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

International Nuclear Information System (INIS)

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

1988-01-01

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

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

International Nuclear Information System (INIS)

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

1991-01-01

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 ± 0.9 to 2.0 ± 1.1 points (p less than 0.05). Computerized analysis revealed a caffeine-mediated reduction in the percent reversibility of the images from 46% ± 16% to 6% ± 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

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

Energy Technology Data Exchange (ETDEWEB)

Smits, P.; Corstens, F.H.; Aengevaeren, W.R.; Wackers, F.J.; Thien, T. (University Hospital Nijmegen (Netherlands))

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.

Role of myocardial ischemia on exercise-induced ST elevation

International Nuclear Information System (INIS)

Saito, Muneyasu; Sumiyoshi, Tetsuya; Nishimura, Tsunehiko; Uehara, Toshiisa; Hayashida, Kouhei; Haze, Kazuo; Fukami, Ken-ichi; Hiramori, Katsuhiko

1986-01-01

Exercise-induced ST elevation in patients with previous myocardial infarction (MI) has been recognized to be related to left ventricular (LV) asynergy, however it is also recognized that myocardial ischemia can induce ST elevation. In this study, factors which determine the extent of ST elevation, with special reference to myocardial ischemia, was re-evaluated using quantitative analysis of stress myocardial scintigraphy (S-SG). Among 65 patients with previous anterior myocardial infarction and documented single vessel disease of left anterior descending artery (LAD), 19 patients who had exercise-induced ST elevation (ΔST ≥ 2.0 mm) had more abnormal Q waves (p < 0.01), lower LV ejection fraction (EF) (p < 0.01), more severe LV asynergy (p < 0.05) and less incidence of post-MI angina pectoris (AP) (p < 0.01), compared to those with ΔST < 2.0 mm, indicating that ST elevation is primarily related to LV asynergy. Correlation studies among clinical, angiographic and scintigraphic parameters show that ΔST was significantly related to a size of MI represented by Tl score or relative defect Tl activity and number of abnormal Q waves (No.Q), the magnitude of work load expressed by changes in double product (ΔDP) and intervals between the onset and exercise test, as well as myocardial ischemia expressed by the extent of redistribution (%RD) in S-SG. Among 23 patients with post-MI AP, ΔST significantly correlated with %RD (r = 0.47), indicating that myocardial ischemia can be a mechanism of exercise-induced ST elevation in patients with previous MI. Furtheremore, among those with ST elevation, concave-type ST elevation was more related to myocardial ischemia compared to convex-type ST elevation as expressed by the incidence of post-MI AP and/or significant redistribution. (J.P.N.)

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

International Nuclear Information System (INIS)

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

1990-01-01

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

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

International Nuclear Information System (INIS)

Marwick, T.H.; Hollman, J.

1990-01-01

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

Stress-induced myocardial ischemia is associated with early post-stress left ventricular mechanical dyssynchrony as assessed by phase analysis of {sup 201}Tl gated SPECT myocardial perfusion imaging

Energy Technology Data Exchange (ETDEWEB)

Chen, Chien-Cheng; Shen, Thau-Yun [Show Chwan Memorial Hospital, Department of Cardiology, Changhua (China); Chang, Ming-Che [Changhua Christian Hospital, Department of Nuclear Medicine, Changhua (China); Hung, Guang-Uei [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Changhua (China); China Medical University, Department of Biomedical Imaging and Radiological Science, Taichung (China); Chen, Wan-Chen [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Changhua (China); Kao, Chia-Hung [China Medical University, Department of Biomedical Imaging and Radiological Science, Taichung (China); Chen, Ji [Emory University School of Medicine, Department of Radiology and Imaging Sciences, Atlanta, GA (United States)

2012-12-15

In {sup 201}Tl SPECT myocardial perfusion imaging (MPI) data are acquired shortly after the stress injection to assess early post-stress left ventricle (LV) function. The purpose of this study was to use {sup 201}Tl SPECT MPI to investigate whether stress-induced myocardial ischemia is associated with LV mechanical dyssynchrony. Enrolled in the study were 75 patients who were referred for dipyridamole stress and rest {sup 201}Tl gated SPECT MPI. The early post-stress scan was started 5 min after injection, and followed by the rest scan 4 h later. The patients were divided into three groups: ischemia group (N = 25, summed stress score, SSS, {>=}5, summed rest score, SRS, <5), infarct group (N = 16, SSS {>=}5, SRS {>=}5) and normal group (N = 34, SSS <5, SRS <5). LV dyssynchrony parameters were calculated by phase analysis, and compared between the stress and rest images. In the ischemia group, LV dyssynchrony was significantly larger during stress than during rest. On the contrary, LV dyssynchrony during stress was significantly smaller than during rest in the normal and infarct groups. LV dyssynchrony during rest was significantly larger in the infarct group than in the normal and ischemia groups. There were no significant differences in LV dyssynchrony during rest between the normal and ischemia groups. Stress-induced myocardial ischemia caused dyssynchronous contraction in the ischemic region, leading to a deterioration in LV synchrony. Normal myocardium had more synchronous contraction during stress. The different dyssynchrony pattern between ischemic and normal myocardium early post-stress may aid the diagnosis of coronary artery disease using {sup 201}Tl gated SPECT MPI. (orig.)

5 years prognostic value of dipyridamole-thallium myocardial imaging

International Nuclear Information System (INIS)

Yang Yifeng; Qian Zhonghao; Jiang Changying

1993-01-01

A prognostic study of dipyridamole-thallium myocardial imaging was conducted with the use of logistic regression. Over a 5 years follow-up period, cardiac events occurred in 13 patients within the 41 patients tested, death in 5 and myocardial infarction in 8. The results of this study indicates that dipyridamole-thallium imaging has significant prognostic utility and that an abnormal scan increased the relative risk for the development of subsequent myocardial infarction or cardiac death (O.R. 18.54). The presence of transient multiple thallium defects further increased the risk of a cardiac event. In conclusion , intravenous dipyridamole thallium imaging is a potentially useful diagnostic test to determine the presence and severity of coronary diseases, and this noninvasive method is also beneficial for prognosis

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

International Nuclear Information System (INIS)

Mays, A.E. Jr.; Cobb, F.R.

1984-01-01

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

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

International Nuclear Information System (INIS)

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

1991-01-01

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

Diagnostic value of exercise induced 18F-FDG myocardial metabolism scintigraphy in myocardial ischemia

International Nuclear Information System (INIS)

Shen Rui; He Zuoxiang; Shi Rongfang; Liu Xiujie; Tian Yueqin; Guo Feng; Wei Hongxing; Wu Yongjian; Qin Xuewen; Gao Runlin

2006-01-01

Objective: To evaluate the feasibility and diagnostic accuracy of exercise induced myocardial imaging with 18 F-fluorodeoxyglucose (FDG) in myocardial ischemia. Methods: Twenty-six patients with known or suspected coronary artery, disease (CAD) and with no prior myocardial infarction underwent simultaneous myocardial perfusion and metabolism imaging following intravenous injection of 99 Tc m -methoxy-isobutylisonitrile ( 99 Tc m -sestamibi) and 18 F-FDG at peak exercise. Subsequently rest perfusion imaging and coronary angiography (CAG) were performed in all patients. Exercise 18 F-FDG myocardial imaging was compared with 99 Tc m -sestamibi imaging and CAG. Results: In 22 patients with ≥50% narrowing over l coronary artery, 18 had perfusion abnormalities (sensitivity 82%), whereas 20 had abnormal myocardial 18 F-FDG uptake (sensitivity 91%, P>0.05). Patients with reversible (12 cases) or partial reversible (3 cases) perfusion abnormalities had increased myocardial 18 F-FDG uptake in abnormal perfusion segments. Compared with CAG, perfusion defect was seen in myocardial segments corresponding to 25 vascular territories of 51 vessels with ≥50% narrowing in 22 patients in 99 Tc m -sestamibi imaging (sensitivity 49%), whereas increased 18 F-FDG uptake was seen in 34 vascular territories (sensitivity 67%, P=0.008). Conclusions: Exercise induced myocardial ischemia can be imaged directly with 18 F-FDG. Combined exercise 18 F-FDG and 99 Tc m -sestamibi imaging provides a better assessment of exercise-induced myocardial ischemia as compared with exercise-rest perfusion imaging. (authors)

Exercise-induced silent myocardial ischemia: Evaluation by thallium-201 emission computed tomography

International Nuclear Information System (INIS)

Kurata, C.; Sakata, K.; Taguchi, T.; Kobayashi, A.; Yamazaki, N.

1990-01-01

Factors associated with silent myocardial ischemia (SMI) during exercise testing were studied by means of thallium-201 emission computed tomography (ECT) in 471 patients. Coronary angiography was done in 290, of whom 167 were found to have significant coronary artery disease (CAD). Exercise-induced ischemia and its severity were defined with ECT. During exercise 108 (62%) of 173 patients with ischemia and 57 (50%) of 115 with ischemia and angiographically documented CAD had no chest pain. One third of the patients showed an inconsistency between scintigraphic ischemia and ischemia ST depression. Age, sex, prior myocardial infarction, and diabetes mellitus were not related to SMI. Patients with SMI had less severe ischemia despite a higher peak double product compared to those with painful ischemia. Among 91 with prior myocardial infarction and exercise-induced ischemia, 51 with periinfarction ischemia had a higher frequency of SMI than did 14 with ischemia remote from the prior infarct zone despite similarities in the severity of ischemia. In conclusion, factors localized within ischemic myocardium such as less severe ischemia or adjacency to a prior infarct made SMI more prevalent

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

International Nuclear Information System (INIS)

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

1987-01-01

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

Exercise induced ST elevation and residual myocardial ischemia in previous myocardial infarction

International Nuclear Information System (INIS)

Shimonagata, Tsuyoshi; Nishimura, Tsunehiko; Uehara, Toshiisa; Hayashida, Kohei; Saito, Muneyasu; Sumiyoshi, Tetsuya

1987-01-01

The purpose of this study was to evaluate the clinical significance of stress induced ST elevation on infarcted area in 65 patients with previous myocardial infarction (single vessel disease) who had stress thallium scan. Stress induced ST changes on infarcted area were compared with quantitative assessment of myocardial ischemia (thallium ischemic score; TIS) and extent of myocardial infarction (defect score; DS) derived from circumferential profile analysis. In patients with previous myocardial infarction in less than 3 month from the onset (n = 36), left ventricular ejection fraction (LVEF) and extent of abnormal LV wall motion were not significantly different between patients with stress induced ST elevation ( ≥ 2 mm, n = 26) and those with stress induced ST elevation ( < 2 mm, n = 10), while, in patients with previous myocardial infarction in more than 3 month (n = 29), patients with stress induced ST elevation ( ≥ 2 mm, n = 15) showed left ventricular dyskinesis more frequently than those with ST elevation ( < 2 mm, n = 14). In addition, the former showed significantly higher DS and significantly lower TIS than the latter. In patients with previous myocardial infarction in less than 3 month, patients with ST elevation ( ≥ 2 mm, n = 15) with prominent upright T wave (n = 15) had transient thallium defect in infarcted area in 73 % and they had significantly higher LVEF and TIS than those with ST elevation ( < 2 mm, n = 11). These results indicated that ST elevation in infarcted area reflect different significance according to the recovery of injured myocardium and stress induced ST elevation with prominent upright T wave in infarcted area reflect residual myocardial ischemia in less than 3 month from the onset of myocardial infarction. (author)

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

International Nuclear Information System (INIS)

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

1990-01-01

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

Prevalence and clinical characteristics of mental stress-induced myocardial ischemia in patients with coronary heart disease.

Science.gov (United States)

Jiang, Wei; Samad, Zainab; Boyle, Stephen; Becker, Richard C; Williams, Redford; Kuhn, Cynthia; Ortel, Thomas L; Rogers, Joseph; Kuchibhatla, Maragatha; O'Connor, Christopher; Velazquez, Eric J

2013-02-19

The goal of this study was to evaluate the prevalence and clinical characteristics of mental stress-induced myocardial ischemia. Mental stress-induced myocardial ischemia is prevalent and a risk factor for poor prognosis in patients with coronary heart disease, but past studies mainly studied patients with exercise-induced myocardial ischemia. Eligible patients with clinically stable coronary heart disease, regardless of exercise stress testing status, underwent a battery of 3 mental stress tests followed by a treadmill test. Stress-induced ischemia, assessed by echocardiography and electrocardiography, was defined as: 1) development or worsening of regional wall motion abnormality; 2) left ventricular ejection fraction reduction ≥ 8%; and/or 3) horizontal or downsloping ST-segment depression ≥ 1 mm in 2 or more leads lasting for ≥ 3 consecutive beats during at least 1 mental test or during the exercise test. Mental stress-induced ischemia occurred in 43.45%, whereas exercise-induced ischemia occurred in 33.79% (p = 0.002) of the study population (N = 310). Women (odds ratio [OR]: 1.88), patients who were not married (OR: 1.99), and patients who lived alone (OR: 2.24) were more likely to have mental stress-induced ischemia (all p mental stress-induced ischemia (all p Mental stress-induced ischemia is more common than exercise-induced ischemia in patients with clinically stable coronary heart disease. Women, unmarried men, and individuals living alone are at higher risk for mental stress-induced ischemia. (Responses of Myocardial Ischemia to Escitalopram Treatment [REMIT]; NCT00574847). Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Noninvasive detection of coronary artery disease by dipyridamole-loading 201thallium myocardial scintigraphy

International Nuclear Information System (INIS)

Hamashige, Naohisa; Doi, Yoshinori; Yonezawa, Yoshihiro; Odawara, Hiroaki; Ozawa, Toshio; Akagi, Naoki; Yoshida, Shoji; Maeda, Tomoho

1986-01-01

Fifty patients with suspected coronary artery disease (CAD) were given i.v. infusion of 0.568 mg/kg of dipyridamole (DP) for 4 min in the supine position, and were loaded by stepping. Myocardial DP scanning (DP scintigraphy) was then performed with i.v. injection of 3 mCi of Tl-201 chloride. Findings were compared with those of coronary angiography and treadmill ECG. DP scintigraphy had higher sensitivity (90 %) and specificity (95 %) than treadmill ECG (76 % and 67 %) in diagnosing a ≥ 75 % coronary stenosis. Twenty nine patients had significant CAD: Reversible defects were associated with chest pain in 79 %, and with ST depression in 76 %. Not only relative differences in blood flow between the normal and diseased sites but also ischemia was suggested to be responsible for these defects. Increased rate pressure product by DP scintigraphy was slight (34 %) compared with that by treadmill ECG (105 %), suggesting a strong involvement of redistribution of coronary blood flow in the occurrence of ischemia. Increased myocardial oxygen consumption due to stepping was considered as the cause of ischemia as well, because the incidence of chest pain and ST depression was higher than previously reported. Chest pain and ST depression improved by i.v. injection of aminophylline. (Namekawa, K.)

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

Science.gov (United States)

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

2009-01-01

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

Exercise-induced ST-T changes and severity of myocardial ischemia in single-vessel coronary artery disease

International Nuclear Information System (INIS)

Shimonagata, Tsuyoshi; Nishimura, Tsunehiko; Uehara, Toshiisa; Hayashida, Kohei; Takamiya, Makoto; Sumiyoshi, Tetsuya; Saito, Muneyasu.

1986-01-01

The purpose of this study was to evaluate how exercise-induced ST-T changes reflect the severity of myocardial ischemia in 66 patients with singlevessel disease (SVD) who underwent stress thallium scans. Quantitative assessment of myocardial ischemia was performed with thallium ischemic score (TIS) derived from circumferential profile analysis. Circumferential profiles of the initial and 4 hr redistribution myocardial image were generated for each of three views (ANT, LAO 45, LAO 70) and TIS was obtained as the average of the area between the initial and 4 hr redistribution profile for each view. In 66 patients with SVD, TIS were compared with coronary angiographic findings. TIS was correlated well with the severity of coronary artery stenosis. In addition, TIS was also correlated well with lung thallium uptake in 46 LAD disease. Therefore, these data proved that TIS was useful for the evaluation of the severity of myocardial ischemia. In 46 LAD disease, TIS, being as the indicator of the severity of myocardial ischemia, was compared precisely with results of stress electrocardiograms to evaluate how exercise-induced ST-T changes reflect the severity of myocardial ischemia. Patients with negative U wave had the highest mean TIS and those with horizontal or down sloping ST depression of 1.0 mm or more had higher mean TIS than those with slow upsloping ST depression of 1.5 mm or more, but there were no significant differences between these groups and those without ST-T change and the mean TIS was not different significantly between V 2-6 ST depression group and V 2-6 , II, III, a V F ST depression group. In conclusion, these results indicated that exercise-induced ST-T changes reflect the severity of myocardial ischemia in some degree but also has a limitation in evaluation of the severity of myocardial ischemia. (author)

Myocardial rest iodine-123-β-methyl-iodophenyl-pentadecanoic acid scintigraphy compared with dipyridamole stress thallium-201 scintigraphy in unstable angina

International Nuclear Information System (INIS)

Misumi, Ikuo; Kimura, Yoshihiro; Hokamura, Youichi; Yamabe, Hiroshige; Ueno, Kazuhiro

1998-01-01

Twelve patients with stable angina and 12 patients with unstable angina underwent rest iodine-123-β-methyl-iodophenyl-pentadecanoic acid (BMIPP), dipyridamole stress thallium scintigraphy and delayed thallium scintigraphy. In stable angina, sensitivity for detecting ischemic segments was higher in dipyridamole thallium (74%) than rest BMIPP (48%) images (p<0.05), but there was no significant difference between the 2 images in unstable angina. In unstable angina, the incidence of segments with higher defect scores on BMIPP images than on delayed thallium images and the opposite pattern was 27 and 5 (p<0.01). In stable angina, there was no difference. The mean defect score on BMIPP (6.3±5.6) was higher than that on delayed thallium scintigraphy (2.9±2.7) and it was almost the same as on the initial dipyridamole stress test (6.5±5.2). In conclusion, BMIPP scintigraphy is safer and may be as useful in detecting myocardial ischemia in patients with unstable angina as thallium scintigraphy. (author)

Danqi Pill regulates lipid metabolism disorder induced by myocardial ischemia through FATP-CPTI pathway.

Science.gov (United States)

Wang, Yong; Li, Chun; Wang, Qiyan; Shi, Tianjiao; Wang, Jing; Chen, Hui; Wu, Yan; Han, Jing; Guo, Shuzhen; Wang, Yuanyuan; Wang, Wei

2015-02-21

Danqi Pill (DQP), which contains Chinese herbs Salvia miltiorrhiza Bunge and Panax notoginseng, is widely used in the treatment of myocardial ischemia (MI) in China. Its regulatory effects on MI-associated lipid metabolism disorders haven't been comprehensively studied so far. We aimed to systematically investigate the regulatory mechanism of DQP on myocardial ischemia-induced lipid metabolism disorders. Myocardial ischemia rat model was induced by left anterior descending coronary artery ligation. The rat models were divided into three groups: model group with administration of normal saline, study group with administration of DanQi aqueous solution (1.5 mg/kg) and positive-control group with administration of pravastatin aqueous solution (1.2 mg/kg). In addition, another sham-operated group was set as negative control. At 28 days after treatment, cardiac function and degree of lipid metabolism disorders in rats of different groups were measured. Plasma lipid disorders were induced by myocardial ischemia, with manifestation of up-regulation of triglyceride (TG), low density lipoprotein (LDL), Apolipoprotein B (Apo-B) and 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMGCR). DQP could down-regulate the levels of TG, LDL, Apo-B and HMGCR. The Lipid transport pathway, fatty acids transport protein (FATP) and Carnitine palmitoyltransferase I (CPTI) were down-regulated in model group. DQP could improve plasma lipid metabolism by up-regulating this lipid transport pathway. The transcription factors peroxisome proliferator-activated receptor α (PPARα) and retinoid X receptors (RXRs), which regulate lipid metabolism, were also up-regulated by DQP. Furthermore, DQP was able to improve heart function and up-regulate ejection fraction (EF) by increasing the cardiac diastolic volume. Our study reveals that DQP would be an ideal alternative drug for the treatment of dyslipidemia which is induced by myocardial ischemia.

Value of dipyridamole stress 201Tl myocardial SPECT in detecting dysfunction of coronary microcirculation

International Nuclear Information System (INIS)

Lou Ying; Jiang Jinqi; Xie Wenhui; Yuan Fang; Wang Tong; Yang Yiqing

2012-01-01

Objective: To evaluate the value of dipyridamole stress 201 Tl myocardial SPECT in detecting dysfunction of coronary microcirculation. Methods: Forty-eight patients diagnosed with cardiac syndrome X underwent dipyridamole stress 201 Tl myocardial SPECT. Dipyridamole (0.56 mg/kg) was intravenously injected over 4 min followed by 201 Tl (111 MBq) injection at 2 min after dipyridamole administration. Image was acquired at 10 min and 240 min post-injection and co-analyzed by over two experienced doctors in nuclear medicine after three-dimensional reconstruction. The patients with 'reverse redistribution' underwent repeated dipyridamole stress 201 Tl SPECT after medical therapy for 2 weeks. The clinical symptoms and results of the treadmill exercise test pre-and post-therapy were compared. Results: Forty two patients (42/48, 87.50%) showed segmental defects: 'reverse redistribution' on delayed (240 min) 201 Tl images. After medical treatment, 36 cases of the 42 'reverse redistribution' patients had improvement in both clinical symptoms and treadmill exercise test. Post-treatment 201 Tl imaging showed improvement in 45/49 (91.84%) defect segments. Six of the 42 patients had no improvement in clinical symptoms and/or treadmill exercise test. Post-treatment 201 Tl imaging showed no improvement in all the 7 defect segments on the first scan. Conclusion: Dipyridamole stress 201 Tl myocardial SPECT may be valuable in evaluation of impaired coronary microcirculation associated with cardiac syndrome X. (authors)

Coronary spasm induced by dipyridamole

International Nuclear Information System (INIS)

Wartski, M.; Caussin, C.; Lancelin, B.

2001-01-01

A 59 years old man was admitted at hospital for recurrent instable angina 1 month after coronary artery bypass surgery. Coronary artery disease started with a transmural antero-septo-apical myocardial infarction without thrombolysis and a percutaneous angioplasty with endo-prothesis on proximal left anterior descendant artery (LAD) is performed Because of recurrent rest angina and subacute stent thrombosis, a coronary artery bypass surgery (CABG) is performed with anastomosis of the left internal thoracic artery on LAD. The patient is admitted for recurrent rest angina one month after CABG. On ECG performed during chest pain, a ST-T segment elevation occurred on inferior leads. Coronary angiography showed no significant stenosis on endo-prothesis and no bypass graft dysfunction. Dipyridamole scintigraphy was realized. 2 minutes after the beginning of Dipyridamole infusion, a ST-T elevation occurred on inferior leads and two marked antero-septal and inferior defects were noticed on myocardial scintigraphy. Images at rest showed a clear improvement in the anterior wall and the inferior wall became normally perfused Patient was treated with anti-spastic drugs and a new coronarography with methyl-ergotamine test was performed inducing chest pain, ST-T elevation on inferior leads and tri-truncular coronary spasm. Patient's treatment was then modified with introduction of Nifedipine. The patient did not experienced new recurrent chest pain and remained totally asymptomatic few months later. (authors)

Comparison of dobutamine-stress magnetic resonance imaging and dipyridamole-Tl-201-SPECT as alternative strategies for the detection of coronary artery disease in patients not suitable for stress-echocardiography

International Nuclear Information System (INIS)

Schmidt, M.; Theissen, P.; Voth, E.; Schicha, H.; Jochims, M.; Baer, F.M.; Crnac, J.; Schneider, C.A.; Erdmann, E.

2001-01-01

Aim: During the past decade stress-echocardiography has gained increasing popularity for detection of myocardial ischemia in patients with coronary artery disease. However, about 10% to 15% of the patients submitted for stress-echocardiography do not have an adequate acoustic window. The purpose of this study was to compare high-dose dobutamine-stress magnetic resonance imaging (dobutamine-MRI) with dipyridamole-Tl-201-SPECT (dipyridamole-SPECT) as alternative strategies for detection of myocardial ischemia in patients with inadequate image quality by stress-echocardiography. Patients and Methods: Of 296 patients which were consecutively submitted to stress-echo-cardiography 45 patients (15%) had two or more segments that could not be evaluated according to the 16-segment-model of the American Society of Echocardiography. They underwent dobutamine-MRI and dipyridamole-SPECT studies, which were evaluated using a 28-segment modell. Myocardial segments were attributed to perfusion territories of the coronary arteries. The results of ischemia detection were compared to the results of coronary angiography (stenosis ≥50%). Results: In comparison to coronary angiography dobutamine-MRI yielded a sensitivity of 87%, a specificity of 86%, a positive predictive value of 93%, a negative predictive value of 75% and a diagnostic accuracy of 86%. For dipyridamole-SPECT results were 90%, 86%, 93%, 80% and 89%, respectively. These values were not significantly different. Conclusions: In patients not suitable for stress-echocardiography, both dobutamine-MRI and dipyridamole-SPECT are reliable strategies for detection of myocardial ischemia. Selection is dependent on the patient criteria, technical considerations, local logistics and experience of the observer. (orig.) [de

Exercise-induced ST-segment depression and myocardial ischemia in patients with hypertrophic cardiomyopathy. Myocardial scintigraphic study

International Nuclear Information System (INIS)

Miyai, Nobuyuki; Kawasaki, Tatsuya; Taniguchi, Takuya; Kamitani, Tadaaki; Kawasaki, Shingo; Sugihara, Hiroki

2005-01-01

Patients with hypertrophic cardiomyopathy (HCM) sometimes develop myocardial ischemia during exercise in the absence of coronary lesions. The relationship between myocardial ischemia and ST-segment depression was investigated during exercise testing in patients with HCM. Regional hypoperfusion and/or transient left ventricular cavity dilation, a parameter of subendocardial hypoperfusion, were assessed on exercise 99 m Tc-tetrofosmin myocardial scintigraphy in 42 patients with non-obstructive HCM. The scintigraphic results were further correlated with the ST-segment responses to exercise. Regional hypoperfusion or transient left ventricular cavity dilation were observed in 19 (45%) or 16 (38%) patients with HCM, respectively. The incidence of ST-segment depression ≥0.1 mV during exercise testing was similar in HCM patients with regional hypoperfusion, with transient left ventricular cavity dilation, and without hypoperfusion (42%, 38%, 38%, p=0.95). Furthermore, exercise-induced ST-segment depression ≥0.1 mV occurred similarly irrespective of symptoms, exercise tolerance, the degree or the site of hypertrophy, or the presence or absence of resting ST-segment depression. ST-segment depression during exercise testing was common in patients with HCM, but seems to be an unreliable marker of myocardial ischemia as assessed by exercise scintigraphy. (author)

Myocardial perfusion imaging for detection of silent myocardial ischemia

International Nuclear Information System (INIS)

Beller, G.A.

1988-01-01

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

Myocardial fatty acid utilisation during exercise induced ischemia in patients with coronary artery disease

International Nuclear Information System (INIS)

Virtanen, K.S.; Nikkinen, P.; Lindroth, L.; Kuikka, J.T.

2002-01-01

Aim: Reversible or irreversible myocardial damage due to ischemia correlates with altered membrane functions of the cells. To compare myocardial free fatty acid (FFA) metabolism and flow during exercise induced ischemia we studied ten patients with coronary artery disease but without previous myocardial infarction. Methods: A series of post-exercise single-photon emission computed tomography (SPECT) measurements was performed after injection of 123 I labelled heptadecanoic acid (HDA). Myocardial perfusion was estimated from the separately performed exercise-redistribution thallium study. Fatty acid metabolic rate, thallium uptake and washout were calculated for anterior, lateral, posterior and septal segments. Results: The more reduced post-exercise FFA metabolic rate (-63±18%, mean ±1 SD) compared to flow (-36±16%) was related to the severity of myocardial ischemia and wall motion abnormalities. Conclusion: In this small group of patients, the reduced post-exercise FFA metabolic rate tentatively suggests a parsimonious workload of the exercising myocardium by reducing oxygen consumption in patients with coronary artery disease. (orig.) [de

The clinical value of chest pain during thallium-201 scintigraphy with dipyridamole

International Nuclear Information System (INIS)

Takeishi, Yasuchika; Tono-oka, Ichiro; Meguro, Mitsuhiko; Hoshi, Hikaru; Yamaguchi, Yoshiko; Masakane, Ikuto; Tsuiki, Kai; Yasui, Shoji

1990-01-01

Sixty patients with suspected coronary artery disease underwent both dipyridamole-loaded thallium-201 scintigraphy and cardiac catheterization. Thirty four patients (57%) developed chest pain during dipyridamole stress testing (the pain group), and the other 26 did not (the no-pain group). Regarding sex, age, history of myocardial infarction, and the presence of coronary artery disease, there was no difference between the pain and no-pain groups. The pain group had significantly increased pulse rate and rate-pressure-product, as compared with the no-pain group. ST depression was more frequently observed in the pain group than the no-pain group. There was no significant difference in the angiographic involvement and the severity of coronary artery disease between the two groups. Nor was there significant difference in dipyridamole-loaded scintigraphic findings, such as defect size, and the extent and degree of decreased washout. However, for patients without a history of myocardial infarction, the pain group had a farther decreased washout than the no-pain group. Chest pain associated with iv injection of dipyridamole may have implications for the occurrence of serious ischemia. (N.K.)

Serial thallium-201 imaging after dipyridamole for coronary disease detection: quantitative analysis using myocardial clearance

International Nuclear Information System (INIS)

Okada, R.D.; Dai, Y.H.; Boucher, C.A.; Pohost, G.M.

1984-01-01

After dipyridamole, canine studies have demonstrated a slower rate of myocardial thallium-201 clearance from zones distal to a coronary artery stenosis compared to normal zones. To determine if criteria based on canine myocardial thallium-201 clearance rates could be applied clinically, 40 patients with and 26 patients without coronary artery disease (CAD) had serial thallium-201 images obtained for 2 to 5 hours after dipyridamole. Regions of interest were manually placed over six left ventricular segments in two projections for each of three imaging times. The myocardial thallium-201 clearance rate was calculated for each of the six segments and, using the clearance rate criterion found in canine studies, was considered abnormal if less than 6.5%/hr. Using this criterion alone, 22 of 26 patients (85%) without CAD had normal and 30 of 40 patients (75%) with CAD had abnormal myocardial thallium-201 clearance rates. A quantitative analysis of regional inhomogeneity in tracer distribution (normal was greater than or equal to 25% difference between segments) was negative in 24 of 26 patients (92%) without CAD and positive in 20 of 40 patients (50%) with CAD. When both clearance rate and regional inhomogeneity were considered, 21 of 26 patients (81%) without CAD had negative and 36 of 40 patients (90%) with CAD had positive results. Thus, post-dipyridamole myocardial clearance rate criteria derived from canine studies can be applied to clinical thallium imaging. Quantitative analysis of serial thallium-201 images after dipyridamole is optimized by using myocardial thallium-201 clearance rates. Such an approach is independent of regional inhomogeneities in tracer distribution

Dipyridamole thallium imaging

International Nuclear Information System (INIS)

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

1991-01-01

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

Safety of intravenous dipyridamole thallium myocardial perfusion imaging: experience in 435 patients

International Nuclear Information System (INIS)

Dubrey, S.W.; Noble, M.I.M.; Jewkes, R.F.; Bomanji, J.B.

1993-01-01

Dipyridamole stress 201 T1 scintigraphy is widely used in the investigation of myocardial ischaemia. We report our experience of adverse effects observed during this diagnostic procedure. A prospective study was undertaken of 435 consecutive patients referred to two nuclear medicine departments for assessment of myocardial perfusion. Patients were monitored prior to and following the infusion of dipyridamole. All symptomatic, haemodynamic and electrocardiographic changes were documented. No deaths occurred in this series. Adverse events were observed in 174 (40%) patients. Of these, three patients experienced 'major' adverse events (0.6%) requiring hospitalization (myocardial infarction = 1; chest pain = 1; simple partial seizure = 1). 'Moderate' adverse events occurred in 39 (8.9%) patients and required intravenous aminophylline to reverse effects (ST segment abnormalities = 26; nausea = 7; headache = 3; chest pain = 2; bronchospasm = 1; protracted vomiting = 1; diarrhoea = 1). 'Minor' adverse events were experienced by 132 (30.3%) patients and did not require aminophylline. Sixty per cent of our patients experienced no ill effects from dipyridamole given as an exercise substitute in conjunction with 201 T1 imaging. The rest had symptoms which were mostly mild, although a few patients found the experience unpleasant. Only one patient experienced a life-threatening episode. (Author)

Reverse 201Tl myocardial redistribution induced by coronary artery spasm

International Nuclear Information System (INIS)

Xiang Dingcheng; Yin Jilin; Gong Zhihua; Xie Zhenhong; Zhang Jinhe; Wen Yanfei; Yi Shaodong

2010-01-01

Objective: To investigate the mechanism of reverse redistribution (RR) on dipyridamole 201 Tl myocardial perfusion studies in the patients with coronary artery spasm. Methods: Twenty-six patients with coronary artery spasm and presented as RR on dipyridamole 201 Tl myocardial perfusion studies were enlisted as RR group, while other 16 patients with no coronary artery stenosis nor RR were enlisted as control group. Dipyridamole test was repeated during coronary angiography. Corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) and TIMI myocardial perfusion grade (TMPG) were measured at RR related and non-RR related coronary arteries before and after dipyridamole infusion respectively. All of the data were analyzed by Student's t-test or χ 2 -test and correlation analysis. Results: Coronary artery angiography showed slower blood flow and lower myocardial perfusion in RR related vessels when compared with non-RR related vessels in RR group, but there was no significant difference among the main coronary arteries in control group. The perfusion defects of RR area at rest were positively related to slower blood velocity at corresponding coronary arteries (r = 0.79, t =10.18, P 0.05). Conclusion: RR is related to the decreased blood flow and myocardial perfusion induced by coronary artery spasm at rest, which may be improved by stress test such as intravenous dipyridamole infusion. (authors)

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

International Nuclear Information System (INIS)

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

1988-01-01

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

Myocardial ischemia in hypertrophic cardiomyopathy

International Nuclear Information System (INIS)

Lima Filho, Moyses de Oliveira; Figueiredo, Geraldo L.; Simoes, Marcus V.; Pyntia, Antonio O.; Marin Neto, Jose Antonio

2000-01-01

Myocardial ischemia in hypertrophic cardiomyopathy is multifactorial and explains the occurrence of angina, in about 50% of patients. The pathophysiology of myocardial ischemia may be explained by the increase of the ventricular mass and relative paucity of the coronary microcirculation; the elevated ventricular filling pressures and myocardial stiffness causing a compression of the coronary microvessels; the impaired coronary vasodilator flow reserve caused by anatomic and functional abnormalities; and the systolic compression of epicardial vessel (myocardial bridges). Myocardial ischemia must be investigated by perfusion scintigraphic methods since its presence influences the prognosis and has relevant clinical implications for management of patients. Patients with hypertrophic cardiomyopathy and documented myocardial ischemia usually need to undergo invasive coronary angiography to exclude the presence of concomitant atherosclerotic coronary disease. (author)

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

International Nuclear Information System (INIS)

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

1986-01-01

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

Simultaneous low level treadmill exercise and intravenous dipyridamole stress thallium imaging

International Nuclear Information System (INIS)

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

1988-01-01

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

Association between aortic valve calcification and myocardial ischemia, especially in asymptomatic patients.

Science.gov (United States)

Yamazato, Ryo; Yamamoto, Hideya; Tadehara, Futoshi; Teragawa, Hiroki; Kurisu, Satoshi; Dohi, Yoshihiro; Ishibashi, Ken; Kunita, Eiji; Utsunomiya, Hiroto; Oka, Toshiharu; Kihara, Yasuki

2012-08-01

Aortic valve calcification (AVC) is recognized as a manifestation of systemic arteriosclerosis. However, it is unclear whether AVC is associated with myocardial ischemia. Stress myocardial perfusion SPECT (MPS) is widely used for the diagnosis of myocardial ischemia. However, routine MPS is not recommended, particularly in asymptomatic patients. Accordingly, we investigated the hypothesis that the presence of AVC is strongly associated with inducible myocardial ischemia, even among asymptomatic patients. We investigated 669 consecutive patients who underwent both adenosine stress (201)Tl MPS and echocardiography. We evaluated the extent and severity of myocardial ischemia by the summed difference score (SDS). We defined the presence of myocardial ischemia as SDS ≥ 3 and moderate to severe ischemia as SDS ≥ 8. We classified the severity of AVC according to the number of affected aortic leaflets. We also compared the mean SDS and the prevalence of SDS ≥ 3 and SDS ≥ 8 among patients stratified by the severity of AVC. The presence of AVC was significantly associated with myocardial ischemia (odds ratio [OR], 1.56; 95% confidence interval [CI], 1.10-2.23; P = 0.013) and moderate to severe ischemia (OR, 2.16; 95% CI, 1.26-3.80; P = 0.0061). In 311 asymptomatic patients, AVC was strongly associated with moderate to severe ischemia (OR, 4.31; 95% CI, 1.67-12.8; P = 0.0043). However, the SDS value and the prevalence of SDS ≥ 3 and SDS ≥ 8 did not increase with increasing number of affected aortic leaflets. The presence of AVC may be associated with the presence of myocardial ischemia, particularly in asymptomatic patients. However, we found no association between the extent of AVC and inducible myocardial ischemia. The presence of AVC may be a useful anatomic marker to help identify patients at high risk of myocardial ischemia, particularly asymptomatic patients.

Diagnostic value for coronary artery disease of ST depression and chest pain during dipyridamole loading

International Nuclear Information System (INIS)

Yonezawa, Yoshihiro; Doi, Yoshinori; Aono, Tadashi; Odawara, Hiroaki; Chikamori, Taishiro; Yamada, Mitsutoshi; Takata, Jun; Ozawa, Toshio; Hamashige, Naohisa.

1991-01-01

The diagnostic significance of both ST depression and chest pain during dipyridamole loading was assessed in 437 patients with coronary artery disease (CRD) who have received dipyridamole-loading thallium-201 myocardial scintigraphy and coronary arteriography. ST depression and chest pain were induced in 35% and 42%, respectively. ST depression occurred in 23% for one vessel disease, 55% for two-vessel disease, 67% for three-vessel disease, and 11% for non-significant disease. In the absence of myocardial infarction, it occurred in as many as 78% for two-vessel disease and 94% for three-vessel disease. ST depression had a sensitivity of 51% and a specificity of 89%. Chest pain had a lower specificity (77%), whereas the sensitivity remained the same (51%). In 42 (31%) of 134 patients with ST depression, coronary revascularization was necessary in the early stage. With a median follow up of 29 months, 3 patients (2%) died of cardiac events, and 12 (9%) had nonfatal cardiac complications. There was a significant correlation between reversible defects (RD) on myocardial scintigrams and ST depression; RD were seen in 81% of ST depression cases, and ST depression occurred in 51% of 210 RD cases. The more diseased vessels, the more frequently ST depression occurred in accordance with RD on myocardial scintigrams. Both ST depression and chest pain during dipyridamole loading tended to be associated with myocardial ischemia, suggesting the diagnostic value in CRD patients with limited exercise loading. RD on myocardial scintigrams was considered attributable to coronary steal phenomenon for multi-vessel disease and to the difference in the relative increase of the coronary flow for single vessel disease. (N.K.)

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

International Nuclear Information System (INIS)

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

1984-01-01

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

Usefulness of dipyridamole stress myocardial imaging in patients who have exercise limitations due to various orthopedic disorders

International Nuclear Information System (INIS)

Tagawa, Hirofumi; Ashihara, Toshiaki; Fukuyama, Takaya; Matsui, Kanji; Yamamoto, Sumiki; Yamamoto, Susumu

1994-01-01

To evaluate the presence of coronary artery disease in patients unable to exercise adequately because of chronic rheumatoid arthritis, osteoarthritis, hip bone fractures or disk herniation, we performed dipyridamole-stress thallium-201 myocardial imaging in thirty-three patients. Twelve of the 33 patients showed perfusion defect and redistribution by thallium imaging. Coronary angiography was performed in 9 patients out of these 12 dipyridamole-positive patients and significant coronary artery stenosis was detected in 7 of them (78%). Due to these results of dipyridamole-imaging and coronary angiograms, surgical intervention for the underlying bone or joint disorder was performed under cardioprotective strategy in 15 patients, in which no cardiovascular events occurred. Thus, dipyridamole-stress myocardial imaging is a satisfactory alternative to the exercise test for detecting coronary artery disease in patients with bone or joint disorders. (author)

Usefulness of percutaneous transluminal coronary angioplasty in silent myocardial ischemia

International Nuclear Information System (INIS)

Hou, Mami

1996-01-01

The usefulness of percutaneous transluminal coronary angioplasty (PTCA) was assessed in patients with exercise-induced asymptomatic myocardial ischemia (silent ischemia) and compared with exercise-induced symptomatic myocardial ischemia (symptomatic ischemia). Patients with single vessel coronary artery disease (51 with angina pectoris, 40 with old myocardial infarction) and evidence of stress-induced ischemia on thallium-201 single photon emission computed tomography (SPECT) underwent successful PTCA. Thirty-seven percent of angina patients and 60% of infarction patients showed asymptomatic exercise-induced ischemia. There was no significant difference in population characteristics between silent and symptomatic patients. Patients with silent angina had significantly higher percentage thallium uptake and washout rate than symptomatic patients. After PTCA, both percentage diameter stenosis and percentage thallium uptake were improved in all patients with angina irrespective of the presence or absence of symptoms. There were no significant differences in percentage thallium uptake and washout rate between patients with silent and symptomatic infarction. After PTCA, percentage diameter stenosis, percentage thallium uptake, and washout rate improved in all infarction patients irrespective of the symptoms. Zero percent of silent angina patients, 12% of symptomatic angina patients, 12% of silent infarction patients, 19% of symptomatic infarction patients had cardiac events during about 4.5 years after PTCA. The incidence of cardiac events did not significantly differ in any patient group. PTCA improved myocardial perfusion in all patients, and the incidence of cardiac events did not differ between the silent and symptomatic groups. Revascularization with PTCA is suitable for patients with silent as well as symptomatic ischemia. (author)

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

Directory of Open Access Journals (Sweden)

Weytjens Caroline

2008-09-01

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

High fat diet-induced glucose intolerance impairs myocardial function, but not myocardial perfusion during hyperaemia: a pilot study

Directory of Open Access Journals (Sweden)

van den Brom Charissa E

2012-06-01

Full Text Available Abstract Background Glucose intolerance is a major health problem and is associated with increased risk of progression to type 2 diabetes mellitus and cardiovascular disease. However, whether glucose intolerance is related to impaired myocardial perfusion is not known. The purpose of the present study was to study the effect of diet-induced glucose intolerance on myocardial function and perfusion during baseline and pharmacological induced hyperaemia. Methods Male Wistar rats were randomly exposed to a high fat diet (HFD or control diet (CD (n = 8 per group. After 4 weeks, rats underwent an oral glucose tolerance test. Subsequently, rats underwent (contrast echocardiography to determine myocardial function and perfusion during baseline and dipyridamole-induced hyperaemia (20 mg/kg for 10 min. Results Four weeks of HFD feeding resulted in glucose intolerance compared to CD-feeding. Contractile function as represented by fractional shortening was not altered in HFD-fed rats compared to CD-fed rats under baseline conditions. However, dipyridamole increased fractional shortening in CD-fed rats, but not in HFD-fed rats. Basal myocardial perfusion, as measured by estimate of perfusion, was similar in CD- and HFD-fed rats, whereas dipyridamole increased estimate of perfusion in CD-fed rats, but not in HFD-fed rats. However, flow reserve was not different between CD- and HFD-fed rats. Conclusions Diet-induced glucose intolerance is associated with impaired myocardial function during conditions of hyperaemia, but myocardial perfusion is maintained. These findings may result in new insights into the effect of glucose intolerance on myocardial function and perfusion during hyperaemia.

Additional diagnostic value of systolic dysfunction induced by dipyridamole stress cardiac magnetic resonance used in detecting coronary artery disease.

Science.gov (United States)

Husser, Oliver; Bodí, Vicente; Sanchís, Juan; Mainar, Luis; Núñez, Julio; López-Lereu, María P; Monmeneu, José V; Ruiz, Vicente; Rumiz, Eva; Moratal, David; Chorro, Francisco J; Llácer, Angel

2009-04-01

Dipyridamole stress perfusion cardiovascular magnetic resonance (CMR) is used to detect coronary artery disease (CAD). However, few data are available on the diagnostic value of the systolic dysfunction induced by dipyridamole. This study investigated whether the induction of systolic dysfunction supplements the diagnostic information provided by perfusion imaging in the detection of CAD. Overall, 166 patients underwent dipyridamole CMR and quantitative coronary angiography, with CAD being defined as a stenosis > or =70%. Systolic dysfunction at rest, systolic dysfunction with dipyridamole, induced systolic dysfunction, and stress first-pass perfussion deficit (PD) and delayed enhancement were quantified. In the multivariate analysis, PD (hazard ratio [HR]=1.6; 95% confidence interval [CI], 1.33-1.91;Pstatistic for predicting CAD (0.81 vs. 0.87; P=.02). Combining induced systolic dysfunction with perfusion imaging increases the diagnostic accuracy of detecting CAD and enables patients with severe ischemia and a high probability of CAD to be identified.

Sepsis-induced myocardial dysfunction and myocardial protection from ischemia/reperfusion injury.

Science.gov (United States)

McDonough, Kathleen H; Virag, Jitka Ismail

2006-01-01

Sepsis, bacteremia and inflammation cause myocardial depression. The mechanism of the dysfunction is not clearly established partly because dysfunction can be elicited by many different mechanisms which can all manifest in disruption of myocardial mechanical function. In addition the models of sepsis and bacteremia and inflammation may vary drastically in the sequence of the coordinated immune response to the inflammatory or septic stimulus. Patterns of cytokine expression can vary as can other responses of the immune system. Patterns of neurohumoral activation in response to the stress of sepsis or bacteremia or inflammation can also vary in both magnitude of response and temporal sequence of response. Stress induced activation of the sympathetic nervous system and humoral responses to stress have a wide range of intensity that can be elicited. The fairly uniform response of the myocardium indicating cardiac dysfunction is surprisingly constant. Systolic performance, as measured by stroke volume or cardiac output and pressure work as estimated by ventricular pressure, are impaired when myocardial contraction is compromised. At times, diastolic function, assessed by ventricular relaxation and filling, is impaired. In addition to the dysfunction that occurs, there is a longer term response of the myocardium to sepsis, and this response is similar to that which is elicited in the heart by multiple brief ischemia/reperfusion episodes and by numerous pharmacological agents as well as heat stress and modified forms of lipopolysaccharide. The myocardium develops protection after an initial stress such that during a second stress, the myocardium does not exhibit as much damage as does a non-protected heart. Many agents can induce this protection which has been termed preconditioning. Both early preconditioning (protection that is measurable min to hours after the initial stimulus) and late preconditioning (protection that is measurable hours to days after the initial

Associations between positive emotional well-being and stress-induced myocardial ischemia: Well-being scores predict exercise-induced ischemia.

