantly higher in comparison with controls. The inclusion of the Zn/Cu ratio into the discriminant analysis using total cholesterol and HDL cholesterol considerably improved the coefficient R2 and decreased the number of cases not properly classified.

  1. A Multidisciplinary Assessment of Remote Myocardial Fibrosis After Reperfused Myocardial Infarction in Swine and Patients.

    PubMed

    Hervas, Arantxa; Ruiz-Sauri, Amparo; Gavara, Jose; Monmeneu, Jose V; de Dios, Elena; Rios-Navarro, Cesar; Perez-Sole, Nerea; Perez, Itziar; Monleon, Daniel; Morales, Jose M; Minana, Gema; Nunez, Julio; Bonanad, Clara; Diaz, Ana; Vila, Jose M; Chorro, Francisco J; Bodi, Vicente

    2016-08-01

    In extensive nonreperfused myocardial infarction (MI), remote fibrosis has been documented. Early reperfusion by primary angioplasty represents the gold standard method to minimize the extension of the infarction. We aimed to ascertain whether fibrosis also affects remote regions in reperfused MI in swine and patients. Swine were subjected to a transient occlusion of the left anterior descending artery followed by 1-week or 1-month reperfusion. Collagen content in the remote area macroscopically, microscopically, by magnetic resonance microimaging, and at the molecular level was similar to controls. In patients with previous MI, samples from autopsies displayed a significant increase in collagen content only in the infarct region. In patients with previous MI submitted to cardiac magnetic resonance-T1 mapping, the extracellular volume fraction in remote segments was similar to that for controls. In all scenarios, the remote region did not show a significant increase of collagen content in comparison with controls.

  2. Formation of binucleated myocardial cells in the neonatal rat. An index for growth hypertrophy.

    PubMed

    Clubb, F J; Bishop, S P

    1984-05-01

    The purposes of this study were to characterize myocardial cell growth in neonatal rats and investigate the mechanism of binucleation in myocardial cells. To test the hypothesis that binucleated myocardial cells result from karyokinesis without cytokinesis, experiments were designed to measure the rate of DNA synthesis and the percentage of binucleated myocardial cells in neonatal rats during growth. Estimates of myocardial cell nuclear divisions were obtained from rats pulsed with tritiated thymidine at 17 days of gestation. Autoradiograms were prepared from isolated myocardial cells of rats killed at various ages postpartum, and the number of developed silver halide grains over myocardial cell nuclei was calculated. This estimated the mitotic activity of nuclei. To determine myocardial cell DNA synthesis postpartum, another set of rats were injected at various time periods with 4 hourly doses of tritiated thymidine, and hearts were fixed by perfusion 1 hour later. Labeling index of myocardial cells was calculated (labeled/total myocardial cells) from autoradiograms prepared on 1 micron thick, methacrylate-embedded heart cross-sections. Results of this study indicated that the growth of myocardial cells in the neonatal period can be divided into three phases: (a) a hyperplastic phase, (b) a transitional phase, and (c) a hypertrophic phase. Binucleation of myocardial cells was not due to fusion of mononucleated cells, because there was continued DNA synthesis in the neonatal hearts, reflected by continued incorporation of tritiated thymidine; in addition, the grain counts per nucleus of the binucleated myocardial cells were half that of mononucleated cells; nor was binucleation due to amitotic splitting of single nuclei, since binucleated myocardial cells had similar grain counts over each nucleus. We conclude that the formation of binucleated myocardial cells is an early indicator of growth hypertrophy in the neonatal rat and a result of mitosis without

  3. Spatial analysis of myocardial infarction in Iran: National report from the Iranian myocardial infarction registry

    PubMed Central

    Ahmadi, Ali; Soori, Hamid; Mehrabi, Yadollah; Etemad, Koorosh

    2015-01-01

    Background: Myocardial infarction (MI) is a leading cause of mortality and morbidity in Iran. No spatial analysis of MI has been conducted to date. The present study was conducted to determine the pattern of MI incidence and to identify the associated factors in Iran by province. Materials and Methods: This study has two parts. One part is prospective and hospital-based, and the other part is an ecological study. In this study, the data of 20,750 new MI cases registered in Iranian Myocardial Infarction Registry in 2012 were used. For spatial analysis in global and local, spatial autocorrelation, Moran's I, Getis-Ord, and logistic regression models were used. Data were analyzed by Stata software and ArcGIS 9.3. Results: Based on autocorrelation coefficient, a specific pattern was observed in the distribution of MI incidence in different provinces (Moran's I: 0.75, P < 0.001). Spatial pattern of incidence was approximately the same in men and women. MI incidence was clustering in six provinces (North Khorasan, Yazd, Kerman, Semnan, Golestan, and Mazandaran). Out of the associated factors with clustered MI in six provinces, temperature, humidity, hypertension, smoking, and body mass index (BMI) could be mentioned. Hypertension, smoking, and BMI contributed to clustering with, respectively, 2.36, 1.31, and 1.31 odds ratio. Conclusion: Addressing the place-based pattern of incidence and clarifying their epidemiologic dimension, including spatial analysis, has not yet been implemented in Iran. Report on MI incidence rate by place and formal borders is useful and is used in the planning and prioritization in different levels of health system. PMID:26487871

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

    PubMed

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

    2014-12-15

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

  5. Low molecular weight heparin for treatment of acute myocardial infarction (FAMI): Fragmin (dalteparin sodium) in acute myocardial infarction.