Science.gov (United States)

Feigal, Jacob P; Boyle, Stephen H; Samad, Zainab; Velazquez, Eric J; Wilson, Jennifer L; Becker, Richard C; Williams, Redford B; Kuhn, Cynthia M; Ortel, Thomas L; Rogers, Joseph G; O'Connor, Christopher M; Jiang, Wei

2017-02-01

Depressive symptoms have been associated with myocardial ischemia induced by mental (MSIMI) and exercise (ESIMI) stress in clinically stable ischemic heart disease (IHD) patients, but the association between positive emotions and inducible ischemia is less well characterized. The objective of this study was to examine the associations between ratings of well-being and stress-induced ischemia. Subjects were adult patients with documented IHD underwent mental and exercise stress testing for the Responses of Myocardial Ischemia to Escitalopram Treatment (REMIT) trial. The General Well-Being Schedule (GWBS), with higher scores reflecting greater subjective well-being, and the Center for Epidemiologic Studies Depression Scale (CES-D) were obtained from the REMIT participants. Echocardiography was used to measure ischemic responses to mental stress and Bruce protocol treadmill exercise testing. Data were analyzed using logistic regression adjusting for age, sex, resting left-ventricular ejection fraction (LVEF), and resting wall motion score index, as well as health-related behaviors. GWBS scores were obtained for 210 individuals, with MSIMI present in 92 (43.8%) and ESIMI present in 64 (30.5%). There was a significant inverse correlation between GWBS-PE (Positive Emotion subscale) scores and probability of ESIMI (OR=0.55 (95%CI 0.36-0.83), p=0.005). This association persisted after additional control for CESD subscales measuring negative and positive emotions and for variables reflecting health-related behaviors. A similar inverse correlation between GWBS-PE and MSIMI was observed, but did not reach statistical significance (OR=0.81 (95%CI 0.54-1.20), p=0.28). This is, to our knowledge, the first study demonstrating that greater levels of self-reported positive emotions are associated with a lower likelihood of ESIMI among patients with known IHD. Our results highlight the important interface functions of the central nervous and cardiovascular systems and underscore

A comparison of maximal exercise and dipyridamole thallium-201 planar gated scintigraphy

International Nuclear Information System (INIS)

Martin, W.; Tweddel, A.C.; Main, G.; Hutton, I.

1992-01-01

Both symptom-limited maximal exercise and intravenously given dipyridamole stress (0.56 mg/kg over 4 min with a 2 min walk) gated thallium scans were performed in 22 patients undergoing coronary arteriography for the assessment of chest pain. All scans were acquired gated to the electrocardiogram in 3 projections and were reported for the presence and extent of defects in 5 myocardial segments in each view. In addition, left and right ventricular myocardial uptake and estimates of right and left lung and liver to left ventricular uptake were assessed relative to the injected dose of thallium-201. Overall, 190/310 segments were abnormal with exercise compared with 169/310 with dipyridamole. Segments were scored greater in extent in 90/310 cases with exercise, compared with 46/310 in which the defect was more extensive with dipyridamole. Non-attenuation corrected percentage myocardial thallium uptakes were similar for both stresses. Left and right lung and liver to left ventricle ratios were all significantly higher with dipyridamole than with exercise. High right and left lung uptakes with dipyridamole were strongly correlated with high exercise values. The liver uptake was weakly correlated between the 2 different stress tests. These results demonstrate that dipyridamole induces fewer and less extensive thallium perfusion defects than maximal exercise, and that liver and lung to myocardial ratios are higher with dipyridamole than with exercise. (orig./MG)

The relation between angina and myocardial ischemia during exercise stress in coronary artery disease

International Nuclear Information System (INIS)

Narita, Michihiro; Kurihara, Tadashi; Murano, Kenichi; Usami, Masahisa

1988-01-01

To examine the mechanism of occurrence of anginal chest pain from the aspect of myocardial ischemia, myocardial Tl-201 SPECT scans were obtained immediately and 3 hr after exercise (Ex) in 35 patients with coronary artery disease (CAD). The extent of ischemia was defined as the percentage of ischemic segments to the entire left ventricle. The minimum washout (WO) rate correlated well with the ratio of Tl uptake in the ischemic area to that in the normal area during Ex in the other 9 patients having single vessel CAD without previous history of myocardial infarction. This suggested that the miminum WO rate reflects the severity of Ex-induced ischemia. According to the development of angina during Ex, patients were classified as having either symptomatic ischemia (n = 16) or silent ischemia (n = 19). In regard to age, sex, a history of myocardial infarction, severity of CAD, and the extent of Ex-induced ischemia, there was no difference between the two groups. The minimum WO rate and the incidence of Ex-induced ST depression were significantly lower and higher, respectively, in the group with symptomatic ischemia than that with silent ischemia. The severity of Ex-induced ischemia has important implications for the development of anginal chest pain. (Namekawa, K.)

Myocardial thallium scintigraphy after dipyridamole injection. Application to the diagnosis and evaluation of coronary disease

International Nuclear Information System (INIS)

Foult, J.M.; Weinmann, P.; Moretti, J.L.; Le Guludec, D.; Faraggi, M.

1992-01-01

Myocardial thallium scintigraphy performed after intravenous injection of dipyridamole is a non-invasive method to diagnose and evaluate coronary disease.It be used as an alternative to post-exercise scintigraphy, both methods having similar sensitivity and specificity. The dipyridamole test is contraindicated in patients with a history of bronchospasm and uncontrolled angina pectoris. Close clinical and electrocardiographic monitoring is required. The wide use of tomographic techniques has notably improved this examination

Myocardial perfusion assessment at rest and after dipyridamole: MR signal intensity characteristics of reversible and persistent hypoperfusion

International Nuclear Information System (INIS)

Wintersperger, B.J.; Penzkofer, H.V.; Huber, A.; Meininger, M.; Scheidler, J.; Reiser, M.; Knez, A.; Haberl, R.; Kerner, M.; Knesewitsch, P.

2000-01-01

Methods: Sixteen patients with CAD underwent MR myocardial perfusion assessment at rest and after dipyridamole-induced hyperemia. Qualitative parameters (SI increase, SI upslope) of the SI time-curves were evaluated and characteristics of normal, reversible and persistent hypoperfused myocardium as assessed by 99m TC-SestaMIBI SPECT were compared. Results: Compared with the rest values, normal myocardium showed a significant increase of the SI upslope during hyperemia (P [de

Study of sympathetic nervous function under effort induced ischemia in patients with angina pectoris with I-123 metaiodobenzylguanidine (MIBG) myocardial SPECT images

International Nuclear Information System (INIS)

Tanaka, Takeshi; Aizawa, Tadanori; Kato, Kazuzo; Ogasawara, Ken; Sakuma, Toru; Kirigaya, Hajime; Hirosaka, Akira; Igarashi, Masaki

1990-01-01

I-123 metaiodobenzylguanidine (MIBG) is a norepinephrine analog, which can be used to study the sympathetic nervous function of the heart. With MIBG myocardial SPECT images sympathetic nervous function under effort induced ischemia were studied in 18 patients with significant coronary artery lesions. In 5 patients with effort induced ischemic region in stress Tl-201 myocardial images rest MIBG images were collected and then exercise stress test was performed. Patients continued exercising for 3 minutes after onset of symptom. Post-stress MIBG images were collected. Definite ischemic region was noted in stress Tl-201 myocardial images, however no differences were noted between rest and post-stress MIBG images. These results suggested that exercise induced ischemia did not enhance release of uptaken MIBG. In 13 patients with significant coronary artery lesions symptom-limited exercise stress test was performed MIBG and Tl-201 were simultaneously injected at onset of symptom and patients continued exercising for an additional one minute. In 6 cases (46%, 6/13) MIBG defects with Tl-201 uptake were noted. These results showed that exercise induced ischemia depressed net MIBG uptake and that sympathetic nervous function (MIBG images) may be more sensitive to ischemic damage than muscle (Tl-201 images). It is suggested that exercise induced ischemia depressed reuptake of norepinephrine at sympathetic nervous endings. MIBG myocardial SPECT images may be useful for evaluating sympathetic nervous function under ischemia. (author)

Mental Stress-Induced-Myocardial Ischemia in Young Patients With Recent Myocardial Infarction: Sex Differences and Mechanisms.

Science.gov (United States)

Vaccarino, Viola; Sullivan, Samaah; Hammadah, Muhammad; Wilmot, Kobina; Al Mheid, Ibhar; Ramadan, Ronnie; Elon, Lisa; Pimple, Pratik M; Garcia, Ernest V; Nye, Jonathon; Shah, Amit J; Alkhoder, Ayman; Levantsevych, Oleksiy; Gay, Hawkins; Obideen, Malik; Huang, Minxuan; Lewis, Tené T; Bremner, J Douglas; Quyyumi, Arshed A; Raggi, Paolo

2018-02-20

Mental stress-induced myocardial ischemia (MSIMI) is frequent in patients with coronary artery disease and is associated with worse prognosis. Young women with a previous myocardial infarction (MI), a group with unexplained higher mortality than men of comparable age, have shown elevated rates of MSIMI, but the mechanisms are unknown. We studied 306 patients (150 women and 156 men) ≤61 years of age who were hospitalized for MI in the previous 8 months and 112 community controls (58 women and 54 men) frequency matched for sex and age to the patients with MI. Endothelium-dependent flow-mediated dilation and microvascular reactivity (reactive hyperemia index) were measured at rest and 30 minutes after mental stress. The digital vasomotor response to mental stress was assessed using peripheral arterial tonometry. Patients received 99m Tc-sestamibi myocardial perfusion imaging at rest, with mental (speech task) and conventional (exercise/pharmacological) stress. The mean age of the sample was 50 years (range, 22-61). In the MI group but not among controls, women had a more adverse socioeconomic and psychosocial profile than men. There were no sex differences in cardiovascular risk factors, and among patients with MI, clinical severity tended to be lower in women. Women in both groups showed a higher peripheral arterial tonometry ratio during mental stress but a lower reactive hyperemia index after mental stress, indicating enhanced microvascular dysfunction after stress. There were no sex differences in flow-mediated dilation changes with mental stress. The rate of MSIMI was twice as high in women as in men (22% versus 11%, P =0.009), and ischemia with conventional stress was similarly elevated (31% versus 16%, P =0.002). Psychosocial and clinical risk factors did not explain sex differences in inducible ischemia. Although vascular responses to mental stress (peripheral arterial tonometry ratio and reactive hyperemia index) also did not explain sex differences in

Technetium-99m sestamibi myocardial tomography based on dipyridamole echocardiography testing in hypertensive patients with chest pain

Energy Technology Data Exchange (ETDEWEB)

Schillaci, O. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Moroni, C. [Department of Internal Medicine, University ``La Sapienza``, Rome (Italy); Scopinaro, F. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Tavolaro, R. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Danieli, R. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Bossini, A. [Department of Internal Medicine, University ``La Sapienza``, Rome (Italy); Cassone, R. [Department of Internal Medicine, University ``La Sapienza``, Rome (Italy); Colella, A.C. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy)

1997-07-01

The aim of this study was to evaluate the diagnostic capability of technetium-99m sestamibi tomography based on dipyridamole echocardiography testing in hypertensives with chest pain, and to compare the scintigraphic results with those of coronary angiography, exercise electrocardiography and dipyridamole echocardiography. Forty subjects with mild to moderate hypertension, chest pain and no previous myocardial infarction were submitted to {sup 99m}Tc-sestamibi tomography (at rest and after high-dose dipyridamole echocardiography) and to exercise electrocardiography testing. At coronary angiography 22 patients (group A) had significant epicardial coronary artery disease ({>=}70% stenosis of at least one major vessel) and 18 normal main coronary vessels (group B). Dipyridamole {sup 99m}Tc-sestamibi imaging was positive in 21/22 patients of group A and in 5/18 of group B. Dipyridamole echocardiography was positive in 18/22 patients of group A and in 5/18 of group B. Exercise electrocardiography was positive in 15/22 patients of group A and in 11/18 of group B. Four out of five subjects in group B with positive results in all the tests showed a slow run-off of angiographic contrast medium, probably due to small-vessel disease. Significant epicardial coronary artery disease in hypertensives with chest pain is unlikely when dipyridamole {sup 99m}Tc-sestamibi tomography is negative. When scintigraphy is positive, either epicardial coronary artery disease or a small-vessel disease condition is possible. The association of scintigraphy with dipyridamole echocardiography testing allows the assessment of contractile function and myocardial perfusion by a single pharmacological stress. (orig./AJ). With 3 figs., 2 tabs.

Prevention of subsequent exercise-induced periinfarct ischemia by emergency coronary angioplasty in acute myocardial infarction: comparison with intracoronary streptokinase

International Nuclear Information System (INIS)

Fung, A.Y.; Lai, P.; Juni, J.E.; Bourdillon, P.D.; Walton, J.A. Jr.; Laufer, N.; Buda, A.J.; Pitt, B.; O'Neill, W.W.

1986-01-01

To compare the efficacy of emergency percutaneous transluminal coronary angioplasty and intracoronary streptokinase in preventing exercise-induced periinfarct ischemia, 28 patients presenting within 12 hours of the onset of symptoms of acute myocardial infarction were prospectively randomized. Of these, 14 patients were treated with emergency angioplasty and 14 patients received intracoronary streptokinase. Recatheterization and submaximal exercise thallium-201 single photon emission computed tomography were performed before hospital discharge. Periinfarct ischemia was defined as a reversible thallium defect adjacent to a fixed defect assessed qualitatively. Successful reperfusion was achieved in 86% of patients treated with emergency angioplasty and 86% of patients treated with intracoronary streptokinase (p = NS). Residual stenosis of the infarct-related coronary artery shown at predischarge angiography was 43.8 +/- 31.4% for the angioplasty group and 75.0 +/- 15.6% for the streptokinase group (p less than 0.05). Of the angioplasty group, 9% developed exercise-induced periinfarct ischemia compared with 60% of the streptokinase group (p less than 0.05). Thus, patients with acute myocardial infarction treated with emergency angioplasty had significantly less severe residual coronary stenosis and exercise-induced periinfarct ischemia than did those treated with intracoronary streptokinase. These results suggest further application of coronary angioplasty in the management of acute myocardial infarction

Myocardial metabolic abnormalities in hypertrophic cardiomyopathy assessed by iodine-123-labeled beta-methyl-branched fatty acid myocardial scintigraphy and its relation to exercise-induced ischemia

International Nuclear Information System (INIS)

Matsuo, Shinro; Nakamura, Yasuyuki; Takahashi, Masayuki; Mitsunami, Kenichi; Kinoshita, Masahiko

1998-01-01

Reversible thallium-201 ( 201 Tl) abnormalities during exercise stress have been used as markers of myocardial ischemia in hypertrophic cardiomyopathy (HCM) and are most likely to identify relatively underperfused myocardium. Although metabolic abnormalities in HCM were reported, the relationship between impaired energy metabolism and exercise-induced ischemia has not been fully elucidated as yet. To assess the relationship between myocardial perfusion abnormalities and fatty acid metabolic abnormalities, 28 patients with HCM underwent exercise 201 Tl and rest 123 I-15-(p-iodophenyl)-3-methyl pentadecanoic acid (BMIPP) scintigraphy. Perfusion abnormalities were observed by exercise 201 Tl in 19/28 patients with HCM. 123 I-BMIPP uptake was decreased compared with delayed 201 Tl in 106/364 (29%) of the total myocardial segments (p 123 I-BMIPP and 201 Tl was observed more often in the 49/75 (65%) segments with reversible exercise 201 Tl defects (p 123 I-BMIPP and 201 Tl suggests that myocardial ischemia may play an important role in metabolic abnormalities in HCM. (author)

The safety of dipyridamole myocardial perfusion scintigraphy (MPS) in patients with end-stage chronic airways limitations (CAL)

International Nuclear Information System (INIS)

Roman, M.R.; Freeman, A.P.; Angelides, S.

2000-01-01

Full text: Dipyridamole MPS is a well-established investigative technique in the diagnosis and pre-operative risk stratification of patients with possible coronary artery disease. However, there remains a concern of its use in patients with end-stage chronic airways limitations (CAL). Lung volume reduction surgery (LVRS) is a recent therapeutic option for such patients. The options for non-invasive pre-operative cardiac assessment in such patients are limited. This study reviewed the safety of dipyridamole use in such a clinical setting. 20 patients (10M, 10F, mean age 64.8 yrs) were evaluated. None had any history of ischaemic heart disease. Dipyridamole was administered intravenously at a dose of 0.05 mg/kg. Six patients remained asymptomatic throughout the procedure, while none experienced any chest pain. Two patients experienced moderate dyspnoea, which was rapidly relieved with aminophylline (100mg IV) during the recovery phase of the study. Two others developed mild dyspnoea; one settled spontaneously, while the other responded promptly to aminophylline. Aminophylline was administered to nine other patients to reverse minor symptoms (headache, flushing sensation). One other patient developed marked hypotension (SBP fell >20mmHg) and bradycardia, but no ECG changes for myocardial ischaemia. He responded well to aminophylline. His myocardial perfusion scan demonstrated extensive reversible myocardial ischaemia. Although the population size was small, dipyridamole appears safe to use in patients with end-stage CAL. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

Myocardial viability in cases with persistent perfusion defects on the dipyridamole thallium-201 scintigram. A comparative study with autopsy findings

International Nuclear Information System (INIS)

Nakayama, Masafumi; Mashima, Saburo; Ohkawa, Shin-ichiro; Tanno, Munehiko; Yamada, Hideo.

1996-01-01

The aim of this study was to assess the incidence of myocardial infarction among persistent perfusion defects in dipyridamole-stress thallium scintigraphy by inspecting autopsied hearts and to evaluate whether the regional thallium activity of a scintigraphic defect can predict the presence of infarction. Autopsied hearts were compared with dipyridamole myocardial scintigrams undertaken during life in 27 patients (mean age 85±8 years). The time interval from stress testing until death was 428±351 days. Regional thallium uptake of delayed perfusion defect was calculated on the short axis images. The grade of regional myocardial fibrosis in autopsy specimens was also quantified to correlate with the corresponding regional thallium uptake. In 6 of 15 (40%) regions with persistent defects on the scintigram, myocardial infarction was not found at autopsy. Regional thallium-201 uptake of delayed defects < 50% diagnosed infarction with a sensitivity of 82% and a specificity of 80%. A linear correlation (r=-0.67) was observed between percent thallium-201 uptake and the degree of myocardial fibrosis. In conclusion, perfusion defects at 4-hour imaging in dipyridamole-stress testing may overestimate the presence of myocardial infarction and regional thallium-201 activity is helpful in distinguishing between defects with and without infarction. (author)

Effects of Chronic and Acute Zinc Supplementation on Myocardial Ischemia-Reperfusion Injury in Rats.

Science.gov (United States)

Ozyıldırım, Serhan; Baltaci, Abdulkerim Kasim; Sahna, Engin; Mogulkoc, Rasim

2017-07-01

The present study aims to explore the effects of chronic and acute zinc sulfate supplementation on myocardial ischemia-reperfusion injury in rats. The study registered 50 adult male rats which were divided into five groups in equal numbers as follows: group 1, normal control; group 2, sham; group 3, myocardial ischemia reperfusion (My/IR): the group which was fed on a normal diet and in which myocardial I/R was induced; group 4, myocardial ischemia reperfusion + chronic zinc: (5 mg/kg i.p. zinc sulfate for 15 days); and group 5, myocardial ischemia reperfusion + acute zinc: the group which was administered 15 mg/kg i.p. zinc sulfate an hour before the operation and in which myocardial I/R was induced. The collected blood and cardiac tissue samples were analyzed using spectrophotometric method to determine levels of MDA, as an indicator of tissue injury, and GSH, as an indicator of antioxidant activity. The highest plasma and heart tissue MDA levels were measured in group 3 (p zinc administration and markedly by chronic zinc supplementation.

The diagnosis of silent myocardial ischemia. Motion-Frozen (or morphing) myocardial perfusion imaging.

Science.gov (United States)

Chang, Cheng; Ye, Bo; Xie, Wenhui; Zhang, Daoliang; Lei, Bei; Ye, Xiaodan

2016-01-01

Silent myocardial ischemia is typically defined as objective evidence of myocardial ischemia in patients without subjective ischemia symptoms. Currently, coronary artery angiography is the gold standard for diagnosis of asymptomatic coronary artery disease (CAD). Computed tomography coronary angiography (CTCA) can visually demonstrate the morphology, trend and extent of coronary stenosis and is commonly used in clinical screening of CAD. Myocardial perfusion imaging can be used not only to identify whether anatomical stenosis causes myocardial dysfunction, but to also assess the risk stratification and prognosis of myocardial disease (MD). Myocardial perfusion imaging using morphing combined with CTCA can simultaneously show the relationship between CAD and myocardial ischemia from an anatomical and functional aspect. This allows earlier diagnosis of asymptomatic CAD myocardial ischemia, accurate identification of the culprit vessels, and could prevent unnecessary interventional therapy. The 1-day dobutamine stress/resting met-hod is also one of the methods used. The combination of CTCA and the morphing technique can provide anatomical and functional information on coronary arteries at the same time, significantly improving the diagnostic sensitivity, specificity, and accuracy of MD.

Sex Differences in Mental Stress-Induced Myocardial Ischemia in Patients With Coronary Heart Disease.

Science.gov (United States)

Vaccarino, Viola; Wilmot, Kobina; Al Mheid, Ibhar; Ramadan, Ronnie; Pimple, Pratik; Shah, Amit J; Garcia, Ernest V; Nye, Jonathon; Ward, Laura; Hammadah, Muhammad; Kutner, Michael; Long, Qi; Bremner, J Douglas; Esteves, Fabio; Raggi, Paolo; Quyyumi, Arshed A

2016-08-24

Emerging data suggest that young women with coronary heart disease (CHD) are disproportionally vulnerable to the adverse cardiovascular effects of psychological stress. We hypothesized that younger, but not older, women with stable CHD are more likely than their male peers to develop mental stress-induced myocardial ischemia (MSIMI). We studied 686 patients (191 women) with stable coronary heart disease (CHD). Patients underwent (99m)Tc-sestamibi myocardial perfusion imaging at rest and with both mental (speech task) and conventional (exercise/pharmacological) stress testing. We compared quantitative (by automated software) and visual parameters of inducible ischemia between women and men and assessed age as an effect modifier. Women had a more-adverse psychosocial profile than men whereas there were few differences in medical history and CHD risk factors. Both quantitative and visual indicators of ischemia with mental stress were disproportionally larger in younger women. For each 10 years of decreasing age, the total reversibility severity score with mental stress was 9.6 incremental points higher (interaction, P<0.001) and the incidence of MSIMI was 82.6% higher (interaction, P=0.004) in women than in men. Incidence of MSIMI in women ≤50 years was almost 4-fold higher than in men of similar age and older patients. These results persisted when adjusting for sociodemographic and medical risk factors, psychosocial factors, and medications. There were no significant sex differences in inducible ischemia with conventional stress. Young women with stable CHD are susceptible to MSIMI, which could play a role in the prognosis of this group. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Screening for silent myocardial ischemia caseof diabetics : interest of myocardial perfusion scintigraphy

International Nuclear Information System (INIS)

Bahri, Haifa

2007-01-01

Silent myocardial ischemia is a major cause of morbidity and mortality in diabetic patients. Its diagnosis by noninvasive means such as myocardial SPECT would improve the management of these patients. The purpose of this study is to assess the frequency of silent myocardial ischemia in asymptomatic diabetics and their evolution. As a result, the myocardial SPECT is a reliable tool for screening for silent myocardial ischemia in diabetic patients. Its prognostic value allows to stratify the cardiac risk and guide therapeutic management. Its integration into a screening strategy in Tunisia seems limited by its low availability and cost. The latter could be reduced by better patient selection.

Left ventricular function abnormalities as a manifestation of silent myocardial ischemia.

Science.gov (United States)

Lambert, C R; Conti, C R; Pepine, C J

1986-11-01

A large body of evidence exists indicating that left ventricular dysfunction is a common occurrence in patients with severe coronary artery disease and represents silent or asymptomatic myocardial ischemia. Such dysfunction probably occurs early in the time course of every ischemic episode in patients with coronary artery disease whether symptoms are eventually manifested or not. The pathophysiology of silent versus symptomatic left ventricular dysfunction due to ischemia appears to be identical. Silent ischemia-related left ventricular dysfunction can be documented during spontaneous or stress-induced perturbations in the myocardial oxygen supply/demand ratio. It also may be detected by nitroglycerin-induced improvement in ventricular function or by salutary changes in wall motion following revascularization. Silent left ventricular dysfunction is a very early occurrence during ischemia and precedes electrocardiographic abnormalities. In this light, its existence should always be kept in mind when dealing with patients with ischemic heart disease. It can be hypothesized that because silent ischemia appears to be identical to ischemia with symptoms in a pathophysiologic sense, prognosis and treatment in both cases should be the same.

Diagnostic Value of Myocardial Perfusion SPECT with Dipyridamole in a Female Population

International Nuclear Information System (INIS)

Perez-Iruela, Juan; Pastor, Purificacion; Lumbreras, Luis; Martin, Ana M.; Ruiz, Francisco J.; Posadas, A.; Puentes, Carmen

2009-01-01

Background: Exercise stress scintigraphy is a safe procedure widely used for the diagnosis of ischemic heart disease. Pharmacologic stress testing is an important alternative. The delayed presentation of ischemic heart disease in women, together with a lower diagnostic accuracy of exercise stress testing in this population, has generated interest in the potential benefits provided by myocardial perfusion imaging tests. Objective: To determine the diagnostic value of myocardial perfusion images with 99m Tc-tetrofosmin in a one day protocol after a pharmacologic stress with dipyridamole in a female population, and the relation with the coronary territories using coronary angiography as a reference technique. Material and Methods: In total, 149 clinical charts of women with suspected ischemic heart disease undergoing myocardial perfusion imaging tests and coronary angiography were retrospectively analyzed. Results: Sensitivity and specificity were 94% (93.47%-94.53%) and 82% (80.94%-83.06%), respectively. Values of sensitivity and specificity according to coronary territories were 71.62% (70.88%-72.36%) and 76% (75.27%-76.73%) for the left anterior descending (LAD) artery, 69.09% (68.11%-70.07%) and 76.84% (76.26%-77.42%) for the left circumflex (LCx) coronary artery, and 87.23% (86.11%-88.36%) and 74.51% (73.97%-75.05%) for the right coronary artery (RCA), respectively. Conclusion: Myocardial perfusion scintigraphy with 99m Tc-tetrofosmin and dipyridamole using a one day stress-rest protocol has high sensitivity and specificity for the diagnosis of ischemic heart disease in women. (authors) [es

Imaging of cocaine-induced global and regional myocardial ischemia

International Nuclear Information System (INIS)

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

1991-01-01

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

Low-fat diet and regular, supervised physical exercise in patients with symptomatic coronary artery disease: reduction of stress-induced myocardial ischemia

International Nuclear Information System (INIS)

Schuler, G.; Schlierf, G.; Wirth, A.

1988-01-01

The effects of physical exercise and normalization of serum lipoproteins on stress-induced myocardial ischemia were studied in 18 patients with coronary artery disease, stable angina pectoris, and mild hypercholesterolemia (total serum cholesterol 242 +/- 32 mg/dl). These patients underwent a combined regimen of low-fat/low-cholesterol diet and regular, supervised physical exercise at high intensity for 12 months. At 1 year serum lipoproteins has been lowered to ideal levels (serum cholesterol 202 +/- 31 mg/dl, low-density lipoproteins 130 +/- 30 mg/dl, very low-density lipoproteins 22 +/- 15 mg/dl, serum triglycerides 105 [69 to 304] mg/dl) and physical work capacity was improved by 21% (p less than .01). No significant effect was noted on high-density lipoproteins, probably as a result of the low-fat/high-carbohydrate diet. Stress-induced myocardial ischemia, as assessed by thallium-201 scintigraphy, was decreased by 54% (p less than .05) despite higher myocardial oxygen consumption. Eighteen patients matched for age and severity of coronary artery disease served as a control group and ''usual medical care'' was rendered by their private physicians. No significant changes with respect to serum lipoproteins, physical work capacity, maximal rate-pressure product, or stress-induced myocardial ischemia were observed in this group. These data indicate that regular physical exercise at high intensity, lowered body weight, and normalization of serum lipoproteins may alleviate compromised myocardial perfusion during stress

Myocardial fatty acid utilisation during exercise induced ischemia in patients with coronary artery disease

Energy Technology Data Exchange (ETDEWEB)

Virtanen, K.S. [First Dept. of Medicine, Helsinki Univ. Central Hospital (Finland); Nikkinen, P. [Dept. of Clinical Chemistry, Helsinki Univ. Central Hospital (Finland); Lindroth, L. [Medix Diacor Lab. Services, Ltd., Espoo (Finland); Kuikka, J.T. [Dept. of Clinical Physiology and Nuclear Medicine, Kuopio Univ. Hospital, Univ. of Kuopio and Niuvanniemi Hospital, Kuopio (Finland)

2002-06-01

Aim: Reversible or irreversible myocardial damage due to ischemia correlates with altered membrane functions of the cells. To compare myocardial free fatty acid (FFA) metabolism and flow during exercise induced ischemia we studied ten patients with coronary artery disease but without previous myocardial infarction. Methods: A series of post-exercise single-photon emission computed tomography (SPECT) measurements was performed after injection of {sup 123}I labelled heptadecanoic acid (HDA). Myocardial perfusion was estimated from the separately performed exercise-redistribution thallium study. Fatty acid metabolic rate, thallium uptake and washout were calculated for anterior, lateral, posterior and septal segments. Results: The more reduced post-exercise FFA metabolic rate (-63{+-}18%, mean {+-}1 SD) compared to flow (-36{+-}16%) was related to the severity of myocardial ischemia and wall motion abnormalities. Conclusion: In this small group of patients, the reduced post-exercise FFA metabolic rate tentatively suggests a parsimonious workload of the exercising myocardium by reducing oxygen consumption in patients with coronary artery disease. (orig.) [German] Ziel: Bei reversibler und irreversibler Myokardschaedigung infolge Ischaemie sind die Membranfunktionen der Zellen veraendert. Um myokardialen Metabolismus freier Fettsaeuren (FFA) und Durchblutung bei belastungsinduzierter Ischaemie zu vergleichen, untersuchten wir zehn Patienten mit Koronarinsuffizienz, aber ohne vorangegangenen Myokardinfarkt. Methoden: Nach Injektion von {sup 123}I-markierter Heptadekansaeure (HDA) wurde eine Serie von SPECT-Messungen nach Belastung aufgenommen. Die myokardiale Perfusion wurde abgeschaetzt durch die separat durchgefuehrte Thalliumverteilungsstudie nach Belastung. Fettsaeurestoffwechsel, Thallium-Uptake und -Washout wurden fuer die anterioren, posterioren und septalen Segmente berechnet. Ergebnisse: Eine eingeschraenktere FFA-Stoffwechselrate (-63{+-}18%, {+-}1 SD

Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block; Perfusao miocardica de estresse com dipiridamol por tomografia computadorizada em pacientes com bloqueio de ramo esquerdo

Energy Technology Data Exchange (ETDEWEB)

Cabeda, Estevan Vieira; Rochitte, Carlos Eduardo; Nomura, Cesar Higa; Parga, Jose Rodrigues; Avila, Luiz Francisco Rodrigues; Falcao, Andrea Maria Gomes; Soares Junior, Jose [Instituto do Coracao (InCor), Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil)

2015-12-15

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. (author)

Significance of dipyridamole-induced transient dilation of the left ventricle during thallium-201 scintigraphy in suspected coronary artery disease

International Nuclear Information System (INIS)

Chouraqui, P.; Rodrigues, E.A.; Berman, D.S.; Maddahi, J.

1990-01-01

The occurrence and significance of transient dilation of the left ventricle during dipyridamole stress-redistribution thallium-201 scintigraphy was studied in 73 patients who underwent both dipyridamole thallium-201 study and coronary angiography. Transient dilation ratio was calculated from planar anterior images by dividing the computer-derived left ventricular area on the initial image by that of the 4-hour image. In 11 patients with normal coronary arteriograms or less than 50% coronary stenosis, the transient dilation ratio was 0.98 +/- 0.046. An abnormal transient dilation ratio was defined as greater than or equal to 1.12, representing greater than or equal to 3 standard deviations above the mean normal value. When the 15 patients with an abnormal ratio were compared with the 58 with a normal ratio, the former group had a significantly higher frequency of 3 critical (greater than or equal to 90%) coronary stenoses (33 vs 5%), higher prevalence of collaterals (67 vs 24%), more extensive myocardial reversible defects by planar (71 vs 10%) or by single-photon emission computed tomography (87.5 vs 35%) imaging and a higher incidence of dipyridamole-induced anginal chest pain (53 vs 22%). No significant difference between the 2 groups was noted with respect to age, gender, prior myocardial infarction, single or double critical coronary stenosis, dipyridamole-induced ischemic electrocardiographic response and increased lung uptake. An abnormal transient dilation ratio of greater than or equal to 1.12 was a specific marker of multivessel (87%) or 3-vessel (85%) critical coronary artery disease

The study of myocardial ischemic quality with weighted-subtraction-bull's-eye analysis

International Nuclear Information System (INIS)

Chen Wuduan; Tian Jiahe; Hou Qingtian

1993-01-01

Weighted-Subtraction-Bull's-eye analysis was studied in 33 normal subjects and 58 patients with coronary artery disease after dipyridamole 99m Tc-MIBI myocardial SPECT imaging. Two kinds of Bull's-eye were produced: (1) subtract rest from 1.2 times dipyridamole from 1.2 times rest Bull's-eye; (2) subtract dipyridamole Bull's-eye. The results showed that the weighted-subtraction-Bull's-eye could clearly displayed the location and puality of ischemic myocardium. And also 74% segments showed so called combined ischemic i.e the blood perfusion reduced, increased and sustained simultaneously after dipyridamole. Therefore weighted-subtraction-Bull's-eye analysis had provided a new method for determination of the quality of ischemia

Comparison of Hyperemic Impedance Echocardiography with Dobutamine Stress Echocardiography to Detect Inducible Myocardial Ischemia: A Pilot Study.

Science.gov (United States)

Patel, Jijibhoy J; Gupta, Ankur; Nanda, Navin C

2016-03-01

Stress echocardiography using exercise or pharmacological stressors is either contraindicated or associated with significant side effects in some patients. This pilot study was designed to evaluate a new technique, hyperemic impedance echocardiography (HIE). It is based on reactive coronary hyperemia when transient limb ischemia is induced by tourniquet inflation. We hypothesized that this physiologic coronary hyperemia can identify inducible myocardial ischemia by assessment of regional wall motion abnormalities on echocardiography when compared with dobutamine stress echocardiography (DSE). Twenty consecutive outpatients with suspected stable coronary artery disease (CAD) who underwent clinically indicated DSE were recruited for performance of HIE after informed consent was obtained. Standard graded dobutamine infusion protocol from 5 to 40 μg/kg per min was used for DSE. HIE was performed by inflating tourniquets at a pressure of 10 mmHg below the systolic blood pressure for 1 minute in three of four extremities at a time for total of four cycles. Echocardiography was performed immediately after the last rotating tourniquet deflation. DSE and HIE were classified as abnormal for development of new or worsening wall motion abnormality in at least one myocardial segment. Test characteristics were also determined for a subset of these patients (n = 12) who underwent clinically indicated coronary angiography. Hyperemic impedance echocardiography showed 86% sensitivity, 67% specificity, 86% positive predictive value, and 67% negative predictive value with a test accuracy of 80% to detect inducible myocardial wall motion abnormalities when compared with DSE. HIE also showed 83% sensitivity, 75% negative predictive value with a test accuracy of 66.7% for detection of significant (≥50% diameter stenosis) CAD on coronary angiography. In this pilot study, HIE was a feasible, safe, and promising method for detection of inducible myocardial ischemia by assessment of

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

International Nuclear Information System (INIS)

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

1989-01-01

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

Myocardial ischemia in hypertrophic cardiomyopathy; Isquemia miocardica na cardiomiopatia hipertrofica

Energy Technology Data Exchange (ETDEWEB)

Lima Filho, Moyses de Oliveira; Figueiredo, Geraldo L.; Simoes, Marcus V.; Pyntia, Antonio O.; Marin Neto, Jose Antonio [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Div. de Cardiologia

2000-08-01

Myocardial ischemia in hypertrophic cardiomyopathy is multifactorial and explains the occurrence of angina, in about 50% of patients. The pathophysiology of myocardial ischemia may be explained by the increase of the ventricular mass and relative paucity of the coronary microcirculation; the elevated ventricular filling pressures and myocardial stiffness causing a compression of the coronary microvessels; the impaired coronary vasodilator flow reserve caused by anatomic and functional abnormalities; and the systolic compression of epicardial vessel (myocardial bridges). Myocardial ischemia must be investigated by perfusion scintigraphic methods since its presence influences the prognosis and has relevant clinical implications for management of patients. Patients with hypertrophic cardiomyopathy and documented myocardial ischemia usually need to undergo invasive coronary angiography to exclude the presence of concomitant atherosclerotic coronary disease. (author)

Dipyridamole induced directory disfunction of infarcted vessel, and estimation of patients with acute myocardial infarction and successful PTCA

International Nuclear Information System (INIS)

Hashimoto, Yasunori; Yamabe, Hiroshi; Kim, Sushik; Yano, Takashi; Fujita, Hideki; Kakimoto, Tetsuya; Namura, Hiroyuki; Maeda, Kazumi; Yokoyama, Mitsuhiro

1993-01-01

The purpose of this study was to determine whether transient disturbance of vascular dilation in the peripheral coronary vessels in patients with myocardial infarction in whom coronary recanalization was successfully attained in the acute stage. The subjects were 6 patients with acute myocardial infarction in whom recanalization was successfully attained without a significant coronary stenosis by emergency percutaneous transluminal coronary angioplasty (PTCA). Dipyridamole-loaded thallium-201 myocardial scintigraphy was undertaken during the acute stage (an average of 5 days after PTCA) and during convalescent stage (an average 24 days after PTCA). Defect was seen in the infarcted areas on early images during the acute stage in all 6 patients, and Tl uptake in the infarcted areas was improved during the convalescent stage in 2 of the 6 patients. In these two patients, fill-in phenomenon was seen in the infarcted area during acute stage when images were acquired after re-injection of Tl-201. These findings suggested that transient disturbance of vascular dilation may occur in the peripheral coronary artery vessels in the infarcted area where recanalization was successfully attained in patients with acute myocardial infarction. (N.K.)

Tramadol Alleviates Myocardial Injury Induced by Acute Hindlimb Ischemia Reperfusion in Rats

Energy Technology Data Exchange (ETDEWEB)

Takhtfooladi, Hamed Ashrafzadeh; Asl, Adel Haghighi Khiabanian [Department of Pathobiology, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Shahzamani, Mehran [Department of Cardiovascular Surgery, Isfahan University of Medical Sciences, Tehran (Iran, Islamic Republic of); Takhtfooladi, Mohammad Ashrafzadeh, E-mail: dr-ashrafzadeh@yahoo.com [Young Researchers and Elites Club, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Allahverdi, Amin [Department of Surgery, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Khansari, Mohammadreza [Department of Physiology, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

2015-08-15

Organ injury occurs not only during periods of ischemia but also during reperfusion. It is known that ischemia reperfusion (IR) causes both remote organ and local injuries. This study evaluated the effects of tramadol on the heart as a remote organ after acute hindlimb IR. Thirty healthy mature male Wistar rats were allocated randomly into three groups: Group I (sham), Group II (IR), and Group III (IR + tramadol). Ischemia was induced in anesthetized rats by left femoral artery clamping for 3 h, followed by 3 h of reperfusion. Tramadol (20 mg/kg, intravenous) was administered immediately prior to reperfusion. At the end of the reperfusion, animals were euthanized, and hearts were harvested for histological and biochemical examination. The levels of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were higher in Groups I and III than those in Group II (p < 0.05). In comparison with other groups, tissue malondialdehyde (MDA) levels in Group II were significantly increased (p < 0.05), and this increase was prevented by tramadol. Histopathological changes, including microscopic bleeding, edema, neutrophil infiltration, and necrosis, were scored. The total injuryscore in Group III was significantly decreased (p < 0.05) compared with Group II. From the histological and biochemical perspectives, treatment with tramadol alleviated the myocardial injuries induced by skeletal muscle IR in this experimental model.

Noninvasive evaluation of myocardial ischemia in patients with heart problems

Directory of Open Access Journals (Sweden)

Mehdi Nikseresht

2018-03-01

Conclusion: It seems that the higher risk of myocardial ischemia in men aged 60-77 years, as compared to men aged 45-59 years, might be related to aging process and imbalance in the risk factors. Promoting physical activity can favorably affect the risk of myocardial ischemia in the middle-aged or elderly men. It is concluded that physical activity effectively decreased the risk of myocardial ischemia.

Myocardial 201Tl washout after combined dipyridamole submaximal exercise stress: Reference values from different patient groups

International Nuclear Information System (INIS)

Fridrich, L.

1989-01-01

Dipyridamole stress is favorable in patients unable to exercise maximally for 201 Tl myocardial scintigraphy. Aside from an analysis of uptake defects, proper washout analysis can be limited by heart rate variations when isolated dipyridamole stress is used. Heart rate standardized 201 Tl washout kinetics after a combined dipyridamole and submaximal exercise stress protocol (CDSE), feasible in elderly patients as well as in patients with peripheral artery disease, were therefore studied to investigate the 201 Tl washout after CDSE in differently defined patient groups: Group I comprised 19 patients with documented heart disease and angiographically excluded coronary artery disease (CAD); group II contained 17 patients with a very low likelihood of CAD determined by both normal exercise radionuclide ventriculography and normal 201 Tl uptake. Group III comprised 56 patients with a 50% pretest likelihood of CAD but normal 201 Tl uptake. Mean washout values were nearly identical in all groups. Despite similar uptake patterns, however, washout standardized by CDSE was significantly lower than the normal washout values after maximal treadmill exercise. Thus an obviously lower 201 Tl washout after CDSE than after maximal treadmill exercise must be considered if washout analysis criteria after dipyridamole are applied to evaluate ischemic heart disease. Nevertheless, heart rate elevation achieved by additional submaximal exercise stress seems necessary, adequate and clinically safe for standardisation of washout analysis in dipyridamole 201 Tl scintigraphy. (orig.)

NT-pro-BNP is associated with inducible myocardial ischemia in mildly symptomatic type 2 diabetic patients.

Science.gov (United States)

Wiersma, Jacobijne J; van der Zee, P Marc; van Straalen, Jan P; Fischer, Johan C; van Eck-Smit, Berthe L F; Tijssen, Jan G P; Trip, Mieke D; Piek, Jan J; Verberne, Hein J

2010-11-19

Baseline levels of N-terminal fragment of the brain natriuretic peptide prohormone (NT-pro-BNP) are associated with myocardial ischemia in non-diabetic patients with stable angina pectoris. A total of 281 patients with diabetes mellitus type 2 and stable angina pectoris underwent myocardial perfusion scintigraphy (MPS). Myocardial ischemia on MPS was present in 140 (50%) patients. These ischemic patients had significantly higher NT-pro-BNP levels compared with patients without ischemia: 183 pg/ml (64-324 pg/ml) vs. 88 pg/ml (34-207 pg/ml), respectively (ppro-BNP ≥180 pg/ml was an independent predictor of the presence of myocardial ischemia (OR 2.36, 95%CI 1.40-3.97, p=0.001). Possible confounding factors such as age and creatinine clearance were of no influence on the predictive value in this specific patient population. These findings strengthen the idea that NT-pro-BNP may be of value in the early detection of diabetic patients with hemodynamic significant coronary artery disease. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

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

Science.gov (United States)

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

2015-01-01

A close link between heart failure (HF) and systemic insulin resistance has been well documented, whereas myocardial insulin resistance and its association with HF are inadequately investigated. This study aims to determine the role of myocardial insulin resistance in ischemic HF and its underlying mechanisms. Male Sprague-Dawley rats subjected to myocardial infarction (MI) developed progressive left ventricular dilation with dysfunction and HF at 4 wk post-MI. Of note, myocardial insulin sensitivity was decreased as early as 1 wk after MI, which was accompanied by increased production of myocardial TNF-α. Overexpression of TNF-α in heart mimicked impaired insulin signaling and cardiac dysfunction leading to HF observed after MI. Treatment of rats with a specific TNF-α inhibitor improved myocardial insulin signaling post-MI. Insulin treatment given immediately following MI suppressed myocardial TNF-α production and improved cardiac insulin sensitivity and opposed cardiac dysfunction/remodeling. Moreover, tamoxifen-induced cardiomyocyte-specific insulin receptor knockout mice exhibited aggravated post-ischemic ventricular remodeling and dysfunction compared with controls. In conclusion, MI induces myocardial insulin resistance (without systemic insulin resistance) mediated partly by ischemia-induced myocardial TNF-α overproduction and promotes the development of HF. Our findings underscore the direct and essential role of myocardial insulin signaling in protection against post-ischemic HF. PMID:26659007

Stress magnetic resonance imaging in coronary artery disease. 11

International Nuclear Information System (INIS)

Pennell, D.J.; Underwood, S.R.

1991-01-01

The feasibility of MRI of wall motion and cardiovascular haemodynamics has been investigated during pharmacological stress with dipyridamole and dobutamine as pharmacological stressors. The authors conclude that dobutamine is preferable to dipyridamole for inducing myocardial ischemia during imaging. (H.W.). 74 refs.; 8 figs.; 5 tabs

Electrophysiological, haemodynamic, and mitochondrial alterations induced by levobupivacaine during myocardial ischemia in a pig model: protection by lipid emulsions?

Science.gov (United States)

Mamou, Zahida; Descotes, Jacques; Chevalier, Philippe; Bui-Xuan, Bernard; Romestaing, Caroline; Timour, Quadiri

2015-10-01

Accidental intravascular or high-dose injection of local anesthetics (LA) can result in serious, potentially life-threatening complications. Indeed, adequate supportive measures and the administration of lipid emulsions are required in such complications. The study's objectives were threefold: (i) evaluate the myocardial toxicity of levobupivacaine when administered intravenously; (ii) investigate levobupivacaine toxicity on cardiomyocytes mitochondrial functions and cellular structure; (iii) assess the protective effects of a lipid emulsion in the presence or absence of myocardial ischemia. Domestic pigs randomized into two groups of 24 animals each, with either preserved coronary circulation or experimental myocardial ischemia. Six animals from each group received either: (i) single IV injection of saline, (ii) lipid emulsion (Intralipid(®) ), (iii) levobupivacaine, (iv) combination levobupivacaine-Intralipid(®) . Serially measured endpoints included: heart rate, duration of the monophasic action potentials (dMAP), mean arterial pressure, and peak of the time derivative of left ventricular pressure (LV dP/dtmax ). In addition, the following cardiomyocytes mitochondrial functions were measured: reactive oxygen species (ROS) production, oxidative phosphorylation, and calcium retention capacity (CRC) as well as the consequences of ROS production on lipids, proteins, and DNA. IV injection of levobupivacaine induced sinus bradycardia and reduced dMAP and LV dP/dtmax . At the mitochondrial level, oxygen consumption and CRC were decreased. In contrast, ROS production was increased leading to enhanced lipid peroxidation and structural alterations of proteins and DNA. Myocardial ischemia was associated with global worsening of all changes. Intralipid(®) quickly improved haemodynamics. However, beneficial effects of Intralipid(®) were less clear after myocardial ischemia. © 2015 Société Française de Pharmacologie et de Thérapeutique.

The causes and clinical significance of exercise-induced silent myocardial ischemia evaluated by ischemic range and intensity with exercise Tl-201 myocardial SPECT

International Nuclear Information System (INIS)

Moriai, Naoki; Nakai, Kenji; Hiramori, Katsuhiko

1992-01-01

We investigated the causes and long-term prognosis of exercise-induced silent myocardial ischemia (SMI) by means of exercise Tl-201 myocardial SPECT (Ex-SPECT) in 97 patients with effort angina or old myocardial infarction (OMI). These patients were proven to have significant stenosis by coronary angiography. The subjects were divided into three groups based on the presence or absence of Tl-201 redistribution (RD) or angina during exercise testing. Group one consisted of 34 patients who had RD on Ex-SPECT and angina during exercise testing: the painful myocardial ischemia (PMI) group. The second group consisted of 38 patients who had RD on Ex-SPECT, but no angina during exercise testing: the SMI group. The third group consisted of 25 patients who had no RD: the RD (-) group. The ischemic range and intensity were quantified by the defect volume ratio (DVR) and defect severity index (DSI), respectively. Comparison of the DVR and DSI values for the PMI and SMI groups revealed that the DVR and DSI values for the SMI group were lower than those of the PMI group. Also the prognosis of the SMI group tended to be worse than that of the RD (-) group. Thus, we concluded that the SMI and PMI groups should receive identical treatment. (author)

Myocardial ischemia and angina pectoris

International Nuclear Information System (INIS)

Selwyn, A.P.; Fox, K.M.; Jonathan, A.; Lavender, P.; Watson, I.

1981-01-01

Ambulatory monitoring of ST segment changes was performed in 60 patients presenting with angina, positive ECG stress tests and coronary artery disease, 85% of ischemic ECG events were asymptomatic, 37% occurred with no increase in heart rate and 15% of episodes either lasted 20 minutes or more or fluctuated in severity. A controlled pilot study in ten patients showed depression. Radionuclide studies in 50 patients with angina and coronary artery disease have shown that stress (i.e., atrial pacing) produced different patterns of disturbed regional myocardial perfusion related to the patient's exercise capacity and eventually leading to a decrease in regional myocardial perfusion during the ischemic episode. ST segment depression appeared only after the decrease in regional myocardial perfusion. These findings combined with past research suggest that patients with angina and coronary artery disease can suffer frequent asymptomatic disturbances of the regional myocardial perfusion. The frequency of these episodes and the time course for the recovery of the metabolic consequences mean that segments of ventricular myocardium may be constantly abnormal. The relative importance of changes in coronary tone and malfunction of platelets in the diseased coronary tree needs to be examined in clinical research. Pilot studies of antiplatelet agents have shown a significant beneficial effect on episodes of ischemia occurring at night and those occurring without any increase in heart rate. The techniques and observations in these patients with coronary artery disease all suggest that acute transient regional myocardial ischemia is caused by a variety of mechnisms. Further research using objective methods is required to discover the causes of ischemia and to rationalize treatment. (orig./MG) [de

Exercise supplementation of dipyridamole for myocardial perfusion imaging

International Nuclear Information System (INIS)

DePuey, E.G.

1991-01-01

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

Myocardial scintigraphy with 16 123I hexadecene-9 oic acid. Study of the influence of isoproterenol, propranolol, dipyridamole and isoptine

International Nuclear Information System (INIS)

Comet, M.; Wolf, J.E.; Pilichowski, P.; Busquet, G.; Dubois, F.; Mathieu, J.P.; Pernin, C.; Riche, F.; Vidal, M.

1983-01-01

After I.V. injection of 123 I hexadecene-9 oic acid to dogs, the decreasing part of the myocardial activity curve is fitted with an exponential which period is calculated. Tacking the anesthetized dogs as his own reference, we study the influence of isoproterenol, propranolol, dipyridamole and isoptine on value of the period. None of the drugs modify significatively the period. Nevertheless, propranolol and isoptine and to a lesser extent dipyridamole have a tendancy to increase the value of the period [fr

Myocardial scintigraphy with 16 /sup 123/I hexadecene-9 oic acid. Study of the influence of isoproterenol, propranolol, dipyridamole and isoptine

Energy Technology Data Exchange (ETDEWEB)

Comet, M.; Wolf, J.E.; Pilichowski, P.; Busquet, G.; Dubois, F.; Mathieu, J.P.; Pernin, C.; Riche, F.; Vidal, M. ( Grenoble Universite, 38 - (France))

1983-01-01

After I.V. injection of /sup 123/I hexadecene-9 oic acid to dogs, the decreasing part of the myocardial activity curve is fitted with an exponential which period is calculated. Taking the anesthetized dog as reference, we study the influence of isoproterenol, propranolol, dipyridamole and isoptine on value of the period. None of the drugs modify significantly the period. Nevertheless, propranolol and isoptine and to a lesser extent dipyridamole have a tendancy to increase the value of the period.

Summation and Cancellation Effects on QRS and ST-Segment Changes Induced by Simultaneous Regional Myocardial Ischemia.

Science.gov (United States)

Vives-Borrás, Miquel; Jorge, Esther; Amorós-Figueras, Gerard; Millán, Xavier; Arzamendi, Dabit; Cinca, Juan

2018-01-01

Simultaneous ischemia in two myocardial regions is a potentially lethal clinical condition often unrecognized whose corresponding electrocardiographic (ECG) patterns have not yet been characterized. Thus, this study aimed to determine the QRS complex and ST-segment changes induced by concurrent ischemia in different myocardial regions elicited by combined double occlusion of the three main coronary arteries. For this purpose, 12 swine were randomized to combination of 5-min single and double coronary artery occlusion: Group 1: left Circumflex (LCX) and right (RCA) coronary arteries ( n = 4); Group 2: left anterior descending artery (LAD) and LCX ( n = 4) and; Group 3: LAD and RCA ( n = 4). QRS duration and ST-segment displacement were measured in 15-lead ECG. As compared with single occlusion, double LCX+RCA blockade induced significant QRS widening of about 40 ms in nearly all ECG leads and magnification of the ST-segment depression in leads V1-V3 (maximal 228% in lead V3, p ST-segment elevation in precordial leads (maximal attenuation of 60% in lead V3 in LAD+LCX and 86% in lead V5 in LAD+RCA, p ST-segment elevation in leads V7-V9 was a specific sign of single LCX occlusion. In conclusion, concurrent infero-lateral ischemia was associated with a marked summation effect of the ECG changes previously elicited by each single ischemic region. By contrast, a cancellation effect on ST-segment changes with no QRS widening was observed when the left anterior descending artery was involved.

Positive and Negative Affect Is Related to Experiencing Chest Pain During Exercise-Induced Myocardial Ischemia.

Science.gov (United States)

Stébenne, Philippe; Bacon, Simon L; Austin, Anthony; Paine, Nicola J; Arsenault, André; Laurin, Catherine; Meloche, Bernard; Gordon, Jennifer; Dupuis, Jocelyn; Lavoie, Kim L

2017-05-01

Silent myocardial ischemia is thought to be associated with worse cardiovascular outcomes due to a lack of perception of pain cues that initiate treatment seeking. Negative affect (NA) has been associated with increased pain reporting and positive affect (PA) with decreased pain reporting, but these psychological factors have not been examined within the context of myocardial ischemia. This study evaluated the associations between PA, NA, and chest pain reporting in patients with and without ischemia during exercise testing. A total of 246 patients referred for myocardial perfusion single-photon emission computed tomography exercise stress testing completed the positive and negative affect schedule-expanded version, a measure of PA and NA. Presence of chest pain and myocardial ischemia were evaluated using standardized protocols. Logistic regression analyses revealed that for every 1-point increase in NA, there was a 13% higher chance for ischemic patients (odds ratio [OR] = 1.13; 95% confidence interval [CI] = 1.02 to 1.26) and an 11% higher chance in nonischemic patients (OR = 1.11; 95% CI = 1.03 to 1.19) to report chest pain. A significant interaction of PA and NA on chest pain reporting (β = 0.02; 95% CI = 0.002 to 0.031) was also observed; nonischemic patients with high NA and PA reported more chest pain (57%) versus patients with low NA and low PA (13%), with high NA and low PA (17%), and with high PA and low NA (7%). Patients who experience higher NA are more likely to report experiencing chest pain. In patients without ischemia, high NA and PA was also associated with a higher likelihood of reporting chest pain. Results suggest that high levels of PA as well as NA may increase the experience and/or reporting of chest pain.

Changes of electrocardiogram and hemodynamics in response to dipyridamole: In vivo comparative analyses using anesthetized beagle dogs and microminipigs.

Science.gov (United States)

Ando, Kentaro; Takahara, Akira; Nakamura, Yuji; Wada, Takeshi; Chiba, Koki; Goto, Ai; Lubna, Nur Jaharat; Hagiwara-Nagasawa, Mihoko; Izumi-Nakaseko, Hiroko; Hoshiai, Kiyotaka; Akie, Yasuki; Naito, Atsuhiko T; Sugiyama, Atsushi

2018-02-01

Microminipigs are expected as a novel animal model for cardiovascular pharmacological experiments. Since inherent vulnerability of coronary circulation of microminipigs has not been characterized, we performed dipyridamole-stress test to both microminipigs and beagle dogs, and compared the results. Dipyridamole in doses of 0.056 and 0.56 mg/kg were intravenously infused over 10 min (n = 4 for each animal). Dipyridamole decreased the systolic/diastolic blood pressures and double product in dogs as well as in microminipigs; but it did not significantly alter the heart rate or the global balance between the myocardial oxygen demand and supply in either animal. While organic coronary arterial stenosis was not detected in either animal, dogs have well-developed epicardial intracoronary networks unlike microminipigs. Like in humans, dipyridamole did not affect the ST segment of microminipigs, whereas it substantially depressed that in dogs. The results indicate the onset of subendocardial ischemia by dipyridamole in dogs may be partly associated with their well-developed native coronary collateral channels. Microminipigs would be more useful to evaluate the drugs which may affect the coronary circulation in the pre-clinical study than dogs. Copyright © 2018 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Myocordial perfusion SPECT with dipyridamole stress test in cardiac syndrome X

International Nuclear Information System (INIS)

Czepczynski, R.; Smolarek, I.; Sowinski, J.; Rogacka, D.; Kazmierczak, M.; Wysocki, H.

2006-01-01

Cardiac syndrome X defines patients with typical anginal chest pain, a positive exercise ECG stress test and angiographically normal coronary arteries. Aim of this study was to evaluate the role of myocardial perfusion SPECT with dipyridamole stress in the diagnosis of cardiac syndrome X. Patients, methods: 68 patients with syndrome X aged 32 to 60 years were subjected to myocardial imaging using 99m Tc-MIBI according to the two-days protocol: at rest and after dipyridamole infusion. Semiquantitative evaluation of the images was based on the assessment of 99m Tc-MIBI uptake in 17 myocardial segments using a 5-points scale (0 point - normal uptake, 4 points - no uptake). Scores obtained in each segment were summed up, constituting the summed rest score (SRS) and summed stress score (SSS). Results: mean SRS was 7.9 ± 4.8 and mean SSS was 7.2 ± 4.4 (non-significant difference). Individual comparison of SRS and SSS values revealed three patterns of scintigraphic images: (1) in 25 patients (36.8%), a paradoxical improvement of perfusion at stress images was found, (2) in 23 patients (33.8%), the myocardial perfusion deteriorated after dipyridamole, (3) in 20 patients (29.4%), no significant change of the myocordial perfusion between rest and stress images occurred. Conclusions: in cardiac syndrome X, myocardial SPECT with dipyridamole stress shows different patterns of myocardial perfusion that reflects heterogeneity of this pathology. (orig.)

[The relationship between ischemic preconditioning-induced infarction size limitation and duration of test myocardial ischemia].

Science.gov (United States)

Blokhin, I O; Galagudza, M M; Vlasov, T D; Nifontov, E M; Petrishchev, N N

2008-07-01

Traditionally infarction size reduction by ischemic preconditioning is estimated in duration of test ischemia. This approach limits the understanding of real antiischemic efficacy of ischemic preconditioning. Present study was performed in the in vivo rat model of regional myocardial ischemia-reperfusion and showed that protective effect afforded by ischemic preconditioning progressively decreased with prolongation of test ischemia. There were no statistically significant differences in infarction size between control and preconditioned animals when the duration of test ischemia was increased up to 1 hour. Preconditioning ensured maximal infarction-limiting effect in duration of test ischemia varying from 20 to 40 minutes.

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

Science.gov (United States)

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

2016-01-01

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. 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. 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 (C c O), 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). The myocardial protective function of SPostC might be associated with the improvement of mitochondrial respiratory function after up-regulation of HIF-1α expression.

delta-Opioid-induced pharmacologic myocardial hibernation during cardiopulmonary resuscitation.

Science.gov (United States)

Fang, Xiangshao; Tang, Wanchun; Sun, Shijie; Weil, Max Harry

2006-12-01

Cardiac arrest and cardiopulmonary resuscitation is an event of global myocardial ischemia and reperfusion, which is associated with severe postresuscitation myocardial dysfunction and fatal outcome. Evidence has demonstrated that mammalian hibernation is triggered by cyclic variation of a delta-opiate-like compound in endogenous serum, during which the myocardial metabolism is dramatically reduced and the myocardium tolerates the stress of ischemia and reperfusion without overt ischemic and reperfusion injury. Previous investigations also proved that the delta-opioid agonist elicited the cardioprotection in a model of regional ischemic intact heart or myocyte. Accordingly, we were prompted to search for an alternative intervention of pharmacologically induced myocardial hibernation that would result in rapid reductions of myocardial metabolism and therefore minimize the myocardial ischemic and reperfusion injury during cardiac arrest and cardiopulmonary resuscitation. Prospective, controlled laboratory study. University-affiliated research laboratory. In the series of studies performed in the established rat and pig model of cardiac arrest and cardiopulmonary resuscitation, the delta-opioid receptor agonist, pentazocine, was administered during ventricular fibrillation. : The myocardial metabolism reflected by the concentration of lactate, or myocardial tissue PCO2 and PO2, is dramatically reduced during cardiac arrest and cardiopulmonary resuscitation. These are associated with less severe postresuscitation myocardial dysfunction and longer duration of postresuscitation survival. delta-Opioid-induced pharmacologic myocardial hibernation is an option to minimize the myocardial ischemia and reperfusion injury during cardiac arrest and cardiopulmonary resuscitation.

Silent ischemia in patients after uncomplicated myocardial infarction

International Nuclear Information System (INIS)

Samarzija, M.; Tezak, S.

1994-01-01

The purpose of this study was to determine the frequency and importance of silent ischemia in patients (pts) after the acute myocardial infarction (A MI) as well as to establish diagnostic and prognostic value of exercise stress test (EST), Holter (H) monitoring and thallium-201 (Tl) scintigraphy. All the three tests were performed 2-4 months following the AMI. The criterion for diagnosing myocardial ischemia on EST and H is 1 mm or more of horizontal or down-sloping ST depression. Additional criteria for Holter imply the ischemic episode should last one minute and be separated from other episodes by at least one minute. Planar thallium images were performed 5-10 minute after the stress test; the delayed images were obtained after 3-6 hours. Visual and quantitative methods were employed in the analysis of TI-scintigraphy. Scintigraphy was considered positive if exercise- induced perfusion defects showed redistribution. The study included 74 asymptomatic patients after the AMI. The patients were divided into two groups by results of quantitative Tl-scintigraphy: Group I - 44 pts with silent ischemia, Group II - 30 pts without ischemia. In Group I, out of 44 pts, 9 had a positive exercise stress, 4 showed a painless ST depression on Holter and 7 had both tests positive, whereas 24 pts had only scintigraphy positive. In Group II one patient had positive EST and H. Sensitivity and specificity were determined by results of coronary arteriography performed on 33 pts: EST (Se=40%, Sp=80%), H (Se=219, Sp=100%) and scintigraphy (Se=93%, Sp =80%). During the follow-up period lasting at least 12 months, in Group I 3 pts died, 1 developed a new myocardial infarction and 15 pts had painful ischemic occurrences. In Group II only 3 pts developed symptoms of angina pectoris. Tl-scintigraphy was the only non-invasive test showing significant correlation with the follow-up outcomes. The diagnostic and prognostic superiority of Tl-scintigraphy justifies its value as the initial

Dipyridamole may induce migraine in patients with migraine without aura

DEFF Research Database (Denmark)

Kruuse, C; Lassen, L H; Iversen, Helle Klingenberg

2006-01-01

Dipyridamole inhibits phosphodiesterase 5 (PDE5) and adenosine re-uptake. The most prominent side-effect is headache. We examined the migraine-generating effects of dipyridamole as well as the cerebral blood velocity response in a single-blind study, including 10 patients with migraine without aura...... repeatedly. Headache was induced in all migraine patients and in eight of 10 healthy subjects (P = 0.47) with no significant difference in headache intensity (P = 0.53). However, five patients but only one healthy subject experienced the symptoms of migraine without aura, according to ICHD-2 criteria, within....... Thus, dipyridamole induces symptoms of migraine and an initial decrease in V(mca) in migraine patients, but not significantly more than in healthy subjects. This relatively low frequency of migraine induction, compared with nitric oxide donors and sildenafil, is probably due to the less specific action...

Hypertension impairs myocardial blood perfusion reserve in subjects without regional myocardial ischemia

International Nuclear Information System (INIS)

Nakajima, Hiroshi; Onishi, Katsuya; Kurita, Tairo

2010-01-01

Quantitative analysis of myocardial perfusion MRI can provide noninvasive assessments of myocardial perfusion reserve (MPR), which is associated with endothelial function. Endothelial function is influenced by various factors, including hypertension, diabetes, dyslipidemia, renal dysfunction and anemia. The purpose of this study was to evaluate which risk factor is the strongest effector of MPR in subjects without regional myocardial ischemia. We studied 110 patients (66 years ±10, male 68%, hypertension 76%, diabetes mellitus (DM) 40% and dyslipidemia 65%) without regional myocardial ischemia. Adenosine triphosphate (ATP) stress and rest first-pass perfusion magnetic resonance (MR) images were acquired with a 1.5-T MR system, and MPR was calculated as the ratio of stress to rest myocardial blood flow (MBF). Average rest MBF in 110 patients was 1.07±0.62 ml min -1 g -1 , whereas stress MBF was 3.15±1.93 ml min -1 g -1 and the MPR was 3.33±1.82. Rest MBF correlated significantly with hematocrit, whereas stress MBF showed a strong correlation with estimated glomerular filtration rate (e-GFR). MPR was associated with hypertension, age, e-GFR, hematocrit and left ventricular mass index (LVMI). In multiple regression analysis, hypertension (P=0.003, β=-0.274) showed the strongest correlation with MPR among other risk factors, such as diabetes (P=ns), dyslipidemia (P=ns), e-GFR (P=ns), LVMI (P=0.007, β=-0.248) and hematocrit (P=ns) after adjusting age and gender. Hypertension is the most important effector of MPR in subjects without myocardial ischemia. (author)

Hypertension impairs myocardial blood perfusion reserve in subjects without regional myocardial ischemia

Energy Technology Data Exchange (ETDEWEB)

Nakajima, Hiroshi; Onishi, Katsuya; Kurita, Tairo [Mie Univ., Graduate School of Medicine, Tsu, Mie (Japan)

2010-11-15

Quantitative analysis of myocardial perfusion MRI can provide noninvasive assessments of myocardial perfusion reserve (MPR), which is associated with endothelial function. Endothelial function is influenced by various factors, including hypertension, diabetes, dyslipidemia, renal dysfunction and anemia. The purpose of this study was to evaluate which risk factor is the strongest effector of MPR in subjects without regional myocardial ischemia. We studied 110 patients (66 years {+-}10, male 68%, hypertension 76%, diabetes mellitus (DM) 40% and dyslipidemia 65%) without regional myocardial ischemia. Adenosine triphosphate (ATP) stress and rest first-pass perfusion magnetic resonance (MR) images were acquired with a 1.5-T MR system, and MPR was calculated as the ratio of stress to rest myocardial blood flow (MBF). Average rest MBF in 110 patients was 1.07{+-}0.62 ml min{sup -1} g{sup -1}, whereas stress MBF was 3.15{+-}1.93 ml min{sup -1} g{sup -1} and the MPR was 3.33{+-}1.82. Rest MBF correlated significantly with hematocrit, whereas stress MBF showed a strong correlation with estimated glomerular filtration rate (e-GFR). MPR was associated with hypertension, age, e-GFR, hematocrit and left ventricular mass index (LVMI). In multiple regression analysis, hypertension (P=0.003, {beta}=-0.274) showed the strongest correlation with MPR among other risk factors, such as diabetes (P=ns), dyslipidemia (P=ns), e-GFR (P=ns), LVMI (P=0.007, {beta}=-0.248) and hematocrit (P=ns) after adjusting age and gender. Hypertension is the most important effector of MPR in subjects without myocardial ischemia. (author)

Coronary vascular age: An alternate means for predicting stress-induced myocardial ischemia in patients with suspected coronary artery disease.

Science.gov (United States)

Nappi, Carmela; Gaudieri, Valeria; Acampa, Wanda; Arumugam, Parthiban; Assante, Roberta; Zampella, Emilia; Mannarino, Teresa; Mainolfi, Ciro Gabriele; Imbriaco, Massimo; Petretta, Mario; Cuocolo, Alberto

2018-01-22

Coronary artery calcium (CAC) can be used to estimate vascular age in adults, providing a convenient transformation of CAC from Agatston units into a year's scale. We investigated the role of coronary vascular age in predicting stress-induced myocardial ischemia in subjects with suspected coronary artery disease (CAD). A total of 717 subjects referred to CAC scoring and 82 Rb PET/CT stress-rest myocardial perfusion imaging for suspected CAD were studied. CAC score was measured according to the Agatston method and coronary vascular age by equating estimated CAD risk for chronological age and CAC using the formula 39.1 + 7.25 × ln(CAC + 1). Stress-induced ischemia was present in 105 (15%) patients. Mean chronological age, CAC score, and coronary vascular age were higher (all P age was added to clinical variables. Including vascular age in the model, the global Chi square further increased from 68.77 to 106.38 (P age to clinical data, continuous net reclassification improvement (cNRI) was 0.57, while adding vascular age to clinical data and chronological age cNRI was 0.62. At decision curve analysis, the model including vascular age was associated with the highest net benefit compared to the model including only clinical data, to the model including chronological age and clinical data, and to a strategy considering that all patients had ischemia. The model including vascular age also showed the largest reduction in false-positive rate without missing any ischemic patients. In subjects with suspected CAD, coronary vascular age is strongly associated with stress-induced ischemia. The communication of a given vascular age would have a superior emotive impact improving observance of therapies and healthier lifestyles.

Effect of flaxseed supplementation and exercise training on lipid profile, oxidative stress and inflammation in rats with myocardial ischemia.

Science.gov (United States)

Nounou, Howaida A; Deif, Maha M; Shalaby, Manal A

2012-10-05

Flaxseed has recently gained attention in the area of cardiovascular disease primarily because of its rich contents of α-linolenic acid (ALA), lignans, and fiber. Although the benefits of exercise on any single risk factor are unquestionable, the effect of exercise on overall cardiovascular risk, when combined with other lifestyle modifications such as proper nutrition, can be dramatic.This study was carried out to evaluate the protective role of flaxseed and exercise on cardiac markers, lipids profile and inflammatory markers in isoproterenol (ISO)-induced myocardial ischemia in rats. The research was conducted on 40 male albino rats, divided into 4 groups (n=10): group I served as control, group II has acute myocardial ischemia induced by isoproterenol, groups III and IV have acute myocardial ischemia induced by isoproterenol pretreated with flaxseed supplementation orally for 6 weeks, additionally group IV practiced muscular exercise through swimming. Alterations of lipid profile, cardiac and inflammatory markers (Il-1β, PTX 3 and TNF- α) were observed in myocardial ischemia group. Flaxseed supplementation combined with exercise training showed significant increase of HDL and PON 1, on the other hand cardiac troponin, Il- 1β and TNF- α levels significantly decreased as compared to myocardial ischemic group. Receiver Operating Characteristics (ROC) analysis of cTnI, PTX 3, Il-1β and TNF- α revealed a satisfactory level of sensitivity and specificity. Regular exercise enhances the improvement in plasma lipoprotein levels and cardiovascular protection that results from flaxseed supplementation by mitigating the pathophysiology of atherosclerosis. Elevation of HDL, the antioxidant PON 1 and the cardioprotective marker PTX 3 emphasizes the protective effects of flaxseed and muscular exercise mutually against the harmful effects of acute myocardial ischemia.

Effect of flaxseed supplementation and exercise training on lipid profile, oxidative stress and inflammation in rats with myocardial ischemia

Directory of Open Access Journals (Sweden)

Nounou Howaida A

2012-10-01

Full Text Available Abstract Background Flaxseed has recently gained attention in the area of cardiovascular disease primarily because of its rich contents of α-linolenic acid (ALA, lignans, and fiber. Although the benefits of exercise on any single risk factor are unquestionable, the effect of exercise on overall cardiovascular risk, when combined with other lifestyle modifications such as proper nutrition, can be dramatic. This study was carried out to evaluate the protective role of flaxseed and exercise on cardiac markers, lipids profile and inflammatory markers in isoproterenol (ISO-induced myocardial ischemia in rats. Methods The research was conducted on 40 male albino rats, divided into 4 groups (n=10: group I served as control, group II has acute myocardial ischemia induced by isoproterenol, groups III and IV have acute myocardial ischemia induced by isoproterenol pretreated with flaxseed supplementation orally for 6 weeks, additionally group IV practiced muscular exercise through swimming. Results Alterations of lipid profile, cardiac and inflammatory markers (Il-1β, PTX 3 and TNF- α were observed in myocardial ischemia group. Flaxseed supplementation combined with exercise training showed significant increase of HDL and PON 1, on the other hand cardiac troponin, Il- 1β and TNF- α levels significantly decreased as compared to myocardial ischemic group. Receiver Operating Characteristics (ROC analysis of cTnI, PTX 3, Il-1β and TNF- α revealed a satisfactory level of sensitivity and specificity. Conclusion Regular exercise enhances the improvement in plasma lipoprotein levels and cardiovascular protection that results from flaxseed supplementation by mitigating the pathophysiology of atherosclerosis. Elevation of HDL, the antioxidant PON 1 and the cardioprotective marker PTX 3 emphasizes the protective effects of flaxseed and muscular exercise mutually against the harmful effects of acute myocardial ischemia.

Evaluation of myocardial ischemia by multiple detector computed tomography

Energy Technology Data Exchange (ETDEWEB)

Fernandes, Fabio Vieira, E-mail: rccury@me.com [Hospital do Coracao (HCor), Sao Paulo, SP (Brazil); Cury, Roberto Caldeira [Hospital Samaritano, Sao Paulo, SP (Brazil)

2015-01-15

For years, cardiovascular diseases have been the leading cause of death worldwide, bringing on important social and economic consequences. Given this scenario, the search for a method capable of diagnosing coronary artery diseases in an early and accurate way is increasingly higher. The coronary computed tomography angiogram is already widely established for the stratification of coronary artery diseases, and, more recently, the computed tomography myocardial perfusion imaging has been providing relevant information by correlating ischemia and the coronary anatomy. The objective of this review is to describe the evaluation of myocardial ischemia by multiple detector computed tomography. This study will resort to controlled clinical trials that show the possibility of a single method to identify the atherosclerotic load, presence of coronary artery luminal narrowing and possible myocardial ischemia, by means of a fast, practical and reliable method validated by a multicenter study. (author)

NT-pro-BNP is associated with inducible myocardial ischemia in mildly symptomatic type 2 diabetic patients

NARCIS (Netherlands)

Wiersma, Jacobijne J.; van der Zee, P. Marc; van Straalen, Jan P.; Fischer, Johan C.; van Eck-Smit, Berthe L. F.; Tijssen, Jan G. P.; Trip, Mieke D.; Piek, Jan J.; Verberne, Hein J.

2010-01-01

Baseline levels of N-terminal fragment of the brain natriuretic peptide prohormone (NT-pro-BNP) are associated with myocardial ischemia in non-diabetic patients with stable angina pectoris. A total of 281 patients with diabetes mellitus type 2 and stable angina pectoris underwent myocardial

Myocardial ischemia in severe aortic regurgitation despite angiographically normal coronary arteries

International Nuclear Information System (INIS)

Aksoy, S.; Cam, N.; Guney, M.R.; Gurkan, U.; Oz, D.; Poyraz, E.; Eksik, A.; Agirbasli, M.

2012-01-01

Patients with severe aortic regurgitation frequently present with angina pectoris. The exact pathophysiology for angina in aortic regurgitation is not clear. Left ventricular hypertrophy and myocardial blood supply-demand mismatch have been the suggested mechanisms to explain ischemia. However, no conclusive clinical study exists to define the incidence of ischemia in patients with severe aortic regurgitation and normal coronary arteries. We, therefore, investigated the frequency of myocardial ischemia in relation to left ventricular hypertrophy or dilatation in patients with severe aortic regurgitation and normal coronary arteries. We reviewed the medical records of all patients (n=311) with aortic valve replacement due to aortic regurgitation between 2007 and 2010. We selected subjects with normal coronary arteries (n=182) for the study purpose, and we identified 35 patients who underwent myocardial perfusion scintigraphy prior to the coronary angiography (19 female and 16 male subjects; age 45.0±8.9 years). Left ventricular hypertrophy and dilatation were detected in 9 (26%) and 5 (14%) patients, respectively. Myocardial perfusion scintigraphy showed evidence of ischemia in 10 (29%) patients with normal coronary arteries. The presence of ischemia did not relate to the presence of left ventricular hypertrophy and/or dilatation. As a potential mechanism, aortic regurgitation causes backflow of blood from the aorta into the left ventricle, hence disturbs coronary flow dynamics. In conclusion, myocardial ischemia is common (nearly one-third) among patients with severe aortic regurgitation even in the absence of coronary obstruction, left ventricular hypertrophy and/or dilatation. (author)

Correlation between left ventricular filling and ischemic extent during exercise-induced myocardial ischemia

International Nuclear Information System (INIS)

Ando, Akitada; Yokota, Mitsuhiro; Iwase, Mitsunori

1993-01-01

The aim of this study was to determine how the extent of exercise-induced myocardial ischemia influence left ventricular filling. Twenty-two consecutive patients with effort angina, consisting of 16 with single vessel disease and 6 with double vessel disease, underwent exercise studies in lying and sitting positions. Extent score (ES) and severity score (SS) were calculated on polar map prepared from early exercise Tl-201 myocardial SPECT images to determine ischemic extent. Pulmonary arterial wedge pressure (PAWP), as obtained at exercise in lying position, correlated significantly well with both ES (r=0.75, p<0.001) and SS (r=0.61, p<0.01). There was, however, no significant correlation between the other hemodynamic parameters, such as heart rate, systolic pressure, rate-pressure product, cardiac index and stroke index, and both ES and SS. Either increased PAWP or ischemic extent was not dependent on the number of diseased vessels. In conclusion, the extent of increased left ventricular filling did not correlate with the number of diseased vessels, but correlated positively with ischemic extent. (N.K.)

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

Science.gov (United States)

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.

Functional role of peripheral opioid receptors in the regulation of cardiac spinal afferent nerve activity during myocardial ischemia

Science.gov (United States)

Longhurst, John C.

2013-01-01

Thinly myelinated Aδ-fiber and unmyelinated C-fiber cardiac sympathetic (spinal) sensory nerve fibers are activated during myocardial ischemia to transmit the sensation of angina pectoris. Although recent observations showed that myocardial ischemia increases the concentrations of opioid peptides and that the stimulation of peripheral opioid receptors inhibits chemically induced visceral and somatic nociception, the role of opioids in cardiac spinal afferent signaling during myocardial ischemia has not been studied. The present study tested the hypothesis that peripheral opioid receptors modulate cardiac spinal afferent nerve activity during myocardial ischemia by suppressing the responses of cardiac afferent nerve to ischemic mediators like bradykinin and extracellular ATP. The nerve activity of single unit cardiac afferents was recorded from the left sympathetic chain (T2–T5) in anesthetized cats. Forty-three ischemically sensitive afferent nerves (conduction velocity: 0.32–3.90 m/s) with receptive fields in the left and right ventricles were identified. The responses of these afferent nerves to repeat ischemia or ischemic mediators were further studied in the following protocols. First, epicardial administration of naloxone (8 μmol), a nonselective opioid receptor antagonist, enhanced the responses of eight cardiac afferent nerves to recurrent myocardial ischemia by 62%, whereas epicardial application of vehicle (PBS) did not alter the responses of seven other cardiac afferent nerves to ischemia. Second, naloxone applied to the epicardial surface facilitated the responses of seven cardiac afferent nerves to epicardial ATP by 76%. Third, administration of naloxone enhanced the responses of seven other afferent nerves to bradykinin by 85%. In contrast, in the absence of naloxone, cardiac afferent nerves consistently responded to repeated application of ATP (n = 7) or bradykinin (n = 7). These data suggest that peripheral opioid peptides suppress the

Detection of myocardial ischemia with myocardial perfusion SPECT in patients with diabetes mellitus

International Nuclear Information System (INIS)

Seo, J. H.; Jeong, S. Y.; Bae, J. H.; Anh, B. C.; Lee, J.; Lee, K. B

2004-01-01

Diabetes mellitus(DM) is a critical disease associated with higher rates of cardiovascular morbidity and mortality. Atherosclerosis accounts for 65-80% of all deaths in diabetic patients and patients with DM are known to show high prevalence of coronary artery diseases(CAD). We evaluated the incidence of scintigraphic evidence of CAD in diabetic patients and results were compared with cardiovascular symptoms and clinical factors. 169 patients with DM(mean age 629years, 68 males) were referred for evaluation of CAD between Jan 2002 and Dec 2003. 101(60%) patients were with chest pain and 68(40%) were asymptomatic. Patients underwent exercise(n=6) or adenosine stress(n=163) SPECT myocardial perfusion imaging(MPI). Exclusion criteria included history of documented myocardial infarction, prior revascularization, clinically significant valvular heart disease, left-bundle branch block on rest ECG. We evaluated symptoms associated with cardiac problem and other clinical and laboratory data to reveal correlation with presence of CAD. MPI were assessed visually and semi-quantitatively with C-Equal program. Myocardial ischemia was detected in 52(31%) patients. Among them, 41 had 1-vessel and 9 had 2-vessel disease. In 52 patients with ischemia, 28(54%) were male and 24(46%) were female. 20/68(29%) asymptomatic and 32/101(32%) symptomatic patients had ischemia. Higher prevalence of neuropathy, hypertension, higher blood glucose level, HbA1c and CRP was noted in patients with myocardial ischemia. Serum levels of cholesterol and LDL was not significantly different between patients with ischemia and with normal MPI findings. Abnormal MPI findings were not related with gender and age. These results show a high prevalence of abnormal MPI results in diabetic patients regardless of symptoms. Screening stress MPI in diabetic patients should be indicated irrespective of symptoms, especially in patients with neuropathy, hypertension, higher level of blood glucose, or increased CRP

Detection of myocardial ischemia with myocardial perfusion SPECT in patients with diabetes mellitus

Energy Technology Data Exchange (ETDEWEB)

Seo, J. H.; Jeong, S. Y.; Bae, J. H.; Anh, B. C.; Lee, J.; Lee, K. B [Kyungpook National University Hospital, Daegu (Korea, Republic of)

2004-07-01

Diabetes mellitus(DM) is a critical disease associated with higher rates of cardiovascular morbidity and mortality. Atherosclerosis accounts for 65-80% of all deaths in diabetic patients and patients with DM are known to show high prevalence of coronary artery diseases(CAD). We evaluated the incidence of scintigraphic evidence of CAD in diabetic patients and results were compared with cardiovascular symptoms and clinical factors. 169 patients with DM(mean age 629years, 68 males) were referred for evaluation of CAD between Jan 2002 and Dec 2003. 101(60%) patients were with chest pain and 68(40%) were asymptomatic. Patients underwent exercise(n=6) or adenosine stress(n=163) SPECT myocardial perfusion imaging(MPI). Exclusion criteria included history of documented myocardial infarction, prior revascularization, clinically significant valvular heart disease, left-bundle branch block on rest ECG. We evaluated symptoms associated with cardiac problem and other clinical and laboratory data to reveal correlation with presence of CAD. MPI were assessed visually and semi-quantitatively with C-Equal program. Myocardial ischemia was detected in 52(31%) patients. Among them, 41 had 1-vessel and 9 had 2-vessel disease. In 52 patients with ischemia, 28(54%) were male and 24(46%) were female. 20/68(29%) asymptomatic and 32/101(32%) symptomatic patients had ischemia. Higher prevalence of neuropathy, hypertension, higher blood glucose level, HbA1c and CRP was noted in patients with myocardial ischemia. Serum levels of cholesterol and LDL was not significantly different between patients with ischemia and with normal MPI findings. Abnormal MPI findings were not related with gender and age. These results show a high prevalence of abnormal MPI results in diabetic patients regardless of symptoms. Screening stress MPI in diabetic patients should be indicated irrespective of symptoms, especially in patients with neuropathy, hypertension, higher level of blood glucose, or increased CRP.

The prevalence and the clinical characteristics of silent myocardial ischemia detected by stress thallium scintigraphy

International Nuclear Information System (INIS)

Matsuo, Hitoshi; Watanabe, Sachiro; Nishida, Yoshio

1992-01-01

The prevalence of silent myocardial ischemia was retrospectively assessed in a group of 100 consecutive patients with angiographically proved coronary artery disease, and diagnostic ECG, by symptom-limited exercise thallium-201 scintigraphy. Twenty-four patients had no evidence of ischemia despite adequate exercise level. So among 76 patients with exercise induced ischemia, only 33 patients (43%) stopped exercise due to anginal pain (symptomatic ischemia: Group 3). And 43 patients with asymptomatic ischemia composed of 23 patients (30%) with ECG change (Group 2B) and 20 patients (26%) without ECG change (Group 2A). Patients background including the history of old myocardial infarction and diabetes mellitus, were similar among Group 2A, 2B, and Group 3. Our Major observation was that the extent and severity of quantified SPECT perfusion defects was nearly identified between 3 groups. Thus in this study group, there was a rather high prevalence rate of silent ischemia (57%) by exercise thallium-201 criteria. Patients with silent ischemia, associated with positive and negative exercise ECG findings, and those with exercise angina had similar background and comparable amount of jeopardized myocardium. (author)

Silent ischemia in patients after the acute myocardial infarction

International Nuclear Information System (INIS)

Samarzija, M.

1991-01-01

The purpose of this study was to determine the frequency and importance of silent ischemia in patients (pts) after acute myocardial infarction (AMI) as well as to establish diagnostic and prognostic values of exercise stress test (EST), Holter (H) monitoring and thallium-201 (Tl) scintigraphy. All the tests were performed 2-4 months following the AMI. The criterion for diagnostic myocardial ischemia on EST and H is 1 mm or more of horizontal or down-sloping ST depression. Additional criteria for Holter imply that the ischemic episode should last one minute and be separated from other episodes by at least one minute. Planar thallium images were performed 5-10 minutes after the stress test; the delayed images were obtained after 3-6 hours. Visual and quantitative methods were employed in the analysis of Tl-scintigraphy. Scintigraphy was considered positive if exercise-induced perfusion defects showed redistribution. The study included 74 asymptomatic patients after the AMI. The patients were divided into two groups by results of quantitative Tl-scintigraphy: Group I - 44 pts with silent ischemia, Group II - 30 pts without ischemia. In Group I, out of 44 pts, 9 had a positive exercise stress test, 4 showed a painless ST depression on Holter and 7 had both tests positive, whereas 24 pts had only scintigraphy positive. In Group II one patient had positive EST and H. Sensitivity and specificity were determined by results of coronary arteriography performed on 33 pts: EST (Se=40%, Sp=80%), H (Se=21%, Sp=100%) and scintigraphy (Se=93%, Sp=80%). During the follow-up period lasting at least 12 months, in Group I 3 pts died, 1 developed a new myocardial infarction and 15 pts had painful ischemic occurrences. In Group II only 3 pts developed symptoms of angina pectoris. Tl-scintigraphy was the only non-invasive test showing significant correlation with the follow-up outcomes. The diagnostic and prognostic superiority of Tl-scintigraphy justifies its value as an initial

Molecular tissue changes in early myocardial ischemia: from pathophysiology to the identification of new diagnostic markers.

Science.gov (United States)

Aljakna, Aleksandra; Fracasso, Tony; Sabatasso, Sara

2018-03-01

Diagnosing early myocardial ischemia (the initial 4 to 6 h after interruption of blood flow to part of the myocardium) remains a challenge for clinical and forensic pathologists. Several immunohistochemical markers have been proposed for improving postmortem detection of early myocardial ischemia; however, no single marker appears to be both sufficiently specific as well as sensitive. This review summarizes the diverse categories of molecular tissue markers that have been investigated in human autopsy samples with acute myocardial infarction as well as in the well-established and widely used in vivo animal model of early myocardial ischemia (permanent ligation of the coronary artery). Recently identified markers appearing during the initial 2 h of myocardial ischemia are highlighted. Among them, only six were tested for specificity (C5b-9, hypoxia-inducible factor 1-alpha, vascular endothelial growth factor, heart fatty acid binding protein, connexin 43, and JunB). Despite the discovery of several potentially promising markers (in terms of early expression and specificity), many of them remain to be tested and validated for application in routine diagnostics in clinical and forensic pathology. In particular, research investigating the postmortem stability of these markers is required before any might be implemented into routine diagnostics. Establishing a standardized panel of immunohistochemical markers may be more useful for improving sensitivity and specificity than searching for a single marker.

201Tl in myocardial diagnosis: studies on the influence of dipyridamole, dobutamine ergometer exercise and background subtraction on the 201Tl myocadial scintiscam

International Nuclear Information System (INIS)

Seiderer, M.

1979-01-01

Changes in 201 Tl myocardial scintiscans upon administration of dipyridamole or dobutamine and upon ergometer exercise relative to scintiscans at rest were investigated as well as the influence of myocardial background subtraction on scintiscan quality and information. A total of 90 201 Tl examinations were carried out in 59 patients. 18 patients had no myocardial disease, 30 patients had a coronary disease, 5 patients suffered from cardiomyopathy and 6 from left ventricular hypertrophy. The findings are discussed in detail. (orig.) [de

Determination of cardiac risk by dipyridamole-thallium imaging before peripheral vascular surgery

International Nuclear Information System (INIS)

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

1985-01-01

To evaluate the severity of coronary artery disease in patients with severe peripheral vascular disease requiring surgery, preoperative dipyridamole-thallium imaging was performed in 54 stable patients with suspected coronary artery disease. Of the 54 patients, 48 had peripheral vascular surgery as scheduled without coronary angiography, of whom 8 (17 per cent) had postoperative cardiac ischemic events. The occurrence of these eight cardiac events could not have been predicted preoperatively by any clinical factors but did correlate with the presence of thallium redistribution. Eight of 16 patients with thallium redistribution had cardiac events, whereas there were no such events in 32 patients whose thallium scan either was normal or showed only persistent defects (P less than 0.0001). Six other patients also had thallium redistribution but underwent coronary angiography before vascular surgery. All had severe multivessel coronary artery disease, and four underwent coronary bypass surgery followed by uncomplicated peripheral vascular surgery. These data suggest that patients without thallium redistribution are at a low risk for postoperative ischemic events and may proceed to have vascular surgery. Patients with redistribution have a high incidence of postoperative ischemic events and should be considered for preoperative coronary angiography and myocardial revascularization in an effort to avoid postoperative myocardial ischemia and to improve survival. Dipyridamole-thallium imaging is superior to clinical assessment and is safer and less expensive than coronary angiography for the determination of cardiac risk

Dipyridamole 201T1 myocardial perfusion tomography and bull's--eye analysis for quantitative evaluation of CAD

International Nuclear Information System (INIS)

Jiang Maosong; Tang Xi

1992-01-01

To assess the ability of quantitative analysis of dipyridamole 201 T1 tomography for detecting and localizing coronary artery disease (CAD), 55 patients with angiographically proved CAD ( = 50% stenosis) were studied. All patients underwent dipyridamole 201 T1 myocardial perfusion tomography and coronary arteriography. The overall sensitivity for detection of CAD by Bull's-eye analysis was 89% (50 patients) and 92% (51 patients) with visual analysis. The sensitivity for detecting individual vessel involvement with the Bull'-eye analysis was 88% for LAD. 81% for RCA and 67% for LCX. With visual analysis, the results were 88%, 83% and 58% respectively. The overall rate of detection was 87% in lesions greater than or equal to 75% stenosis vs 59% in those under 75% stenosis (P 201 T1 tomography using Bull's-eye display is a highly accurate reproducible technique for the detection of patients with CAD and the localization of individual coronary vessel, and it offers the potential to quantify the percentage of the abnormally perfused myocardium

The safety of dipyridamole in patients undergoing myocardial perfusion scintigraphy prior to lung volume reduction surgery

International Nuclear Information System (INIS)

Roman, M.R.; Angelides, S.; Parker, M.K.; Silva, I. da; Freeman, A.P.