    PubMed

    Kakkar, V V; Iyengar, S S; De Lorenzo, F; Hargreaves, J R; Kadziola, Z A

    2000-01-01

    The benefit of using subcutaneous low molecular weight heparin for the treatment of acute myocardial infarction is not known. The aim of this study was to determine the efficacy of a low molecular weight heparin (dalteparin sodium) for the treatment of acute myocardial infarction in patients not treated with thrombolytic therapy. Twenty-nine cardiological centres from leading hospitals in India participated in this prospective, multicentre, double-blind, placebo-controlled study in two phases which included 1128 patients with acute myocardial infarction. In the acute phase (between day 1 and 3 of admission) all the patients received a weight-adjusted dose of subcutaneous dalteparin (120 IU/kg twice daily). In the second, double-blind phase of acute myocardial infarction, patients were randomised to receive a fixed dose of dalteparin (7,500 IU) or an identical placebo injection for 30 days. A composite primary endpoint of death, reinfarction, recurrence of angina and emergency revascularisation was used. All the 1128 patients with acute myocardial infarction were included in the trial. In the acute phase, the composite primary endpoint was observed in 58 (5.1%) patients. Of 1037 paients who were randomly assigned to receive a fixed dose of dalteparin (n=519) or placebo (n=518), the composite primary event rate was 6.7 percent and 7.0 percent, respectively (RR 0.97; 95% CI 0.62-1.52; p=0.90). To conclude, treatment with dalteparin administered subcutaneously in a weight-adjusted dose of 120 IU/kg twice daily resulted in a lower than expected mortality during the acute phase of myocardial infarction. A lower fixed once daily dose of 7,500 IU during the chronic phase did not confer additional protection.

  6. Sevoflurane postconditioning improves myocardial mitochondrial respiratory function and reduces myocardial ischemia-reperfusion injury by up-regulating HIF-1

    PubMed Central

    Yang, Long; Xie, Peng; Wu, Jianjiang; Yu, Jin; Yu, Tian; Wang, Haiying; Wang, Jiang; Xia, Zhengyuan; Zheng, Hong

    2016-01-01

    Background: Sevoflurane postconditioning (SPostC) can exert myocardial protective effects similar to ischemic preconditioning. However, the exact myocardial protection mechanism by SPostC is unclear. Studies indicate that hypoxia-inducible factor-1 (HIF-1) maintains cellular respiration homeostasis by regulating mitochondrial respiratory chain enzyme activity under hypoxic conditions. This study investigated whether SPostC could regulate the expression of myocardial HIF-1α and to improve mitochondrial respiratory function, thereby relieving myocardial ischemia-reperfusion injury in rats. Methods: The myocardial ischemia-reperfusion rat model was established using the Langendorff isolated heart perfusion apparatus. Additionally, postconditioning was performed using sevoflurane alone or in combination with the HIF-1α inhibitor 2-methoxyestradiol (2ME2). The changes in hemodynamic parameters, HIF-1α protein expression levels, mitochondrial respiratory function and enzyme activity, mitochondrial reactive oxygen species (ROS) production rates, and mitochondrial ultrastructure were measured or observed. Results: Compared to the ischemia-reperfusion (I/R) group, HIF-1α expression in the SPostC group was significantly up-regulated. Additionally, cardiac function indicators, mitochondrial state 3 respiratory rate, respiratory control ratio (RCR), cytochrome C oxidase (CcO), NADH oxidase (NADHO), and succinate oxidase (SUCO) activities, mitochondrial ROS production rate, and mitochondrial ultrastructure were significantly better than those in the I/R group. However, these advantages were completely reversed by the HIF-1α specific inhibitor 2ME2 (P<0.05). Conclusion: The myocardial protective function of SPostC might be associated with the improvement of mitochondrial respiratory function after up-regulation of HIF-1α expression. PMID:27830025

  7. Osteoprotegerin levels in ST-elevation myocardial infarction: Temporal profile and association with myocardial injury and left ventricular function

    PubMed Central

    Shetelig, Christian; Limalanathan, Shanmuganathan; Eritsland, Jan; Hoffmann, Pavel; Seljeflot, Ingebjørg; Gran, Jon Michael; Aukrust, Pål; Ueland, Thor; Andersen, Geir Øystein

    2017-01-01

    Background Elevated levels of osteoprotegerin (OPG) have been associated with adverse outcomes in ST-elevation myocardial infarction (STEMI). However, the role of OPG in myocardial injury and adverse remodeling in STEMI patients remains unclear. The aims of this observational cohort study were to evaluate: 1) the temporal profile of OPG during STEMI, 2) possible associations between OPG measured acutely and after 4 months, with infarct size, adverse left ventricular (LV) remodeling, microvascular obstruction (MVO) and myocardial salvage and 3) the effect of heparin administration on OPG levels. Methods Blood samples were drawn repeatedly from 272 STEMI patients treated with primary percutaneous coronary intervention (PCI). Cardiac magnetic resonance imaging (CMR) was performed in the acute phase and after 4 months. The effect of heparin administration on OPG levels was studied in 20 patients referred to elective coronary angiography. Results OPG levels measured acutely were significantly higher than Day 1 and during follow-up. OPG levels were correlated with age. No association was found between early OPG levels and CMR measurements at 4 months. Patients with >median OPG levels measured at Day 1 had larger final infarct size, lower LV ejection fraction (LVEF) at 4 months and higher frequency of MVO. There were no associations between OPG and change in end-diastolic volume or myocardial salvage. OPG remained associated with infarct size and LVEF after adjustment for relevant covariates, except peak troponin T and CRP. A 77% increase in OPG levels following heparin administration was found in patients undergoing elective coronary angiography. Conclusions OPG was found to be associated with myocardial injury, but not with LV remodeling or myocardial salvage. The use of OPG as a biomarker in STEMI patients seems to be limited by a strong association with age, confounding effect of heparin administration, and little additive value to established biomarkers. PMID

  8. Clinical efforts to reduce myocardial infarct size--the next step.

    PubMed

    Braunwald, Eugene

    2011-01-01

    Prompt myocardial reperfusion reduces infarct size in patients experiencing coronary occlusion. However, its clinical value is limited because reperfusion also causes ischemic myocardial reperfusion injury (IMRI). Considerable research to reduce IMRI has been conducted. Three interventions appear to be promising: 1) myocardial conditioning, which consists of repetitive occlusions of coronary or other arteries prior to or at the time of myocardial reperfusion; 2) the administration of cyclosporine A; and 3) the administration of adenosine. A plan for the testing of these interventions in patients with acute myocardial infarction is described.

  9. Myocardial uptake of indium-111-labeled antimyosin in acute subendocardial infarction: Clinical, histochemical, and autoradiographic correlation of myocardial necrosis

    SciTech Connect

    Hendel, R.C.; McSherry, B.A.; Leppo, J.A. )

    1990-11-01

    Indium-111-labeled antimyosin has been utilized in the diagnosis and localization of acute transmural myocardial infarction. The present report describes a patient who presented with a massive subendocardial infarction. Two days after the injection of antimyosin, the patient's clinical status markedly deteriorated and he expired. Postmortem examination demonstrated severe three-vessel coronary artery disease with extensive myocyte death in the endocardium. Autoradiography and histochemical staining of the prosected heart demonstrated high correlation for myocardial necrosis and corresponded to clinical evidence for diffuse subendocardial infarction.

  10. Effects of carbon monoxide on myocardial ischemia.

    PubMed Central

    Allred, E N; Bleecker, E R; Chaitman, B R; Dahms, T E; Gottlieb, S O; Hackney, J D; Pagano, M; Selvester, R H; Walden, S M; Warren, J

    1991-01-01

    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. The exposures resulted in postexercise carboxyhemoglobin (COHb) levels of 0.6% +/- 0.3%, 2.0% +/- 0.1%, and 3.9% +/- 0.1%. The results obtained on the 2%-COHb day and 3.9%-COHb day were compared to those on the room air day. There were 5.1% (p = 0.01) and 12.1% (p less than or equal to 0.0001) decreases in the time to development of ischemic ST-segment changes after exposures producing 2.0 and 3.9% COHb, respectively, compared to the control day. In addition, there were 4.2% (p = 0.027) and 7.1% (p = 0.002) decreases in time to the onset of angina after exposures producing 2.0 and 3.9% COHb, respectively, compared to the control day. 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 tests 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. PMID:2040254

  11. Myocardial bridges of the coronary arteries in the human fetal heart.

    PubMed

    Cakmak, Yusuf Ozgür; Cavdar, Safiye; Yalin, Aymelek; Yener, Nuran; Ozdogmus, Omer

    2010-09-01

    During the last century, many investigators reported on myocardial bridges in the adult human heart. In the present study, 39 human fetal hearts (the mean gestastional age was 30 weeks) were studied for myocardial bridging, and the results were correlated with adult data. Among the 39 (27 male and 12 female) fetal hearts studied, 26 bridges were observed on 18 fetal hearts (46.2%). Ten of the bridges had one myocardial bridge, whereas double myocardial bridges were observed in eight fetal hearts. The most frequent myocardial bridges were observed on the left anterior descending artery (LAD), which had 13 bridges (50%). Eight (30.7%) myocardial bridges were on the diagonal artery, and on the posterior descending artery there were five (19.3%). Myocardial bridges were not observed on the circumflex artery. The data presented in this study may provide potentially useful information for the preoperative evaluation of the newborn and may have a clinical implication for sudden fetal death.