2001-01-01

Patients with end-stage chronic obstructive pulmonary disease (COPD) undergoing lung volume reduction surgery (LVRS) are at high risk of peri-operative cardiac complications, and myocardial perfusion scintigraphy (MPS) is commonly used for risk stratification. This study prospectively assessed the safety of dipyridamole in these patients and compared the incidence of side-effects (particularly dyspnoea) with that in patients undergoing dipyridamole MPS prior to elective non-cardiothoracic surgery. Fifty patients were enrolled: 25 in the LVRS cohort (13 males, 12 females), with a mean age of 65 years and a mean FEV 1 of 0.79 l, and 25 (with no history of asthma or COPD) in the control cohort (14 males, 11 females), with a mean age of 66 years. Fourteen patients (56%) in each group developed side-effects. Dyspnoea was reported by five patients (20%) in the LVRS and two patients (8%) in the control cohort (P=NS). One patient in each cohort developed severe hypotension and bradycardia. Eight (32%) other patients developed minor side-effects in the LVRS cohort compared with 11 (44%) in the control group. All side-effects responded promptly to intravenous aminophylline. In summary, there was a statistically non-significant increase in the incidence of dyspnoea in patients with end-stage COPD and all side-effects responded to aminophylline. Thus, dipyridamole can be used safely in these patients. (orig.)

Novel curcumin analogue 14p protects against myocardial ischemia reperfusion injury through Nrf2-activating anti-oxidative activity

Energy Technology Data Exchange (ETDEWEB)

Li, Weixin [Department of Cardiology, The 5th Affiliated Hospital of Wenzhou Medical University, Lishui, Zhejiang (China); Chemical Biology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, Zhejiang (China); Wu, Mingchai [Department of Pharmacy, The Third Affiliated Hospital of Wenzhou Medical University, Wenzou, Zhejiang (China); Tang, Longguang; Pan, Yong; Liu, Zhiguo [Chemical Biology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, Zhejiang (China); Zeng, Chunlai [Department of Cardiology, The 5th Affiliated Hospital of Wenzhou Medical University, Lishui, Zhejiang (China); Wang, Jingying [Chemical Biology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, Zhejiang (China); Wei, Tiemin, E-mail: lswtm@sina.com [Department of Cardiology, The 5th Affiliated Hospital of Wenzhou Medical University, Lishui, Zhejiang (China); Liang, Guang, E-mail: wzmcliangguang@163.com [Chemical Biology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, Zhejiang (China)

2015-01-15

Background: Alleviating the oxidant stress associated with myocardial ischemia reperfusion has been demonstrated as a potential therapeutic approach to limit ischemia reperfusion (I/R)-induced cardiac damage. Curcumin, a natural compound with anti-oxidative activity, exerts beneficial effect against cardiac I/R injury, but poor chemical and metabolic stability. Previously, we have designed and synthesized a series of mono-carbonyl analogues of curcumin (MACs) with high stability. This study aims to find new anti-oxidant MACs and to demonstrate their effects and mechanisms against I/R-induced heart injury. Methods: H9c2 cells challenged with H{sub 2}O{sub 2} or TBHP were used for in vitro bio-screening and mechanistic studies. The MDA, H{sub 2}O{sub 2} and SOD levels in H9C2 cells were determined, and the cell viability was assessed by MTT assay. Myocardial I/R mouse models administrated with or without the compound were used for in vivo studies. Results: The in vitro cell-based screening showed that curcumin analogues 8d and 14p exhibited strong anti-oxidative effects. Pre-treatment of H9c2 cells with 14p activated Nrf2 signaling pathway, attenuated H{sub 2}O{sub 2}-increased MDA and SOD level, followed by the inhibition of TBHP-induced cell death and Bax/Bcl-2–caspase-3 pathway activation. Silencing Nrf2 significantly reversed the protective effects of 14p. In in vivo animal model of myocardial I/R, administration of low dose 14p (10 mg/kg) reduced infarct size and myocardial apoptosis to the same extent as the high dose curcumin (100 mg/kg). Conclusion: These data support the novel curcumin analogue 14p as a promising antioxidant to decrease oxidative stress and limit myocardial ischemia reperfusion injury via activating Nrf2. - Highlights: • Mono-carbonyl analogue of curcumin, 14p, exhibited better chemical stability. • Compound 14p inhibited TBHP-induced apoptosis through activating Nrf2 in vitro. • Compound 14p limited myocardial ischemia

Repetitive Transient Ischemia-Induced Cardiac Angiogenesis is Mediated by Camkii Activation

Directory of Open Access Journals (Sweden)

Zhuobin Chen

2018-05-01

Full Text Available Background/Aims: Coronary angiogenesis is an important protective mechanism in response to myocardial ischemia in coronary artery disease. However, the underlying mechanisms remain largely unclear. Here, we investigated the role of CaMKII activation in ischemia-induced cardiac angiogenesis. Methods: Repetitive transient ischemia model was established in C57/BL6 mice by daily multiple episodes (3 times/day of short time (5 min occlusion of the left anterior descending coronary artery for 7 days. Coronary angiogenesis was detected by immunofluorescent staining. RT-qPCR and Western blot analyses were used to detect the mRNA and protein levels of CaMKII, p-CaMKII and VEGF. Primary cardiac microvascular endothelial cells (CMECs were isolated to investigate the effects of KN93 on cell proliferation and migration in hypoxic condition. Results: We found that angiogenesis was induced in the ischemic myocardium and suppressed by chronic intraperitoneal injection of CaMKII inhibitor KN93. RT-qPCR and Western blot analyses showed that myocardial ischemia induced an increased expression and autophosphorylation of CaMKII. VEGF expression was increased in the ischemia model but blunted by KN93. Moreover, KN93 suppressed the proliferation and migration of cardiac endothelial cells in hypoxic condition in which the protein expression of CaMKII, p-CaMKII and VEGF was increased. Conclusion: CaMKII is an important mediator for the ischemia-induced coronary angiogenesis, in which CaMKII-triggered VEGF expression plays a key role.

A new function for ATP: activating cardiac sympathetic afferents during myocardial ischemia.

Science.gov (United States)

Fu, Liang-Wu; Longhurst, John C

2010-12-01

Myocardial ischemia activates cardiac sympathetic afferents leading to chest pain and reflex cardiovascular responses. Brief myocardial ischemia leads to ATP release in the interstitial space. Furthermore, exogenous ATP and α,β-methylene ATP (α,β-meATP), a P2X receptor agonist, stimulate cutaneous group III and IV sensory nerve fibers. The present study tested the hypothesis that endogenous ATP excites cardiac afferents during ischemia through activation of P2 receptors. Nerve activity of single unit cardiac sympathetic afferents was recorded from the left sympathetic chain or rami communicates (T(2)-T(5)) in anesthetized cats. Single fields of 45 afferents (conduction velocities = 0.25-4.92 m/s) were identified in the left ventricle with a stimulating electrode. Five minutes of myocardial ischemia stimulated 39 of 45 cardiac afferents (8 Aδ, 37 C fibers). Epicardial application of ATP (1-4 μmol) stimulated six ischemically sensitive cardiac afferents in a dose-dependent manner. Additionally, epicardial ATP (2 μmol), ADP (2 μmol), a P2Y agonist, and α,β-meATP (0.5 μmol) significantly activated eight other ischemically sensitive afferents. Third, pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid, a P2 receptor antagonist, abolished the responses of six afferents to epicardial ATP (2 μmol) and attenuated the ischemia-related increase in activity of seven other afferents by 37%. In the absence of P2 receptor blockade, cardiac afferents responded consistently to repeated application of ATP (n = 6) and to recurrent myocardial ischemia (n = 6). Finally, six ischemia-insensitive cardiac spinal afferents did not respond to epicardial ATP (2-4 μmol), although these afferents did respond to epicardial bradykinin. Taken together, these data indicate that, during ischemia, endogenously released ATP activates ischemia-sensitive, but not ischemia-insensitive, cardiac spinal afferents through stimulation of P2 receptors likely located on the cardiac sensory

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

Science.gov (United States)

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

2017-02-01

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

Evaluation of the Efficacy of Treatment of Newborns with Transient Myocardial Ischemia

Directory of Open Access Journals (Sweden)

Yulia N. Dovnar

2018-01-01

Full Text Available The purpose of the study: a comprehensive assessment of the effectiveness of the treatment of newborns with transient myocardial ischemia in the intensive care unit.Materials and methods. 102 newborns with transient myocardial ischemia, with a history of ante- and/or intranatal hypoxia, at the age of 1 to 7 days, with a gestational age from 29 to 42 weeks, underwent a clinical and instrumental examination of the heart before and during the treatment. The Group 1 consisted of 30 infants with 1 degree circulatory failure (CF; the Group 2 was comprised of 39 infants with 2A degree of CF, and the Group 3 included 33 infants with the 2B degree of CF. All children received cardiotropic drugs; infants from Groups 2 and 3 received cardiotonic drugs.Results. The study demonstrated an increase in biochemical parameters of blood (myocardial CPK, lactate dehydrogenase, aspartate aminotransferase, de Ritis ratio, manifestations of subendocardial ischemia in the electrocardiogram (depression of ST segment in one or more leads in combination with a T-wave defect, changes in systolic cardiac function during echocardiography (stroke volume, ejection and shortening factions, left ventricular TEI index, cardiac output, and cardiac index that correlated with the severity of myocardial ischemia and circulatory failure and their reverse development during the treatment. Various correlative links between parameters of left ventricular systolic function and blood biochemistry before and during the treatment reflecting the myocardial dysfunction with a gradual reverse development have been found.Conclusion. Infants with transient myocardial ischemia suffered from disorders of the clinical and functional state of the heart depending on the degree of ischemia and circulatory failure. Most infants exebited gradual reverse development during a complex intensive therapy. 

Detection of exercise-induced myocardial ischemia from symptomatology experienced during testing in men and women

Science.gov (United States)

D’Antono, Bianca; Dupuis, Gilles; Fortin, Christophe; Arsenault, André; Burelle, Denis

2006-01-01

BACKGROUND AND OBJECTIVES To examine the capacity of angina and related symptoms experienced during exercise-stress testing to detect the presence of ischemia, controlling for other clinical factors. METHOD The authors undertook a prospective study of 482 women and 425 men (mean age 58 years) undergoing exercise stress testing with myocardial perfusion imaging. One hundred forty-six women and 127 men reported chest pain, and of these, 25% of women and 66% of men had myocardial perfusion imaging evidence of ischemia during testing. The present article focuses on patients with chest pain during testing. MAIN OUTCOME MEASURES Outcome measures included chest pain localization, extension, intensity and quality, as well as the presence of various nonpain-related symptoms. Backward logistical regression analyses were performed separately on men and women who had experienced chest pain during testing. RESULTS Men who described their chest pain as ‘heavy’ were 4.6 times more likely to experience ischemia during testing (P=0.039) compared with other men, but this pain descriptor only slightly improved accuracy of prediction beyond that provided by control variables. In women, several symptoms added to the sensitivity of the prediction, such as a numb feeling in the face or neck region (OR 4.5; P=0.048), a numb feeling in the chest area (OR 14.6; P=0.003), muscle tension (OR 5.2; P=0.013), and chest pain that was described as hot or burning (OR 4.3; P=0.014). CONCLUSIONS A more refined evaluation of symptoms experienced during testing was particularly helpful in improving detection of ischemia in women, but not in men. Attention to these symptoms may favour timely diagnosis of myocardial perfusion defects in women. PMID:16639477

Comparison of myocardial blood flow induced by adenosine triphosphate and dipyridamole in patients with coronary artery disease

International Nuclear Information System (INIS)

Mamede, M.; Tadamura, Eiji; Hosokawa, Ryohei

2005-01-01

Myocardial perfusion imaging with adenosine triphosphate (ATP) has been used increasingly to diagnose coronary artery disease (CAD) and assess risk for this disease. This study compared absolute myocardial blood flow (MBF) and myocardial flow reserve index (MFR) with ATP and dipyridamole (DIP) in patients with CAD. MBF was quantified by 15 O-H 2 O PET in 21 patients with CAD (17 male, 4 female), aged 55 to 81 years. MBF was measured at rest, during intravenous injection of ATP (0.16 mg/kg/min), and again after DIP infusion (0.56 mg/kg). Regions of interest were drawn in nonischemic and ischemic segments based on findings from thallium-201 ( 201 Tl) scintigraphy and coronary angiography (CAG). Absolute MBF values and indexes of MFR were calculated in nonischemic and ischemic segments. Intravenous injection of ATP and DIP significantly increased MBF in nonischemic (2.4±0.9 and 2.1±0.8 ml/g/min, respectively; p<0.01, for both) and in ischemic segments (1.3±0.4 and 1.5±0.4 ml/g/min, respectively; p<0.01, for both). There was a significant difference in MBF values between ATP and DIP in nonischemic segments (p<0.05), which was not observed in ischemic segments. In nonischemic segments, ATP produced higher MFR than DIP (2.1±0.8 and 1.8±0.7, respectively; p<0.05), while no significant difference was observed in ischemic segments (1.5±0.6 and 1.7±0.3, respectively). ATP produced a greater hyperemia than DIP between the ischemic and nonischemic myocardium in patients with CAD. ATP is as effective as DIP for the diagnosis of CAD. (author)

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

DEFF Research Database (Denmark)

Kruuse, Christina; Jacobsen, T B; Lassen, L H

2000-01-01

Dipyridamole is used for secondary prophylaxis in ischemic stroke and as a vasodilator agent in myocardial scintigraphy. An important side effect to administering dipyridamole is headache. The aim of the current study was to investigate the effects of dipyridamole on cerebral blood flow, large ar...... causes a modest pCO2 independent dilatation of the MCA, which is time-linked to the onset, but not to the cessation, of headache....... a mean 5.6% +/- 6.7 (P = 0.005) relative increase of the arterial diameter. After dipyridamole the median peak headache score was 2 (range 0 to 7) compared with 0 (range 0 to 3) after placebo (P = 0.02). Dilatation of the middle cerebral artery outlasted the headache response. In conclusion, dipyridamole...

Validation of [1-11C]acetate as a tracer for noninvasive assessment of oxidative metabolism with positron emission tomography in normal, ischemic, postischemic, and hyperemic canine myocardium

International Nuclear Information System (INIS)

Armbrecht, J.J.; Buxton, D.B.; Schelbert, H.R.

1990-01-01

Extraction and clearance kinetics of [1-11C]acetate were examined in 65 experiments in 30 open-chest dogs. Twenty-nine studies were performed at control, 13 during ischemia, eight after reperfusion, 13 during dipyridamole-induced hyperemia, and two during alteration of cardiac workload. [1-11C]acetate was injected directly into the left anterior descending coronary artery, and myocardial tissue-time activity curves were recorded with a gamma probe. The single-pass extraction fraction averaged 64.2 +/- 9.7% in control, 65.3 +/- 9.1% in ischemia, 70.0 +/- 4.4% in reperfusion, and 46.5 +/- 7.4% in dipyridamole-induced hyperemia groups. 11C clearance was biexponential in all cases. The rate constant k1 for the first rapid clearance phase correlated closely with myocardial oxygen consumption (r = 0.94) in control, ischemia, reperfusion, and dipyridamole-induced hyperemia groups. Monoexponential fitting of only the first linear part of the clearance curve yielded the rate constant kmono, which also correlated with myocardial oxygen consumption (r = 0.96). Arterial lactate concentrations and the amount of free fatty acid oxygen equivalents consumed by the myocardium were shown to have a small but statistically significant impact on the relation between [1-11C]acetate clearance rate constants and myocardial oxygen consumption. The fraction of 14CO2 activity contributing to overall 14C activity leaving the myocardium after simultaneous injection of [1-14C]acetate (n = 24) was relatively high in all cases , indicating that externally measured 11C clearance corresponds to CO2 production and thus to tricarboxylic acid cycle activity. In conclusion, the results validate the use of [1-11C]acetate as a tracer of oxidative myocardial metabolism for use with positron emission tomography

Gated single photon emission computer tomography for the detection of silent myocardial ischemia

International Nuclear Information System (INIS)

Pena Q, Yamile; Coca P, Marco Antonio; Batista C, Juan Felipe; Fernandez-Britto, Jose; Quesada P, Rodobaldo; Pena C; Andria

2009-01-01

Background: Asymptomatic patients with severe coronary atherosclerosis may have a normal resting electrocardiogram and stress test. Aim: To assess the yield of Gated Single Photon Emission Computer Tomography (SPECT) for the screening of silent myocardial ischemia in type 2 diabetic patients. Material and methods: Electrocardiogram, stress test and gated-SPECT were performed on 102 type 2 diabetic patients aged 60 ± 8 years without cardiovascular symptoms. All subjects were also subjected to a coronary angiography, whose results were used as gold standard. Results: Gated-SPECT showed myocardial ischemia on 26.5% of studied patients. The sensibility, specificity, accuracy, positive predictive value and negative predictive value were 92.3%, 96%, 95%, 88.8%, 97.3%, respectively. In four and six patients ischemia was detected on resting electrocardiogram and stress test, respectively. Eighty percent of patients with doubtful resting electrocardiogram results and 70% with a doubtful stress test had a silent myocardial ischemia detected by gated-SPECT. There was a good agreement between the results of gated-SPECT and coronary angiography (k =0.873). Conclusions: Gated-SPECT was an useful tool for the screening of silent myocardial ischemia

Assessment of ischemic heart disease by dipyridamole stress electrocardiographic gated myocardial single photon emission computed tomography with technetium-99m tetrofosmin

International Nuclear Information System (INIS)

Kanna, Masahiko; Mitani, Isao; Nakamaru, Masashi; Shibuya, Ken; Takeda, Kazuyoshi; Asahina, Shigeru; Kitamura, Yutaka; Higuma, Kikuhiko; Ishii, Masao

1998-01-01

Simultaneous assessment of stress perfusion and rest function is possible with gated single photon emission computed tomography (SPECT) using stress injected technetium-99m ( 99m Tc) tetrofosmin (TF). The feasibility of dipyridamole stress electrocardiographic gated myocardial SPECT (GSPECT) with TF was examined as an alternative to conventional stress/rest imaging. Fifty-one patients underwent stress GSPECT. 740 MBq of TF was administered 3 min after dipyridamole infusion. GSPECT acquisition was performed one hour after the injection. Additional rest SPECT was performed on another day only in patients with abnormal perfusion on stress images. Perfusion and thickening were analyzed visually on 17 segments of the left ventricle. Percentage of wall thickening (%WT) was also calculated in 17 segments of the polar map. Thirty-two of 51 patients (63%) had normal stress perfusion and normal rest thickening. Nineteen of 51 patients (37%) had abnormal perfusion on stress images. Among 157 abnormal perfusion segments of the 19 patients, 139 segments (89%) had thickening and the rest (11%) had no thickening. %WT was higher in the reversible segments with or without thickening. There was better agreement for the identification of normal segments and the presence of reversibility between stress GSPECT and the conventional stress/rest study in patients without previous myocardial infarction than in those with previous myocardial infarction (89% vs 79%). These results suggest that stress GSPECT may substitute for conventional stress/rest perfusion study in patients without previous myocardial infarction, allowing shorter examination time and lower cost. However, stress GSPECT does not replace the need for rest perfusion study in patients with previous myocardial infarction, because of underestimation of viability, but %WT may eliminate this underestimation. (author)

Comparison of Diagnostic Accuracy for Detecting coronary Artery Disease of Dipyridamole 99mTc-MIBI Myocardial SPECT and It's Defect Map between Men and Women

International Nuclear Information System (INIS)

Lee, Dong Soo; Oh, Byung Hee; Chung, June Key; Lee, Myoung Mook; Park, Young Bae; Lee, Myung Chul; Seo, Jung Don; Lee, Young Woo; Koh, Chang Soon

1993-01-01

To evaluate the usefulness and differences in diagnosing coronary artery disease (CAD) between men and women of intravenous dipyridamole 99m Tc-MIBI myocardial SPECT, we obtained 99m Tc-MIBI myocardial SPECT and compared with the findings of coronary angiographies. Ninety eight male and 37 female patients who underwent dipyridamole 99m Tc- MIBI myocardial imaging within one month of cardiac catheterization were studied. Scans were considered abnormal if perfusion defect was detected and the defect size was more than 12% for left anterior descending artery (LAD) and circumflex(LCX) and 8% for right coronary artery (RCA) territories. Lesions ≥ 50% luminal diameter narrowing were considered significant CAD. Overall sensitivity for detection of CAD was 94.3% in men and 96.4% in women; specificity was 70% in men and 52.6% in women (P=not significant, ns). Vessel-matched sensitivity was 75.3% in men and 72.7% in women (P=ns); specificity was 84.6% in men and 67.9% in women (P 99m Tc-MIBI myocardial SPECT is a safe, noninvasive test for evaluation of CAD. There was no gender difference to detect CAD, but more false-positive rate in women especially in the territory of LAD.

Hypercholesterolemia aggravates myocardial ischemia reperfusion injury via activating endoplasmic reticulum stress-mediated apoptosis.

Science.gov (United States)

Wu, Nan; Zhang, Xiaowen; Jia, Pengyu; Jia, Dalin

2015-12-01

The effect of hypercholesterolemia on myocardial ischemia reperfusion injury (MIRI) is in controversy and the underlying mechanism is still not well understood. In the present study, we firstly detected the effects of hypercholesterolemia on MIRI and the role of endoplasmic reticulum (ER) stress-mediated apoptosis pathway in this process. The infarct size was determined by TTC staining, and apoptosis was measured by the TUNEL method. The marker proteins of ER stress response and ER stress-mediated apoptosis pathway were detected by Western blot. The results showed that high cholesterol diet-induced hypercholesterolemia significantly increased the myocardial infarct size, the release of myocardium enzyme and the ratio of apoptosis, but did not affect the recovery of cardiac function. Moreover, hypercholesterolemia also remarkably up-regulated the expressions of ER stress markers (glucose-regulated protein 78 and calreticulin) and critical molecules in ER stress-mediated apoptosis pathway (CHOP, caspase 12, phospho-JNK). In conclusion, our study demonstrated that hypercholesterolemia enhanced myocardial vulnerability/sensitivity to ischemia reperfusion injury involved in aggravation the ER stress and activation of ER stress-mediated apoptosis pathway and it gave us a new insight into the underlying mechanisms associated with hypercholesterolemia-induced exaggerated MIRI and also provided a novel target for preventing MIRI in the presence of hypercholesterolemia. Copyright © 2015 Elsevier Inc. All rights reserved.

EFFECTS OF EARLY ANGIOTENSIN-CONVERTING ENZYME-INHIBITION IN A PIG MODEL OF MYOCARDIAL-ISCHEMIA AND REPERFUSION

NARCIS (Netherlands)

VANWIJNGAARDEN, J; TOBE, TJM; WEERSINK, EGL; BEL, KJ; DEGRAEFF, PA; DELANGEN, CDJ; VANGILST, WH; WESSELING, H

In a blind, randomized study, the effects of perindopril, a nonsulfhydryl-containing angiotensin-converting enzyme (ACE) inhibitor, were compared with those of placebo in a closed-chest pig model of myocardial infraction. In anesthetized pigs, my ocardinal ischemia and reperfusion were induced by

Genetically determined angiotensin converting enzyme level and myocardial tolerance to ischemia

OpenAIRE

Messadi, Erij; Vincent, Marie-Pascale; Griol-Charhbili, Violaine; Mandet, Chantal; Colucci, Juliana; Krege, John H.; Bruneval, Patrick; Bouby, Nadine; Smithies, Oliver; Alhenc-Gelas, François; Richer, Christine

2010-01-01

Angiotensin I-converting enzyme (ACE; kininase II) levels in humans are genetically determined. ACE levels have been linked to risk of myocardial infarction, but the association has been inconsistent, and the causality underlying it remains undocumented. We tested the hypothesis that genetic variation in ACE levels influences myocardial tolerance to ischemia. We studied ischemia-reperfusion injury in mice bearing 1 (ACE1c), 2 (ACE2c, wild type), or 3 (ACE3c) functional copies of the ACE gene ...

[Vasoprotective effect of adaptation to hypoxia in myocardial ischemia and reperfusion injury].

Science.gov (United States)

Manukhina, E B; Terekhina, O L; Belkina, L M; Abramochkin, D V; Budanova, O P; Mashina, S Yu; Smirin, B V; Yakunina, E B; Downey, H F

2013-01-01

Adaptation to hypoxia is known to be cardioprotective in ischemic and reperfusion (IR) injury of the myocardium. This study was focused on investigating a possibility for prevention of endothelial dysfunction in IR injury of the rat heart using adaptation to intermittent hypoxia, which was performed in a cyclic mode (5-10 min of hypoxia interspersed with 4 min of normoxia, 5-8 cycles daily) for 21 days. Endothelial function of coronary blood vessels was evaluated after the in vitro IR of isolated heart (15 min of ischemia and 10 min of reperfusion) by the increment of coronary flow rate in response to acetylcholine. Endothelium-dependent relaxation of isolated rat aorta was evaluated after the IR myocardial injury in situ (30 min of ischemia and 60 min of reperfusion) by a relaxation response of noradrenaline-precontracted vessel rings to acetylcholine. The following major results were obtained in this study: 1) IR myocardial injury induced endothelial dysfunction of coronary blood vessels and the aorta, a non-coronary blood vessel, remote from the IR injury area; and 2) adaptation to hypoxia prevented the endothelial dysfunction of both coronary and non-coronary blood vessels associated with the IR injury. Therefore, adaptation to hypoxia is not only cardioprotective but also vasoprotective in myocardial IR injury.

Functional tests for myocardial ischemia

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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

1988-01-01

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

In vivo study of myocardial elastography under graded ischemia conditions

Energy Technology Data Exchange (ETDEWEB)

Lee, Wei-Ning; Provost, Jean; Konofagou, Elisa E [Department of Biomedical Engineering, Columbia University, New York, NY (United States); Fujikura, Kana [Department of Radiology, Columbia University, New York, NY (United States); Wang Jie, E-mail: ek2191@columbia.edu [Department of Medicine, Columbia University, New York, NY (United States)

2011-02-21

The capability of currently available echocardiography-based strain estimation techniques to fully map myocardial abnormality at early stages of myocardial ischemia is yet to be investigated. In this study, myocardial elastography (ME), a radio-frequency (RF)-based strain imaging technique that maps the full 2D transmural angle-independent strain tensor in standard echocardiographic views at both high spatial and temporal resolution is presented. The objectives were to (1) evaluate the performance of ME on mapping the onset, extent and progression of myocardial ischemia at graded coronary constriction levels (from partial to complete coronary flow reduction), and (2) validate the accuracy of the strain estimates against sonomicrometry (SM) measurements. A non-survival canine ischemic model (n = 5) was performed by gradually constricting the left anterior descending (LAD) coronary blood flow from 0% (baseline blood flow) to 100% (zero blood flow) at 20% increments. An open-architecture ultrasound system was used to acquire RF echocardiograms in a standard full short-axis view at the frame rate of 211 fps, at least twice higher than what is typically used in conventional echocardiographic systems, using a previously developed, fully automated composite technique. Myocardial deformation was estimated by ME and validated against sonomicrometry. ME estimates and maps transmural (1) 2D displacements using RF cross-correlation and recorrelation; and (2) 2D polar (radial and circumferential) strains, derived from 2D (i.e. both lateral and axial) displacement components, at high accuracy. Full-view strain images were shown and found to reliably depict decreased myocardial function in the region at risk at increased levels of coronary flow reduction. The ME radial strain was deemed to be a more sensitive, quantitative, regional measure of myocardial ischemia as a result of coronary flow reduction when compared to the conventional wall motion score index and ejection fraction

Myocardial perfusion scintigraphy in the detection of silent ischemia in asymptomatic diabetic patients

Energy Technology Data Exchange (ETDEWEB)

Oki, Glaucia Celeste Rossatto [Clinica Diagnoson and Hospital Aristides Maltez, Salvador, BA (Brazil). Servicos de Medicina Nuclear; Pavin, Elizabeth Joao; Parisi, Maria Candida R. [Universidade Estadual de Campinas (Unicamp), Campinas, SP (Brazil). Department of Internal Medicine. Service of Endocrinology; Coelho, Otavio Rizzi; Almeida, Raitany C. [Universidade Estadual de Campinas (Unicamp), Campinas, SP (Brazil). Department of Internal Medicine. Service of Cardiology; Etchebehere, Elba Cristina Sa de Camargo; Ramos, Celso Dario, E-mail: cdramos@unicamp.br [Universidade Estadual de Campinas (Unicamp), Campinas, SP (Brazil). Department of Radiology. Service of Nuclear Medicine; Camargo, Edwaldo Eduardo [Hospital Sirio-Libanes, Campinas, SP (Brazil). Service of Nuclear Medicine

2013-01-15

Objective: This study was aimed to evaluate myocardial perfusion in asymptomatic patients with type 1 (DM1) and type 2 diabetes mellitus (DM2) without previous diagnoses of coronary artery disease (CAD) or cerebral infarction. Materials and Methods: Fifty-nine consecutive asymptomatic patients (16 DM1, 43 DM2) underwent myocardial perfusion scintigraphy with {sup 99m}Tc-sestamibi (MPS). They were evaluated for body mass index, metabolic control of DM, type of therapy, systemic arterial hypertension, dyslipidemia, nephropathy, retinopathy, peripheral neuropathy, smoking, and familial history of CAD. Results: MPS was abnormal in 15 patients (25.4%): 12 (20.3%) with perfusion abnormalities, and 3 with isolated left ventricular dysfunction. The strongest predictors for abnormal myocardial perfusion were: age 60 years and above (p = 0.017; odds ratio [OR] = 6.0), peripheral neuropathy (p = 0.028; OR = 6.1), nephropathy (p = 0.031; OR = 5.6), and stress ECG positive for ischemia (p = 0.049; OR = 4.08). Conclusion: Silent myocardial ischemia occurs in more than one in five asymptomatic diabetic patients. The strongest predictors of ischemia in this study were: patient age, peripheral neuropathy, nephropathy, retinopathy and a stress ECG positive for ischemia. (author)

Myocardial perfusion scintigraphy in the detection of silent ischemia in asymptomatic diabetic patients

International Nuclear Information System (INIS)

Oki, Glaucia Celeste Rossatto; Pavin, Elizabeth Joao; Parisi, Maria Candida R.; Coelho, Otavio Rizzi; Almeida, Raitany C.; Etchebehere, Elba Cristina Sa de Camargo; Ramos, Celso Dario; Camargo, Edwaldo Eduardo

2013-01-01

Objective: This study was aimed to evaluate myocardial perfusion in asymptomatic patients with type 1 (DM1) and type 2 diabetes mellitus (DM2) without previous diagnoses of coronary artery disease (CAD) or cerebral infarction. Materials and Methods: Fifty-nine consecutive asymptomatic patients (16 DM1, 43 DM2) underwent myocardial perfusion scintigraphy with 99m Tc-sestamibi (MPS). They were evaluated for body mass index, metabolic control of DM, type of therapy, systemic arterial hypertension, dyslipidemia, nephropathy, retinopathy, peripheral neuropathy, smoking, and familial history of CAD. Results: MPS was abnormal in 15 patients (25.4%): 12 (20.3%) with perfusion abnormalities, and 3 with isolated left ventricular dysfunction. The strongest predictors for abnormal myocardial perfusion were: age 60 years and above (p = 0.017; odds ratio [OR] = 6.0), peripheral neuropathy (p = 0.028; OR = 6.1), nephropathy (p = 0.031; OR = 5.6), and stress ECG positive for ischemia (p = 0.049; OR = 4.08). Conclusion: Silent myocardial ischemia occurs in more than one in five asymptomatic diabetic patients. The strongest predictors of ischemia in this study were: patient age, peripheral neuropathy, nephropathy, retinopathy and a stress ECG positive for ischemia. (author)

[Protective effects of endogenous carbon monoxide against myocardial ischemia-reperfusion injury in rats].

Science.gov (United States)

Zhou, Zhen; Ma, Shuang; Liu, Jie; Ji, Qiao-Rong; Cao, Cheng-Zhu; Li, Xiao-Na; Tang, Feng; Zhang, Wei

2018-04-25

The present study is aimed to explore the effects of endogenous carbon monoxide on the ischemia-reperfusion in rats. Wistar rats were intraperitoneally injected with protoporphyrin cobalt chloride (CoPP, an endogenous carbon monoxide agonist, 5 mg/kg), zinc protoporphyrin (ZnPP, an endogenous carbon monoxide inhibitor, 5 mg/kg) or saline. Twenty-four hours after injection, the myocardial ischemia-reperfusion model was made by Langendorff isolated cardiac perfusion system, and cardiac function parameters were collected. Myocardial cGMP content was measured by ELISA, and the endogenous carbon monoxide in plasma and myocardial enzymes in perfusate at 10 min after reperfusion were measured by colorimetry. The results showed that before ischemia the cardiac functions of CoPP, ZnPP and control groups were stable, and there were no significant differences. After reperfusion, cardiac functions had significant differences among the three groups (P endogenous carbon monoxide can maintain cardiac function, shorten the time of cardiac function recovery, and play a protective role in cardiac ischemia-reperfusion.

Tomographic myocardial perfusion scintigraphy in children with Kawasaki disease

International Nuclear Information System (INIS)

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

1987-01-01

Myocardial infarction and stenotic coronary lesions are serious late complications in children with Kawasaki disease. For the noninvasive assessment of myocardial perfusion, dipyridamole-redistribution 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 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

Serial thallium-201 myocardial imaging after dipyridamole infusion: diagnostic utility in detecting coronary stenoses and relationship to regional wall motion

International Nuclear Information System (INIS)

Leppo, J.; Boucher, C.A.; Okada, R.D.; Newell, J.B.; Strauss, H.W.; Pohost, G.M.

1982-01-01

After a 4-minute i.v. dipyridamole infusion, 0.14 mg/kg/min, serial thallium-201 scans were obtained in 60 patients undergoing cardia catheterization. Forty patients had significant (greater than or equal to50% stenosis) coronary artery disease (CAD), and 20 patients had normal coronary arteries or trivial lesions. The images were graded qualitatively for thallium activity by three observers. Sensitivity was 93% (37 of 40) and specificity was 80% (16 of 20). The sensitivity and specificity of the thallium-201 study were not affected by the extent of CAD, the presence of Q waves, or propranolol therapy. Twenty-seven of 37 patients who had initial defects (73%) had complete thallium redistribution of one or more defects. Patient-by-patient anlaysis using a regression model of all patients showed that the fate of a segmental thallium defect predicted abnormal wall motion by angiography better than ECG Q waves. The presence of propranolol therapy or collaterals did not significantly affect the thallium redistribution results. It is concluded that qualitative interpretation by multiple observers of thallium images after dipyridamole infusion is a highly sensitive and specific test for CAD. After dipyridamole, as with exercise stress, the extent of thallium redistribution is related to the degree of myocardial wall motion abnormality

RP105 Protects Against Apoptosis in Ischemia/Reperfusion-Induced Myocardial Damage in Rats by Suppressing TLR4-Mediated Signaling Pathways

Directory of Open Access Journals (Sweden)

Jun Yang

2015-07-01

Full Text Available Background: Myocardial apoptosis is heavily implicated in the myocardial damage caused by ischemia-reperfusion (I/R. Toll-like receptor 4 (TLR4 is a potent inducer of these apoptotic cascades. In contrast, the radioprotective 105 kDa protein (RP105 is a specific negative regulator of TLR4 signaling pathways. However, the precise mechanisms by which RP105 inhibits myocardium apoptosis via TLR4-associated pathways during I/R is not fully understood. Methods: We utilized a rat model of myocardial ischemic reperfusion injury (MIRI. Animals were pre-treated with Ad-EGFP adenovirus, Ad-EGFP-RP105 adenovirus, saline, or nothing (sham. After three days, rats underwent a 30min left anterior descending coronary artery occlusion and a 4h reperfusion. Mycardial tissue was assessed by immunohistochemistry, TUNEL-staining, Western blot, quantitative RT-PCR, and a morphometric assay. Results: RP105 overexpression resulted in a reduction in infarct size, fewer TUNEL-positive cardiomyocytes, and a reduction in mitochondrial-associated apoptosis cascade activity. Further, RP105 overexpression repressed I/R-induced myocardial injury by attenuating myocardial apoptosis. This was mediated by inhibiting TLR4 activation and the phosphorylation of P38MAPK and the downstream transcription factor AP-1. Conclusion: RP105 overexpression leads to the de-activation of TLR4, P38MAPK, and AP-1 signaling pathways, and subsequently represses apoptotic cascades and ensuing damage of myocardial ischemic reperfusion. These findings may become the basis of a novel therapeutic approach for reducing of cardiac damage caused by MIRI.

Dobutamine stress MRI. Part II. Risk stratification with dobutamine cardiovascular magnetic resonance in patients suspected of myocardial ischemia

International Nuclear Information System (INIS)

Kuijpers, Dirkjan; Dijkman, Paul R.M. van; Janssen, Caroline H.C.; Vliegenthart, Rozemarijn; Zijlstra, Felix; Oudkerk, Matthijs

2004-01-01

The aim of this study was to determine the prognostic value of dobutamine cardiovascular magnetic resonance (CMR) in patients suspected of myocardial ischemia. Clinical data and dobutamine-CMR results were analyzed in 299 consecutive patients. Follow-up data were analyzed in categories of risk levels defined by the history of coronary artery disease and presence of rest wall motion abnormalities (RWMA). Major adverse cardiac events (MACE) as evaluated end points included cardiac death, nonfatal myocardial infarction and clinically indicated coronary revascularization. Follow-up was completed in 214 (99%) patients with a negative dobutamine-CMR study (no signs of inducible myocardial ischemia) with an average of 24 months. The patients with a negative dobutamine-CMR study and RWMA showed a significantly higher annual MACE rate (18%) than the patients without RWMA (0.56%) (P<0.001). Patients without RWMA showed an annual MACE rate of 2% when they had a history of coronary artery disease and <0.1% without a previous coronary event (P<0.001). Dobutamine-CMR showed a positive and negative predictive value of 95 and 93%, respectively. The cardiovascular occurrence-free survival rate was 96.2%. In patients suspected of myocardial ischemia, dobutamine-CMR is able to assess risk levels for coronary events with high accuracy. (orig.)

Dobutamine stress MRI. Part II. Risk stratification with dobutamine cardiovascular magnetic resonance in patients suspected of myocardial ischemia

Energy Technology Data Exchange (ETDEWEB)

Kuijpers, Dirkjan [State University and Academic Hospital Groningen, Department of Radiology and Cardiology, Groningen (Netherlands); Bronovo Hospital, Department of Radiology and Cardiology, Bronovolaan 1, P.O. Box 96900, The Hague (Netherlands); Dijkman, Paul R.M. van [Bronovo Hospital, Department of Radiology and Cardiology, Bronovolaan 1, P.O. Box 96900, The Hague (Netherlands); Janssen, Caroline H.C.; Vliegenthart, Rozemarijn; Zijlstra, Felix; Oudkerk, Matthijs [State University and Academic Hospital Groningen, Department of Radiology and Cardiology, Groningen (Netherlands)

2004-11-01

The aim of this study was to determine the prognostic value of dobutamine cardiovascular magnetic resonance (CMR) in patients suspected of myocardial ischemia. Clinical data and dobutamine-CMR results were analyzed in 299 consecutive patients. Follow-up data were analyzed in categories of risk levels defined by the history of coronary artery disease and presence of rest wall motion abnormalities (RWMA). Major adverse cardiac events (MACE) as evaluated end points included cardiac death, nonfatal myocardial infarction and clinically indicated coronary revascularization. Follow-up was completed in 214 (99%) patients with a negative dobutamine-CMR study (no signs of inducible myocardial ischemia) with an average of 24 months. The patients with a negative dobutamine-CMR study and RWMA showed a significantly higher annual MACE rate (18%) than the patients without RWMA (0.56%) (P<0.001). Patients without RWMA showed an annual MACE rate of 2% when they had a history of coronary artery disease and <0.1% without a previous coronary event (P<0.001). Dobutamine-CMR showed a positive and negative predictive value of 95 and 93%, respectively. The cardiovascular occurrence-free survival rate was 96.2%. In patients suspected of myocardial ischemia, dobutamine-CMR is able to assess risk levels for coronary events with high accuracy. (orig.)

Dobutamine stress MRI. Part II. Risk stratification with dobutamine cardiovascular magnetic resonance in patients suspected of myocardial ischemia.

Science.gov (United States)

Kuijpers, Dirkjan; van Dijkman, Paul R M; Janssen, Caroline H C; Vliegenthart, Rozemarijn; Zijlstra, Felix; Oudkerk, Matthijs

2004-11-01

The aim of this study was to determine the prognostic value of dobutamine cardiovascular magnetic resonance (CMR) in patients suspected of myocardial ischemia. Clinical data and dobutamine-CMR results were analyzed in 299 consecutive patients. Follow-up data were analyzed in categories of risk levels defined by the history of coronary artery disease and presence of rest wall motion abnormalities (RWMA). Major adverse cardiac events (MACE) as evaluated end points included cardiac death, nonfatal myocardial infarction and clinically indicated coronary revascularization. Follow-up was completed in 214 (99%) patients with a negative dobutamine-CMR study (no signs of inducible myocardial ischemia) with an average of 24 months. The patients with a negative dobutamine-CMR study and RWMA showed a significantly higher annual MACE rate (18%) than the patients without RWMA (0.56%) ( P<0.001). Patients without RWMA showed an annual MACE rate of 2% when they had a history of coronary artery disease and <0.1% without a previous coronary event ( P<0.001). Dobutamine-CMR showed a positive and negative predictive value of 95 and 93%, respectively. The cardiovascular occurrence-free survival rate was 96.2%. In patients suspected of myocardial ischemia, dobutamine-CMR is able to assess risk levels for coronary events with high accuracy.

Comparison of the myocardial blood flow response to regadenoson and dipyridamole: a quantitative analysis in patients referred for clinical 82Rb myocardial perfusion PET

International Nuclear Information System (INIS)

Goudarzi, Behnaz; Fukushima, Kenji; Bravo, Paco; Merrill, Jennifer; Bengel, Frank M.

2011-01-01

Regadenoson is a novel selective A 2A adenosine receptor agonist, which is administered as an intravenous bolus at a fixed dose. It is currently not clear if the absolute flow increase in response to this fixed dose is a function of distribution volume in individual patients or if it is generally comparable to the previous standard agents dipyridamole or adenosine, which are dosed based on weight. We used quantitative analysis of clinical 82 Rb PET/CT studies to obtain further insights. A total of 104 subjects with normal clinical rest/stress 82 Rb perfusion PET/CT were included in a retrospective analysis. To rule out confounding factors, none had evidence of prior cardiac disease, ischaemia or infarction, cardiomyopathy, diabetes with insulin use, calcium score >400, renal disease or other significant systemic disease. A group of 52 patients stressed with regadenoson were compared with a group of 52 patients stressed with dipyridamole before regadenoson became available. The groups were matched for clinical characteristics, risk factors and baseline haemodynamics. Myocardial blood flow (MBF) and myocardial flow reserve (MFR) were quantified using a previously validated retention model, after resampling of dynamic studies from list-mode 82 Rb datasets. At rest, heart rate, blood pressure and MBF were comparable between the groups. Regadenoson resulted in a significantly higher heart rate (34 ± 14 vs. 23 ± 10 beats per minute increase from baseline; p < 0.01) and rate-pressure product. Patients in the regadenoson group reported less severe symptoms and required less aminophylline. Stress MBF and MFR were not different between the groups (2.2 ± 0.6 vs. 2.1 ± 0.6 ml/min/g, p = 0.39, and 2.9 ± 0.8 vs. 2.8 ± 0.7, p = 0.31, respectively). In the regadenoson group, there was no correlation between stress flow or MFR and body weight or BMI. Despite its administration at a fixed dose, regadenoson results in an absolute increase in MBF which is comparable to that

Myocardial ischemia and angina pectoris. The clinical problem in patients

Energy Technology Data Exchange (ETDEWEB)

Selwyn, A.P.; Fox, K.M.; Jonathan, A.; Lavender, P.; Watson, I.

1981-02-01

Ambulatory monitoring of ST segment changes was performed in 60 patients presenting with angina, positive ECG stress tests and coronary artery disease, 85% of ischemic ECG events were asymptomatic, 37% occurred with no increase in heart rate and 15% of episodes either lasted 20 minutes or more or fluctuated in severity. A controlled pilot study in ten patients showed depression. Radionuclide studies in 50 patients with angina and coronary artery disease have shown that stress (i.e., atrial pacing) produced different patterns of disturbed regional myocardial perfusion related to the patient's exercise capacity and eventually leading to a decrease in regional myocardial perfusion during the ischemic episode. ST segment depression appeared only after the decrease in regional myocardial perfusion. These findings combined with past research suggest that patients with angina and coronary artery disease can suffer frequent asymptomatic disturbances of the regional myocardial perfusion. The frequency of these episodes and the time course for the recovery of the metabolic consequences mean that segments of ventricular myocardium may be constantly abnormal. The relative importance of changes in coronary tone and malfunction of platelets in the diseased coronary tree needs to be examined in clinical research. Pilot studies of antiplatelet agents have shown a significant beneficial effect on episodes of ischemia occurring at night and those occurring without any increase in heart rate. The techniques and observations in these patients with coronary artery disease all suggest that acute transient regional myocardial ischemia is caused by a variety of mechanisms. Further research using objective methods is required to discover the causes of ischemia and to rationalize treatment.

Semiquantitative SPECT myocardial perfusion with dipyridamole in patients unable to exercise. Event rate during 4 years of follow up

International Nuclear Information System (INIS)

Balestrini, V.R.; Arja, V.J.; Sandrin, A.L.; Calvo, G.R.; Gomez Bosh, Z.; Quiroga, W.; Balestrini, C.E.; Joekes, S.

2002-01-01

The increasingly numbers of patients (P) that can't reach an adequate level of exercise in order to evaluate CAD, lead us to use pharmacological and technical tools available for this subgroup of P. Aim: evaluate the prognostic significance of myocardial perfusion SPECT imaging with pharmacological stress in P without LBBB, unable to exercise. Material and Methods: 209 P were included. Mean age: 65 years old (39-88), male 66%. Clinical: Pre test likelihood 8: 28%; SDS 0 and SRS 0: 31.7%; SDS 0 + SRS >=1: 21%; SDS >=1: 47.3%. III) Follow up: 13 patients were early re-vascularized induced by SPECT study results, 10 patients get lost and 186 were follow up by a mean 1086 days. Cumulative events rate: 1st year SCE 9.7%, HCE 1.6%; 2nd year SCE 14%, HCE 4.3%; 3rd year SCE 17.7%, HCE 5.4%; 4th year SCE 21%, HCE 5,4%. Scintigraphic indices and events rate relationship are presented. Conclusion: There was a relationship between scintigraphic indices and hard cardiac events. The semiquantitative myocardial perfusion with dipyridamole stress was a safe test and useful to discriminate groups of P with different risk of events

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

International Nuclear Information System (INIS)

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

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

Science.gov (United States)

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

2016-03-03

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

Angina and exertional myocardial ischemia in diabetic and nondiabetic patients: assessment by exercise thallium scintigraphy

International Nuclear Information System (INIS)

Nesto, R.W.; Phillips, R.T.; Kett, K.G.; Hill, T.; Perper, E.; Young, E.; Leland, O.S. Jr.

1988-01-01

Patients with diabetes mellitus and coronary artery disease are thought to have painless myocardial ischemia more often than patients without diabetes. We studied 50 consecutive patients with diabetes and 50 consecutive patients without diabetes, all with ischemia, on exercise thallium scintigraphy to show the reliability of angina as a marker for exertional ischemia. The two groups had similar clinical characteristics, treadmill test results, and extent of infarction and ischemia, but only 7 patients with diabetes compared with 17 patients without diabetes had angina during exertional ischemia. In diabetic patients the extent of retinopathy, nephropathy, or peripheral neuropathy was similar in patients with and without angina. Angina is an unreliable index of myocardial ischemia in diabetic patients with coronary artery disease. Given the increased cardiac morbidity and mortality in such patients, periodic objective assessments of the extent of ischemia are warranted

Evaluation of myocardial preconditioning and adenosine effects in cardioprotection in rat hearts with ischemia-reperfusion injury using 99MTc-glucarate imaging

International Nuclear Information System (INIS)

Liu Zhonglin; Barrett, H.H.; Koon Yan Pak

2004-01-01

Significant tolerance to myocardial ischemia-reperfusion injury, as assessed by biochemical assay and noninvasive infarct-avid imaging, was induced with an IPC protocol in the rat model. The cardioprotection of IPC could be simulated by adenosine receptor A1 agonist CCPA, or blocked by antagonist SPT. Thus, adenosine mediates protection by ischemic preconditioning in this specific rat heart model. 99mTc-glucarate imaging is not only useful in detecting early ischemia-reperfusion injury, but also invaluable in evaluating the effects of cardioprotective treatments. uantitative anal ses on dynamic images with 99m Tc-glucarate would make it possible to identify myocardial ischemia-reperfusion injury more accurate, and provide a unique tool for evaluation of cardioprotection. The FASTSPECT imaging with the ischenuc-reperfused rat heart model provides a solution-specific approach with high-resolution and fast dynamic acquisition for kinetic studies of new myocardial imaging agents as the evidence of its major role in the present study. (authors)

Electrocardiographically and symptomatically silent myocardial ischemia during exercise testing

International Nuclear Information System (INIS)

Kurata, Chinori; Tawarahara, Kei; Sakata, Kazuyuki; Taguchi, Takahisa; Fukumoto, Yoshihiro; Kobayashi, Akira; Yamazaki, Noboru; Tanaka, Hiroshi

1991-01-01

Certain patients with coronary artery disease (CAD) may have neither ST depression nor chest pain during exercise despite the presence of myocardial ischemia. The frequency and characteristics of such electrocardiographically and symptomatically silent ischemia were studied in 171 patients with both angiographically documented CAD and scintigraphically documented ischemia. Fifty-six (33%) of 171 patients had neither ST depression nor chest pain (Group N), and 115 (67%) had ST depression and/or chest pain (Group P). The two groups were similar with respect to age, gender, the prevalence of prior infarction, and peak systolic blood pressure. Group N patients, however, had a higher mean peak heart rate and rate-pressure product, less severe scintigraphic ischemia, a lower lung thallium-201 uptake, and a smaller number of diseased vessels. Stepwise discriminant analysis showed a history of effort angina, lung thallium-201 uptake, and scintigraphic severity of ischemia to be significant discriminators between Groups N and P. In conclusion, electrocardiographically and symptomatically silent ischemia may be common during exercise in patients with CAD, and less severe ischemia may be one of important determinants. (author)

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

Science.gov (United States)

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

2011-01-01

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

Inhibition of Fas-associated death domain-containing protein (FADD protects against myocardial ischemia/reperfusion injury in a heart failure mouse model.

Directory of Open Access Journals (Sweden)

Qian Fan

Full Text Available As technological interventions treating acute myocardial infarction (MI improve, post-ischemic heart failure increasingly threatens patient health. The aim of the current study was to test whether FADD could be a potential target of gene therapy in the treatment of heart failure.Cardiomyocyte-specific FADD knockout mice along with non-transgenic littermates (NLC were subjected to 30 minutes myocardial ischemia followed by 7 days of reperfusion or 6 weeks of permanent myocardial ischemia via the ligation of left main descending coronary artery. Cardiac function were evaluated by echocardiography and left ventricular (LV catheterization and cardiomyocyte death was measured by Evans blue-TTC staining, TUNEL staining, and caspase-3, -8, and -9 activities. In vitro, H9C2 cells transfected with ether scramble siRNA or FADD siRNA were stressed with chelerythrin for 30 min and cleaved caspase-3 was assessed.FADD expression was significantly decreased in FADD knockout mice compared to NLC. Ischemia/reperfusion (I/R upregulated FADD expression in NLC mice, but not in FADD knockout mice at the early time. FADD deletion significantly attenuated I/R-induced cardiac dysfunction, decreased myocardial necrosis, and inhibited cardiomyocyte apoptosis. Furthermore, in 6 weeks long term permanent ischemia model, FADD deletion significantly reduced the infarct size (from 41.20 ± 3.90% in NLC to 26.83 ± 4.17% in FADD deletion, attenuated myocardial remodeling, improved cardiac function and improved survival. In vitro, FADD knockdown significantly reduced chelerythrin-induced the level of cleaved caspase-3.Taken together, our results suggest FADD plays a critical role in post-ischemic heart failure. Inhibition of FADD retards heart failure progression. Our data supports the further investigation of FADD as a potential target for genetic manipulation in the treatment of heart failure.

Coronary arterial BK channel dysfunction exacerbates ischemia/reperfusion-induced myocardial injury in diabetic mice.

Science.gov (United States)

Lu, Tong; Jiang, Bin; Wang, Xiao-Li; Lee, Hon-Chi

2016-09-01

The large conductance Ca(2+)-activated K(+) (BK) channels, abundantly expressed in coronary artery smooth muscle cells (SMCs), play a pivotal role in regulating coronary circulation. A large body of evidence indicates that coronary arterial BK channel function is diminished in both type 1 and type 2 diabetes. However, the consequence of coronary BK channel dysfunction in diabetes is not clear. We hypothesized that impaired coronary BK channel function exacerbates myocardial ischemia/reperfusion (I/R) injury in streptozotocin-induced diabetic mice. Combining patch-clamp techniques and cellular biological approaches, we found that diabetes facilitated the colocalization of angiotensin II (Ang II) type 1 receptors and BK channel α-subunits (BK-α), but not BK channel β1-subunits (BK-β1), in the caveolae of coronary SMCs. This caveolar compartmentation in vascular SMCs not only enhanced Ang II-mediated inhibition of BK-α but also produced a physical disassociation between BK-α and BK-β1, leading to increased infarct size in diabetic hearts. Most importantly, genetic ablation of caveolae integrity or pharmacological activation of coronary BK channels protected the cardiac function of diabetic mice from experimental I/R injury in both in vivo and ex vivo preparations. Our results demonstrate a vascular ionic mechanism underlying the poor outcome of myocardial injury in diabetes. Hence, activation of coronary BK channels may serve as a therapeutic target for cardiovascular complications of diabetes.

Comparison of the myocardial blood flow response to regadenoson and dipyridamole: a quantitative analysis in patients referred for clinical {sup 82}Rb myocardial perfusion PET

Energy Technology Data Exchange (ETDEWEB)

Goudarzi, Behnaz; Fukushima, Kenji; Bravo, Paco; Merrill, Jennifer [Johns Hopkins University, Division of Nuclear Medicine, Russell H Morgan Department of Radiology, Baltimore, MD (United States); Bengel, Frank M. [Johns Hopkins University, Division of Nuclear Medicine, Russell H Morgan Department of Radiology, Baltimore, MD (United States); Hannover Medical School, Department of Nuclear Medicine, Hannover (Germany)

2011-10-15

Regadenoson is a novel selective A{sub 2A} adenosine receptor agonist, which is administered as an intravenous bolus at a fixed dose. It is currently not clear if the absolute flow increase in response to this fixed dose is a function of distribution volume in individual patients or if it is generally comparable to the previous standard agents dipyridamole or adenosine, which are dosed based on weight. We used quantitative analysis of clinical {sup 82}Rb PET/CT studies to obtain further insights. A total of 104 subjects with normal clinical rest/stress {sup 82}Rb perfusion PET/CT were included in a retrospective analysis. To rule out confounding factors, none had evidence of prior cardiac disease, ischaemia or infarction, cardiomyopathy, diabetes with insulin use, calcium score >400, renal disease or other significant systemic disease. A group of 52 patients stressed with regadenoson were compared with a group of 52 patients stressed with dipyridamole before regadenoson became available. The groups were matched for clinical characteristics, risk factors and baseline haemodynamics. Myocardial blood flow (MBF) and myocardial flow reserve (MFR) were quantified using a previously validated retention model, after resampling of dynamic studies from list-mode {sup 82}Rb datasets. At rest, heart rate, blood pressure and MBF were comparable between the groups. Regadenoson resulted in a significantly higher heart rate (34 {+-} 14 vs. 23 {+-} 10 beats per minute increase from baseline; p < 0.01) and rate-pressure product. Patients in the regadenoson group reported less severe symptoms and required less aminophylline. Stress MBF and MFR were not different between the groups (2.2 {+-} 0.6 vs. 2.1 {+-} 0.6 ml/min/g, p = 0.39, and 2.9 {+-} 0.8 vs. 2.8 {+-} 0.7, p = 0.31, respectively). In the regadenoson group, there was no correlation between stress flow or MFR and body weight or BMI. Despite its administration at a fixed dose, regadenoson results in an absolute increase in MBF

Reversible cold-induced abnormalities in myocardial perfusion and function in systemic sclerosis

International Nuclear Information System (INIS)

Alexander, E.L.; Firestein, G.S.; Weiss, J.L.; Heuser, R.R.; Leitl, G.; Wagner, H.N. Jr.; Brinker, J.A.; Ciuffo, A.A.; Becker, L.C.

1986-01-01

The effects of peripheral cold exposure on myocardial perfusion and function were studied in 13 patients with scleroderma without clinically evident myocardial disease. Ten patients had at least one transient, cold-induced, myocardial perfusion defect visualized by thallium-201 scintigraphy, and 12 had reversible, cold-induced, segmental left ventricular hypokinesis by two-dimensional echocardiography. The 10 patients with transient perfusion defects all had anatomically corresponding ventricular wall motion abnormalities. No one in either of two control groups (9 normal volunteers and 7 patients with chest pain and normal coronary arteriograms) had cold-induced abnormalities. This study is the first to show the simultaneous occurrence of cold-induced abnormalities in myocardial perfusion and function in patients with scleroderma. The results suggest that cold exposure in such patients may elicit transient reflex coronary vasoconstriction resulting in reversible myocardial ischemia and dysfunction. Chronic recurrent episodes of coronary spasm may lead to focal myocardial fibrosis

Detection of myocardial stunning with gated SPECT and its relationship with location, extension and severity of perfusion defects induced by exercise or pharmacologic stress

International Nuclear Information System (INIS)

Mut, F.; Beretta, M.; Vidal, I.; Rener, A.; Alonso, O.

2002-01-01

Aim: To investigate the relationship between transient ventricular dysfunction detected by gated SPECT with the location, extension and severity of ischemic areas in patients with reversible perfusion defects. Material and Methods: We retrospectively studied 83 patients (61±11 yrs., 61 men, 27 with previous MI) submitted for coronary artery disease (CAD) evaluation with 99mTc-MIBI gated SPECT using a 2-day protocol whose perfusion imaging pattern had been reported positive for myocardial ischemia. Stress test was exercise in 54 cases, dipyridamole in 28 and dobutamine in 1. Previous work from our group demonstrated up to 12% change in LVEF from rest to post-stress in a population with low likelihood of CAD and a normal perfusion pattern. Thus, according to % variation of left ventricular ejection fraction (LVEF) from rest to post-stress we further divided the population into 2 subgroups, (A) with less than 12% change in LVEF (n=56) and (B) with more than 12% negative variation (n=27). For evaluation of perfusion, a simplified 7-segment division of the myocardium was used and a combined ischemic score was obtained by multiplying the number of segments with reversible defects by the 1-4 assigned severity score. Results: There was no significant difference between the two groups regarding age, gender, stress result (clinical or ECG), number of fixed perfusion defects or rest LVEF. Dipyridamole test was more frequent among patients of group B. Post-stress LVEF was 49±14% for group A and 41±15% for group B, p=0.0125. Combined ischemic score was 6.82±6.5 vs. 11.96±12 respectively, p=0.014. In patients of group A, defects corresponding to the right coronary territory were more frequent, while the left descending artery territory was more commonly affected in group B patients, however this was not statistically significant. Left circumflex territory was equally affected in both groups. Conclusion: Transient ventricular dysfunction after a stress test can be

Allogeneic amniotic membrane-derived mesenchymal stromal cell transplantation in a porcine model of chronic myocardial ischemia

Directory of Open Access Journals (Sweden)

Kimura M

2012-01-01

Full Text Available Introduction. Amniotic membrane contains a multipotential stem cell population and is expected to possess the machinery to regulate immunological reactions. We investigated the safety and efficacy of allogeneic amniotic membrane-derived mesenchymal stromal cell (AMSC transplantation in a porcine model of chronic myocardial ischemia as a preclinical trial. Methods. Porcine AMSCs were isolated from amniotic membranes obtained by cesarean section just before delivery and were cultured to increase their numbers before transplantation. Chronic myocardial ischemia was induced by implantation of an ameroid constrictor around the left circumflex coronary artery. Four weeks after ischemia induction, nine swine were assigned to undergo either allogeneic AMSC transplantation or normal saline injection. Functional analysis was performed by echocardiography, and histological examinations were carried out by immunohistochemistry 4 weeks after AMSC transplantation. Results. Echocardiography demonstrated that left ventricular ejection fraction was significantly improved and left ventricular dilatation was well attenuated 4 weeks after AMSC transplantation. Histological assessment showed a significant reduction in percentage of fibrosis in the AMSC transplantation group. Injected allogeneic green fluorescent protein (GFP-expressing AMSCs were identified in the immunocompetent host heart without the use of any immunosuppressants 4 weeks after transplantation. Immunohistochemistry revealed that GFP colocalized with cardiac troponin T and cardiac troponin I. Conclusions. We have demonstrated that allogeneic AMSC transplantation produced histological and functional improvement in the impaired myocardium in a porcine model of chronic myocardial ischemia. The transplanted allogeneic AMSCs survived without the use of any immunosuppressants and gained cardiac phenotype through either their transdifferentiation or cell fusion.

Significance of exercise-induced ST segment depression in patients with myocardial infarction involving the left circumflex artery. Evaluation by exercise thallium-201 myocardial single photon emission computed tomography

International Nuclear Information System (INIS)

Koitabashi, Norimichi; Toyama, Takuji; Hoshizaki, Hiroshi

2000-01-01

The significance of exercise-induced ST segment depression in patients with left circumflex artery involvement was investigated by comparing exercise electrocardiography with exercise thallium-201 single photon emission computed tomography (Tl-SPECT) and the wall motion estimated by left ventriculography. Tl-SPECT and exercise electrocardiography were simultaneously performed in 51 patients with left circumflex artery involvement (angina pectoris 30, myocardial infarction 21). In patients with myocardial infarction, exercise-induced ST depression was frequently found in the V 2 , V 3 and V 4 leads. In patients with angina pectoris, ST depression was frequently found in the II, III, aV F , V 5 and V 6 leads. There was no obvious difference in the leads of ST depression in patients with myocardial infarction with ischemia and without ischemia on Tl-SPECT images. In patients with myocardial infarction, the lateral wall motion of the infarcted area evaluated by left ventriculography was more significantly impaired in the patients with ST depression than without ST depression (p<0.01). Exercise-induced ST depression in the precordial leads possibly reflects wall motion abnormality rather than ischemia in the lateral infarcted myocardium. (author)

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

International Nuclear Information System (INIS)

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

1990-01-01

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

Intermittent peripheral tissue ischemia during coronary ischemia reduces myocardial infarction through a KATP-dependent mechanism: first demonstration of remote ischemic perconditioning

DEFF Research Database (Denmark)

Schmidt, Michael Rahbek; Smerup, M; Konstantinov, I E

2006-01-01

. Intermittent limb ischemia during myocardial ischemia reduces MI, preserves global systolic and diastolic function, and protects against arrhythmia during the reperfusion phase through a K(ATP) channel-dependent mechanism. Understanding this process may have important therapeutic implications for a range...

Value of myocardial perfusion SPECT in pediatric population

International Nuclear Information System (INIS)

Massardo, T.; Coll, C.; Prat, H.; Gonzalez, P.; Doggenweiller, P.; Castillo, M.E.; Solis, A.

2002-01-01

Isotopic myocardial perfusion studies are less frequently used in children than in adults and their indications are also different. Our goal was to analyze retrospectively the experience with stress perfusion myocardial SPECT in pediatric population. Method: Since 1998 to 2001, ten studies were performed to 5 girls and 3 boys. Their mean age was 7±3 years ranging from 1-11. Three of them presented abnormal coronary arteries pre and post surgical intervention with or without coil; three had Kawasaki disease with coronary aneurysms and the other two, congenital cardiopathies (Cantrell pentalogy and great vessel transposition,both with posterior left ventricular hypokinesia post surgery). Stress was obtained using dipyridamole infusion (0.56 mg/kg) in 6 cases and treadmill exercise using Bruce protocol in 4. All those tests were well tolerated. Sestamibi Tc99m was selected in 80% of the cases and Tl 201 in the rest. Only 2 small children required anesthesia during SPECT acquisition. Results: Stress EKG did not demonstrated ischemia in any case. Coronary angiography was performed only in 50% of the patients, it was concordant with SPECT features in all, two of those patients presented transient perfusion defects (one Kawasaki and one abnormal coronary artery with a fistulae).The repaired pentalogy presented ischemia and septal infarction; in that patient echocardiographic hipokinesia was concordant with fixed hypoperfusion. One case with abnormal coronary plus mitral regurgitation (without isotopic ischemia) was submitted to embolization posteriorly, obtaining motion improvement. Clinical outcome was concordant with the presence or absence of isotopic ischemia in the rest of the patients. Conclusion: SPECT myocardial perfusion was helpful in the therapeutic approach and in prediction of outcome in children

Detection of myocardial ischemia of hypertrophic cardiomyopathy with gated 99Tcm-MIBI myocardial perfusion imaging

International Nuclear Information System (INIS)

Jia Peng; Guo Wanhua; Du Minghua; Gao Ling

2010-01-01

Objective: To evaluate the value of gated 99 Tc m -methoxyisobutylisonitrile (MIBI) myocardial perfusion imaging in detection of myocardial ischemia in hypertrophic cardiomyopathy. Methods: Sixty-nine patients with clinically proven hypertrophic cardiomyopathy were divided into 2 groups using coronary angiogram as 'gold standard': positive group (n=19, narrowing ≥ 50%) and negative group (n=50, narrowing 99 Tc m -MIBI myocardial perfusion imaging was performed and positive in all 69 patients (41 males, 28 females, aged 35-75 years). Comparative analysis between the two groups was carried out using t-test. Results: In the positive group, reversible and irreversible perfusion defects were detected in 9 and 10 patients, respectively. Left ventricular ejection fraction (LVEF) increased to (69.1 ± 2.8)% in 8 patients and decreased to (42.8 ± 2.1)% in 11 patients. In the negative group, reversible and irreversible perfusion defects were found in 37 and 13 patients, respectively. LVEF increased to (70.8 ± 4.0)% in 38 patients and decreased to (48.9 ± 2.7)% in 12 patients. The values of ischemic area, severity and extent of perfusion defect, and LVEF were significantly different between the two groups (t=9.28, 16.51, 2.65; P 99 Tc m -MIBI myocardial perfusion imaging is valuable in assessing patients with hypertrophic cardiomyopathy. Detection for the presence or absence of coexisting coronary artery disease and myocardial ischemia has an important prognostic indication and management indication for these patients. (authors)

IDENTIFIKASI SINYAL ECG IRAMA MYOCARDIAL ISCHEMIA DENGAN PENDEKATAN FUZZY LOGIC

Directory of Open Access Journals (Sweden)

Azhar A N

2009-07-01

Full Text Available The heart is one of vital organs in human body. Incidence of heart disease can be fatal for the patient. Myocardial ischemia, the disease that is often suffered by the human, is a disease due to clogged heart arteries blood vessels. One of the ways to detect this disease is by reading the graph output of electrocardiogram (ECG signal. ECG signal represents the condition and activity of the heart. Specialized knowledge, accuration and expertise are required to read ECG graph. To help expert or doctor, expert system based on artificial intelligent, such as Fuzzy Logic approach, can be applied to improve diagnostic accuracy and thoroughness. Fuzzy logic can be applied because of it flexibility to understand the linguistic variables used in identifying myocardial ischemia disease.

Blood conservation with membrane oxygenators and dipyridamole.

Science.gov (United States)

Teoh, K H; Christakis, G T; Weisel, R D; Madonik, M M; Ivanov, J; Wong, P Y; Mee, A V; Levitt, D; Benak, A; Reilly, P

1987-07-01

Cardiopulmonary bypass induces platelet activation and dysfunction, which result in platelet deposition and depletion. Reduced platelet numbers and abnormal platelet function may contribute to postoperative bleeding. A membrane oxygenator may preserve platelets and reduce bleeding more than a bubble oxygenator, and the antiplatelet agent dipyridamole may protect platelets intraoperatively and reduce bleeding postoperatively. A prospective randomized trial was performed in 44 patients undergoing elective coronary artery bypass grafting to assess the effects of the membrane oxygenator and dipyridamole on platelet counts, platelet activation products, and postoperative bleeding. Patients who were randomized to receive a bubble oxygenator and no dipyridamole had the lowest postoperative platelet counts, the greatest blood loss, and the most blood products transfused. Platelet counts were highest and blood loss was least in patients randomized to receive a membrane oxygenator and dipyridamole (p less than .05). A bubble oxygenator with dipyridamole and a membrane oxygenator without dipyridamole resulted in intermediate postoperative platelet counts and blood loss. Arterial thromboxane B2 and platelet factor 4 concentrations were elevated on cardiopulmonary bypass in all groups. Both the membrane oxygenator and dipyridamole were independently effective (by multivariate analysis) in preserving platelets. Optimal blood conservation was achieved with a membrane oxygenator and dipyridamole.

Intracoronary levosimendan during ischemia prevents myocardial apoptosis.

Directory of Open Access Journals (Sweden)

Markus eMalmberg

2012-02-01

Full Text Available Background. Levosimendan is a calcium-sensitizing inotropic agent that prevents myocardial contractile depression following cardiac surgery. Levosimendan has also anti-apoptotic properties, but the role of this mechanism is not clear. We studied whether levosimendan prevents cardiomyocyte apoptosis and post-operative stunning after either intracoronary administration or intravenous infusion in an experimental model. Methods. Pigs (n=24 were subjected to 40 minutes of global, cardioplegic ischemia under cardiopulmonary bypass and 240 minutes of reperfusion. L-IV group received intravenous infusion of levosimendan (65 μg/kg 40 minutes before ischemia and L-IC group received levosimendan (65 μg/kg during ischemia administered intracoronary. Control group was operated without levosimendan. Echocardiography was performed to all animals. Apoptosis was determined from transmyocardial biopsies taken from left ventricle using TUNEL assay and immunohistochemistry of active caspace-3. Results. Apoptosis was induced after ischemia-reperfusion in all groups (pre L-IV 0.002±0.004 % vs. post L-IV 0.020±0.017 % p=0.02, pre L-IC 0.001±0.004 % vs. post L-IC 0.020±0.017 % p<0.001, pre control 0.007±0.013 % vs. post control 0.062±0.044 % p=0.01. The amount of apoptosis was higher in the controls, compared with the L-IV (p=0.03 and the L-IC (p=0.03 groups. Longitudinal left ventricular contraction was significantly reduced in the L-IC and the control groups when compared to the L-IV group (L-IV 0.75±0.12 mm vs. L-IC 0.53±0.11 mm p=0.003, L-IV vs. control 0.54±0.11 p=0.01. Conclusions. Both intracoronary administration and pre-ischemic intravenous infusion of levosimendan equally prevented apoptosis, but intravenous administration was required for optimal preservation of the post-operative systolic left ventricle function.

Brain SPECT using dipyridamole for evaluation of vascular reserve

International Nuclear Information System (INIS)

Kim, Su Zy; Park, Chan Hee; Yoon, Soo Hwan; Pai, Moon Sun; Yoon, Suk Nam; Cho, Kyung Kee

1997-01-01

Baseline and stress brain SPECT studies using CO 2 inhalation, acetazolamide (Diamox R ) and adenosine administrations have been used in the evaluation of cerebral vascular reserve. Recently dipyridamole (Persantine R ) which is one of the pharmacologic myocardial perfusion SPECT agents as a potent vasodilator is suggested as another cerebral vasodilator. IV Diamox R is not available in Korea. Therefore, the purpose of our study was to evaluate dipyridamole in stress brain SPECT in patients with Moya Moya disease. Eight patients with angiographically proven Moya Moya disease were studied. Their ages ranged from 7 to 62 year old. There were 4 males and 4 females. Each patient had a baseline and persantine brain SPECT studies with 1 to 3 days' interval. Dipyridamole was given intravenously at a dose of 0.56 mg/kg over 4 minutes while watching vital signs such as blood pressure, heart rate, and electrocardiogram. Three minutes after the completion of the infusion, 99mTc-ECD (0.2 mCi/Ib body weight) was injected. Brain SPECT was performed 30 minutes later using a tripple head gamma camera equipped with LEHR collimators. A total of 128 projections with an acquisition time of 30 second per projection was obtained and reconstructed by filtered back projections without attenuation correction. The difference between the baseline and persantine studies was analysed by visual and semiquantitavely. During the infusion of persantine, heart rate, blood pressure and side effects such as headache, chest discomfort were similar to the persantine myocardial SPECT studies. Five of eight patients showed a significant decrease in rCBF on persantine brain SPECT in comparison to the baseline study. The remaining three revealed no significant change in rCBF. Our study suggests that the dipyridamole stress brain SPECT is feasible and useful in assessing cerebral blood flow reserve. However we need to evaluate more number of patients in the future

Myocardial Ischemia Screening in Middle-Aged and Elderly Men

Czech Academy of Sciences Publication Activity Database

Boudík, F.; Reissigová, Jindra; Tomečková, Marie; Anger, Z.; Bultas, J.; Šimek, S.

2010-01-01

Roč. 17, č. 5 (2010), s. 2-7 ISSN 1667-9059 R&D Projects: GA MŠk(CZ) 1M06014 Institutional research plan: CEZ:AV0Z10300504 Keywords : body surface mapping * stress ECG test * myocardial ischemia * risk factors Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

Serum caffeine levels after 24 hours of caffeine abstention: observations on clinical patients undergoing myocardial perfusion imaging with dipyridamole or adenosine

International Nuclear Information System (INIS)

Jacobson, A.F.; Cerqueira, M.D.; Raisys, V.; Shattuc, S.

1994-01-01

Although caffeine attenuates the vasodilatation produced by dipyridamole and adenosine, and is therefore contraindicated when these agents are used for myocardial perfusion scintigraphy, caffeine levels in clinical patients undergoing standard imaging protocols have not been studied. Eighty-six patients undergoing clinically indicated intravenous dipyridamole (n=75) or adenosine (n=11) thallium-201 myocardial perfusion scintigraphy, all of whom reported abstention from products containing caffeine for 24 h, were studied prospectively. Blood samples were drawn prior to initiation of the pharmacologic infusion, and serum caffeine levels were determined using an enzyme immunoassay technique. Results of these determinations were correlated with maximum pulse and blood pressure changes measured during and immediately after the stressor infusion, and thallium imaging findings. Detectable caffeine levels were found in 34 patients (40%), ranging from 0.1 to 5.0 mg/l. There was no significant difference in mean systolic blood pressure decrease or mean pulse increase between patients with caffeine levels > 1.0 mg/l (20.4 ± 18.2 mmHg, 11.0 ± 8.9 BPM; n=5) and those with lower (0.1 to 0.9 mg/l) (15.4 ± 9.5 mmHg, 14.4 ± 8.2 BPM; n=29) or no detectable caffeine levels (18.0 ± 11.5 mmHg, 16.6 ± 10.1 BPM; n=52). Redistribution on thallium imaging was also identified with a similar frequency in these three groups (2/5, 40%; 8/29, 28%; 22/52, 42% respectively). (orig.)

Serum caffeine levels after 24 hours of caffeine abstention: observations on clinical patients undergoing myocardial perfusion imaging with dipyridamole or adenosine

Energy Technology Data Exchange (ETDEWEB)

Jacobson, A.F. (Nuclear Medicine Section, Dept. of Veterans Affairs Medical Center, Seattle, WA (United States) Univ. of Washington, Seattle, WA (United States)); Cerqueira, M.D. (Nuclear Medicine Section, Dept. of Veterans Affairs Medical Center, Seattle, WA (United States) Univ. of Washington, Seattle, WA (United States)); Raisys, V. (Dept. of Lab. Medicine, Harborview Medical Center, Seattle, WA (United States) Univ. of Washington, Seattle, WA (United States)); Shattuc, S. (Univ. of Washington, Seattle, WA (United States))

1994-01-01

Although caffeine attenuates the vasodilatation produced by dipyridamole and adenosine, and is therefore contraindicated when these agents are used for myocardial perfusion scintigraphy, caffeine levels in clinical patients undergoing standard imaging protocols have not been studied. Eighty-six patients undergoing clinically indicated intravenous dipyridamole (n=75) or adenosine (n=11) thallium-201 myocardial perfusion scintigraphy, all of whom reported abstention from products containing caffeine for 24 h, were studied prospectively. Blood samples were drawn prior to initiation of the pharmacologic infusion, and serum caffeine levels were determined using an enzyme immunoassay technique. Results of these determinations were correlated with maximum pulse and blood pressure changes measured during and immediately after the stressor infusion, and thallium imaging findings. Detectable caffeine levels were found in 34 patients (40%), ranging from 0.1 to 5.0 mg/l. There was no significant difference in mean systolic blood pressure decrease or mean pulse increase between patients with caffeine levels > 1.0 mg/l (20.4 [+-] 18.2 mmHg, 11.0 [+-] 8.9 BPM; n=5) and those with lower (0.1 to 0.9 mg/l) (15.4 [+-] 9.5 mmHg, 14.4 [+-] 8.2 BPM; n=29) or no detectable caffeine levels (18.0 [+-] 11.5 mmHg, 16.6 [+-] 10.1 BPM; n=52). Redistribution on thallium imaging was also identified with a similar frequency in these three groups (2/5, 40%; 8/29, 28%; 22/52, 42% respectively). (orig.)

Myocardial capillary permeability after regional ischemia and reperfusion in the in vivo canine heart. Effect of superoxide dismutase

DEFF Research Database (Denmark)

Svendsen, Jesper Hastrup; Bjerrum, P J; Haunsø, S

1991-01-01

coronary artery followed by 1 hour of reperfusion. Myocardial plasma flow rate and capillary extraction of chromium 51-labeled EDTA or technetium 99m-labeled diethylenetriaminepentaacetic acid were measured by the single-injection, residue-detection method before ischemia and 5 and 60 minutes after...... fibrillation in contrast to none in the superoxide dismutase group. Before ischemia, plasma flow rate, myocardial capillary extraction fraction, and PS values were similar in the two groups. Five minutes after the start of reperfusion, plasma flow rate increased significantly (p less than 0.01) in both groups....... In the control group, capillary extraction fraction increased by 12% (p = NS) in spite of the higher plasma flow; these increases in capillary extraction fraction and plasma flow induced a 69% increase in PS (p less than 0.01). In the superoxide dismutase-treated group, capillary extraction fraction decreased...

The extracellular matrix metalloproteinase inducer EMMPRIN is a target of nitric oxide in myocardial ischemia/reperfusion.

Science.gov (United States)

Tarin, Carlos; Lavin, Begoña; Gomez, Monica; Saura, Marta; Diez-Juan, Antonio; Zaragoza, Carlos

2011-07-15

Nitric oxide (NO) is an important defense against myocardial ischemia/reperfusion (I/R) injury. Although matrix metalloproteinase (MMP)-mediated necrosis of cardiac myocytes is well characterized, the role of inducible NO synthase (iNOS)-derived NO in this process is poorly understood. I/R injury was increased in iNOS-deficient mice and in mice treated with 1400 W (a pharmacological iNOS inhibitor) and was associated with significantly increased expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and EMMPRIN-associated MMPs. Transcriptional activity of an EMMPRIN luciferase promoter reporter expressed in cardiac myocytes was inhibited by NO in a cGMP-dependent manner, and this transcriptional inhibition was abolished by mutation of a putative E2F site. Consistent with these findings, EMMPRIN null mice, in which iNOS is normally induced, are partially protected against I/R injury. Pharmacological inhibition of iNOS in EMMPRIN null mice had no additional protective effect, suggesting that EMMPRIN is a downstream target of NO. Administration of anti-EMMPRIN neutralizing antibodies partly reduced the excess heart damage and MMP-9 expression induced by I/R in iNOS null mice, indicating that regulation of EMMPRIN is an important mechanism of NO-mediated cardioprotection. Copyright © 2011 Elsevier Inc. All rights reserved.

Effects of intracoronary melatonin on ischemia-reperfusion injury in ST-elevation myocardial infarction

DEFF Research Database (Denmark)

Ekeløf, Sarah V; Halladin, Natalie L; Jensen, Svend E

2016-01-01

Acute coronary occlusion is effectively treated by primary percutaneous coronary intervention. However, myocardial ischemia-reperfusion injury is at the moment an unavoidable consequence of the procedure. Oxidative stress is central in the development of ischemia-reperfusion injury. Melatonin......, an endogenous hormone, acts through antioxidant mechanisms and could potentially minimize the myocardial injury. The aim of the experimental study was to examine the cardioprotective effects of melatonin in a porcine closed-chest reperfused infarction model. A total of 20 landrace pigs were randomized...... to a dosage of 200 mg (0.4 mg/mL) melatonin or placebo (saline). The intervention was administered intracoronary and intravenous. Infarct size, area at risk and microvascular obstruction were determined ex vivo by cardiovascular magnetic resonance imaging. Myocardial salvage index was calculated. The plasma...

Usefulness of Myocardial Annular Velocity Change During Mental Stress to Predict Cardiovascular Outcome in Patients With Coronary Artery Disease (From the Responses of Mental Stress-Induced Myocardial Ischemia to Escitalopram Treatment Trial).

Science.gov (United States)

Alenezi, Fawaz; Brummett, Beverly H; Boyle, Stephen H; Samad, Zainab; Babyak, Michael A; Alzaeim, Nabil; Wilson, Jennifer; Romano, Minna M D; Sun, Julia L; Ersboll, Mads; O'Connor, Christopher M; Velazquez, Eric J; Jiang, Wei

2017-11-01

Mental stress-induced myocardial ischemia is common and a prognostic factor of adverse cardiovascular outcomes in patients with coronary artery disease (CAD). The present study aimed at examining associations between mental stress-induced myocardial annular velocity (MAV) and cardiovascular outcome in patients with CAD. MAV, specifically, diastolic early (e'), diastolic late (a'), and systolic (s') velocities were obtained at rest and during mental stress testing in 224 patients with clinically stable CAD. Using Cox regression models, age, sex, and baseline-adjusted mental stress-induced MAV measures were examined as predictors of a priori defined composite event term that comprised all-cause mortality and/or nonfatal cardiovascular events, resulting in an unplanned hospitalization (major adverse cardiovascular events [MACE]). Median follow-up was 4 years. The sample was predominantly male, Caucasian with New York Heart Association functional class I and a mean age of 63 ± 10.2 years. MS-induced changes in e' (hazard ratio [HR] = .73) and s' (HR = .73) were significant (p Mental stress-induced MAV changes independently predict an adverse cardiovascular outcome in patients with stable CAD. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Directory of Open Access Journals (Sweden)

Ersagun Karaguzel

2016-02-01

Full Text Available ABSTRACT Purpose To investigate the protective effects against ischemia reperfusion injury of dipyridamole in a model of induced priapism in rats. Materials and Methods Twenty-four male Sprague-Dawley rats were divided into four groups, control, P/R, P/R+DMSO and P/R+D. 3ml blood specimens were collected from vena cava inferior in order to determine serum MDA, IMA, TAS, TOS and OSI values, and penile tissue was taken for histopathological examination in control group. Priapism was induced in P/R group. After 1h, priapism was concluded and 30 min reperfusion was performed. In P/R+DMSO group 1ml/kg DMSO was administered intraperitoneally 30 min before reperfusion, while in P/R+D group 10mg/kg dipyridamole was administered intraperitoneally 30 min before reperfusion. Blood and penis specimens were collected after the end of 30 min reperfusion period. Sinusoidal area (µm2, tears in tunica albuginea and injury parameters in sinusoidal endothelium of penis were investigated. Results Histopathological examination revealed no significant changes in term of sinusoidal area. A decrease in tears was observed in P/R+D group compared to P/R group (p0.05. There were no significant differences in MDA and IMA values between groups. A significant increase in TOS and OSI values was observed in P/R+D group compared to P/R group. A significant decrease in TAS levels was observed in P/R+D group compared to the P/R group. Conclusions The administration of dipyridamole before reperfusion in ischemic priapism model has a potential protective effect against histopathological injury of the penis.

Effects of chlorthalidone and diltiazem on myocardial ischemia in elderly patients with hypertension and coronary artery disease

Directory of Open Access Journals (Sweden)

Serro-Azul João Batista

2001-01-01

Full Text Available OBJETIVE: Antihypertensive therapy with thiazides decreases coronary events in elderly patients. However, the influence of diuretics on myocardial ischemia has not been fully investigated. The aim of this study was to compare the effect of chlorthalidone and diltiazem on myocardial ischemia. METHODS: Following a randomized, double-blind, crossover protocol, we studied 15 elderly hypertensive patients aged 73.6±4.6 years with myocardial ischemia. All patients had angiographically documented coronary artery disease. We measured patients using 48- hour ambulatory electrocardiogram monitoring and exercise testing. After a 2-week period using placebo, patients received chlorthalidone or diltiazem for 4 weeks. RESULTS: Both treatments lowered systolic and diastolic blood pressures. The number of ischemic episodes on ambulatory electrocardiogram recordings was reduced with the use of chlorthalidone (2.5±3.8 and diltiazem (3.2±4.2 when compared with placebo (7.9±8.8; p<0.05. The total duration of ischemic episodes was reduced in both treatments when compared with placebo (chlorthalidone: 19.2±31.9min; diltiazem: 19.3±29.6min; placebo: 46.1±55.3min; p<0.05. CONCLUSION: In elderly hypertensive patients with coronary artery disease, chlorthalidone reduced myocardial ischemia similarly to diltiazem. This result is consistent with epidemiological studies and suggests that reduction of arterial blood pressure with thiazide therapy plays an important role in decreasing myocardial ischemia.

Effect of Escitalopram on Mental Stress-Induced Myocardial Ischemia: The Results of the REMIT Trial

Science.gov (United States)

Jiang, Wei; Velazquez, Eric J.; Kuchibhatla, Maragatha; Samad, Zainab; Boyle, Stephen H.; Kuhn, Cynthia; Becker, Richard C.; Ortel, Thomas L.; Williams, Redford B.; Rogers, Joseph G.; O’Connor, Christopher

2015-01-01

Importance Mental-stress-induced myocardial ischemia (MSIMI) is an intermediate surrogate endpoint representing the pathophysiological link between psychosocial risk factors and adverse outcomes of coronary heart disease (CHD). However, pharmacological interventions aimed at reducing MSIMI have not been well studied. Objective To examine the effects of 6 weeks of escitalopram treatment vs. placebo on MSIMI and other psychological stress-related biophysiological and emotional parameters. Design, Setting, and Participants The REMIT study is a randomized, double-blind, placebo-controlled trial of patients with clinically stable CHD and laboratory MSIMI. Enrollment occurred from 7/24/2007–8/24/2011 at a tertiary medical center. Interventions Eligible participants were randomized 1:1 to receive escitalopram (dose began at 5 mg with titration to 20 mg/day in 3 weeks) or placebo over 6 weeks. Main Outcome Measure Occurrence of MSIMI, defined as (1) development or worsening of regional wall motion abnormality; (2) left ventricular ejection fraction reduction ≥8%; and/or (3) horizontal or downsloping ST-segment depression ≥1mm in ≥2 leads lasting for ≥3 consecutive beats during ≥1 of 3 mental tasks. Results 127 participants were randomized to escitalopram (n=64) or placebo (n=63); 112 (96.1%) completed endpoint assessments (n=56 in each arm). At the end of 6 weeks, more patients taking escitalopram (34.2% [95% CI, 25.4 to 43.0]) had absence of MSIMI during the 3 mental stressors compared with patients taking placebo (17.5% [95% CI, 10.4 to 24.5]) based on unadjusted multiple imputation model for intention-to-treat analysis. A significant difference favoring escitalopram was observed (OR=2.62 [95% CI, 1.06 to 6.44]). Rates of exercise-induced ischemia were slightly lower at 6 weeks in the escitalopram group (45.8% [95% CI, 36.6 to 55.0]) than in patients receiving placebo (52.5% [95% CI, 43.3 to 61.7]), compared with baseline escitalopram (49.2% [95% CI, 39.9 to

Human Umbilical Cord-Derived Mesenchymal Stromal Cells Improve Left Ventricular Function, Perfusion, and Remodeling in a Porcine Model of Chronic Myocardial Ischemia

Science.gov (United States)

Liu, Chuan-Bin; Huang, He; Sun, Ping; Ma, Shi-Ze; Liu, An-Heng; Xue, Jian; Fu, Jin-Hui; Liang, Yu-Qian; Liu, Bing; Wu, Dong-Ying

2016-01-01

Stem cell therapy has emerged as a new strategy for treatment of ischemic heart disease. Although umbilical cord-derived mesenchymal stromal cells (UC-MSCs) have been used preferentially in the acute ischemia model, data for the chronic ischemia model are lacking. In this study, we investigated the effect of UC-MSCs originated from Wharton’s jelly in the treatment of chronic myocardial ischemia in a porcine model induced by ameroid constrictor. Four weeks after ameroid constrictor placement, the surviving animals were divided randomly into two groups to undergo saline injection (n = 6) or UC-MSC transplantation (n = 6) through the left main coronary artery. Two additional intravenous administrations of UC-MSCs were performed in the following 2 weeks to enhance therapeutic effect. Cardiac function and perfusion were examined just before and at 4 weeks after intracoronary transplantation. The results showed that pigs with UC-MSC transplantation exhibited significantly greater left ventricular ejection fraction compared with control animals (61.3% ± 1.3% vs. 50.3% ± 2.0%, p UC-MSC treatment improves left ventricular function, perfusion, and remodeling in a porcine model with chronic myocardial ischemia. Significance Ischemic heart disease is the leading cause of death worldwide. Many patients with chronic myocardial ischemia are not suitable for surgery and have no effective drug treatment; they are called “no-option” patients. This study finds that umbilical cord-derived mesenchymal stromal cells transplanted by intracoronary delivery combined with two intravenous administrations was safe and could significantly improve left ventricular function, perfusion, and remodeling in a large-animal model of chronic myocardial ischemia, which provides a new choice for the no-option patients. In addition, this study used clinical-grade mesenchymal stem cells with delivery and assessment methods commonly used clinically to facilitate further clinical transformation. PMID

Diagnostic Criteria for Transient Myocardial Ischemia in Newborn Infants with Intrauterine Growth Retardation

Directory of Open Access Journals (Sweden)

Umida F. Nasirova, PhD

2012-06-01

Full Text Available Metabolic and hemodynamic disturbances in newborns with intrauterine growth retardation resulting from the transferred intrauterine hypoxia, lead to the development of transient myocardial ischemia. Study included 158 newborn infants with intrauterine growth retardation, 83% of which have the asymmetric and 17% - the symmetric form of IUGR, revealed differences in heart rate due to higher dispersion parameters of cardiac rhythm. It was determined that in infants with intrauterine growth retardation heart rate, respiratory rate accelerated and blood pressure increased in compare with the newborns in the control group. According to the ECG examination results, were revealed the signs of focal changes of ST-T, accompanied by inversion of the ST-T segment below the isoline, which accompanied with the positive and peaked T waves, considered as myocardial ischemia. In infants with intrauterine growth retardation, survived after perinatal damage of the central nervous system, the prolongation of the QRST interval was noted in compare with the control group newborns, which could be an indicator of conjunction of hypoxic and ischemic changes in the myocardium. Clinical manifestations of transient myocardial ischemia followed by pale skin, acrocyanosis, and perioral cyanosis against dullness of heart sounds. Obtained results deepened an understanding of posthypoxic myocardial dysfunction, which is characterized by cardiac rhythm and conductivity disturbances, as well as changes in ventricular complex, and causing the need for electrocardiographic screening in the neonatal period

Myocardial Ischemia Screening in Middle-Aged and Elderly Men

Czech Academy of Sciences Publication Activity Database

Boudík, F.; Reissigová, Jindra; Tomečková, Marie; Anger, Z.; Bultas, J.; Šimek, S.

2010-01-01

Roč. 17, č. 4 (2010), s. 352-356 ISSN 1667-8982 R&D Projects: GA MŠk(CZ) 1M06014 Institutional research plan: CEZ:AV0Z10300504 Keywords : body surface mapping * stress ECG test * myocardial ischemia * risk factors Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.028, year: 2010

Vagal modulation of high mobility group box-1 protein mediates electroacupuncture-induced cardioprotection in ischemia-reperfusion injury.

Science.gov (United States)

Zhang, Juan; Yong, Yue; Li, Xing; Hu, Yu; Wang, Jian; Wang, Yong-qiang; Song, Wei; Chen, Wen-ting; Xie, Jian; Chen, Xue-mei; Lv, Xin; Hou, Li-li; Wang, Ke; Zhou, Jia; Wang, Xiang-rui; Song, Jian-gang

2015-10-26

Excessive release of high mobility group box-1 (HMGB1) protein from ischemic cardiomyocytes activates inflammatory cascades and enhances myocardial injury after reperfusion. Here we report evidence that electroacupuncture of mice at Neiguan acupoints can inhibit the up-regulation of cardiac HMGB1 following myocardial ischemia and attenuate the associated inflammatory responses and myocardial injury during reperfusion. These benefits of electroacupuncture were partially reversed by administering recombinant HMGB1 to the mice, and further potentiated by administering anti-HMGB1 antibody. Electroacupuncture-induced inhibition of HMGB1 release was markedly reduced by unilateral vagotomy or administration of nicotinic receptor antagonist, but not by chemical sympathectomy. The cholinesterase inhibitor neostigmine mimicked the effects of electroacupuncture on HMGB1 release and myocardial ischemia reperfusion injury. Culture experiments with isolated neonatal cardiomyocytes showed that acetylcholine, but not noradrenaline, inhibited hypoxia-induced release of HMGB1 via a α7nAchR-dependent pathway. These results suggest that electroacupuncture acts via the vagal nerve and its nicotinic receptor-mediated signaling to inhibit HMGB1 release from ischemic cardiomyocytes. This helps attenuate pro-inflammatory responses and myocardial injury during reperfusion.