  12. Diagnostic and therapeutic implications of type 2 myocardial infarction: review and commentary.

    PubMed

    Alpert, Joseph S; Thygesen, Kristian A; White, Harvey D; Jaffe, Allan S

    2014-02-01

    The Task Force for the Universal Definition of Myocardial Infarction recently published updated guidelines for the clinical and research diagnosis of myocardial infarction under a variety of circumstances and in a variety of categories. A type 1 myocardial infarction (MI) is usually the result of atherosclerotic coronary artery disease with thrombotic coronary arterial obstruction secondary to atherosclerotic plaque rupture, ulceration, fissuring, or dissection, causing coronary arterial obstruction with resultant myocardial ischemia and necrosis. Patients with a type 2 MI do not have atherosclerotic plaque rupture. In this latter group of patients, myocardial necrosis occurs because of an increase in myocardial oxygen demand or a decrease in myocardial blood flow. Type 2 MI has been the subject of considerable clinical discussion and confusion. This review by knowledgeable members of the Task Force seeks to help clinicians resolve the confusion surrounding type 2 MI.

  13. Feasibility of voxel-based statistical analysis method for myocardial PET

    NASA Astrophysics Data System (ADS)

    Ram Yu, A.; Kim, Jin Su; Paik, Chang H.; Kim, Kyeong Min; Moo Lim, Sang

    2014-09-01

    Although statistical parametric mapping (SPM) analysis is widely used in neuroimaging studies, to our best knowledge, there was no application to myocardial PET data analysis. In this study, we developed the voxel based statistical analysis method for myocardial PET which provides statistical comparison results between groups in image space. PET Emission data of normal and myocardial infarction rats were acquired For the SPM analysis, a rat heart template was created. In addition, individual PET data was spatially normalized and smoothed. Two sample t-tests were performed to identify the myocardial infarct region. This developed SPM method was compared with conventional ROI methods. Myocardial glucose metabolism was decreased in the lateral wall of the left ventricle. In the result of ROI analysis, the mean value of the lateral wall was 29% decreased. The newly developed SPM method for myocardial PET could provide quantitative information in myocardial PET study.

  14. Calpain system and its involvement in myocardial ischemia and reperfusion injury

    PubMed Central

    Neuhof, Christiane; Neuhof, Heinz

    2014-01-01

    Calpains are ubiquitous non-lysosomal Ca2+-dependent cysteine proteases also present in myocardial cytosol and mitochondria. Numerous experimental studies reveal an essential role of the calpain system in myocardial injury during ischemia, reperfusion and postischemic structural remodelling. The increasing Ca2+-content and Ca2+-overload in myocardial cytosol and mitochondria during ischemia and reperfusion causes an activation of calpains. Upon activation they are able to injure the contractile apparatus and impair the energy production by cleaving structural and functional proteins of myocytes and mitochondria. Besides their causal involvement in acute myocardial dysfunction they are also involved in structural remodelling after myocardial infarction by the generation and release of proapoptotic factors from mitochondria. Calpain inhibition can prevent or attenuate myocardial injury during ischemia, reperfusion, and in later stages of myocardial infarction. PMID:25068024

  15. [Myocardial function analysis with echocardiography-Doppler in septic shock].

    PubMed

    Fayssoil, A; Checinski, A

    2012-02-01

    Septic shock is a severe sepsis associated with cardio-circulatory failure and tissular hypoperfusion. Echocardiography-Doppler remains essential for the assessment of myocardial function in septic shock. This ultrasound procedure helps clinicians for the analysis of left ventricular systolic function, left ventricular diastolic function, right ventricular function and cardiac filling.

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

    PubMed

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

    2016-07-01

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

  17. Modeling the myocardial dilution curve of a pure intravascular indicator.

    PubMed

    Lee, J S; Karch, J; Jayaweera, A R; Lindner, J R; Lee, L P; Skyba, D M; Kaul, S

    1997-10-01

    The dispersion and dilution of contrast medium through the myocardial vasculature is examined first with a serial model comprised of arterial, capillary, and venous components in series to determine their time-concentration curves (TCC) and the myocardial dilution curve (MDC). Analysis of general characteristics shows that the first moment of the MDC, adjusted for that of the aortic TCC and mean transit time (MTT) from the aorta to the first intramyocardial artery, is one-half the MTT of the myocardial vasculature and that the ratio of the area of the MDC and aortic TCC is the fractional myocardial blood volume (MBV). The use of known coronary vascular morphometry and a set of transport functions indicates that the temporal change in MDC is primarily controlled by the MTT. An analysis of several models with heterogeneous flow distributions justifies the procedures to calculate MTT and MBV from the measured MDC. Compared with previously described models, the present model is more general and provides a physical basis for the effects of flow dispersion and heterogeneity on the characteristics of the MDC.