Diagnosis of silent myocardial ischemia in type 2 diabetic patients by electrocardiogram, ergometry and Gated-SPECT

International Nuclear Information System (INIS)

Penna Quian, Yamile; Fernandez-Britto Rodriguez, Jose; Bacallao Gallestey, Jorge; Batista Cuellar, Juan Felipe; Coca Perez, Marco Antonio; Toirac Garcia, Noresma; Penna Coego, Andria

2008-01-01

31 asymptomatic type 2 diabetic patients were studied by lab tests, electrocardiogram, ergometry, Gated-SPECT and coronariography to determine the relation between the atherosclerotic risk factors and the silent myocardial ischemia. Patients were classified into two groups: positive SPECT and negative SPECT. Association tests were made for each variable and ROC curves were constructed to identify risk markers. In 35.5% of the patients silent myocardial ischemia was detected with a good angiographic correlation. A significant association was evidenced between positive SPECT and the atherosclerotic risk factors, namely, low values of HDLc, family pathological history of ischemic heart disease and peripheral vascular disease. The logistic regression models showed that low values of HDLc together with family pathological history of ischemic heart disease may be strong predictors of silent myocardial ischemia in asymptomatic type 2 diabetic patients

Effects of steal-prone anatomy on intraoperative myocardial ischemia. The SPI Research Group.

Science.gov (United States)

Leung, J M; Hollenberg, M; O'Kelly, B F; Kao, A; Mangano, D T

1992-11-01

Our study objective was to determine whether the presence of steal-prone anatomy conferred an increased risk in the development of intraoperative myocardial ischemia. Coronary artery steal of collateral blood flow has been demonstrated for many vasodilators, including isoflurane, the most commonly used inhalational anesthetic agent in the United States. It has been postulated that patients with steal-prone anatomy (total occlusion of one coronary artery that is supplied distally by collateral flow from another coronary artery with a > or = 50% stenosis) may be particularly at risk for the development of intraoperative myocardial ischemia when an anesthetic with a vasodilator property is being administered. We evaluated the risk of myocardial ischemia under isoflurane anesthesia (vs. a high dose narcotic technique using sufentanil) using continuous intraoperative electrocardiography and transesophageal echocardiography in patients with and without steal-prone anatomy undergoing coronary artery bypass graft surgery. Sixty-two (33%) of the 186 patients had steal-prone anatomy: in 5 (8%) the collateral-supplying vessel was > or = 50% to 69% stenosed, in 24 (39%) it was > or = 70% to 89% stenosed and in 33 (53%) it was > or = 90% stenosed. The incidence of ischemia (transesophageal echocardiography or intraoperative electrocardiography, or both) was similar in patients with and without steal-prone coronary anatomy (18 [29%] of 62 patients vs. 39 [31%] of 124 patients, p = 0.87, 95% confidence interval = -0.13 to 0.17). The incidence of intraoperative ischemia was similar in patients who received isoflurane or sufentanil anesthesia (20 [32%] of 62 patients vs. 37 [30%] of 124 patients, p = 0.87). The incidence of tachycardia and hypotension was low (increases in heart rate = 9.8%, and decreases in systolic blood pressure = 10.8% of total monitoring time during the prebypass period compared with preoperative baseline values). The incidence of adverse cardiac outcome was

Mild troponin I elevation does not predict ischemia on myocardial perfusion imaging

Directory of Open Access Journals (Sweden)

Le Dung Ha

2017-08-01

Full Text Available IntroductionData are limited on the degree of mild troponin I elevation and clinical risk factors in predicting myocardial ischemia.MethodsHospitalized adult patients who underwent myocardial perfusion imaging (MPI from 2015 to 2016 at Rochester General Hospital and had mild troponin I elevation (>0.1 and <1.5 ng/mL were included. Predictors of outcomes were determined using logistic regression model.ResultsOne hundred and sixty-six patients with mild troponin I elevation who underwent MPI were followed. Mean age was 69.6 ± 12.5 years and 53.0% of the patients were female. Fourteen patients (8.4% presented with typical chest pain (CP, 60 patients (36.1% had atypical CP and 92 patients (55.4% had no CP on presentation. MPI was positive for ischemia in 45 patients (27.1%. There was no difference in peak troponin I level with ischemia versus no ischemia on MPI (0.34 ng/dL [0.13-0.69] vs. 0.23 ng/dL [0.14-0.50], p value 0.254. Atypical CP did not predict the presence of ischemia on MPI (odds ratio [OR] 1.97, 95% confidence interval [CI] 0.91-4.26. Coronary artery disease (CAD history (age and sex adjusted p value 0.013, diabetes (adjusted p value 0.036, creatinine ≥2 mg/dL (adjusted p value 0.019 and dialysis (adjusted p value 0.006 were statistically significant predictors of ischemia on MPI.ConclusionsIn patients presenting with mild troponin I elevation, peak troponin I level did not predict ischemia on MPI. The presence of CAD history, diabetes, elevated creatinine and dialysis were predictors of ischemia on MPI.

Vitamin E deficiency fails to affect myocardial performance during in vivo ischemia-reperfusion.

Science.gov (United States)

Coombes, J S; Powers, S K; Demirel, H A; Hamilton, K L; Jessup, J; Vincent, H K; Shanely, R A

2000-12-01

Vitamin E content of cardiac tissue has been proposed to play a major role in the damage caused by myocardial ischemia-reperfusion (I-R). Previous studies using in vitro models have examined vitamin E deficiency and I-R-induced myocardial damage with equivocal results. The purpose of this study was to use an in vivo model of myocardial I-R to determine the effects of vitamin E deficiency on myocardial I-R-induced damage. Female Sprague-Dawley rats (4-mo old) were assigned to either: 1) control diet (CON), or 2) vitamin E deficient diet (VE-DEF). The CON diet was prepared to meet AIN-93M standards, which contains 75 IU vitamin E/kg diet. The VE-DEF diet was the AIN-93M diet prepared with tocopherol stripped corn oil and no vitamin E. Following a 14-week feeding period, significant differences (p CON = 48.2 +/- 3.5; VE-DEF = 12.4 +/- 1.4 micrograms VE/g wet weight). Animals from both experimental groups were subjected to an in vivo I-R protocol consisting of 25 minutes of left coronary artery occlusion followed by 10 minutes of reperfusion. No group differences (p > 0.05) existed in cardiac performance (peak arterial pressure or ventricular work) or the incidence of ventricular arrhythmias during the I-R protocol. VE-DEF animals had significantly higher (p CON animals. These data suggest that although vitamin E deficiency increases oxidative damage resulting from myocardial I-R, it does not affect cardiac performance during the insult.

Prevalência de isquemia induzida por estresse mental Prevalence of induced ischemia by mental distress

Directory of Open Access Journals (Sweden)

Gustavo Borges Barbirato

2010-03-01

ischemia through a particular physiopathology when compared to radionuclide imaging with physical or pharmacological distress. OBJECTIVE: To assess the prevalence of induced myocardial ischemia by mental distress in patients with thoracic pain and radionuclide imaging with normal conventional distress, with 99mTc-Sestamibi. METHODS: Twenty-two patients were admitted with thoracic pain at emergency or were referred to the nuclear medicine service of our institution, where myocardial radionuclide imaging of distress or rest without ischemic alterations was carried out. The patients were, then, invited to go through an additional phase with mental distress induced by color conflict (Strop Color Test with the objective of detecting myocardial ischemia. Two cardiologists and nuclear physicians performed the blind analysis of perfusional data and consequent quantification through Summed Difference Score (SDS, punctuating the segments that were altered after mental distress and comparing it to the rest period image. The presence of myocardial ischemia was considered if SDS > 3. RESULTS: The prevalence of mental distress-induced myocardial ischemia was 40% (9 positive patients. Among the 22 studied patients, there were no statistical differences with regard to the number of risk factors, mental distress-induced hemodynamic alterations, usage of medications, presented symptoms, presence or absence of coronary disease and variations of ejection fraction and final systolic volume of Gated SPECT. CONCLUSION: In a selected sample of patients with thoracic pain and normal myocardial radionuclide imaging, the research of myocardial ischemia induced by mental distress through radionuclide imaging may be positive in up to 40% of cases.

Relationship Between Coronary Contrast-Flow Quantitative Flow Ratio and Myocardial Ischemia Assessed by SPECT MPI.

Science.gov (United States)

Smit, Jeff M; Koning, Gerhard; van Rosendael, Alexander R; Dibbets-Schneider, Petra; Mertens, Bart J; Jukema, J Wouter; Delgado, Victoria; Reiber, Johan H C; Bax, Jeroen J; Scholte, Arthur J

2017-10-01

A new method has been developed to calculate fractional flow reserve (FFR) from invasive coronary angiography, the so-called "contrast-flow quantitative flow ratio (cQFR)". Recently, cQFR was compared to invasive FFR in intermediate coronary lesions showing an overall diagnostic accuracy of 85%. The purpose of this study was to investigate the relationship between cQFR and myocardial ischemia assessed by single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI). Patients who underwent SPECT MPI and coronary angiography within 3 months were included. The cQFR computation was performed offline, using dedicated software. The cQFR computation was based on 3-dimensional quantitative coronary angiography (QCA) and computational fluid dynamics. The standard 17-segment model was used to determine the vascular territories. Myocardial ischemia was defined as a summed difference score ≥2 in a vascular territory. A cQFR of ≤0.80 was considered abnormal. Two hundred and twenty-four coronary arteries were analysed in 85 patients. Overall accuracy of cQFR to detect ischemia on SPECT MPI was 90%. In multivariable analysis, cQFR was independently associated with ischemia on SPECT MPI (OR per 0.01 decrease of cQFR: 1.10; 95% CI 1.04-1.18, p = 0.002), whereas clinical and QCA parameters were not. Furthermore, cQFR showed incremental value for the detection of ischemia compared to clinical and QCA parameters (global chi square 48.7 to 62.6; p relationship between cQFR and SPECT MPI was found. cQFR was independently associated with ischemia on SPECT MPI and showed incremental value to detect ischemia compared to clinical and QCA parameters.

Cardioprotective Effect of the Aqueous Extract of Lavender Flower against Myocardial Ischemia/Reperfusion Injury

Directory of Open Access Journals (Sweden)

Dong Wang

2014-01-01

Full Text Available This study was conducted to evaluate the cardioprotective property of the aqueous extract of lavender flower (LFAE. The myocardial ischemia/reperfusion (I/R injury of rat was prepared by Langendorff retrograde perfusion technology. The heart was preperfused with K-H solution containing LFAE for 10 min before 20 minutes global ischemia, and then the reperfusion with K-H solution was conducted for 45 min. The left ventricular developed pressure (LVDP and the maximum up/downrate of left ventricular pressure (±dp/dtmax were recorded by physiological recorder as the myocardial function and the myocardial infarct size was detected by TTC staining. Lactate dehydrogenase (LDH and creatine kinase (CK activities in the effluent were measured to determine the myocardial injury degree. The superoxide anion dismutase (SOD and malondialdehyde (MDA in myocardial tissue were detected to determine the oxidative stress degree. The results showed that the pretreatment with LFAE significantly decreased the myocardial infarct size and also decreased the LDH, CK activities, and MDA level, while it increased the LVDP, ±dp/dtmax, SOD activities, and the coronary artery flow. Our findings indicated that LFAE could provide protection for heart against the I/R injury which may be related to the improvement of myocardial oxidative stress states.

Noninvasive identification of left main and triple vessel coronary artery disease using dipyridamole thallium scintigraphy

International Nuclear Information System (INIS)

Chikamori, Taishiro; Doi, Yoshinori; Yonezawa, Yoshihiro; Yamada, Mitsutoshi; Seo, Hiromi; Kawai, Kazuya; Yabe, Toshikazu; Ozawa, Toshio

1993-01-01

The diagnostic value of dipyridamole thallium scintigraphy for the noninvasive identification of left main (LM) and triple vessel (TV) coronary artery disease (CAD) was evaluated in 615 consecutive patients with known or suspected CAD. One hundred thirty-nine patients had LM or TVCAD; the remaining 476 patients had limited CAD (double vessel CAD in 112, single vessel CAD in 235, insignificant lesions in 129). Patients with LM or TVCAD, compared to those with limited CAD, had a higher incidence of diffuse slow washout (58 vs 20%, p<0.0001), extensive fixed defects (21 vs 6%, p<0.0001) and extensive reversible defects (32 vs 8%, p<0.0001). During dipyridamole loading, the incidence of chest pain was higher (65 vs 41%, p<0.0001), and the magnitude of ST depression was greater (0.16±0.14 vs 0.04±0.07 mV, p<0.001) in patients with LM or TVCAD than in those with limited CAD. Stepwise discriminant analysis using scintigraphic imaging achieved a sensitivity of 69%, a specificity of 79%, and an accuracy of 77% for diagnosing patients with LM or TVCAD. After including clinical markers of ischemia during dipyridamole loading, multivariate analysis revealed an improved diagnosis with a sensitivity of 71%, a specificity of 85%, and an accuracy of 82%. These results clearly show the usefulness of scintigraphic imaging as well as the significance of careful assessment of clinical markers of ischemia during dipyridamole loading for the noninvasive identification of LM and TVCAD. (author)

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

International Nuclear Information System (INIS)

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

1991-01-01

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

The Olson method for detection of acute myocardial ischemia in patients with coronary occlusion.

Science.gov (United States)

Lindow, Thomas; Olson, Charles W; Swenne, Cees A; Man, Sumche; Pahlm, Olle

An automated ECG-based method may provide diagnostic support in the management of patients with acute coronary syndrome. The Olson method has previously proved to accurately identify the culprit artery in patients with acute coronary occlusion. The Olson method was applied to 360 patients without acute myocardial ischemia and 52 patients with acute coronary occlusion. This study establishes the normal variation of the Olson wall scores in patients without acute myocardial ischemia, which provides the basis for implementation of the Olson method for triage of patients with acute coronary syndrome. All patients with acute occlusion had Olson wall scores above the upper limit of normal. The Olson method can be used for ischemia detection with very high sensitivity. Future studies are needed to explore specificity in patients with non-ischemic ST elevation. Copyright © 2016 Elsevier Inc. All rights reserved.

Serial Holter ST-segment monitoring after first acute myocardial infarction. Prevalence, variability, and long-term prognostic importance of transient myocardial ischemia

DEFF Research Database (Denmark)

Mickley, H; Nielsen, J R; Berning, J

1998-01-01

Based on serial Holter monitoring performed 7 times within 3 years after a first acute myocardial infarction, we assessed the prevalence, variability and long-term clinical importance of transient myocardial ischemia (TMI) defined as episodes of ambulatory ST-segment depression. In all, 121...... consecutive male patients variability was found within and between patients...

Body mass index and risk for mental stress induced ischemia in coronary artery disease.

Science.gov (United States)

Soufer, Robert; Fernandez, Antonio B; Meadows, Judith; Collins, Dorothea; Burg, Matthew M

2016-05-19

Acute emotionally reactive mental stress (MS) can provoke prognostically relevant deficits in cardiac function and myocardial perfusion, and chronic inflammation increases risk for this ischemic phenomenon. We have described parasympathetic withdrawal and generation of inflammatory factors in MS. Adiposity is also associated with elevated markers of chronic inflammation. High body mass index (BMI) is frequently used as a surrogate for assessment of excess adiposity, and associated with traditional CAD risk factors, and CAD mortality. BMI is also associated with autonomic dysregulation, adipose tissue derived proinflammatory cytokines, which are also attendant to emotion provoked myocardial ischemia. Thus, we sought to determine if body mass index (BMI) contributes to risk of developing myocardial ischemia provoked by mental stress. We performed a prospective interventional study in a cohort of 161 patients with stable CAD. They completed an assessment of myocardial blood flow with single photon emission computed tomography (SPECT) simultaneously during 2 conditions: laboratory mental stress and at rest. Multivariate logistic regression determined the independent contribution of BMI to the occurrence of mental-stress induced ischemia. Mean age was 65.6±9.0 years; 87.0% had a history of hypertension, and 28.6% had diabetes. Mean BMI was 30.4±4.7. Prevalence of mental stress ischemia was 39.8%. BMI was an independent predictor of mental stress ischemia, OR=1.10, 95% CI [1.01-1.18] for one-point increase in BMI and OR=1.53, 95% CI [1.06-2.21] for a 4.7 point increase in BMI (one standard deviation beyond the cohort BMI mean), p=0.025 for all. These data suggest that BMI may serve as an independent risk marker for mental stress ischemia. The factors attendant with greater BMI, which include autonomic dysregulation and inflammation, may represent pathways by which high BMI contribute to this risk and serve as a conceptual construct to replicate these findings in larger

High-intensity training reduces intermittent hypoxia-induced ER stress and myocardial infarct size.

Science.gov (United States)

Bourdier, Guillaume; Flore, Patrice; Sanchez, Hervé; Pepin, Jean-Louis; Belaidi, Elise; Arnaud, Claire

2016-01-15

Chronic intermittent hypoxia (IH) is described as the major detrimental factor leading to cardiovascular morbimortality in obstructive sleep apnea (OSA) patients. OSA patients exhibit increased infarct size after a myocardial event, and previous animal studies have shown that chronic IH could be the main mechanism. Endoplasmic reticulum (ER) stress plays a major role in the pathophysiology of cardiovascular disease. High-intensity training (HIT) exerts beneficial effects on the cardiovascular system. Thus, we hypothesized that HIT could prevent IH-induced ER stress and the increase in infarct size. Male Wistar rats were exposed to 21 days of IH (21-5% fraction of inspired O2, 60-s cycle, 8 h/day) or normoxia. After 1 wk of IH alone, rats were submitted daily to both IH and HIT (2 × 24 min, 15-30m/min). Rat hearts were either rapidly frozen to evaluate ER stress by Western blot analysis or submitted to an ischemia-reperfusion protocol ex vivo (30 min of global ischemia/120 min of reperfusion). IH induced cardiac proapoptotic ER stress, characterized by increased expression of glucose-regulated protein kinase 78, phosphorylated protein kinase-like ER kinase, activating transcription factor 4, and C/EBP homologous protein. IH-induced myocardial apoptosis was confirmed by increased expression of cleaved caspase-3. These IH-associated proapoptotic alterations were associated with a significant increase in infarct size (35.4 ± 3.2% vs. 22.7 ± 1.7% of ventricles in IH + sedenary and normoxia + sedentary groups, respectively, P < 0.05). HIT prevented both the IH-induced proapoptotic ER stress and increased myocardial infarct size (28.8 ± 3.9% and 21.0 ± 5.1% in IH + HIT and normoxia + HIT groups, respectively, P = 0.28). In conclusion, these findings suggest that HIT could represent a preventive strategy to limit IH-induced myocardial ischemia-reperfusion damages in OSA patients. Copyright © 2016 the American Physiological Society.

201Tl myocardial SPECT and β-endorphin levels in patients with suspected silent ischemia

International Nuclear Information System (INIS)

Lind, P.; Binter, G.; Koeltringer, P.; Eber, O.; Eber, B.; Klein, W.; Brandt, D.

1990-01-01

Today silent myocardial ischemia (SMI) is a well-recognized phenomenon. Treadmill exercise according to the Bruce protocol, 201 Tl myocardial SPECT and coronary angiography were performed in a total of 106 patients with suspected SMI. In group I (high probability of ischemia; n=46), reversible defects detected by SPECT correlated well with significant stenoses and irreversible defects with subtotal stenoses or complete occlusions. SPECT sensitivity in the detection of ischemia was 91%, its specificity 96%. In group II (low probability of ischemia; n=60), SPECT sensitivity was as high as in group I (94%) but due to a high number of false-positive results (e.g. cardiomyopathy) specificity was only 75%. However, SPECT was superior to exercise ECG (sensitivity 70%; specificity 56%) in the detection of SMI. In addition, β-endorphin levels were determined in 180 healthy subjects, 37 patients with symptomatic CAD and in 34 patients with SMI before and during maximum exercise. Exercise values in patients with SMI were significantly higher than in healthy subjects or in patients with symptomatic CAD. (orig./MG) [de

Epilepsy-induced electrocardiographic alterations following cardiac ischemia and reperfusion in rats

Energy Technology Data Exchange (ETDEWEB)

Tavares, J.G.P. [Departamento de Farmacologia, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Universidade Iguaçu, Campos V, Itaperuna, RJ (Brazil); Faculdade de Minas, Muriaé, MG (Brazil); Vasques, E.R. [Departamento de Gastroenterologia, LIM 37, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Arida, R.M. [Departamento de Fisiologia, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Cavalheiro, E.A. [Departamento de Neurologia e Neurocirurgia, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Cabral, F.R.; Torres, L.B. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Menezes-Rodrigues, F.S.; Jurkiewicz, A.; Caricati-Neto, A. [Departamento de Farmacologia, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Godoy, C.M.G. [Departamento de Ciência e Tecnologia, Universidade Federal de São Paulo, São José dos Campos, SP (Brazil); Gomes da Silva, S. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Núcleo de Pesquisas Tecnológicas, Programa Integrado em Engenharia Biomédica, Universidade de Mogi das Cruzes, Mogi das Cruzes, SP (Brazil)

2015-01-13

The present study evaluated electrocardiographic alterations in rats with epilepsy submitted to an acute myocardial infarction (AMI) model induced by cardiac ischemia and reperfusion. Rats were randomly divided into two groups: control (n=12) and epilepsy (n=14). It was found that rats with epilepsy presented a significant reduction in atrioventricular block incidence following the ischemia and reperfusion procedure. In addition, significant alterations were observed in electrocardiogram intervals during the stabilization, ischemia, and reperfusion periods of rats with epilepsy compared to control rats. It was noted that rats with epilepsy presented a significant increase in the QRS interval during the stabilization period in relation to control rats (P<0.01). During the ischemia period, there was an increase in the QRS interval (P<0.05) and a reduction in the P wave and QT intervals (P<0.05 for both) in rats with epilepsy compared to control rats. During the reperfusion period, a significant reduction in the QT interval (P<0.01) was verified in the epilepsy group in relation to the control group. Our results indicate that rats submitted to an epilepsy model induced by pilocarpine presented electrical conductivity alterations of cardiac tissue, mainly during an AMI episode.

Epilepsy-induced electrocardiographic alterations following cardiac ischemia and reperfusion in rats

International Nuclear Information System (INIS)

Tavares, J.G.P.; Vasques, E.R.; Arida, R.M.; Cavalheiro, E.A.; Cabral, F.R.; Torres, L.B.; Menezes-Rodrigues, F.S.; Jurkiewicz, A.; Caricati-Neto, A.; Godoy, C.M.G.; Gomes da Silva, S.

2015-01-01

The present study evaluated electrocardiographic alterations in rats with epilepsy submitted to an acute myocardial infarction (AMI) model induced by cardiac ischemia and reperfusion. Rats were randomly divided into two groups: control (n=12) and epilepsy (n=14). It was found that rats with epilepsy presented a significant reduction in atrioventricular block incidence following the ischemia and reperfusion procedure. In addition, significant alterations were observed in electrocardiogram intervals during the stabilization, ischemia, and reperfusion periods of rats with epilepsy compared to control rats. It was noted that rats with epilepsy presented a significant increase in the QRS interval during the stabilization period in relation to control rats (P<0.01). During the ischemia period, there was an increase in the QRS interval (P<0.05) and a reduction in the P wave and QT intervals (P<0.05 for both) in rats with epilepsy compared to control rats. During the reperfusion period, a significant reduction in the QT interval (P<0.01) was verified in the epilepsy group in relation to the control group. Our results indicate that rats submitted to an epilepsy model induced by pilocarpine presented electrical conductivity alterations of cardiac tissue, mainly during an AMI episode

Relationship between coronary contrast-flow quantitative flow ratio and myocardial ischemia assessed by SPECT MPI

Energy Technology Data Exchange (ETDEWEB)

Smit, Jeff M.; Rosendael, Alexander R. van; Jukema, J.W.; Delgado, Victoria; Bax, Jeroen J.; Scholte, Arthur J. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Koning, Gerhard [Medis Medical Imaging Systems B.V., Leiden (Netherlands); Dibbets-Schneider, Petra [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands); Mertens, Bart J. [Leiden University Medical Center, Department of Medical Statistics, Leiden (Netherlands); Reiber, Johan H.C. [Medis Medical Imaging Systems B.V., Leiden (Netherlands); Leiden University Medical Center, Department of Radiology, Leiden (Netherlands)

2017-10-15

A new method has been developed to calculate fractional flow reserve (FFR) from invasive coronary angiography, the so-called ''contrast-flow quantitative flow ratio (cQFR)''. Recently, cQFR was compared to invasive FFR in intermediate coronary lesions showing an overall diagnostic accuracy of 85%. The purpose of this study was to investigate the relationship between cQFR and myocardial ischemia assessed by single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI). Patients who underwent SPECT MPI and coronary angiography within 3 months were included. The cQFR computation was performed offline, using dedicated software. The cQFR computation was based on 3-dimensional quantitative coronary angiography (QCA) and computational fluid dynamics. The standard 17-segment model was used to determine the vascular territories. Myocardial ischemia was defined as a summed difference score ≥2 in a vascular territory. A cQFR of ≤0.80 was considered abnormal. Two hundred and twenty-four coronary arteries were analysed in 85 patients. Overall accuracy of cQFR to detect ischemia on SPECT MPI was 90%. In multivariable analysis, cQFR was independently associated with ischemia on SPECT MPI (OR per 0.01 decrease of cQFR: 1.10; 95% CI 1.04-1.18, p = 0.002), whereas clinical and QCA parameters were not. Furthermore, cQFR showed incremental value for the detection of ischemia compared to clinical and QCA parameters (global chi square 48.7 to 62.6; p <0.001). A good relationship between cQFR and SPECT MPI was found. cQFR was independently associated with ischemia on SPECT MPI and showed incremental value to detect ischemia compared to clinical and QCA parameters. (orig.)

The white-coat effect is an independent predictor of myocardial ischemia in resistant hypertension.

Science.gov (United States)

Modolo, Rodrigo; Ruggeri Barbaro, Natália; de Faria, Ana Paula; Rodrigues Sabbatini, Andréa; Paganelli, Maria Ondina; Fontana, Vanessa; Moreno, Heitor

2014-10-01

White-coat hypertension (WCH), commonly found in pseudoresistant hypertension, does not pose higher cardiovascular risk than hypertensive status. However, when the decrease of the out-of-office blood pressure does not reach normal levels - the white-coat effect (WCE) - the repercussions are still obscure. We investigated the repercussions of the WCE in myocardial perfusion in resistant hypertension (RHTN). We enrolled 129 asymptomatic RHTN subjects - divided into WCE (n = 63) and non-WCE (n = 66) - to perform rest and stress myocardial perfusion scintigraphy and biochemical tests. Groups were equal regarding age, gender and body mass index. There was a high prevalence of WCE (49%). WCE was associated with higher prevalence of myocardial ischemia (49.2% vs 7.6%, p < 0.001), microalbuminuria (60.3% vs 36.4%, p = 0.01) and higher heart rate (72 [64-80] vs 64 [60-69], p < 0.001), compared with non-WCE patients. On an adjusted logistic regression, heart rate was considered a predictor of WCE (OR = 1.10, 95% CI 1.04-1.15; p < 0.001), but not MA (OR = 1.8, 95% CI 0.8-3.9; p = 0.15). On a second model of adjusted logistic regression, WCE was an independent predictor of myocardial ischemia (OR = 14.7, 95% CI 4.8-44.8; p < 0.001). We found a high prevalence of WCE in RHTN, and this effect may predict silent myocardial ischemia in this subset of hypertensive patients. In this group of hypertensives special attention should be given to the WCE.

Detection of viable myocardium in canine model with myocardial ischemia and ischemia-reperfusion by 125I-BMIPP: relation to regional blood flow

International Nuclear Information System (INIS)

Huang Gang; Zhao Huiyang; Shen Xuedong; Li Qing; Yuan Jimin; Zhu Cuiying

1999-01-01

Objective: The effects of BMIPP (β-methyl-iodophenyl pentadecanoic acid) on detecting viable myocardium and the relation between regional blood flow and the uptake of BMIPP were evaluated in canine model of myocardial ischemia and ischemia-reperfusion. Methods: 12 open-chest dogs under anesthesia were divided into two groups. Group I (ischemia group) had left circumflex coronary arterial occlusion for 2 h and group II (ischemia-reperfusion group) was occluded for 1 h and followed by 2 h reperfusion. Myocardial blood flow was measured with 99 Tc m -microspheres. 30 min after intravenous injection of 125 I-BMIPP and 99 Tc m -microspheres, the heart was excised rapidly and stained with Evans blue and NBT. Tissue samples (divided into approximately 1 g) of left ventricle were obtained, weighed and counted for 125 I and 99 Tc m . Regional blood flow and the uptake of BMIPP were expressed as percentages of average values in non-ischemic myocardium (two to three tissue samples) from the normal myocardium. Results: In ischemic myocardium (NBT positive samples), the uptake of BMIPP was relatively higher compared with regional blood flow [(67 +- 23)% vs (42 +- 19)%, P 0.05]. In ischemia-reperfusion group, regional blood flow was increased in ischemic and necrotic tissues, but the uptake of BMIPP was not enhanced with the increasing blood flow. Conclusions: BMIPP uptake seems to provide metabolic information independent of regional blood flow. The mismatching between regional blood flow and BMIPP uptake may indicate myocardial viability in the regions of hypoperfusion and the uptake of BMIPP in ischemic myocardium was related to existence of cellular metabolism

Pharmacological radionuclide ventriculography for detection of myocardial contractile reserve in patients after myocardial infarction: head-to-head comparison of low dose dobutamine and low dose dypiridamole

International Nuclear Information System (INIS)

Petrasinovic, Z.; Ostojic, M.; Beleslin, B.; Stojkovic, S.; Nedeljkovic, M.; Stankovic, G.; Dikic, A.; Pavlovic, S.; Sobic, D.

2002-01-01

Background. Low dose pharmacological stress echocardiography with either dobutamine or dipyridamole infusion has been proposed for recognition of myocardial viability. However, dependence on adequate acoustic window, observer experience, and the mild degree of wall motion changes make the viability assessment by stress echocardiography especially bothersome. The objective of the study was to evaluate the ability of low dose dobutamine and low dose dipyridamole radionuclide ventriculography to detect contractile reserve in patients after myocardial infarction and functional recovery after coronary angioplasty. Methods. The study group consisted of 20 consecutive patients (52±10 years, 17 male) with previous myocardial infarction and resting regional dyssynergy, in whom diagnostic cardiac catheterization revealed significant one-vessel coronary artery stenosis suitable for angioplasty. Each patient underwent equilibrium 99m-Tc radionuclide ventriculography which was performed at rest and during low dose dipyridamole (0.28 mg/kg over 2 minutes) and low dose dobutamine infusion (up to 10 mcg/kg/min). Left ventricular global and regional ejection fractions were determined. Increase of regional ejection fraction for >5% (inferoapical and posterolateral regions) or >10% (anteroseptal regions) during low dose dobutamine and dipyridamole in infarcted regions, as well as in the follow up period, was considered as index of contractile reserve. After 8 weeks of successful angioplasty, resting radionuclide ventriculography was repeated in all patients in order to identify functional recovery of the infarct zone. Results. Out of the 180 analyzed segments (20x9), 90 regional ejection fractions have shown depressed contractility. The mean of the regional ejection fractions showing depressed contractility increased from the resting value of 34±12% to 42±14% in the follow-up period (p=0.06). Of the 90 with baseline dyssynergy, 46 were responders during low-dose dobutamine (51

Patients with stable chronic obstructive pulmonary disease can safely undergo intravenous dipyridamole thallium-201 imaging.

Science.gov (United States)

Shaffer, J; Simbartl, L; Render, M L; Snow, E; Chaney, C; Nishiyama, H; Rauf, G C; Wexler, L F

1998-08-01

Patients with chronic obstructive pulmonary disease are usually excluded from intravenous dipyridamole thallium-201 testing. We developed a nurse-administered protocol to screen and pretreat patients so they could be safely tested. We prospectively screened patients referred for intravenous dipyridamole thallium testing and retrospectively reviewed a comparison group of patients who had undergone intravenous dipyridamole testing before our bronchospasm protocol. We studied 492 consecutive patients referred for intravenous dipyridamole thallium testing, separating those with complete data (n = 451) into two groups: group A (n = 72), patients assessed to be at risk for intravenous dipyridamole-induced bronchospasm who received our bronchospasm treatment protocol; and group B (n = 379), patients assessed to be free of risk, who did not receive our bronchospasm protocol. Group C (n = 89) was a retrospective comparison group of patients who had undergone intravenous dipyridamole testing before initiation of the protocol. Patients were considered at risk for an adverse event if any of the following were present: peak flow 400 ml after bronchodilator treatment, wheezing audible with stethoscope, history of chronic obstructive pulmonary disease or asthma or dyspnea on exertion at less than four blocks, or resting respiratory rate >18 breaths/min. The test was considered contraindicated if resting oxygen saturation was respiratory rate stethoscope but without marked respiratory distress), (2) marked events (severe bronchospasm or severe ischemia defined as wheezing audible with or without stethoscope, respiratory rate >20 breaths/min or increased by 10 from pretest evaluation, oxygen desaturation to respiratory rate with decreased mental status], respiratory arrest, chest pain, horizontal ST-segment depression > or =1 mm on the electrocardiogram in any lead, symptomatic hypotension), or (3) other intravenous dipyridamole-induced side effects (persistent headache, dizziness

Myocardial energy metabolism during global ischemia and reperfusion in SHR hypertrophic rat heart assessed by 31P-NMR

International Nuclear Information System (INIS)

Shirotani, Hitoshi; Oka, Hiroshi; Katayama, Osamu; Nishioka, Takazumi; Oku, Hidetaka

1983-01-01

An experiment regarding myocardial ischemia and reperfusion was performed under various conditions in SHR hypertrophic and WKY non-hypertrophic rat hearts. An effect of cardioplegia was evaluated in the following 4 conditions, that is, Group 1: hypothermia only, Group 2: hypothermia with intermittent infusion of GIK solution, Group 3: hypothermia with intermittent infusion of cold blood cardioplegia, Group 4: hypothermia with intermittent infusion of cold blood cardioplegia and administration of coenzyme Q 10 prior to isolation of the heart. 1) In WKY heart, ATP contents after 90 minutes myocardial ischemia at 15 0 C decreased to 25% in Group 1,42% in Group 2,52% in Group 3 and 62% in Group 4, and the contents after 30 minutes reperfusion increased to 42, 50, 60 and 75%, respectively. On the other hand, in SHR heart, ATP contents decreased to 22, 38, 40 and 41% but no trend of recovery was present. 2) Creatine phosphate content in SHR heart was 50% of that in WKY heart during isolated perfusion. Creatine phosphate decreased to zero after 30 minutes myocardial ischemia. In WKY heart, the content was recovered to over 100% by 30 minutes reperfusion after 90 minutes myocardial ischemia in all groups. On the contrary, in SHR heart, the contents increased to only 10, 15, 22 and 41%, in 4 groups, respectively. 3) In WKY heart, pH fell to 6.2, 6.7, 6.8 and 6.8, in 4 groups, respectively, a fter 90 minutes myocardial ischemia, and returned to the preischemic value of 7.2 after 30 minutes reperfusion in all groups. In SHR heart, pH fell to 6.1 in group 1, 6.3 in group 2, 6.4 in group 3 and 6.7 in group 4 after 90 minutes myocardial ischemia and the values returned to 6.5, 6.6, 6.7 and 6.8, respectively, after 30 minutes reperfusion. The latter values were lower than preischemic value of 7.0. (J.P.N.)

August rats are more resistant to arrhythmogenic effect of myocardial ischemia and reperfusion than Wistar rats.

Science.gov (United States)

Belkina, L M; Kirillina, T N; Pshennikova, M G; Arkhipenko, Yu V

2002-06-01

As differentiated from Wistar rats, myocardial ischemia and reperfusion produce no ventricular fibrillation in August rats. Pretreatment with nitric oxide synthase inhibitor Nw-nitro-L-arginine increased mortality rate in August rats with acute myocardial infarction from 20 to 40%. Under these conditions mortality rate in Wistar rats increased from 50 to 71%. Interstrain differences in the resistance of these animals to the arrhythmogenic effect of ischemia are probably associated with higher activity of the nitric oxide system in August rats compared to Wistar rats.

Noninvasive identification of significant narrowing of the left main coronary artery by dipyridamole thallium scintigraphy

International Nuclear Information System (INIS)

Chikamori, T.; Doi, Y.L.; Yonezawa, Y.; Yamada, M.; Seo, H.; Ozawa, T.

1991-01-01

To evaluate the usefulness of dipyridamole thallium scintigraphy with low-level exercise for the identification of left main (LM) coronary artery disease (CAD), 466 consecutive patients with CAD were studied. Thirty-eight patients (8%) had LM stenosis (diameter narrowing greater than or equal to 50%). The LM scintigraphic pattern was present in 9 of 38 patients with LMCAD and 38 of 428 CAD patients without LMCAD (24 vs 9%; p less than 0.005). This pattern was present in 6 of 9 patients with LMCAD without right CAD and in only 3 of 29 patients with LM and right CAD (67 vs 10%; p = 0.0005). Patients with LMCAD had a higher incidence of premature cessation of low-level exercise (53 vs 21%; p less than 0.0001), chest pain (68 vs 48%; p less than 0.02), blood pressure decrease of greater than or equal to 20 mm Hg (44 vs 16%; p less than 0.002) and greater ST depression (0.17 ± 0.13 vs 0.06 ± 0.10 mV; p less than 0.001) during dipyridamole loading than patients without LMCAD. Stepwise discriminant analysis revealed that the LM scintigraphic pattern and markers of ischemia during dipyridamole loading best identified (p less than 0.0001) patients with LMCAD without right CAD (sensitivity 67%, specificity 91%), but this predictability is no better than the LM scintigraphic pattern alone. The combination of clinical markers of ischemia during dipyridamole loading and scintigraphic findings of diffuse slow washout, extensive fixed defects and the LM pattern best identified (p less than 0.0001) patients with LM and right CAD (sensitivity 72%, specificity 80%)

Dorsal spinal cord stimulation obtunds the capacity of intrathoracic extracardiac neurons to transduce myocardial ischemia.

Science.gov (United States)

Ardell, Jeffrey L; Cardinal, René; Vermeulen, Michel; Armour, J Andrew

2009-08-01

Populations of intrathoracic extracardiac neurons transduce myocardial ischemia, thereby contributing to sympathetic control of regional cardiac indices during such pathology. Our objective was to determine whether electrical neuromodulation using spinal cord stimulation (SCS) modulates such local reflex control. In 10 anesthetized canines, middle cervical ganglion neurons were identified that transduce the ventricular milieu. Their capacity to transduce a global (rapid ventricular pacing) vs. regional (transient regional ischemia) ventricular stress was tested before and during SCS (50 Hz, 0.2 ms duration at 90% MT) applied to the dorsal aspect of the T1 to T4 spinal cord. Rapid ventricular pacing and transient myocardial ischemia both activated cardiac-related middle cervical ganglion neurons. SCS obtunded their capacity to reflexly respond to the regional ventricular ischemia, but not rapid ventricular pacing. In conclusion, spinal cord inputs to the intrathoracic extracardiac nervous system obtund the latter's capacity to transduce regional ventricular ischemia, but not global cardiac stress. Given the substantial body of literature indicating the adverse consequences of excessive adrenergic neuronal excitation on cardiac function, these data delineate the intrathoracic extracardiac nervous system as a potential target for neuromodulation therapy in minimizing such effects.

Impairment of endothelial-myocardial interaction increases the susceptibility of cardiomyocytes to ischemia/reperfusion injury.

Directory of Open Access Journals (Sweden)

Thorsten M Leucker

Full Text Available Endothelial-myocardial interactions may be critically important for ischemia/reperfusion injury. Tetrahydrobiopterin (BH4 is a required cofactor for nitric oxide (NO production by endothelial NO synthase (eNOS. Hyperglycemia (HG leads to significant increases in oxidative stress, oxidizing BH4 to enzymatically incompetent dihydrobiopterin. How alterations in endothelial BH4 content impact myocardial ischemia/reperfusion injury remains elusive. The aim of this study was to examine the effect of endothelial-myocardial interaction on ischemia/reperfusion injury, with an emphasis on the role of endothelial BH4 content. Langendorff-perfused mouse hearts were treated by triton X-100 to produce endothelial dysfunction and subsequently subjected to 30 min of ischemia followed by 2 h of reperfusion. The recovery of left ventricular systolic and diastolic function during reperfusion was impaired in triton X-100 treated hearts compared with vehicle-treated hearts. Cardiomyocytes (CMs were co-cultured with endothelial cells (ECs and subsequently subjected to 2 h of hypoxia followed by 2 h of reoxygenation. Addition of ECs to CMs at a ratio of 1∶3 significantly increased NO production and decreased lactate dehydrogenase activity compared with CMs alone. This EC-derived protection was abolished by HG. The addition of 100 µM sepiapterin (a BH4 precursor or overexpression of GTP cyclohydrolase 1 (the rate-limiting enzyme for BH4 biosynthesis in ECs by gene trasfer enhanced endothelial BH4 levels, the ratio of eNOS dimer/monomer, eNOS phosphorylation, and NO production and decreased lactate dehydrogenase activity in the presence of HG. These results demonstrate that increased BH4 content in ECs by either pharmacological or genetic approaches reduces myocardial damage during hypoxia/reoxygenation in the presence of HG. Maintaining sufficient endothelial BH4 is crucial for cardioprotection against hypoxia/reoxygenation injury.

Myocardial and Peripheral Ischemia Causes an Increase in Circulating Pregnancy-Associated Plasma Protein-A in Non-atherosclerotic, Non-heparinized Pigs.

Science.gov (United States)

Steffensen, Lasse Bach; Poulsen, Christian Bo; Shim, Jeong; Bek, Marie; Jacobsen, Kevin; Conover, Cheryl A; Bentzon, Jacob Fog; Oxvig, Claus

2015-12-01

The usefulness of circulating pregnancy-associated plasma protein-A (PAPP-A) as a biomarker for acute coronary syndrome (ACS) is widely debated. We used the pig as a model to assess PAPP-A dynamics in the setting of myocardial ischemia. Induction of myocardial ischemia by ligation of the left anterior descending (LAD) coronary artery caused a systemic rise in PAPP-A. However, the ischemic myocardium was excluded as the source of PAPP-A. Interestingly, induction of ischemia in peripheral tissues by ligation of the left femoral artery caused a systemic rise in PAPP-A originating from the left hind limb. This is the first study to demonstrate PAPP-A elevations in the absence of atherosclerosis or heparin during myocardial ischemia. Our findings thus add to the current discussion of the usefulness of PAPP-A as a biomarker for ACS.

Detecting Myocardial Ischemia With 99mTechnetium-Tetrofosmin Myocardial Perfusion Imaging in Ischemic Stroke.

Science.gov (United States)

Giannopoulos, Sotirios; Markoula, Sofia; Sioka, Chrissa; Zouroudi, Sofia; Spiliotopoulou, Maria; Naka, Katerina K; Michalis, Lampros K; Fotopoulos, Andreas; Kyritsis, Athanassios P

2017-10-01

To assess the myocardial status in patients with stroke, employing myocardial perfusion imaging (MPI) with 99m Technetium-tetrofosmin ( 99m Tc-TF)-single-photon emission computed tomography (SPECT). Fifty-two patients with ischemic stroke were subjected to 99m Tc-TF-SPECT MPI within 1 month after stroke occurrence. None of the patients had any history or symptoms of coronary artery disease or other heart disease. Myocardial perfusion imaging was evaluated visually using a 17-segment polar map. Myocardial ischemia (MIS) was defined as present when the summed stress score (SSS) was >4; MIS was defined as mild when SSS was 4 to 8, and moderate/severe with SSS ≥9. Patients with SSS >4 were compared to patients with SSS SSS >9 were compared to patients with SSS SSS, with the oldest age exhibiting the highest SSS ( P = .01). The association of age with SSS remained statistically significant in the multivariate analysis ( P = .04). The study suggested that more than half of patients with stroke without a history of cardiac disease have MIS. Although most of them have mild MIS, we suggest a thorough cardiological evaluation in this group of patients for future prevention of severe myocardial outcome.

ESPRIT: is aspirin plus dipyridamole superior to aspirin alone in TIA or minor stroke patients?

Science.gov (United States)

Rouhl, R P W; Lodder, J

2008-11-01

Transient ischemic attack (TIA) or a (minor) ischemic stroke increases the risk of a recurrent stroke or death. Antiplatelet therapy with aspirin or clopidogrel is, in the absence of a potential cardiac embolic source, common practice to lower this risk. Until recently, adjuvant dipyridamole or low intensity oral anticoagulation were not generally prescribed in secondary prevention. In this article, we will summarize and discuss the published results of the European/Australasian Stroke Prevention in Reversible Ischemia Trial (ESPRIT). In this trial, treatments with anticoagulants, aspirin alone and the combination of aspirin plus dipyridamole were compared, in a multicenter, three-armed, randomized, open-label study in patients with TIA or minor stroke.

Silent myocardial ischemia in patients with symptomatic intracranial atherosclerosis: associated factors.

Science.gov (United States)

Arenillas, Juan F; Candell-Riera, Jaume; Romero-Farina, Guillermo; Molina, Carlos A; Chacón, Pilar; Aguadé-Bruix, Santiago; Montaner, Joan; de León, Gustavo; Castell-Conesa, Joan; Alvarez-Sabín, José

2005-06-01

Optimization of coronary risk evaluation in stroke patients has been encouraged. The relationship between symptomatic intracranial atherosclerosis and occult coronary artery disease (CAD) has not been evaluated sufficiently. We aimed to investigate the prevalence of silent myocardial ischemia in patients with symptomatic intracranial atherosclerosis and to identify factors associated with its presence. From 186 first-ever transient ischemic attack or ischemic stroke patients with intracranial stenoses, 65 fulfilled selection criteria, including angiographic confirmation of a symptomatic atherosclerotic stenosis and absence of known CAD. All patients underwent a maximal-stress myocardial perfusion single-photon emission computed tomography (SPECT). Lipoprotein(a) [Lp(a)], C-reactive protein, and homocysteine (Hcy) levels were determined before SPECT. Stress-rest SPECT detected reversible myocardial perfusion defects in 34 (52%) patients. Vascular risk factors associated with a pathologic SPECT were hypercholesterolemia (P=0.045), presence of >2 risk factors (P=0.004) and high Lp(a) (P=0.023) and Hcy levels (P=0.018). Ninety percent of patients with high Lp(a) and Hcy levels had a positive SPECT. Existence of a stenosed intracranial internal carotid artery (ICA; odds ratio [OR], 7.22, 2.07 to 25.23; P=0.002) and location of the symptomatic stenosis in vertebrobasilar arteries (OR, 4.89, 1.19 to 20.12; P=0.027) were independently associated with silent myocardial ischemia after adjustment by age, sex, and risk factors. More than 50% of the patients with symptomatic intracranial atherosclerosis and not overt CAD show myocardial perfusion defects on stress-rest SPECT. Stenosed intracranial ICA, symptomatic vertebrobasilar stenosis and presence of high Lp(a) and Hcy levels may characterize the patients at a higher risk for occult CAD.

The additional value of first pass myocardial perfusion imaging during peak dose of dobutamine stress cardiac MRI for the detection of myocardial ischemia

NARCIS (Netherlands)

Lubbers, Daniel D.; Janssen, Caroline H. C.; Kuijpers, Dirkjan; Van Dijkman, Paul R. M.; Overbosch, Jelle; Willems, Tineke P.; Oudkerk, Matthijs

Purpose of this study was to assess the additional value of first pass myocardial perfusion imaging during peak dose of dobutamine stress Cardiac-MR (CMR). Dobutamine Stress CMR was performed in 115 patients with an inconclusive diagnosis of myocardial ischemia on a 1.5 T system (Magnetom Avanto,

45. Ezetimibe and statins yields on silent holter ambulatory myocardial ischemia

Directory of Open Access Journals (Sweden)

W. Kadro

2016-07-01

Full Text Available Further cholestrol lowering may affect silent ischemia detected on holter monitoring. Cholesterol lowering is associated with a reduction in cardiovascular morbidity and mortality. Statins are the main drugs for cholesterol lowering. Ezetimibe when added to statins gives further reduction in cholesterol but its long-term effect on cardiovascular morbidity and mortality and ischemic events is not known. This study sought to determine whether further cholesterol lowering with ezitimibe will also results in a reduction of myocardial ischemia during daily life. We enrolled 50 patients with proven stable coronary artery disease (CAD and at least one episode of ST-segment depression on ambulatory ECG monitoring. All of them were receiving optimal therapy for CAD including statin therapy for cholesterol reduction. 25 patients were randomized to continue their statin therapy (Statin only group and 25 to recieve statin plus ezitimibe 10 mg/day (ezitimibe group. Serum cholesterol and LDL cholesterol levels and ambulatory monitoring were repeated after 4–6 months of therapy. The two groups were comparable with respect to baseline characteristics, number of episodes of ST-segment depression, and baseline serum cholesterol levels. The ezitimibe group had lower mean total and LDL cholesterol levels at study end and experienced a significant reduction in the number of episodes of ST-segment depression compared with the statin only group. ST-segment depression was completely resolved in 13 of 25 patients (52% in the ezitimibe group versus 3 of 25 (12% in the statin only group. The ezitimibe group exhibited a highly significant reduction in ambulatory ischemia (P < .001. By logistic regression, treatment with ezitimibe was an independent predictor of ischemia resolution. Further cholesterol lowering with ezitimibe can result in reduction or resolution of myocardial ischemia recorded as episodes of ST-segment depression in ambulatory monitoring of the ECG.

Relation of N-Terminal Pro B-Type Natriuretic Peptide Levels After Symptom-Limited Exercise to Baseline and Ischemia Levels

NARCIS (Netherlands)

van der Zee, P. Marc; Verberne, Hein J.; van Spijker, Rianne C.; van Straalen, Jan P.; Fischer, Johan C.; Sturk, Augueste; van Eck-Smit, Berthe L. F.; de Winter, Robbert J.

2009-01-01

Circulating levels of B-type natriuretic peptide (BNP) and the amino-terminal portion of the prohormone (NT-proBNP) have been reported to increase immediately after myocardial ischemia. The association between extent of exercise-induced myocardial ischemia measured using myocardial perfusion

The Cardioprotective Effects of Citric Acid and L-Malic Acid on Myocardial Ischemia/Reperfusion Injury

Science.gov (United States)

Tang, Xilan; Liu, Jianxun; Dong, Wei; Li, Peng; Li, Lei; Lin, Chengren; Zheng, Yongqiu; Hou, Jincai; Li, Dan

2013-01-01

Organic acids in Chinese herbs, the long-neglected components, have been reported to possess antioxidant, anti-inflammatory, and antiplatelet aggregation activities; thus they may have potentially protective effect on ischemic heart disease. Therefore, this study aims to investigate the protective effects of two organic acids, that is, citric acid and L-malic acid, which are the main components of Fructus Choerospondiatis, on myocardial ischemia/reperfusion injury and the underlying mechanisms. In in vivo rat model of myocardial ischemia/reperfusion injury, we found that treatments with citric acid and L-malic acid significantly reduced myocardial infarct size, serum levels of TNF-α, and platelet aggregation. In vitro experiments revealed that both citric acid and L-malic acid significantly reduced LDH release, decreased apoptotic rate, downregulated the expression of cleaved caspase-3, and upregulated the expression of phosphorylated Akt in primary neonatal rat cardiomyocytes subjected to hypoxia/reoxygenation injury. These results suggest that both citric acid and L-malic acid have protective effects on myocardial ischemia/reperfusion injury; the underlying mechanism may be related to their anti-inflammatory, antiplatelet aggregation and direct cardiomyocyte protective effects. These results also demonstrate that organic acids, besides flavonoids, may also be the major active ingredient of Fructus Choerospondiatis responsible for its cardioprotective effects and should be attached great importance in the therapy of ischemic heart disease. PMID:23737849

Neural control hierarchy of the heart has not evolved to deal with myocardial ischemia.

Science.gov (United States)

Kember, G; Armour, J A; Zamir, M

2013-08-01

The consequences of myocardial ischemia are examined from the standpoint of the neural control system of the heart, a hierarchy of three neuronal centers residing in central command, intrathoracic ganglia, and intrinsic cardiac ganglia. The basis of the investigation is the premise that while this hierarchical control system has evolved to deal with "normal" physiological circumstances, its response in the event of myocardial ischemia is unpredictable because the singular circumstances of this event are as yet not part of its evolutionary repertoire. The results indicate that the harmonious relationship between the three levels of control breaks down, because of a conflict between the priorities that they have evolved to deal with. Essentially, while the main priority in central command is blood demand, the priority at the intrathoracic and cardiac levels is heart rate. As a result of this breakdown, heart rate becomes less predictable and therefore less reliable as a diagnostic guide as to the traumatic state of the heart, which it is commonly used as such following an ischemic event. On the basis of these results it is proposed that under the singular conditions of myocardial ischemia a determination of neural control indexes in addition to cardiovascular indexes has the potential of enhancing clinical outcome.

Utility of the premature cocked in SPECT of myocardial perfusion with technetium and artery-dilators. Inherent problems and analysis of local preliminary experience

International Nuclear Information System (INIS)

Gutierrez, Daniela; Massardo, Teresa; Jaimovich, Rodrigo; Anzoategui, Wilfredo; Guzman, Alfonso; Lavados, Hugo; Alliende, Isabel

2007-01-01

Using myocardial perfusion studies, severe coronary artery disease (CAD) with left ventricular dysfunction could be observed through transient cavity dilation and radiopharmaceutical lung uptake increase, described initially with stress 201 Tl. Dipyridamole (DIP) induced ischemia also can diminish systolic function. Delayed post stress left ventricular ejection fraction (FEVI) may not be able to detect this phenomena, depending on the acquisition timing. There are diverse reports and results in this issue. Goal: Evaluate the correlation between left ventricular parameters and ischemia presence in early gated DIP tomography in patients referred for CAD evaluation along to review the new protocol difficulties.Methods: From 158 patients evaluated initially, 31% presenting extra-cardiac activity were excluded due to interference with automatic edge detection. The analyzed group included 109 subjects between 33 and 91 years, mean age 64.3 ± 11.7; 52% women. Thirty of them were known CAD patients; 18 with myocardial infarction and 31 with ischemia in perfusion images. 99m Tc-Sestamibi SPECT was carried out during the 60 min post DIP infusion, using 1 day protocol. Cedars QGS QPS Programs were used to measure LVEF and left ventricular volumes. Diastolic transient ischemic dilation (TID) calculation was performed as well as lung/heart index (LHR). Results: The mean time lapse between DIP injection and acquisition was 27 min (range: 18-43 min). There was not significant difference between DIP and rest LVEF (66.55±17.33% vs 67.58±18.41%) LVEF delta was 1.03±6.72%. There was not correlation observed between measured functional parameters and presence of ischemia, infarction or known CAD. There was clear difference in left ventricular volumes in patients with and without CAD and known myocardial infarction. Conclusion: Nor association between LHR, LVEF delta or TID and ischemia was demonstrated in early post DIP SPECT acquisition using Sestamibi. In addition, significant

Cardiac function improved by sarcoplasmic reticulum Ca2+-ATPase overexpression in a heart failure model induced by chronic myocardial ischemia

Directory of Open Access Journals (Sweden)

Wei XIN

2011-04-01

Full Text Available Objective Chronic myocardial ischemia(CMI has become an important cause of heart failure(HF.The aim of present study was to examine the effects of Sarco-endoplasmic reticulum calcium ATPase(SERCA2a gene transfer in HF model in large animal induced by CMI.Methods HF was reproduced in minipigs by ligating the initial segment of proximal left anterior descending(LAD coronary artery with an ameroid constrictor to produce progressive vessel occlusion and ischemia.After confirmation of myocardial perfusion defect and cardiac function impairment by SPECT and echocardiography in the model,animals were divided into 4 groups: HF group;HF+enhanced green fluorescent protein(EGFP group;HF+SERCA2a group;and sham operation group as control.rAAV1-EGFP and rAAV1-SERCA2a(1×1012 vg for each animal were directly and intramyocardially injected to the animals of HF+EGFP and HF+SERCA2a groups.Sixty days after the gene transfer,the expression of SERCA2a at the protein level was examined by Western blotting and immunohistochemistry,the changes in cardiac function were determined by echocardiographic and hemodynamic analysis,and the changes in serum inflammatory and neuro-hormonal factors(including BNP,TNF-a,IL-6,ET-1 and Ang II were determined by radioimmunoassay.Results Sixty days after gene transfer,LVEF,Ev/Av and ±dp/dtmax increased significantly(P < 0.05,along with an increase of SERCA2a protein expression in the ischemic myocardium(PP < 0.05,accompanied by a significant decrease of inflammatory and neural-hormonal factors(PP < 0.05 in HF+SERCA2a group as compared with HF/HF+EGFP group.Conclusions Overexpression of SERCA2a may significantly improve the cardiac function of the ischemic myocardium of HF model induced by CMI and reverse the activation of neural-hormonal factors,implying that it has a potential therapeutic significance in CMI related heart failure.

Myocardial energy metabolism during global ischemia and reperfusion in SHR hypertrophic rat heart assessed by /sup 31/P-NMR

Energy Technology Data Exchange (ETDEWEB)

Shirotani, Hitoshi; Oka, Hiroshi; Katayama, Osamu; Nishioka, Takazumi; Oku, Hidetaka [Kinki Univ., Higashi-Osaka, Osaka (Japan)

1983-12-01

An experiment regarding myocardial ischemia and reperfusion was performed under various conditions in SHR hypertrophic and WKY non-hypertrophic rat hearts. An effect of cardioplegia was evaluated in the following 4 conditions, that is, Group 1: hypothermia only, Group 2: hypothermia with intermittent infusion of GIK solution, Group 3: hypothermia with intermittent infusion of cold blood cardioplegia, Group 4: hypothermia with intermittent infusion of cold blood cardioplegia and administration of coenzyme Q/sub 10/ prior to isolation of the heart. 1) In WKY heart, ATP contents after 90 minutes myocardial ischemia at 15/sup 0/ C decreased to 25% in Group 1,42% in Group 2,52% in Group 3 and 62% in Group 4, and the contents after 30 minutes reperfusion increased to 42, 50, 60 and 75%, respectively. On the other hand, in SHR heart, ATP contents decreased to 22, 38, 40 and 41% but no trend of recovery was present. 2) Creatine phosphate content in SHR heart was 50% of that in WKY heart during isolated perfusion. Creatine phosphate decreased to zero after 30 minutes myocardial ischemia. In WKY heart, the content was recovered to over 100% by 30 minutes reperfusion after 90 minutes myocardial ischemia in all groups. On the contrary, in SHR heart, the contents increased to only 10, 15, 22 and 41%, in 4 groups, respectively. 3) In WKY heart, pH fell to 6.2, 6.7, 6.8 and 6.8, in 4 groups, respectively, a fter 90 minutes myocardial ischemia, and returned to the preischemic value of 7.2 after 30 minutes reperfusion in all groups. In SHR heart, pH fell to 6.1 in group 1, 6.3 in group 2, 6.4 in group 3 and 6.7 in group 4 after 90 minutes myocardial ischemia and the values returned to 6.5, 6.6, 6.7 and 6.8, respectively, after 30 minutes reperfusion. The latter values were lower than preischemic value of 7.0.

The Effect of PM 10 on Ischemia- Reperfusion Induced Arrhythmias in Rats

Directory of Open Access Journals (Sweden)

Esmat Radmanesh

Full Text Available ABSTRACT Epidemiological studies show that particulate matter (PM is the principal instigator of some adverse clinical symptoms involving cardiovascular diseases. PM exposure can increase experimental infarct size and potentiate myocardial ischemia and arrhythmias in experimental MI models such as ischemia-reperfusion (I/R injury.The present study was aimed to evaluate the effects of particulate matter (PM10 on ischemia- reperfusion induced arrhythmias with emphasis on the protective role of VA as an antioxidant on them. Male Wistar rats were divided into 8 groups (n=10: Control, VAc, Sham, VA, PM1 (0.5 mg/kg, PM2 (2.5 mg/kg, PM3 group (5 mg/kg, PM3 + VA group. Within 48 hours, PM10 was instilled into trachea in two stages. Then the hearts were isolated, transferred to a Langendorff apparatus, and subjected to global ischemia (30 minutes followed by reperfusion (60 minutes. The ischemia- reperfusion induced ventricular arrhythmias were assessed according to the Lambeth conventions.In the present study,the number, incidence and duration of arrhythmiasduring30 minutes ischemia were demonstrated to be more than those in the reperfusion stage. PM exposure increased significantly the number, incidence and duration of arrhythmias in the ischemia and reperfusion duration. Vanillic acid reduced significantly the number, incidence and duration of arrhythmias during the ischemia and reperfusion period.In summary, the results of this study demonstrated that the protective and dysrhythmic effects of VA in the PM exposure rats in I/R model are probably related to its antioxidant properties.

[Silent myocardial ischemia in patients with transient ischemic attacks].

Science.gov (United States)

Sánchez Valiente, S; Mostacero, E; del Río, A; Morales, F

1994-10-01

Given evidence that ischemic heart disease is the most frequent cause of death in patients with cerebrovascular disease, we used ergometrics to screen 80 patients with TIA for silent myocardial ischemia (SMI) at the neurological unit of Hospital Clínico Universitario in Zaragoza, Spain. The patients were compared with a control group of 80 with no signs of heart disease. Neither the patients nor the controls had ever shown clinical signs of coronary ischemia and their baseline electrocardiograms were normal. Stress test results were positive in 25 (31%) of the TIA patients, and in 4 (5%) (p Hiperlipidemia (75% testing positive versus 43% negative, p < 0.01) and diabetes (31% testing positive versus 13% negative, p < 0.01) were the risk factors statistically related with a positive stress test.

Cardioprotective Effect of Aloe vera Biomacromolecules Conjugated with Selenium Trace Element on Myocardial Ischemia-Reperfusion Injury in Rats.

Science.gov (United States)

Yang, Yang; Yang, Ming; Ai, Fen; Huang, Congxin

2017-06-01

The present study was undertaken to evaluate the cardioprotection potential and underlying molecular mechanism afforded by a selenium (Se) polysaccharide (Se-AVP) from Aloe vera in the ischemia-reperfusion (I/R) model of rats in vivo. Myocardial I/R injury was induced by occluding the left anterior descending coronary artery (LAD) for 30 min followed by 2-h continuous reperfusion. Pretreatment with Se-AVP (100, 200, and 400 mg/kg) attenuated myocardial damage, as evidenced by reduction of the infarct sizes, increase in serum and myocardial endogenous antioxidants (superoxide dismutase (SOD), glutathione peroxidase (GSH), and catalase (CAT)), and decrease in the malondialdehyde (MDA) level in the rats suffering I/R injury. This cardioprotective activity afforded by Se-AVP is further supported by the decreased levels of cardiac marker enzymes creatine kinase (CK) and lactate dehydrogenase (LDH), as well as the rise of myocardial Na + -K + -ATPase and Ca 2+ -Mg 2+ -ATPase activities in I/R rats. Additionally, cardiomyocytic apoptosis was measured by terminal-deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) staining and the result showed that the percent of TUNEL-positive cells in myocardium of Se-AVP-treated groups was lower than I/R rats. In conclusion, we clearly demonstrated that Se-AVP had a protective effect against myocardial I/R injury in rats by augmenting endogenous antioxidants and protecting rat hearts from oxidative stress-induced myocardial apoptosis.

Clinical evaluation of adenosine and exercise stress 99Tcm-MIBI myocardial imaging in detection of myocardial ischemia in patients with untypical chest pain

International Nuclear Information System (INIS)

Tian Yueqin; He Zuoxiang; Wang Qi; Hu Fenghuan; Yang Weixian; Qiao Shubing; Liu Xiujie

2005-01-01

Objective: To evaluate the value of adenosine and exercise stress 99 Tc m -methoxyisobutylisonitrile (MIBI) myocardial imaging for the diagnosis of myocardial ischemia in patients with untypical chest pain. Methods: Two groups included. Group 1: 67 cases of adenosine 99 Tc m -MIBI myocardial imaging. Group 2: 81 cases of exercise stress 99 Tc m -MIBI myocardial imaging. All of the patients had coronary angiography (CAG). The results of them were compared. Results: 23 out of 67 patients in group 1 had significant coronary stenosis after CAG, 16 showed reversible perfusion abnormalities in adenosine imaging. 41 of 44 patients with normal CAG showed normal adenosine imaging. The sensitivity, specificity and accuracy of adenosine imaging for coronary artery disease detection were 70%, 93% and 85%, respectively. Group 2: 22 out of 31 patients with significant coronany stenosis after CAG showed reversible perfusion abnormalities, 48 of 50 patients with normal CAG showed normal exercise imaging. The sensitivity, specificity and accuracy of exercise imaging for coronary artery disease detection were 71%, 96% and 86%, respectively. Conclusion: Reversible perfusion abnormalities found both in adenosine and exercise stress 99 Tc m -MIBI myocardial imaging were the key point for diagnosis of myocardial ischemia in patients with untypical chest pain. (authors)

Cardiovascular risk evaluation and prevalence of silent myocardial ischemia in subjects with asymptomatic carotid artery disease

Directory of Open Access Journals (Sweden)

Ciccone M

2011-03-01

Full Text Available Marco Matteo Ciccone1, Artor Niccoli-Asabella2, Pietro Scicchitano1, Michele Gesualdo1, Antonio Notaristefano2, Domenico Chieppa1, Santa Carbonara1, Gabriella Ricci1, Marco Sassara1, Corinna Altini2, Giovanni Quistelli1, Mario Erminio Lepera1, Stefano Favale1, Giuseppe Rubini21Cardiovascular Diseases Section, Department of Emergency and Organ Transplantation (DETO, 2Nuclear Medicine Unit, Department of Internal Medicine and of Public Medicine, University of Bari, Bari, ItalyIntroduction: Silent ischemia is an asymptomatic form of myocardial ischemia, not associated with angina or anginal equivalent symptoms, which can be demonstrated by changes in ECG, left ventricular function, myocardial perfusion, and metabolism. The aim of this study was to evaluate the prevalence of silent myocardial ischemia in a group of patients with asymptomatic carotid stenosis.Methods: A total of 37 patients with asymptomatic carotid plaques, without chest pain or dyspnea, was investigated. These patients were studied for age, sex, hypertension, diabetes, dyslipidemia, smoking, and family history of cardiac disease, and underwent technetium-99 m sestamibi myocardial stress-rest scintigraphy and echo-color Doppler examination of carotid arteries.Results: A statistically significant relationship (P = 0.023 was shown between positive responders and negative responders to scintigraphy test when both were tested for degree of stenosis. This relationship is surprising in view of the small number of patients in our sample. Individuals who had a positive scintigraphy test had a mean stenosis degree of 35% ± 7% compared with a mean of 44% ± 13% for those with a negative test. Specificity of our detection was 81%, with positive and negative predictive values of 60% and 63%, respectively.Conclusion: The present study confirms that carotid atherosclerosis is associated with coronary atherosclerosis and highlights the importance of screening for ischemic heart disease in

ECG-manifest and ECG-silent dipyridamole technetium-99m sestamibi SPET perfusion defects in patients with ischaemic heart disease

International Nuclear Information System (INIS)

Galli, M.; Marcassa, C.; Bosimini, E.; Zoccarato, O.; Comazzi, F.; Giannuzzi, P.

1997-01-01

To investigate the relationship between ECG changes and perfusion abnormalities, body surface maps were recorded during dipyridamole infusion in 55 subjects (11 normals and 44 patients with ischaemic heart disease) undergoing dipyridamole technetium-99m sestamibi single-photon emission tomography (SPET). All had a normal resting ECG. The extent and severity of the sestamibi defect were quantified. New negative areas in the isointegral maps and rest-dipyridamole map differences >2 SD from normal limits were considered abnormal. After dipyridamole in normals, neither perfusion defects nor ≥1 mm ST segment depression on 12-lead ECG nor new negative areas in isointegral maps occurred. In patients, dipyridamole induced new perfusion defects in 35 (80%) but ST segment depression in only 18 (41%, P<0.001). Of the 35 patients with perfusion defects, 17 (49%, group 1) showed ST segment depression, while the other 18 (51%, group 2) did not. Abnormal body surface maps were found in 100% of group 1 and 88% of group 2 patients (NS). In group 1, the provoked hypoperfusion was of greater extent (P=0.007) and severity (P=0.01) and the onset of map abnormalities was significantly earlier (P<0.001) than in group 2; time to map abnormalities was also significantly shorter than time to ST segment depression (P=0.01). In the 35 patients with complete scintigraphic, body map and angiographic data, the severity of reversible perfusion defect proved to be the strongest correlate of ST segment depression upon logistic regression analysis. Thus, sestamibi SPET abnormalities after dipyridamole are almost always associated with electrical changes on body surface maps, suggesting myocardial ischaemia as their cause. The much less common 12-lead ECG changes are slower to appear and reflect a more severe hypoperfusion. (orig./MG). With 5 figs., 4 tabs

Aspirin plus dipyridamole versus aspirin alone after cerebral ischaemia of arterial origin (ESPRIT): randomised controlled trial.

Science.gov (United States)

Halkes, P H A; van Gijn, J; Kappelle, L J; Koudstaal, P J; Algra, A

2006-05-20

Results of trials of aspirin and dipyridamole combined versus aspirin alone for the secondary prevention of vascular events after ischaemic stroke of presumed arterial origin are inconsistent. Our aim was to resolve this uncertainty. We did a randomised controlled trial in which we assigned patients to aspirin (30-325 mg daily) with (n=1363) or without (n=1376) dipyridamole (200 mg twice daily) within 6 months of a transient ischaemic attack or minor stroke of presumed arterial origin. Our primary outcome event was the composite of death from all vascular causes, non-fatal stroke, non-fatal myocardial infarction, or major bleeding complication, whichever happened first. Treatment was open, but auditing of outcome events was blinded. Primary analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial (number ISRCTN73824458) and with (NCT00161070). Mean follow-up was 3.5 years (SD 2.0). Median aspirin dose was 75 mg in both treatment groups (range 30-325); extended-release dipyridamole was used by 83% (n=1131) of patients on the combination regimen. Primary outcome events arose in 173 (13%) patients on aspirin and dipyridamole and in 216 (16%) on aspirin alone (hazard ratio 0.80, 95% CI 0.66-0.98; absolute risk reduction 1.0% per year, 95% CI 0.1-1.8). Addition of the ESPRIT data to the meta-analysis of previous trials resulted in an overall risk ratio for the composite of vascular death, stroke, or myocardial infarction of 0.82 (95% CI 0.74-0.91). Patients on aspirin and dipyridamole discontinued trial medication more often than those on aspirin alone (470 vs 184), mainly because of headache. The ESPRIT results, combined with the results of previous trials, provide sufficient evidence to prefer the combination regimen of aspirin plus dipyridamole over aspirin alone as antithrombotic therapy after cerebral ischaemia of arterial origin.

Protective Effect of Ischemic Postconditioning against Ischemia Reperfusion-Induced Myocardium Oxidative Injury in IR Rats

Directory of Open Access Journals (Sweden)

Jiangwei Ma

2012-03-01

Full Text Available Brief episodes of myocardial ischemia-reperfusion (IR employed during reperfusion after a prolonged ischemic insult may attenuate the total ischemia-reperfusion injury. This phenomenon has been termed ischemic postconditioning. In the present study, we studied the possible effect of ischemic postconditioning on an ischemic reperfusion (IR-induced myocardium oxidative injury in rat model. Results showed that ischemic postconditioning could improve arrhythmia cordis, reduce myocardium infarction and serum creatin kinase (CK, lactate dehydrogenase (LDH and aspartate transaminase (AST activities in IR rats. In addition, ischemic postconditioning could still decrease myocardium malondialdehyde (MDA level, and increased myocardium Na+-K+-ATPase, Ca2+-Mg2+-ATPase, superoxide dismutase (SOD, catalase (CAT, glutathione peroxidase (GSH-Px and glutathione reductase (GR activities. It can be concluded that ischemic postconditioning possesses strong protective effects against ischemia reperfusion-induced myocardium oxidative injury in IR rats.

Involvement of adenosine and standardization of aqueous extract of garlic (Allium sativum Linn.) on cardioprotective and cardiodepressant properties in ischemic preconditioning and myocardial ischemia-reperfusion induced cardiac injury

Science.gov (United States)

Sharma, Ashish Kumar; Munajjam, Arshee; Vaishnav, Bhawna; Sharma, Richa; Sharma, Ashok; Kishore, Kunal; Sharma, Akash; Sharma, Divya; Kumari, Rita; Tiwari, Ashish; Singh, Santosh Kumar; Gaur, Samir; Jatav, Vijay Singh; Srinivasan, Barthu Parthi; Agarwal, Shyam Sunder

2012-01-01

The present study investigated the effect of garlic (Allium sativum Linn.) aqueous extracts on ischemic preconditioning and ischemia-reperfusion induced cardiac injury, as well as adenosine involvement in ischemic preconditioning and garlic extract induced cardioprotection. A model of ischemia-reperfusion injury was established using Langendorff apparatus. Aqueous extract of garlic dose was standardized (0.5%, 0.4%, 0.3%, 0.2%, 0.1%, 0.07%, 0.05%, 0.03%, 0.01%), and the 0.05% dose was found to be the most effective. Higher doses (more than 0.05%) were highly toxic, causing arrhythmia and cardiodepression, whereas the lower doses were ineffective. Garlic exaggerated the cardioprotective effect of ischemic preconditioning. The cardioprotective effect of ischemic preconditioning and garlic cardioprotection was significantly attenuated by theophylline (1,000 µmol/L) and 8-SPT (10 mg/kg, i.p.) and expressed by increased myocardial infarct size, increased LDH level, and reduced nitrite and adenosine levels. These findings suggest that adenosine is involved in the pharmacological and molecular mechanism of garlic induced cardioprotection and mediated by the modulation of nitric oxide. PMID:23554727

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

Energy Technology Data Exchange (ETDEWEB)

Boettcher, M.; Czernin, J.; Sun, K. [Univ. of California, Los Angeles, CA (United States)] [and others

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.

Relevance of tissue Doppler in the quantification of stress echocardiography for the detection of myocardial ischemia in clinical practice

Directory of Open Access Journals (Sweden)

Sicari Rosa

2005-01-01

Full Text Available Abstract In the present article we review the main published data on the application of Tissue Doppler Imaging (TDI to stress echocardiography for the detection of myocardial ischemia. TDI has been applied to stress echocardiography in order to overcome the limitations of visual analysis for myocardial ischemia. The introduction of a new technology for clinical routine use should pass through the different phases of scientific assessment from feasibility studies to large multicenter studies, from efficacy to effectiveness studies. Nonetheless the pro-technology bias plays a major role in medicine and expensive and sophisticated techniques are accepted before their real usefulness and incremental value to the available ones is assessed. Apparently, TDI is not exempted by this approach : its applications are not substantiated by strong and sound results. Nonetheless, conventional stress echocardiography for myocardial ischemia detection is heavily criticized on the basis of its subjectivity. Stress echocardiography has a long lasting history and the evidence collected over 20 years positioned it as an established tool for the detection and prognostication of coronary artery disease. The quantitative assessment of myocardial ischemia remains a scientific challenge and a clinical goal but time has not come for these newer ultrasonographic techniques which should be restricted to research laboratories.

Hypoxia-inducible factor-1α upregulation in microglia following hypoxia protects against ischemia-induced cerebral infarction.

Science.gov (United States)

Huang, Tao; Huang, Weiyi; Zhang, Zhiqiang; Yu, Lei; Xie, Caijun; Zhu, Dongan; Peng, Zizhuang; Chen, Jiehan

2014-10-01

Activated microglia were considered to be the toxic inflammatory mediators that induce neuron degeneration after brain ischemia. Hypoxia can enhance the expression of hypoxia-inducible factor-1α (HIF-1α) in microglia and cause microglial activation. However, intermittent hypoxia has been reported recently to be capable of protecting the body from myocardial ischemia. We established a high-altitude environment as the hypoxic condition in this study. The hypoxic condition displayed a neuroprotective effect after brain ischemia, and mice exposed to this condition presented better neurological performance and smaller infarct size. At the same time, a high level of HIF-1α, low level of isoform of nitric oxide synthase, and a reduction in microglial activation were also seen in ischemic focus of hypoxic mice. However, this neuroprotective effect could be blocked by 2-methoxyestradiol, the HIF-1α inhibitor. Our finding suggested that HIF-1α expression was involved in microglial activation in vitro and was regulated by oxygen supply. The microglia were inactivated by re-exposure to hypoxia, which might be due to overexpression of HIF-1α. These results indicated that hypoxic conditions can be exploited to achieve maximum neuroprotection after brain ischemia. This mechanism possibly lies in microglial inactivation through regulation of the expression of HIF-1α.

Depolarization changes during acute myocardial ischemia by evaluation of QRS slopes: standard lead and vectorial approach.

Science.gov (United States)

Romero, Daniel; Ringborn, Michael; Laguna, Pablo; Pahlm, Olle; Pueyo, Esther

2011-01-01

Diagnosis and risk stratification of patients with acute coronary syndromes can be improved by adding information from the depolarization phase (QRS complex) to the conventionally used ST-T segment changes. In this study, ischemia-induced changes in the main three slopes of the QRS complex, upward ( ℑ(US)) and downward ( ℑ(DS) ) slopes of the R wave as well as the upward ( ℑ(TS)) slope of the terminal S wave, were evaluated as to represent a robust measure of pathological changes within the depolarization phase. From ECG recordings both in a resting state (control recordings) and during percutaneous coronary intervention (PCI)-induced transmural ischemia, we developed a method for quantification of ℑ(US), ℑ(DS), and ℑ(TS) that incorporates dynamic ECG normalization so as to improve the sensitivity in the detection of ischemia-induced changes. The same method was also applied on leads obtained by projection of QRS loops onto their dominant directions. We show that ℑ(US), ℑ(DS), and ℑ(TS) present high stability in the resting state, thus providing a stable reference for ischemia characterization. Maximum relative factors of change ( ℜ(ℑ)) during PCI were found in leads derived from the QRS loop, reaching 10.5 and 13.7 times their normal variations in the control for ℑ(US) and ℑ(DS), respectively. For standard leads, the relative factors of change were 6.01 and 9.31. The ℑ(TS) index presented a similar behavior to that of ℑ(DS). The timing for the occurrence of significant changes in ℑ(US) and ℑ(DS) varied with lead, ranging from 30 s to 2 min after initiation of coronary occlusion. In the present ischemia model, relative ℑ(DS) changes were smaller than ST changes in most leads, however with only modest correlation between the two indices, suggesting they present different information about the ischemic process. We conclude that QRS slopes offer a robust tool for evaluating depolarization changes during myocardial ischemia.

Assessment of Myocardial Ischemia in Obese Individuals Undergoing Physical Stress Echocardiography (PSE

Directory of Open Access Journals (Sweden)

Mara Graziele Maciel Silveira

2015-05-01

Full Text Available Background: Physical stress echocardiography is an established methodology for diagnosis and risk stratification of coronary artery disease in patients with physical capacity. In obese (body mass index ≥ 30 kg/m2 the usefulness of pharmacological stress echocardiography has been demonstrated; however, has not been reported the use of physical stress echocardiography in this growing population group. Objective: To assess the frequency of myocardial ischemia in obese and non-obese patients undergoing physical stress echocardiography and compare their clinical and echocardiographic differences. Methods: 4,050 patients who underwent treadmill physical stress echocardiography were studied according to the Bruce protocol, divided into two groups: obese (n = 945; 23.3% and non-obese (n = 3,105; 76.6%. Results: There was no difference regarding gender. Obese patients were younger (55.4 ± 10.9 vs. 57.56 ± 11.67 and had a higher frequency of hypertension (75.2% vs. 57, 2%; p < 0.0001, diabetis mellitus (15.2% vs. 10.9%; p < 0.0001, dyslipidemia (59.5% vs 51.9%; p < 0.0001, family history of coronary artery disease (59.3% vs. 55.1%; p = 0.023 and physical inactivity (71.4% vs. 52.9%, p < 0.0001. The obese had greater aortic dimensions (3.27 vs. 3.14 cm; p < 0.0001, left atrium (3.97 vs. 3.72 cm; p < 0.0001 and the relative thickness of the ventricule (33.7 vs. 32.8 cm; p < 0.0001. Regarding the presence of myocardial ischemia, there was no difference between groups (19% vs. 17.9%; p = 0.41. In adjusted logistic regression, the presence of myocardial ischemia remained independently associated with age, female gender, diabetes and hypertension. Conclusion: Obesity did not behave as a predictor of the presence of ischemia and the physical stress echocardiography. The application of this assessment tool in large scale sample demonstrates the feasibility of the methodology, also in obese.

Concordance between myocardial perfusion scan assessed by SPECT and fractional flow reserve findings for detection of significant ischemia

Directory of Open Access Journals (Sweden)

Morteza Safi

2016-09-01

Conclusion: FFR and MPI with SPECT techniques showed significant concordance for detection of myocardial ischemia, regardless of the type of diseased coronary arteries. In this context, SPECT has high sensitivity and NPV for detection of ischemia compared with FFR.

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

International Nuclear Information System (INIS)

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

1987-01-01

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

NMR studies of myocardial energy metabolism and ionic homeostasis during ischemia and reperfusion

International Nuclear Information System (INIS)

Kirkels, J.H.

1989-01-01

In this study several aspects of myocardial energy metabolism and ionic homeostasis during ischemia and reperfusion were investigated in isolated perfused rat hearts, regionally ischemic rabbit hearts, and ex vivo human donor hearts during long term hypothermic cardioplegia. Phosphorus-31 nuclear magnetic resonance ( 31 P NMR) spectroscopy was used as a powerful tool to non-destructively follow the time course in changes in intracellular high-energy phosphates, (creatine phosphate and ATP), inorganic phosphate, and pH. In addition, changes in intracellular free magnesium were followed during ischemia and reperfusion. Sodium-23 ( 23 Na) NMR spectroscopy was used to study intracellular sodium during ischemia and reperfusion and during calcium-free perfusion. (author). 495 refs.; 33 figs.; 11 tabs

Withholding or Continuing Beta-Blocker Treatment Before Dipyridamole Myocardial Perfusion Imaging for the Diagnosis of Coronary Artery Disease? a Randomized Clinical Trial

Directory of Open Access Journals (Sweden)

Babak Fallahi

2013-01-01

Full Text Available Although it has been shown that acute beta-blocker administration may reduce the presence or severity of myocardial perfusion defects with dipyridamole stress, little information is available about the potential effect of chronic beta-blocker treatment on the sensitivity of dipyridamole myocardial perfusion imaging (DMPI.Methods As a randomized clinical trial, one hundred twenty patients (103 male and 17 female with angiographically confirmed CAD who were on long-term beta blocker therapy ([greater than or equal to]3 months enrolled in a randomized clinical trial study. The patients were allocated into two groups: Group A (n=60 in whom the beta-blocker agent was discontinued for 72h before DMPI and Group B (n=60 without discontinuation of beta-blockers prior to DMPI.ResultsNo significant difference was noted between the groups concerning age, sex, type of the injected radiotracer and number of involved coronary vessels. The mean rank of total perfusion scores for whole myocardium (irrespective of reversibility or irreversibility in group B was not significantly different from that of group A, (65.75 vs. 55.25, P=0.096. Regarding the only irreversible perfusion defects, the mean rank of perfusion score in group B was higher than that of group A for whole myocardium (72 vs. 49, P=0.0001; however, no difference was noted between two groups for only reversible perfusion defects (61.0 vs. 60.0, P=0.898. The overall sensitivity of DMPI for the diagnosis of CAD in group A (91.7% was not statistically different from group B (90%.ConclusionBeta-blocker withholding before DMPI did not generally affect the sensitivity of the test for the diagnostic purposes in our study. Thus, beta-blocker withdrawal for just the purpose of diagnostic imaging is not mandatory particularly when medication discontinuation may cause the patients to face increased risk of heart events.

Is there any cardioprotective role of Taurine during cold ischemic period following global myocardial ischemia?

Directory of Open Access Journals (Sweden)

Gamsizkan Mehmet

2011-03-01

Full Text Available Abstract Background The aim of the present study was to investigate the cardioprotective effect of Taurine on the donor hearts during cold ischemic period. Methods 32 rats were divided into four groups (sham, taurine, ischemia, treatment group, 8 rats in each. All rats were fed with rat food for three weeks. Taurine and treatment groups were given a 200 mg/kg/day dose of Taurine by oral gavage besides rat feed. Cardiectomy was performed in all rats after three weeks. In ischemia and treatment groups, harvested hearts were kept in 0.9% sodium chloride at +4 degrees C for 5 hours. Tissue samples were taken from left ventricle in all groups. These samples were evaluated by histopathologic and biochemical examination. Results In the present study results of the biochemical and histopathological examination reveals the protective effects of Taurine. As a marker of lipid peroxidation, Malondialdehyde (MDA levels in ischemia group were significantly higher than both Sham and Taurine groups. MDA values were recorded; 3.62 ± 0.197 in the sham group, 2.07 ± 0.751 in the Taurine group, 9.71 ± 1.439 in the ischemia group and 7.68 ± 1.365 in the treatment group. MDA levels decreased in treatment group. (p Conclusion Taurine decreased myocardial damage during cold ischemic period following global myocardial ischemia.

Current technology in assessing painless and painful ischemia

International Nuclear Information System (INIS)

Selwyn, A.P.

1990-01-01

Recent technologic advances have yielded diverse techniques for studying myocardial ischemia, a useful functional expression of coronary artery disease. These techniques have revealed new characteristics and expanded our understanding of myocardial ischemia. In turn this has led to the establishment of more realistic and discriminating criteria on which to base diagnostic and management decisions. Many of the techniques are noninvasive and can be performed in the cardiologist's office. These include treadmill exercise testing; radioisotope techniques, including ejection fraction studies, stress thallium scintigraphy, and tomographic imaging; and ambulatory monitoring. Other, newer techniques include provocative tests that induce ischemia in patients who cannot exercise. These new noninvasive tests should be used to detect transient ischemia, estimate its severity, and thus record a measure of the patient's risk for adverse coronary events

Roles of myocardial blood volume and flow in coronary artery disease: an experimental MRI study at rest and during hyperemia

International Nuclear Information System (INIS)

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

2010-01-01

To validate fast perfusion mapping techniques in a setting of coronary artery stenosis, and to further assess the relationship of absolute myocardial blood volume (MBV) and blood flow (MBF) to global myocardial oxygen demand. A group of 27 mongrel dogs were divided into 10 controls and 17 with acute coronary stenosis. On 1.5-T MRI, first-pass perfusion imaging with a bolus injection of a blood-pool contrast agent was performed to determine myocardial perfusion both at rest and during either dipyridamole-induced vasodilation or dobutamine-induced stress. Regional values of MBF and MBV were quantified by using a fast mapping technique. Color microspheres and 99m Tc-labeled red blood cells were injected to obtain respective gold standards. Microsphere-measured MBF and 99m Tc-measured MBV reference values correlated well with the MR results. Given the same changes in MBF, changes in MBV are twofold greater with dobutamine than with dipyridamole. Under dobutamine stress, MBV shows better association with total myocardial oxygen demand than MBF. Coronary stenosis progressively reduced this association in the presence of increased stenosis severity. MR first-pass perfusion can rapidly estimate regional MBF and MBV. Absolute quantification of MBV may add additional information on stenosis severity and myocardial viability compared with standard qualitative clinical evaluations of myocardial perfusion. (orig.)

Roles of myocardial blood volume and flow in coronary artery disease: an experimental MRI study at rest and during hyperemia

Science.gov (United States)

McCommis, Kyle S.; Goldstein, Thomas A.; Abendschein, Dana R.; Misselwitz, Bernd; Pilgram, Thomas; Gropler, Robert J.

2010-01-01

Objective To validate fast perfusion mapping techniques in a setting of coronary artery stenosis, and to further assess the relationship of absolute myocardial blood volume (MBV) and blood flow (MBF) to global myocardial oxygen demand. Methods A group of 27 mongrel dogs were divided into 10 controls and 17 with acute coronary stenosis. On 1.5-T MRI, first-pass perfusion imaging with a bolus injection of a blood-pool contrast agent was performed to determine myocardial perfusion both at rest and during either dipyridamole-induced vasodilation or dobutamine-induced stress. Regional values of MBF and MBV were quantified by using a fast mapping technique. Color microspheres and 99mTc-labeled red blood cells were injected to obtain respective gold standards. Results Microsphere-measured MBF and 99mTc-measured MBV reference values correlated well with the MR results. Given the same changes in MBF, changes in MBV are twofold greater with dobutamine than with dipyridamole. Under dobutamine stress, MBV shows better association with total myocardial oxygen demand than MBF. Coronary stenosis progressively reduced this association in the presence of increased stenosis severity. Conclusions MR first-pass perfusion can rapidly estimate regional MBF and MBV. Absolute quantification of MBV may add additional information on stenosis severity and myocardial viability compared with standard qualitative clinical evaluations of myocardial perfusion. PMID:20182731

Protective effect of active perfusion in porcine models of acute myocardial ischemia

Science.gov (United States)

Feng, Zanxiang; Mao, Zhifu; Dong, Shengjun; Liu, Baohui

2016-01-01

Mortality rates associated with off-pump coronary artery bypass (CAB) are relatively high, as the majority of patients requiring CAB are at a high risk for cardiac events. The present study aimed to establish porcine models of acute myocardial ischemia, and evaluate the protective role of shunt and active perfusion. A total of 30 pigs were randomly assigned to five groups, as follows: i) Sham (control); ii) A1 (shunt; stenosis rate, 55%); iii) A2 (shunt; stenosis rate, 75%); iv) B1 (active perfusion; stenosis rate, 55%); and v) B2 (active perfusion; stenosis rate, 75%) groups. Aortic pressure (P0), left anterior descending coronary pressure (P1), and coronary effective perfusion pressure (P1/P0) were measured. The expression levels of tumor necrosis factor-α (TNF-α), cardiac troponin (cTnI), creatine kinase-myocardial band (CK-MB), interleukin (IL)-6, IL-10, B-cell lymphoma 2 (Bcl-2), and caspase-3 were detected using enzyme-linked immunosorbent assay or western blotting. The myocardial apoptosis rate was determined using the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Ischemia models with stenosis rates of 55 and 75% were successfully constructed following suturing of the descending artery. Compared with the control, the 55 and 75% stenosis groups demonstrated significantly decreased P1/P0, increased expression levels of TNF-α, cTnI, CK-MB, IL-6, IL-10 and caspase-3, an increased rate of myocardial apoptosis, and a decreased expression level of anti-apoptotic protein, Bcl-2. At 30 min following successful establishment of the model (ST segment elevation to 1 mm), group B demonstrated significantly increased P1/P0, decreased expression levels of TNF-α, cTnI, CK-MB, IL-6, IL-10 and caspase-3, a decreased rate of myocardial apoptosis, and an increased expression level of anti-apoptotic protein, Bcl-2. Furthermore, the current study indicated that active perfusion was more efficacious in maintaining myocardial perfusion and alleviating

[Effect of Electroacupuncture at "Neiguan"(PC 6) on Serum and Myocardial Metabolites in Rats with Myocardial Ischemia Reperfusion Injury Based on Nuclear Magnetic Resonance Spectroscopy].