  18. A History of Streptokinase Use in Acute Myocardial Infarction

    PubMed Central

    Sikri, Nikhil; Bardia, Amit

    2007-01-01

    A serendipitous discovery by William Smith Tillett in 1933, followed by many years of work with his student Sol Sherry, laid a sound foundation for the use of streptokinase as a thrombolytic agent in the treatment of acute myocardial infarction. The drug found initial clinical application in combating fibrinous pleural exudates, hemothorax, and tuberculous meningitis. In 1958, Sherry and others started using streptokinase in patients with acute myocardial infarction and changed the focus of treatment from palliation to “cure.” Initial trials that used streptokinase infusion produced conflicting results. An innovative approach of intracoronary streptokinase infusion was initiated by Rentrop and colleagues in 1979. Subsequently, larger trials of intracoronary infusion achieved reperfusion rates ranging from 70% to 90%. The need for a meticulously planned and systematically executed randomized multicenter trial was fulfilled by the Gruppo Italiano per la Sperimentazione della Streptochinasi nell'Infarto Miocardico (GISSI) trial in 1986, which not only validated streptokinase as an effective therapeutic method but also established a fixed protocol for its use in acute myocardial infarction. Currently, despite the wide use of tissue plasminogen activator in developed nations, streptokinase remains essential to the management of acute myocardial infarction in developing nations. PMID:17948083

  19. Myocardial Scar Detection by Standard CT Coronary Angiography

    PubMed Central

    Jeevarethinam, Anand; Venuraju, Shreenidhi; Mehta, Vishal Shahil; Atwal, Satvir; Raval, Usha; Rakhit, Roby; Davar, Joseph; Lahiri, Avijit

    2014-01-01

    We have described a myocardial infarct scar identified by a standard dual source CT coronary angiography (CTCA). We were able to detect the scar during the routine coronary assessment without contrast late enhancement and without additional radiation exposure. It is therefore feasible to assess chronic scar using a standard CTCA technique.

  20. Thrombolytic therapy for myocardial infarction. Treatment introduced in northern Ontario.

    PubMed Central

    Hutten-Czapski, P.

    1993-01-01

    In remote regions of Canada, most patients with acute myocardial infarctions (MI) are treated by general practitioners. In hospitals served by cardiologists, intravenous thrombolytic therapy for MI is now routinely available. In a survey of northern Ontario general hospitals, 32 of 45 offered IV thrombolytic therapy. The use of streptokinase in one family physician-run hospital was also reviewed. PMID:8257484

  1. Myocardial Fibrosis as an Early Manifestation of Hypertrophic Cardiomyopathy

    PubMed Central

    Ho, Carolyn Y.; López, Begoña; Coelho-Filho, Otavio R.; Lakdawala, Neal K.; Cirino, Allison L.; Jarolim, Petr; Kwong, Raymond; González, Arantxa; Colan, Steven D.; Seidman, J.G.; Díez, Javier; Seidman, Christine E.

    2011-01-01

    BACKGROUND Myocardial fibrosis is a hallmark of hypertrophic cardiomyopathy and a proposed substrate for arrhythmias and heart failure. In animal models, profibrotic genetic pathways are activated early, before hypertrophic remodeling. Data showing early profibrotic responses to sarcomere-gene mutations in patients with hypertrophic cardiomyopathy are lacking. METHODS We used echocardiography, cardiac magnetic resonance imaging (MRI), and serum biomarkers of collagen metabolism, hemodynamic stress, and myocardial injury to evaluate subjects with hypertrophic cardiomyopathy and a confirmed genotype. RESULTS The study involved 38 subjects with pathogenic sarcomere mutations and overt hypertrophic cardiomyopathy, 39 subjects with mutations but no left ventricular hypertrophy, and 30 controls who did not have mutations. Levels of serum C-terminal propeptide of type I procollagen (PICP) were significantly higher in mutation carriers without left ventricular hypertrophy and in subjects with overt hypertrophic cardiomyopathy than in controls (31% and 69% higher, respectively; P<0.001). The ratio of PICP to C-terminal telopeptide of type I collagen was increased only in subjects with overt hypertrophic cardiomyopathy, suggesting that collagen synthesis exceeds degradation. Cardiac MRI studies showed late gadolinium enhancement, indicating myocardial fibrosis, in 71% of subjects with overt hypertrophic cardiomyopathy but in none of the mutation carriers without left ventricular hypertrophy. CONCLUSIONS Elevated levels of serum PICP indicated increased myocardial collagen synthesis in sarcomere-mutation carriers without overt disease. This profibrotic state preceded the development of left ventricular hypertrophy or fibrosis visible on MRI. (Funded by the National Institutes of Health and others.) PMID:20818890

  2. Myocardial iron overload in thalassaemia major. How early to check?

    PubMed

    Borgna-Pignatti, Caterina; Meloni, Antonella; Guerrini, Giulia; Gulino, Letizia; Filosa, Aldo; Ruffo, Giovan B; Casini, Tommaso; Chiodi, Elisabetta; Lombardi, Massimo; Pepe, Alessia

    2014-02-01

    The age at which it is necessary to start Cardiovascular Magnetic Resonance (CMR) T2* screening in thalassaemia major (TM) is still uncertain. To clarify this point, we evaluated the prevalence of myocardial iron overload (MIO), function and fibrosis by CMR in TM patients younger than 10 years. We retrospectively selected 35 TM patients enrolled in the Myocardial Iron Overload in Thalassaemia network. MIO was measured by T2* multislice multiecho technique. Biventricular function parameters were evaluated by cine images. To detect myocardial fibrosis, late gadolinium enhancement images were acquired. Patients' age ranged from 4·2 to 9·7 years. All scans were performed without sedation. Nine patients showed no MIO, 22 patients had heterogeneous MIO with a T2* global value ≥20 ms; two patients had heterogeneous MIO with a T2* global value <20 ms and two patients showed homogeneous MIO. No patient showed myocardial fibrosis. Among the patients with heart T2*<20 ms, the youngest was 6 years old, none showed heart dysfunction and the iron transfused was <35 g in all cases. Cardiac iron loading can occur much earlier than previously described. The first cardiac T2* assessment should be performed as early as feasible without sedation, especially if chelation is started late or if poor compliance is suspected.

  3. [Description of the two surgical myocardial revascularisation techniques].

    PubMed

    Ouazzani, Marouane; Sinquet, Jean Claude; Frapier, Jean Marc; Rouvière, Philippe; Albat, Bernard; Demaria, Roland

    2015-03-01

    A coronary artery bypass involves taking blood vessels from another part of the patient's body to bypass one or several major coronary stenoses. Coronary artery bypass using cardiopulmonary bypass and off-pump coronary artery bypass are the two methods used to revascularise the heart after a myocardial infarction.

  4. Effects of activation of endocannabinoid system on myocardial metabolism.

    PubMed

    Polak, Agnieszka; Harasim, Ewa; Chabowski, Adrian

    2016-05-21

    Endocannabinoids exert their effect on the regulation of energy homeostasis via activation of specific receptors. They control food intake, secretion of insulin, lipids and glucose metabolism, lipid storage. Long chain fatty acids are the main myocardial energy substrate. However, the heart exerts enormous metabolic flexibility emphasized by its ability to utilzation not only fatty acids, but also glucose, lactate and ketone bodies. Endocannabinoids can directly act on the cardiomyocytes through the CB1 and CB2 receptors present in cardiomyocytes. It appears that direct activation of CB1 receptors promotes increased lipogenesis, pericardial steatosis and bioelectrical dysfunction of the heart. In contrast, stimulation of CB2 receptors exhibits cardioprotective properties, helping to maintain appropriate amount of ATP in cardiomyocytes. Furthermore, the effects of endocannabinoids at both the central nervous system and peripheral tissues, such as liver, pancreas, or adipose tissue, resulting indirectly in plasma availability of energy substrates and affects myocardial metabolism. To date, there is little evidence that describes effects of activation of the endocannabinoid system in the cardiovascular system under physiological conditions. In the present paper the impact of metabolic diseases, i. e. obesity and diabetes, as well as the cardiovascular diseases - hypertension, myocardial ischemia and myocardial infarction on the deregulation of the endocannabinoid system and its effect on the metabolism are described.

  5. Left ventricular hypertrophy: an initial response to myocardial injury.

    PubMed

    Francis, G S; McDonald, K M

    1992-06-04

    The prevailing wisdom generally has been that the failing heart hypertrophies in response to increased wall stress. The increase in myocardial mass observed in heart failure is therefore a relatively late compensatory event geared to normalize wall stress. Although this is undoubtedly true, especially for heart failure resulting from a large anterior myocardial infarction accompanied by rapid left ventricular expansion, it is possible that an important form of hypertrophy occurs much earlier as an initial response to myocardial injury. One can hypothesize that the initial response to injury is a nonspecific phenotypic alteration of the cardiac myocyte to one of growth and development. Such changes may be driven by both trophic and mechanical forces and may be important in altering the architecture of the myocardial cell and surrounding cardiac interstitium. Preliminary data from a variety of models support the concept that neuroendocrine activity is an important component in the ventricular remodeling process, and that pharmacologic interventions designed to block systemic and tissue neuroendocrine activity may prevent excessive cardiac enlargement and its ultimate consequences. Because this concept has important implications for preventive cardiology, the results of several prevention trials, including the Cooperative North Scandinavian Enalapril Survival Study (CONSENSUS), Studies of Left Ventricular Dysfunction (SOLVD), and Survival and Ventricular Enlargement (SAVE) are awaited eagerly.

  6. [Microscopic myocardial changes and their significance for forensic medical diagnosis].

    PubMed

    Kapustin, A V

    2006-01-01

    Morphological myocardial changes essential for diagnosis in forensic medical medicine are listed as well as alterations in the vessels of the myocardium, cardiac muscular fibers and cardiomyocytes important for diagnosis of death of ischemic heart disease, acute alcohol poisoning, alcohol cardiomyopathy, closed cardiac lesions. Changes induced by reflex impacts on the heart and postmortem alterations are also shown.

  7. Estimation of myocardial volume at risk from CT angiography

    NASA Astrophysics Data System (ADS)

    Zhu, Liangjia; Gao, Yi; Mohan, Vandana; Stillman, Arthur; Faber, Tracy; Tannenbaum, Allen

    2011-03-01

    The determination of myocardial volume at risk distal to coronary stenosis provides important information for prognosis and treatment of coronary artery disease. In this paper, we present a novel computational framework for estimating the myocardial volume at risk in computed tomography angiography (CTA) imagery. Initially, epicardial and endocardial surfaces, and coronary arteries are extracted using an active contour method. Then, the extracted coronary arteries are projected onto the epicardial surface, and each point on this surface is associated with its closest coronary artery using the geodesic distance measurement. The likely myocardial region at risk on the epicardial surface caused by a stenosis is approximated by the region in which all its inner points are associated with the sub-branches distal to the stenosis on the coronary artery tree. Finally, the likely myocardial volume at risk is approximated by the volume in between the region at risk on the epicardial surface and its projection on the endocardial surface, which is expected to yield computational savings over risk volume estimation using the entire image volume. Furthermore, we expect increased accuracy since, as compared to prior work using the Euclidean distance, we employ the geodesic distance in this work. The experimental results demonstrate the effectiveness of the proposed approach on pig heart CTA datasets.

  8. Delayed diagnosis of Fabry disease presenting as myocardial ischaemia.

    PubMed

    Marcì, Marcello; Duro, Giovanni; Tuttolomondo, Antonino; Tuttolomondo, Bruno; Pinto, Antonio; Cirrincione, Vincenzo; Sanfilippo, Nicola

    2012-01-01

    Cardiovascular complications due to the accumulation of globotriaosylceramide in cardiac cells occur in almost all patients affected by Anderson-Fabry disease. Cardiac manifestations include left ventricular hypertrophy, mitral regurgitation, conduction disturbances and myocardial ischaemia. We report a case of Fabry's disease diagnosed several years after the onset of early cardiac symptoms.

  9. Antioxidant enzymes attenuate myocardial stunning in the conscious dog

    SciTech Connect

    Triana, J.F.; Unisa, A.; Bolli, R. )

    1990-02-26

    Several studies have shown that postischemic myocardial dysfunction (myocardial stunning) is attenuated by antioxidants, implying a pathogenetic role of oxy-radicals in this phenomenon. However, since all these studies have been performed in open-chest preparations, artifacts due to anesthesia, trauma, and other nonphysiologic conditions cannot be excluded. Accordingly, chronically instrumented dogs underwent a 15-minute occlusion (o) of the left anterior descending artery followed by reperfusion. Dogs received i.v. either saline or superoxide dismutase (SOD) plus catalase (CAT) (16,000 U/kg and 55,000 U/kg, respectively, over 1 hour starting 15 minutes before O). Regional myocardial function was assessed as systolic wall thickening (WTh) using a pulsed Doppler probe. WTh after reperfusion was significantly greater in treated dogs, and this difference could not be ascribed to differences in collateral flow or hemodynamics. The authors conclude that SOD plus catalase attenuate myocardial stunning in the conscious dog, indicating that oxy-radicals play a pathogenetic role in this phenomenon under physiologic conditions.

  10. Characterization of nontransmural myocardial infarction by positron-emission tomography

    SciTech Connect

    Geltman, E.M.; Biello, D.; Welch, M.J.; Ter-Pogossian, M.M.; Roberts, R.; Sobel, B.E.

    1982-04-01

    The present study was performed to determine whether positron emission tomography (PET) performed after i.v. 11C-palmitate permits detection and characterization of nontransmural myocardial infarction. PET was performed after the i.v. injection of 11C-palmitate in 10 normal subjects, 24 patients with initial nontransmural myocardial infarction (defined electrocardiographically), and 22 patients with transmural infarction. Depressed accumulation of 11C-palmitate was detected with sagittal, coronal and transverse reconstructions, and quantified based on 14 contiguous transaxial reconstructions. Defects with homogeneously intense depression of accumulation of tracer were detected in all 22 patients with transmural infarction (100%). Abnormalities of the distribution of 11C-palmitate in the myocardium were detected in 23 patients with nontransmural infarction (96%). Thallium scintigrams were abnormal in only 11 of 18 patients with nontransmural infarction (61%). Tomographically estimated infarct size was greater among patients with transmural infarction (50.4 +/- 7.8 PET-g-Eq/m2 (+/- SEM SEM)) compared with those with nontransmural infarction (19 +/- 4 PET-g-Eq, p less than 0.01). Residual accumulation of 11C-palmitate within regions of infarction was more intensely depressed among patients with transmural compared to nontransmural infarction (33 +/- 1 vs 39 +/- 1% maximal myocardial radioactivity, p less than 0.01). Thus, PET and metabolic imaging with 11C-palmitate is a sensitive means of detecting, quantifying and characterizing nontransmural and transmural myocardial infarction.

  11. Does Cardiac Rehabilitation After Myocardial Infarction Favorably Affect Prognosis?

    ERIC Educational Resources Information Center

    Shephard, Roy J.

    1988-01-01

    This article discusses the limitations of 14 randomized controlled trials of exercise rehabilitation for patients who sustained myocardial infarction. The difficulty of sampling patients and controlling the sample size is discussed and the benefits of pooled statistical evidence are considered. (JL)

  12. Adaptation to a Myocardial Infarction from a Developmental Perspective.

    ERIC Educational Resources Information Center

    Meyer, Robert

    1983-01-01

    Explored the interactional effect between victims' (N=30) adult developmental stage and their coping and emotional reactions following a myocardial infarction (MI). The findings point to the usefulness of adult developmental psychology in understanding the divergent emotional and coping reactions of MI patients across the life-cycle. (Author/JAC)

  13. Controlled Trial of Psychological Intervention in Myocardial Infarction.

    ERIC Educational Resources Information Center

    Oldenburg, Brian; And Others

    1985-01-01

    Compared hospital-based psychological interventions for improving the physical, psychological, and life-style status of patients after myocardial infarction with routine medical and nursing care. Follow-ups showed intervention groups performed significantly better on measures of psychological and life-style functioning; they also reported fewer…

  14. Group Counseling Approaches with Persons Who Have Sustained Myocardial Infarction.

    ERIC Educational Resources Information Center

    Livneh, Hanoch; Sherwood-Hawes, Ardis

    1993-01-01

    Presents group counseling strategies for working with clients who have sustained myocardial infarctions, or heart attacks. MI victims can be assisted with transition from hospital, readjustment to daily life, coping with fears and frustrations of life and the illness. Advantages of counseling, primary goals, and common topics are discussed.…

  15. Coronary vasodilator reserve persists despite tachycardia and myocardial ischemia

    SciTech Connect

    Bristow, J.D.; McFalls, E.O.; Anselone, C.G.; Pantely, G.A. )

    1987-08-01

    During myocardial ischemia, the authors tested whether coronary blood flow measured with radioactive microspheres labeled with {sup 141}Ce, {sup 51}Cr, {sup 103}Ru, and {sup 95}Nb would increase in response to tachycardia thereby employing known coronary flow reserve. The authors instrumented the left anterior descending (LAD) coronary circulation in anesthetized pigs and performed three sets of experiments while coronary pressure was controlled and several heart rate increases were produced. (1) Pacing-induced tachycardia at normal LAD pressure was characterized by increased LAD flow and myocardial oxygen consumption, without production of lactate. (2) Tachycardia at a mean LAD pressure of 38 mmHg was associated with a lower, fixed coronary flow and oxygen consumption. Lactate was produced at all rates and local myocardial function declined progressively. (3) Coronary flow at low LAD pressure doubled during tachycardia when intracoronary adenosine was added. The increase to the subepicardium was >100%, whereas subendocardial flow changed little. There is persistent coronary flow reserve during moderately severe myocardial ischemia, even when metabolic demand is increased by tachycardia. This reserve, however, is predominantly subepicardial.

  16. Acute myocardial infarction in a young man using anabolic steroids.

    PubMed

    Wysoczanski, Mariusz; Rachko, Maurice; Bergmann, Steven R

    2008-01-01

    Anabolic-androgenic steroids are used worldwide to help athletes gain muscle mass and strength. Their use and abuse is associated with numerous side effects, including acute myocardial infarction (MI). We report a case of MI in a young 31-year-old bodybuilder. Because of the serious cardiovascular complications of anabolic steroids, physicians should be aware of their abuse and consequences.

  17. Myocardial Contrast Echocardiography in the Evaluation of Hypertensive Heart Disease

    PubMed Central

    Madu, Ernest C.; Potu, Chiranjivi; Baugh, Dainia; Tulloch-Reid, Edwin

    2011-01-01

    Myocardial contrast echocardiography (MCE) has an established role in left ventricular assessment by improving the ventricular opacification and endocardial border definition especially in patients with sub-optimal echocardiographic images. With advances in cardiac ultrasound imaging technology and the development of new contrast agents, the clinical utility of this technique has greatly expanded to include assessment of coronary reperfusion in the setting of acute myocardial infarction, determination of myocardial viability within infarct zones as well as assessment of coronary microcirculation and flow reserve in patients with microvascular coronary disease. Improvements in image quality with intravenous contrast agents can facilitate image acquisition and enhance delineation of regional wall motion abnormalities at peak levels of exercise. Numerous studies have confirmed the clinical utility of contrast enhancement during echocardiographic studies, particularly in patients undergoing stress testing. In this paper, we explore the evidence in support of MCE and its potential clinical applications. Our review aims to summarize (1) the basic principles of myocardial contrast echocardiography including recent advances in the ultrasound technology and contrast agents (2) its clinical applications in the diagnosis of cardiovascular diseases and finally, (3) its potential role in risk stratification and assessment of microvascular perfusion in patients with hypertensive heart disease.

  18. [Acute myocardial infarction in a 5-year-old boy].

    PubMed

    Romero Ibarra, C; Bueno Campaña, M; Barriuso Lapresa, L M; de Miguel Medina, C; Maraví Poma, E

    1996-11-01

    We present the case of a child five and half years-old that died suddenly due to an acute myocardial infarction. The anatomopathological study showed a total obstruction of the left coronary ostium by mixoide dysplasia of the aortic valve. We revise the literature and briefly expose the more frequent causes of infarction in infancy.

  19. 123I-metaiodobenzylguanidine myocardial scintigraphy in Parkinson's disease

    PubMed Central

    Orimo, S; Ozawa, E; Nakade, S; Sugimoto, T; Mizusawa, H

    1999-01-01

    OBJECTIVES