Science.gov (United States)

Tang, Ya-Ni; Tan, Cheng-Fu; Liu, Wei-Wei; Yan, Jie; Wang, Chao; Liu, Mi; Lin, Dong-Hai; Huang, Cai-Hua; Du, Lin; Chen, Mei-Lin; Li, Jiao-Lan; Zhu, Ding-Ming

2018-03-25

We have repeatedly demonstrated that electroacupuncture (EA) of "Neiguan"(PC 6) can improve myocardial ischemia in rats. The present study was designed to investigate the metabolomic profile of peripheral blood se-rum and myocardium involving EA-induced improvement of myocardial ischemia-reperfusion injury (MIRI) in rats by using nuclear magnetic resonance spectroscopy. Thirty male SD rats were equally randomized into blank control, model and EA groups. Rats of the control group were only banded for 20 min, once a day for 7 days. The MIRI model was established by occlusion of the anterior descending branch of the left coronary artery for 40 min, followed by reperfusion for 60 min, and rats of the model group were banded as those in the control group. EA (10 Hz/50 Hz, 1 mA) was applied to bilateral PC 6 for 20 min, once daily for 7 days. The blood samples and left ventricular myocardial tissues were collected for assaying the profiles of differential metabolites using 1 H nuclear magnetic resonance ( 1 H NMR) spectroscopy and multivariate statistical analysis such as the principal components analysis (PCA), partial least squares-discriminant analysis (PLS-DA) and orthogonal PLS-DA (O-PLS-DA) with SIMCA-P software 12.0. A total of 19 differential metabolites (17 down-regulated, 2 up-regulated) in the serum and 14 differential metabolites (13 down-regulated and 1 up-regulated) in the ischemic left myocardium were identified after MIRI. Of the 19 serum differential metabolites, amino acids (leucine, isoleucine, valine,alanine, lysine, glycine, glutamine), 3-hydroxy butyric acid (3-HB), lactic acid, acetate, N-acetyl glycoprotein (NAc), acetone, acetoacetate, succinate, polyunsaturated fatty acids (PUFA), creatine, glycerophosphocholine (GPC) were down-regulated; while low density lipoprotein (LDL), LDL/very low density lipoprotein(LDL/VLDL)and glucose obviously up-regulated. Of the 14 myocardial differential metabolites, amino acids (alanine, lysine, glutamate

Reduced coronary flow and resistance reserve in primary scleroderma myocardial disease

International Nuclear Information System (INIS)

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

1986-01-01

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

Ambulatory monitoring of myocardial ischemia in the 21st century-an opportunity for high frequency QRS analysis

Czech Academy of Sciences Publication Activity Database

Leinveber, Pavel; Halámek, Josef; Jurák, Pavel

2016-01-01

Roč. 49, č. 6 (2016), s. 902-906 ISSN 0022-0736 R&D Projects: GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : ambulatory monitoring * HF-QRS * myocardial Ischemia * silent Ischemia * Holter monitoring Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.514, year: 2016

Evaluation of exercise-induced myocardial stunning by means of immediate post-exercise Tc-99m sestamibi gated SPECT

International Nuclear Information System (INIS)

Ouvrier, M.J.; Hitzel, A.; Vera, P.; Manrique, A.; Bernard, M.; Manrique, A.

2009-01-01

Aim: Repeated episodes of myocardial stunning may lead to chronic ventricular dysfunction. We attempted to assess the parameters related to post-exercise stunning in patients undergoing gated SPECT. Methods: Six hundred patients undergoing a one-day stress/rest 99m Tc-sestamibi gated SPECT were studied. Stress imaging was acquired within 15 minutes after injection. Summed perfusion scores (S.S.S., S.R.S. and S.D.S.) were calculated using Q.P.S., and L.V. function assessed using Q.G.S.. Stunning was defined as the association of ischemia (S.S.S. = 4 and SDS > 0) and a minimum of 5% decrease in post-stress E.F.. Results: Ischemia was found in 225 (37.5%) patients. Among these, 67 (30%) showed myocardial stunning. Patients with stunning had a lower rest E.S.V. (47 ± 24 ml vs 65 ± 52 ml, p < 0.0003) and E.D.V. (108± 35 ml vs 122 ± 66 ml, p 0.03), an increased rest L.V.E.F. (58 ± 10% vs 52 ± 13%, p < 0.0001) and a decreased post-stress L.V.E.F. (49 ± 10% vs 53 ± 13%, p < 0.02) compared to patients with no stunning. The number of myocardial segments showing reversible perfusion defects was increased in patients with stunning (2.7 ± 2.6 vs 1.7 ± 2.1, p < 0.02). On logistic regression, an extent of ischemia greater than two segments and a rest E.F. greater than 45% were independent predictors of the occurrence of myocardial stunning in patients with ischemia. Conclusions: In patients with ischemia, exercise-induced stunning was associated with an increased extent of ischemia but also preserved rest ventricular function. (authors)

Long-term effects of invasive treatment in patients with a post-thrombolytic Q-wave myocardial infarction

DEFF Research Database (Denmark)

Kofoed, Klaus F; Madsen, Jan Kyst; Grande, Peer

2010-01-01

Abstract Objectives. The aim of the present study was to assess the effect of a deferred invasive treatment strategy on long-term outcome in patients with a post-thrombolytic Q-wave myocardial infarction and inducible myocardial ischemia. Design. Patients (N=751) with post-thrombolytic Q-wave myo......Abstract Objectives. The aim of the present study was to assess the effect of a deferred invasive treatment strategy on long-term outcome in patients with a post-thrombolytic Q-wave myocardial infarction and inducible myocardial ischemia. Design. Patients (N=751) with post-thrombolytic Q...

Dynamic myocardial perfusion in a porcine balloon-induced ischemia model using a prototype spectral detector CT

Science.gov (United States)

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

2015-03-01

Myocardial CT perfusion (CTP) imaging is an application that should greatly benefit from spectral CT through the significant reduction of beam hardening (BH) artifacts using mono-energetic (monoE) image reconstructions. We used a prototype spectral detector CT (SDCT) scanner (Philips Healthcare) and developed advanced processing tools (registration, segmentation, and deconvolution-based flow estimation) for quantitative myocardial CTP in a porcine ischemia model with different degrees of coronary occlusion using a balloon catheter. The occlusion severity was adjusted with fractional flow reserve (FFR) measurements. The SDCT scanner is a single source, dual-layer detector system, which allows simultaneous acquisitions of low and high energy projections, hence enabling accurate projection-based material decomposition and effective reduction of BH-artifacts. In addition, the SDCT scanner eliminates partial scan artifacts with fast (0.27s), full gantry rotation acquisitions. We acquired CTP data under different hemodynamic conditions and reconstructed conventional 120kVp images and projection-based monoenergetic (monoE) images for energies ranging from 55keV-to-120keV. We computed and compared myocardial blood flow (MBF) between different reconstructions. With balloon completely deflated (FFR=1), we compared the mean attenuation in a myocardial region of interest before iodine arrival and at peak iodine enhancement in the left ventricle (LV), and we found that monoE images at 70keV effectively minimized the difference in attenuation, due to BH, to less than 1 HU compared to 14 HU with conventional 120kVp images. Flow maps under baseline condition (FFR=1) were more uniform throughout the myocardial wall at 70keV, whereas with 120kVp data about 12% reduction in blood flow was noticed on BH-hypoattenuated areas compared to other myocardial regions. We compared MBF maps at different keVs under an ischemic condition (FFR < 0.7), and we found that flow

Cardiac-Specific SOCS3 Deletion Prevents In Vivo Myocardial Ischemia Reperfusion Injury through Sustained Activation of Cardioprotective Signaling Molecules.

Directory of Open Access Journals (Sweden)

Takanobu Nagata

Full Text Available Myocardial ischemia reperfusion injury (IRI adversely affects cardiac performance and the prognosis of patients with acute myocardial infarction. Although myocardial signal transducer and activator of transcription (STAT 3 is potently cardioprotective during IRI, the inhibitory mechanism responsible for its activation is largely unknown. The present study aimed to investigate the role of the myocardial suppressor of cytokine signaling (SOCS-3, an intrinsic negative feedback regulator of the Janus kinase (JAK-STAT signaling pathway, in the development of myocardial IRI. Myocardial IRI was induced in mice by ligating the left anterior descending coronary artery for 1 h, followed by different reperfusion times. One hour after reperfusion, the rapid expression of JAK-STAT-activating cytokines was observed. We precisely evaluated the phosphorylation of cardioprotective signaling molecules and the expression of SOCS3 during IRI and then induced myocardial IRI in wild-type and cardiac-specific SOCS3 knockout mice (SOCS3-CKO. The activation of STAT3, AKT, and ERK1/2 rapidly peaked and promptly decreased during IRI. This decrease correlated with the induction of SOCS3 expression up to 24 h after IRI in wild-type mice. The infarct size 24 h after reperfusion was significantly reduced in SOCS3-CKO compared with wild-type mice. In SOCS3-CKO mice, STAT3, AKT, and ERK1/2 phosphorylation was sustained, myocardial apoptosis was prevented, and the expression of anti-apoptotic Bcl-2 family member myeloid cell leukemia-1 (Mcl-1 was augmented. Cardiac-specific SOCS3 deletion led to the sustained activation of cardioprotective signaling molecules including and prevented myocardial apoptosis and injury during IRI. Our findings suggest that SOCS3 may represent a key factor that exacerbates the development of myocardial IRI.

Mechanism of the Protective Effect of Yulangsan Flavonoid on Myocardial Ischemia/Reperfusion Injury in Rats

Directory of Open Access Journals (Sweden)

Xudong Zhang

2014-09-01

Full Text Available Aims: Effect and mechanism of Yulangsan flavonoid (YLSF on rat myocardial ischemia/reperfusion injury (MI/RI has been investigated. Methods: Sprague-Dawley (SD rats were randomly divided into seven groups (sham group, model group and NS group: 2 mL of normal saline/kg body weight was administered; diltiazem group: 5 mg of diltiazem hydrochloride/kg body weight was administered; YLSFL, YLSFM and YLSFH groups: 20, 40 and 80 mg of YLSF/kg body weight was administered and the MI/RI model was established. Myocardial infarct area, levels of myocardial enzymes and nitric oxide synthase (NOS were measured. Caspase-3 and adenine nucleotide translocator-1 (ANT1 mRNA expression were evaluated by reverse transcription polymerase chain reaction (RT-PCR. Pathological structure and cardiocyte ultrastructure were also analysed. Results: Compared with the MI/RI group, pretreatment with YLSF or diltiazem hydrochloride decreased the infarct area, levels of inducible nitric oxide synthase (iNOS, caspase-3 as well as the leakage of myocardial enzyme and increased activities of total nitric oxide synthase (tNOS as well as constitutive nitric oxide synthase (cNOS. Cellular edema and the infiltration of inflammatory cells were alleviated. Conclusions: The experiment showed that YLSF protected the heart against MI/RI, possibly by reducing lipid peroxidation damage, regulating NOS activity and modulating the apoptosis genes expression.

The effect of intermittent fasting and water restriction on myocardial ischemia/reperfusion-induced arrhythmia in rats

OpenAIRE

KAYA, Salih Tunç; BOZDOĞAN, Ömer

2011-01-01

To investigate the effect of intermittent fasting and water restriction on ischemia/reperfusion-induced arrhythmias. Materials and methods: Six minutes of ischemia followed by 6 min of reperfusion was produced by the ligation and then releasing of the left coronary artery. Intermittent fasting and water restriction were applied during 1 month for 12 h/day. The duration, type, and incidence of arrhythmias during reperfusion and the survival rate at the end of reperfusion were determined and c...

The relationship between coronary artery calcification detected by non-gated multi-detector CT in patients with suspected ischemic heart disease and myocardial ischemia detected by thallium exercise stress testing

International Nuclear Information System (INIS)

Nishida, Chikako; Okajima, Kaoru; Yamamoto, Takashi; Hattori, Ryuichi; Kudo, Takashi; Nishimura, Yasumasa

2005-01-01

The objective of this study was to examine whether we could predict myocardial ischemia when coronary artery calcification is detected by non-gated multidetector CT in patients with suspected ischemic heart disease. Eighty-three patients suspected of having ischemic heart disease (55 men, 28 women; age range 36-83 years; mean age 68 years) underwent multidetector CT and Tl-201 single photon emission computed tomography. Prediction of myocardial ischemia by coronary arterial calcification detected on CT was evaluated by comparing the coronary artery territories that showed calcification with the area of myocardial ischemia determined by SPECT. The sensitivity, specificity, positive predictive value, and negative predictive value of multidetector CT for predicting myocardial ischemia were calculated. Coronary angiography was also examined and compared with multidetector CT. Risk factors, including hypertension, smoking, hyperlipidemia, diabetes, and family history, were compared for evidence of coronary artery calcification detected by multidetector CT and myocardial ischemia detected by thallium nuclear scans. For analysis by patients, the sensitivity, specificity, positive predictive value, and negative predictive value of coronary artery calcification for myocardial ischemia detection were 65, 63, 56, and 71%, respectively. Similarly, for analysis by coronary arterial territories, those values were 56, 77, 41 and 86%, respectively. Coronary stenosis on CAG was also related to the ischemia determined by SPECT and calcification on multidetector CT. Ischemia was better influenced by risk factors than was coronary arterial calcification. For analysis by coronary arterial territories, the specificity and negative predictive value of coronary arterial calcification seen by multidetector CT are relatively high. (author)

Non invasive evaluation of the coronary atherosclerosis illness in patients with silent ischemia: utility of the SPECT of myocardial perfusion. Electric, angiographic and image correlation

International Nuclear Information System (INIS)

Puente B, A.; Roffe G, F.; Aceves C, J.; Gomez A, E.

2005-01-01

The objective of the work was to determine the utility of the SPECT (Single Photon Emission Computerized Tomography) of myocardial perfusion for the ischemia detection in asymptomatic patients with Coronary Atherosclerosis Illness. It was concluded that the SPECT of myocardial perfusion has a high sensitivity (97%) for the silent ischemia diagnosis

Landiolol suppression of electrical storm of torsades de pointes in patients with congenital long-QT syndrome type 2 and myocardial ischemia

Directory of Open Access Journals (Sweden)

Ryota Kitajima, MD

2017-10-01

Full Text Available A 76-year-old man who had been diagnosed with long-QT syndrome type 2 had frequent syncopal attacks. The electrocardiogram was monitored, and frequent torsades de pointes (TdP was detected despite administration of conventional medications: oral propranolol, verapamil, intravenous magnesium sulfate, verapamil, and lidocaine. In contrast, 2 μg/kg/min landiolol could completely suppress TdP. Subsequently, an implantable cardioverter defibrillator was placed, and he was diagnosed with silent myocardial ischemia using myocardial perfusion scintigraphy and coronary angiography. This is the first case report wherein landiolol effectively suppressed TdP due to long-QT syndrome with silent myocardial ischemia.

Effect of limb ischemic preconditioning on myocardial apoptosis-related proteins in ischemia-reperfusion injury

OpenAIRE

GAO, JIANZHI; ZHAO, LINJING; WANG, YONGLING; TENG, QINGLEI; LIANG, LIDONG; ZHANG, JINYING

2013-01-01

The aim of this study was to investigate the effect of limb ischemic preconditioning (LIPC) on myocardial apoptosis in myocardial ischemia-reperfusion injury (MIRI), as well as the regulation of caspase-3 and the B cell lymphoma 2 (Bcl-2) gene in LIPC. A total of 50 rats were divided randomly into 5 groups (n=10). Four rats in each group were drawn out for detection of apoptosis. The sham, MIRI and LIPC groups underwent surgery without additional treatment. In the LY294002 group, LY294002 pre...

Nuclear Scan Strategy and Outcomes in Chest Pain Patients Value of Stress Testing with Dipyridamole or Adenosine

International Nuclear Information System (INIS)

Conti, Alberto; Mariannini, Yuri; Canuti, Erica; Petrova, Tetyana; Innocenti, Francesca; Zanobetti, Maurizio; Gallini, Chiara; Costanzo, Egidio

2014-01-01

To update the prognostic value of scan strategy with pharmacological stress agent in chest pain (CP) patients presenting with normal electrocardiography (ECG) and troponin. Two consecutive nonrandomized series of patients with CP and negative first-line workup inclusive of serial ECG, serial troponin, and echocardiography underwent myocardial perfusion imaging single photon emission computed tomography (SPECT) in the emergency department. Of 170 patients enrolled, 52 patients underwent dipyridamole-SPECT and 118 adenosine-SPECT. Patients with perfusion defects underwent angiography, whereas the remaining patients were discharged and followed-up. Primary endpoint was the composite of nonfatal myocardial infarction, unstable angina, revascularization, and cardiovascular death at follow-up or the presence of coronary stenosis > 50% at angiography. At multivariate analysis, the presence of perfusion defects or hypertension was independent predictor of the primary endpoint. Sensitivity and negative predictive value were higher in patients subjected to adenosine-SPECT (95% and 99%, respectively) versus dipyridamole-SPECT (56% and 89%; yield 70% and 11%, respectively; P < 0.03). Of note, sensitivity, negative, and positive predictive values were high in patients with hypertension (100%, 93%, and 60%, respectively) or nonischemic echocardiography alterations (100%, 100%, and 100%, respectively). In CP patients, presenting with normal ECG and troponin, adenosine-SPECT adds incremental prognostic values to dipyridamole-SPECT. Costly scan strategy is more appropriate and avoids unnecessary angiograms in patients with hypertension or nonischemic echocardiography alterations

Prevalence of Ischemia on Myocardial Perfusion Scintigraphy of Pre- and Postmenopausal Women

Energy Technology Data Exchange (ETDEWEB)

Santos, Daniel Augusto Message dos, E-mail: danielmessage@cardiol.br; Navarro, Wendy Yasdin Sierraalta; Alexandre, Leonardo Machado; Cestari, Priscila Feitosa; Smanio, Paola Emanuela Poggio [Instituto Dante Pazzanese de Cardiologia, São Paulo, SP (Brazil)

2013-12-15

In postmenopausal women, the presence of risk factors for coronary artery disease (CAD) increases. However, the difference in prevalence of ischemia between pre- and postmenopausal women with multiple risk factors for CAD has not been well established. To compare the prevalence of ischemia on Tc{sup 99m}-sestamibi myocardial perfusion scintigraphy (MPS) in pre-and postmenopausal women, and to evaluate whether menopause can be considered an independent risk predictor of ischemia in women with multiple risk factors for CAD. This study retrospectively assessed 500 MPS of pre- and postmenopausal women with multiple risk factors for CAD. Statistical analysis was performed by using Fisher exact test and univariate and multivariate analysis, a p value ≤ 0.05 being considered significant. Postmenopausal women represented 55.9% of the sample; 83.3% were hypertensive; 28.9%, diabetic; 32.1%, smokers; 25%, obese; 61.2% had high cholesterol levels; and 34.3% had known CAD. Postmenopausal women were more often hypertensive, diabetic and dyslipidemic, and had lower functional capacity on exercise testing (p = < 0.005). The presence of ischemia on MPS did not significantly differ between the pre- and postmenopausal groups (p = 0.395). The only variable associated with ischemia on MPS was known CAD (p = 0.004). The results suggest that, in women with multiple risk factors for CAD, menopause was not an independent predictor of ischemia on MPS. Those data support the idea that the investigation of ischemia via MPS in women with multiple risk factors for CAD should begin prior to menopause.

Prevalence of Ischemia on Myocardial Perfusion Scintigraphy of Pre- and Postmenopausal Women

International Nuclear Information System (INIS)

Santos, Daniel Augusto Message dos; Navarro, Wendy Yasdin Sierraalta; Alexandre, Leonardo Machado; Cestari, Priscila Feitosa; Smanio, Paola Emanuela Poggio

2013-01-01

In postmenopausal women, the presence of risk factors for coronary artery disease (CAD) increases. However, the difference in prevalence of ischemia between pre- and postmenopausal women with multiple risk factors for CAD has not been well established. To compare the prevalence of ischemia on Tc 99m -sestamibi myocardial perfusion scintigraphy (MPS) in pre-and postmenopausal women, and to evaluate whether menopause can be considered an independent risk predictor of ischemia in women with multiple risk factors for CAD. This study retrospectively assessed 500 MPS of pre- and postmenopausal women with multiple risk factors for CAD. Statistical analysis was performed by using Fisher exact test and univariate and multivariate analysis, a p value ≤ 0.05 being considered significant. Postmenopausal women represented 55.9% of the sample; 83.3% were hypertensive; 28.9%, diabetic; 32.1%, smokers; 25%, obese; 61.2% had high cholesterol levels; and 34.3% had known CAD. Postmenopausal women were more often hypertensive, diabetic and dyslipidemic, and had lower functional capacity on exercise testing (p = < 0.005). The presence of ischemia on MPS did not significantly differ between the pre- and postmenopausal groups (p = 0.395). The only variable associated with ischemia on MPS was known CAD (p = 0.004). The results suggest that, in women with multiple risk factors for CAD, menopause was not an independent predictor of ischemia on MPS. Those data support the idea that the investigation of ischemia via MPS in women with multiple risk factors for CAD should begin prior to menopause

Myocardial Ablation of G Protein-Coupled Receptor Kinase 2 (GRK2 Decreases Ischemia/Reperfusion Injury through an Anti-Intrinsic Apoptotic Pathway.

Directory of Open Access Journals (Sweden)

Qian Fan

Full Text Available Studies from our lab have shown that decreasing myocardial G protein-coupled receptor kinase 2 (GRK2 activity and expression can prevent heart failure progression after myocardial infarction. Since GRK2 appears to also act as a pro-death kinase in myocytes, we investigated the effect of cardiomyocyte-specific GRK2 ablation on the acute response to cardiac ischemia/reperfusion (I/R injury. To do this we utilized two independent lines of GRK2 knockout (KO mice where the GRK2 gene was deleted in only cardiomyocytes either constitutively at birth or in an inducible manner that occurred in adult mice prior to I/R. These GRK2 KO mice and appropriate control mice were subjected to a sham procedure or 30 min of myocardial ischemia via coronary artery ligation followed by 24 hrs reperfusion. Echocardiography and hemodynamic measurements showed significantly improved post-I/R cardiac function in both GRK2 KO lines, which correlated with smaller infarct sizes in GRK2 KO mice compared to controls. Moreover, there was significantly less TUNEL positive myocytes, less caspase-3, and -9 but not caspase-8 activities in GRK2 KO mice compared to control mice after I/R injury. Of note, we found that lowering cardiac GRK2 expression was associated with significantly lower cytosolic cytochrome C levels in both lines of GRK2 KO mice after I/R compared to corresponding control animals. Mechanistically, the anti-apoptotic effects of lowering GRK2 expression were accompanied by increased levels of Bcl-2, Bcl-xl, and increased activation of Akt after I/R injury. These findings were reproduced in vitro in cultured cardiomyocytes and GRK2 mRNA silencing. Therefore, lowering GRK2 expression in cardiomyocytes limits I/R-induced injury and improves post-ischemia recovery by decreasing myocyte apoptosis at least partially via Akt/Bcl-2 mediated mitochondrial protection and implicates mitochondrial-dependent actions, solidifying GRK2 as a pro-death kinase in the heart.

Predictors of abnormal heart rate response to dipyridamole in patients undergoing myocardial perfusion SPECT

International Nuclear Information System (INIS)

De Souza Leao Lima, R.; Machado, L.; Azevedo, A.B.; De Lorenzo, A.

2011-01-01

The objective of this study was to identify predictors of abnormal HR response to dipyridamole (DIP) in patients undergoing myocardial perfusion SPECT (MPS). Patients with a reduced heart rate (HR) response to DIP have higher cardiac mortality, but the mechanism is unknown. We studied 432 patients who underwent dual-isotope gated MPS. DIP (0.56 mg/kg) was infused over 4 min, and Tc-99m tetrofosmin was injected 3 min after the end of the infusion. MPS was semiquantitatively interpreted. Left ventricular ejection fraction (LVEF) and volumes were automatically calculated. The population was categorized into quartiles according to HR ratio, and characteristics in each quartile were compared. Logistic regression analysis was performed to identify predictors of abnormal HR response, using the lowest quartile as the independent variable. Patients with abnormal HR response were more frequently without chest pain, with a history of chronic renal failure and taking digoxin. Baseline HR was higher and had fewer symptoms during stress. The stress and rest perfusion defects were greater, but reversibility was not; in addition, LVEF was lower. Multivariable logistic regression analysis demonstrated that the independent predictors of abnormal HR response were baseline HR and low LVEF. LV dysfunction is an independent predictor of abnormal HR response to DIP, and the association between low LVEF and low HR ratio may explain the link between abnormal HR ratio and increased mortality. (author)

Evaluation of Coronary Artery Disease with Gated Blood Pool Scan Using Dipyridamole

International Nuclear Information System (INIS)

Kim, Gwang Weon; Choi, Chung Il; Chung, Byung Cheon; Lee, Jae Tae; Lee, Kyu Bo; Chae, Shung Chull; Jun, Jae Eun; Park, Wee Hyun; Park, Hee Myung

1991-01-01

Thirty-one patients with coronary artery disease and twenty-six normal subjects underwent 99m Tc-GBPS before and after coronary vasodilatation was induced by dipyridamole 0.54 mg/kg given IV over 4 min. LVKF, EF and regional wall motion by phase analysis were measured during rest and dipyridamole infusion. The results were as follows: 1) Mean LVEF of normal subjects was significantly higher than that of MI group (p=0.001), but similar to that of angina group during rest. Among Ml group, mean LVEF of anterior MI group was significantly lower than that of inferior MI group during rest (p=0,024). 2) The normal subjects had a significant increase in mean LVEF during dipyridamole infusion (+ 12 ± 3.8), while the CAD group had no increase (+ 2=5.0) (p<0.001). If an increase of LVEF during stress is less than 5%, it suggests an abnormality. The sensitivity and specificity of LUEF changes after dipyridamole infusion were 81%, 96%, respectively. 3) With phase analysis, LV mean phase angle of normal subjects and CAD patients was 143 + 20, 5, 132 ± 20.6 respectively, during rest (p=0.049). But an increase of LV mean phase angle during dipyridamole infusion in these two groups was not significantly different. Dipyridamole infusion did not affect standard deviation and FWHM of phase angle. 4) Regional wall motion was abnormal in 5 patients (16%) during dipyridamole infusion. 5) Side effects with dipyridamole infusion include; headache, angina pain, chest discomfort, nausea, weakness sense. In conclusion, dipyridamole GBPS might be useful in detection and follow up of CAD.

Availability of a baseline Electrocardiogram changes the application of the Sclarovsky-Birnbaum Myocardial Ischemia Grade

DEFF Research Database (Denmark)

Carlsen, Esben A; Bang, Lia E; Køber, Lars

2014-01-01

BACKGROUND AND AIMS: The electrocardiogram (ECG) based Sclarovsky-Birnbaum Ischemia Grade may be used to determine the prognosis of patients with ST-elevation myocardial infarction (STEMI). However, application of the method is based on assumption of the baseline QRS morphology. Thus, the aims...

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

Science.gov (United States)

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

2016-01-01

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

Effect of different doses of oxytocin on cardiac electrophysiology and arrhythmias induced by ischemia.

Science.gov (United States)

Houshmand, Fariba; Faghihi, Mahdieh; Imani, Alireza; Kheiri, Soleiman

2017-01-01

The onset of acute myocardial ischemia (MI) is accompanied by a rapid increase in electrical instability and often fatal ventricular arrhythmias. This study investigated that whether oxytocin (OT) can modulate ischemia-induced arrhythmias and considered relationships between the severity of arrhythmia and the electrocardiogram parameters during ischemia. OT (0.0001-1 μg) was administrated intraperitoneally 30 min before ischemia. To examine receptor involved, a selective OT-receptor antagonist, atosiban (ATO), was infused 10 min before OT. OT caused a significant and biphasic dose-dependent reduction in ectopic heart activity and arrhythmia score. OT doses that reduced ventricular arrhythmia elicited significant increase in QT interval. OT attenuated the electrophysiological changes associated with MI and there was significant direct relationship between QRS duration and arrhythmia score. ATO treatment reduced beneficial effects of OT on arrhythmogenesis. Nevertheless, ATO failed to alter OT effects on premature ventricular contractions. We assume that the ability of OT to modulate the electrical activity of the heart may play an important role in the antiarrhythmic actions of OT.

Effect of different doses of oxytocin on cardiac electrophysiology and arrhythmias induced by ischemia

Directory of Open Access Journals (Sweden)

Fariba Houshmand

2017-01-01

Full Text Available The onset of acute myocardial ischemia (MI is accompanied by a rapid increase in electrical instability and often fatal ventricular arrhythmias. This study investigated that whether oxytocin (OT can modulate ischemia-induced arrhythmias and considered relationships between the severity of arrhythmia and the electrocardiogram parameters during ischemia. OT (0.0001–1 μg was administrated intraperitoneally 30 min before ischemia. To examine receptor involved, a selective OT-receptor antagonist, atosiban (ATO, was infused 10 min before OT. OT caused a significant and biphasic dose-dependent reduction in ectopic heart activity and arrhythmia score. OT doses that reduced ventricular arrhythmia elicited significant increase in QT interval. OT attenuated the electrophysiological changes associated with MI and there was significant direct relationship between QRS duration and arrhythmia score. ATO treatment reduced beneficial effects of OT on arrhythmogenesis. Nevertheless, ATO failed to alter OT effects on premature ventricular contractions. We assume that the ability of OT to modulate the electrical activity of the heart may play an important role in the antiarrhythmic actions of OT.

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

International Nuclear Information System (INIS)

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

1990-01-01

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

Myocardial bridging causing ischemia and recurrent chest pain: a case report

Directory of Open Access Journals (Sweden)

Abdou Mohamed

2011-07-01

Full Text Available Abstract Background Myocardial bridging is present when a segment of a major epicardial coronary artery runs intramurally through the myocardium. It usually has a benign prognosis, but in some cases myocardial ischemia, infarction and sudden cardiac death have been reported. We are here reporting a case of myocardial bridging which was complicated with recurrent chest pain and transient ST-segment elevation during exercise treadmill test. Case presentation A 40 year-old-man presented with recurrent retrosternal chest pain of 2 months duration. He had history of smoking and was obese, otherwise no physical abnormalities were detected by examination. Electrocardiogram and blood tests were normal apart from impaired glucose tolerance with elevated triglycerides and decreased level of high density lipoprotein cholesterol. While doing exercise treadmill test, the patient developed chest pain and significant ST-segment elevation in almost all precordial leads that persisted for about 15 minutes through recovery. We decided to admit the patient to the coronary care unit for further management and to perform coronary angiogram. Myocardial bridging was observed in the mid segment of the left anterior descending coronary artery. Medical treatment was decided. At one year follow up, our patient was healthy and had no cardiac complaints. In conclusion, myocardial bridging may predispose to coronary vasospasm that may leads to ischemic complications.

Hyoscine-N-Butyl-Bromide-Induced Hypotension and Myocardial Ischemia

Directory of Open Access Journals (Sweden)

Guan-Liang Chen

2013-01-01

Full Text Available Hyoscine N-butyl bromide, also known as scopolamine, is a type of antimuscarinic agent. This drug is associated with numerous common side effects, including abdominal fullness, constipation, urinary retention, blurred vision, skin flushing, tachycardia, decreased sweating, and salivation. The most unfavorable side effect is hemodynamic instability. In the present case, hypotension and acute myocardial infarction developed after intravenous hyoscine injection as a premedication therapy for colonoscopy. It was difficult to differentiate the cause-effect relationship between myocardial infarction and hypotension. Because both conditions were present under drug effects, we considered 2 possible diagnoses. One was coronary spasm with cardiogenic shock, and the other was myocardial ischemic sequela due to shock status. The latter diagnosis was confirmed after a series of examinations.

Evaluation of myocardial abnormalities in patients with collagen diseases by thallium-201 myocardial scintigram

Energy Technology Data Exchange (ETDEWEB)

Yamano, Shigeru (Nara Medical Univ., Kashihara (Japan))

1992-08-01

This study was performed to evaluate myocardial lesions in patients with collagen diseases by rest and exercise thallium-201 myocardial scintigraphies. A total of 76 patients without ischemic ECG changes, consisting of 27 cases of systemic lupus erythematosus (SLE), 17 cases of polymyositis or dermatomyositis (PM[center dot]DM), 11 cases of progressive systemic sclerosis (PSS), and 21 cases of Sjoegren's syndrome (SjS), were enrolled in this study. Reversible exercise-induced defects suggesting myocardial ischemia were noted in 12 cases of SLE, 5 cases of PM[center dot]DM, 3 cases of PSS, and 3 cases of SjS. Of the 23 patients who had exercise-induced defects, 9 patients showed normal coronary angiograms by cardiac catheterization. Fixed hypoperfusion areas were observed in 5 cases of SLE, 6 cases of PM[center dot]DM, 4 cases of PSS and 3 cases of SjS. Rest thallium-201 myocardial scintigraphy disclosed hypoperfusion areas, which were not induced by exercise, in 1 case of SLE, 4 cases of PM[center dot]DM, 1 case of PSS and 5 cases of SjS. Endomyocardial biopsy was performed on 20 patients. Myocardial lesions in PM[center dot]DM and PSS were more severe and wide spread than in SLE. Ejection fraction and fractional shortening evaluated by echocardiography had no significant differences between each disease group and the healthy control group. These findings suggest that patients with collagen diseases show the presence of abnormalities of coronary circulation at the level of the intramyocardial vasculature in the stage before impairment of cardiac function, myocardial fibrosis and functional abnormalities of the cell membrane level that were not dependent on myocardial ischemia. (author).

Dictionary-driven Ischemia Detection from Cardiac Phase-Resolved Myocardial BOLD MRI at Rest

Science.gov (United States)

Bevilacqua, Marco; Dharmakumar, Rohan; Tsaftaris, Sotirios A.

2016-01-01

Cardiac Phase-resolved Blood-Oxygen-Level Dependent (CP–BOLD) MRI provides a unique opportunity to image an ongoing ischemia at rest. However, it requires post-processing to evaluate the extent of ischemia. To address this, here we propose an unsupervised ischemia detection (UID) method which relies on the inherent spatio-temporal correlation between oxygenation and wall motion to formalize a joint learning and detection problem based on dictionary decomposition. Considering input data of a single subject, it treats ischemia as an anomaly and iteratively learns dictionaries to represent only normal observations (corresponding to myocardial territories remote to ischemia). Anomaly detection is based on a modified version of One-class Support Vector Machines (OCSVM) to regulate directly the margins by incorporating the dictionary-based representation errors. A measure of ischemic extent (IE) is estimated, reflecting the relative portion of the myocardium affected by ischemia. For visualization purposes an ischemia likelihood map is created by estimating posterior probabilities from the OCSVM outputs, thus obtaining how likely the classification is correct. UID is evaluated on synthetic data and in a 2D CP–BOLD data set from a canine experimental model emulating acute coronary syndromes. Comparing early ischemic territories identified with UID against infarct territories (after several hours of ischemia), we find that IE, as measured by UID, is highly correlated (Pearson’s r = 0.84) w.r.t. infarct size. When advances in automated registration and segmentation of CP–BOLD images and full coverage 3D acquisitions become available, we hope that this method can enable pixel-level assessment of ischemia with this truly non-invasive imaging technique. PMID:26292338

Correlation of QRS complex after percutaneous coronary intervention with myocardial ischemia reperfusion injury and apoptosis molecule contents

Directory of Open Access Journals (Sweden)

Ming-Min Jiang

2017-11-01

Full Text Available Objective: To study the correlation of QRS complex after percutaneous coronary intervention (PCI with myocardial ischemia reperfusion injury and apoptosis molecule contents. Methods: Patients with non-ST-segment elevation myocardial infarction who were treated in Nanchong Central Hospital between June 2014 and August 2016 were selected and divided into the PCI group who received emergency PCI surgery and the control group who accepted selective PCI or refused emergency PCI after the medical data were retrospectively analyzed. The fQRS as well as the contents of ischemia reperfusion injury indexes and apoptosis molecules was determined after 1 week of treatment. Results: The incidence of fQRS in PCI group was significantly lower than that in control group; serum MDA, cTnI, H-FABP, sTWEAK, sFas, sTRAIL and Caspase-3 contents as well as peripheral blood Nrf-2 and HO-1 expression of PCI group were greatly lower than those of control group; serum MDA, cTnI, H-FABP, sTWEAK, sFas, sTRAIL and Caspase-3 contents as well as peripheral blood Nrf-2 and HO-1 expression of PCI group of patients with fQRS complex (+ were greatly higher than those of patients with fQRS complex (-. Conclusion: The occurrence of fQRS after PCI is closely related to myocardial ischemia reperfusion injury and apoptosis.

Advances in gene therapy of myocardial ischemia and the monitoring with molecular imaging

International Nuclear Information System (INIS)

Zhang Guopeng; Zhang Yongxue

2008-01-01

Cardiovascular diseases are harmful for people. Recent advances in understanding the molecular basis of cardiovascular diseases, together with some studies of the gene therapy on cardiovascular disorders, have offered possibilities for new treatments. Gene therapies have demonstrated potential usefulness in treating myocardial ischemia. Therefore, the monitoring of the expression of therapy gene and therapeutic efficacy has become an important issue. (authors)

Effects and Mechanisms of Chinese Herbal Medicine in Ameliorating Myocardial Ischemia-Reperfusion Injury

Directory of Open Access Journals (Sweden)

Qing Liu

2013-01-01

Full Text Available Myocardial ischemia-reperfusion (MIR injury is a major contributor to the morbidity and mortality associated with coronary artery disease, which accounts for approximately 450,000 deaths a year in the United States alone. Chinese herbal medicine, especially combined herbal formulations, has been widely used in traditional Chinese medicine for the treatment of myocardial infarction for hundreds of years. While the efficacy of Chinese herbal medicine is well documented, the underlying molecular mechanisms remain elusive. In this review, we highlight recent studies which are focused on elucidating the cellular and molecular mechanisms using extracted compounds, single herbs, or herbal formulations in experimental settings. These studies represent recent efforts to bridge the gap between the enigma of ancient Chinese herbal medicine and the concepts of modern cell and molecular biology in the treatment of myocardial infarction.

A possible relationship between gluconeogenesis and glycogen metabolism in rabbits during myocardial ischemia

Directory of Open Access Journals (Sweden)

RAQUEL R. DE AGUIAR

2017-08-01

Full Text Available ABSTRACT Ischemia is responsible for many metabolic abnormalities in the heart, causing changes in organ function. One of modifications occurring in the ischemic cell is changing from aerobic to anaerobic metabolism. This change causes the predominance of the use of carbohydrates as an energy substrate instead of lipids. In this case, the glycogen is essential to the maintenance of heart energy intake, being an important reserve to resist the stress caused by hypoxia, using glycolysis and lactic acid fermentation. In order to study the glucose anaerobic pathways utilization and understand the metabolic adaptations, New Zealand white rabbits were subjected to ischemia caused by Inflow occlusion technique. The animals were monitored during surgery by pH and lactate levels. Transcription analysis of the pyruvate kinase, lactate dehydrogenase and phosphoenolpyruvate carboxykinase enzymes were performed by qRT-PCR, and glycogen quantification was determined enzymatically. Pyruvate kinase transcription increased during ischemia, followed by glycogen consumption content. The gluconeogenesis increased in control and ischemia moments, suggesting a relationship between gluconeogenesis and glycogen metabolism. This result shows the significant contribution of these substrates in the organ energy supply and demonstrates the capacity of the heart to adapt the metabolism after this injury, sustaining the homeostasis during short-term myocardial ischemia.

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

International Nuclear Information System (INIS)

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

1989-01-01

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

Detection of myocardial ischemia before infarction, based on accumulation of labeled pyruvate

International Nuclear Information System (INIS)

Goldstein, R.A.; Klein, M.S.; Sobel, B.E.

1980-01-01

To determine whether ischemic, but not irreversibly injured myocardium, can be differentiated from normal tissue based on accumulation of labeled pyruvate, isolated hearts were perfused with buffer containing [ 14 C]pyruvate under conditions of normal or low flow. Fifteen minutes after the hearts were exposed to labeled material, myocardial radioactivity was fourfold greater in ischemic compared to control hearts, due to accumulation of label in sequestered lactate produced from the pyruvate. Open-chest rabbits subjected to coronary occlusion exhibited a 1.73:1 ratio of radioactivity in ischemic compared with normal myocardium 15 min after systemic injection of [ 14 C]pyruvate. The results obtained suggest that zones of myocardial ischemia should be detectable in vivo by positron tomography after systemic administration of [ 11 C]pyruvate as well

Morphine Reduces Myocardial Infarct Size via Heat Shock Protein 90 in Rodents

Directory of Open Access Journals (Sweden)

Bryce A. Small

2015-01-01

Full Text Available Opioids reduce injury from myocardial ischemia-reperfusion in humans. In experimental models, this mechanism involves GSK3β inhibition. HSP90 regulates mitochondrial protein import, with GSK3β inhibition increasing HSP90 mitochondrial content. Therefore, we determined whether morphine-induced cardioprotection is mediated by HSP90 and if the protective effect is downstream of GSK3β inhibition. Male Sprague-Dawley rats, aged 8–10 weeks, were subjected to an in vivo myocardial ischemia-reperfusion injury protocol involving 30 minutes of ischemia followed by 2 hours of reperfusion. Hemodynamics were continually monitored and myocardial infarct size determined. Rats received morphine (0.3 mg/kg, the GSK3β inhibitor, SB216763 (0.6 mg/kg, or saline, 10 minutes prior to ischemia. Some rats received selective HSP90 inhibitors, radicicol (0.3 mg/kg, or deoxyspergualin (DSG, 0.6 mg/kg alone or 5 minutes prior to morphine or SB216763. Morphine reduced myocardial infarct size when compared to control (42 ± 2% versus 60 ± 1%. This protection was abolished by prior treatment of radicicol or DSG (59 ± 1%, 56 ± 2%. GSK3β inhibition also reduced myocardial infarct size (41 ± 2% with HSP90 inhibition by radicicol or DSG partially inhibiting SB216763-induced infarct size reduction (54 ± 3%, 47 ± 1%, resp.. These data suggest that opioid-induced cardioprotection is mediated by HSP90. Part of this protection afforded by HSP90 is downstream of GSK3β, potentially via the HSP-TOM mitochondrial import pathway.

The clinical application value of myocardial perfusion imaging in evaluating coronary artery myocardial bridge patients with symptoms

International Nuclear Information System (INIS)

Wang Yuetao; Fu Ning; Ding Xuemei; Lu Cunzhi; Zhu Feng; Wang Guanmin; Huang Yijie; Wang Linguang

2008-01-01

Objective: Myocardial bridge is a common inborn coronary artery anomaly, myocardial bridge may be associated with myocardial ischemia. Only a few patients with coronary artery myocardial bridge were evaluated with nuclear medicine techniques. The aim of this study was to investigate the role of nuclear cardiology with myocardial perfusion technique in symptomatic myocardial bridge patients. Methods Nineteen myocardial bridge patients with the symptoms of chest pain and chest distress were analyzed retrospectively. 99 Tc m -methoxyisobutylisonitrile (MIBI) myocardial perfusion images (both exercise and rest) were performed in all. Imaging results were compared with the results of movement electrocardiogram (ECG) and coronary arteriography. The t test or χ 2 test was used to statistically analyze the data with Stata 7.0 software. Results: Of the 19 patients, 18 patients had myocardial bridge locating at the left anterior descending artery, 1 patient at the left anterior descending and left circumflex artery, the mean angiographic systolic occlusion within the myocardial bridge was (65.4 ± 22.1)%. Of these 19 patients, Exercise-rest 99 Tc m -MIBI myocardial perfusion imaging defined positive myocardial ischemia in 10 and negative in 9 patients. Of the 10 patients with 99 Tc m -MIBI myocardial perfusion imaging defined myocardial ischemia, 8 had reversible radioactive defect of partial anterior wall and (or) apex, 1 had reversible defect of post lateral wall and post septal wall, and 1 had reversible defect of inferior wall. The positive predictive value of myocardial perfusion imaging was 52.6% (10/19), which was higher than movement ECG [21.1% (4/19), χ 2 = 4.07, P 99 Tc m -MIBI myocardial periusion imaging defined myocardial ischemia. Six cases with Grade II stenosis, two were 99 Tc m -MIBI myocardial perfusion imaging defined myocardial ischemia. Eight cases with Grade III stenosis, seven were 99 Tc m -MIBI myocardial perfusion imaging defined myocardial

Exercise-induced thallium-201 myocardial perfusion defects in angina pectoris without significant coronary artery stenosis

International Nuclear Information System (INIS)

Nakazato, Masayasu; Maruoka, Yuji; Sunagawa, Osahiko; Kinjo, Kunihiko; Tomori, Masayuki; Fukiyama, Koshiro

1990-01-01

We performed exercise thallium-201 myocardial scintigraphy in 32 patients with angina pectoris to study the incidence of perfusion defects, who had no significant organic stenosis on coronary angiography. None of them had myocardial infarction or cardiomyopathy. Thallium-201 myocardial scintigraphy and 12-lead ECG recording were performed during supine bicycle ergometer exercise. Perfusion defects in thallium-201 scintigrams in SPECT images were assessed during visual analysis by two observers. In the coronary angiograms obtained during intravenous infusion of nitroglycerin, the luminal diameter of 75% stenosis or less in the AHA classification was regarded as an insignificant organic stenosis. Myocardial perfusion defects in the thallium-201 scintigrams were detected in eight (25%) of the 32 patients. Six of these eight patients had variant angina documented during spontaneous attacks with ST elevations in standard 12-lead ECGs. Perfusion defects were demonstrated at the inferior or infero-posterior regions in six patients, one of whom had concomitant anteroseptal defect. The defects were not always accompanied by chest pain. All but one patient demonstrating inferior or inferoposterior defects showed ST depression in leads II, III and aV F on their ECGs, corresponding to inferior wall ischemia. The exception was a case with right bundle branch block. Thus, 25% of the patients with angina pectoris, who had no evidence of significant organic stenosis on their coronary angiograms, exhibited exercise-induced perfusion defects in their thallium-201 scintigrams. Coronary spasms might have caused myocardial ischemia in these patients. (author)

Clinical Characteristics and Outcomes of Patients with Myocardial Infarction, Myocardial Injury, and Nonelevated Troponins

DEFF Research Database (Denmark)

Sarkisian, Laura; Saaby, Lotte; Poulsen, Tina S

2016-01-01

BACKGROUND: Cardiac troponins have emerged as the preferred biomarkers for detecting myocardial necrosis and diagnosing myocardial infarction. However, current cardiac troponin assays do not discriminate between ischemic and nonischemic causes of myocardial cell death. Thus, when an increased...... troponin value is encountered in the absence of obvious myocardial ischemia, a careful search for other clinical conditions is crucial. METHODS: In 2010 to 2011, we prospectively studied hospitalized patients who had cardiac troponin I measured on clinical indication. An acute myocardial infarction...... was diagnosed in cases of a cardiac troponin I increase or decrease pattern with at least 1 value >30 ng/L (99th percentile) together with myocardial ischemia. Myocardial injury was defined as cardiac troponin I values >30 ng/L, but without signs or symptoms indicating overt cardiac ischemia. Patients with peak...

Correlation of myocardial p-(123)I-iodophenylpentadecanoic acid retention with (18)F-FDG accumulation during experimental low-flow ischemia.

Science.gov (United States)

Shi, Cindy Q; Young, Lawrence H; Daher, Edouard; DiBella, Edward V R; Liu, Yi-Hwa; Heller, Eliot N; Zoghbi, Sami; Wackers, Frans J Th; Soufer, Robert; Sinusas, Albert J

2002-03-01

Myocardial ischemia is associated with reduced free fatty acid (FFA) beta-oxidation and increased glucose utilization. This study evaluated the potential of dynamic SPECT imaging of a FFA analog, p-(123)I-iodophenylpentadecanoic acid (IPPA), for detection of ischemia and compares retention of IPPA with (18)F-FDG accumulation. In a canine model of regional low-flow ischemia (n = 9), serial IPPA SPECT images (2 min per image) were acquired over 52--90 min. In a subset of dogs (n = 6), (18)F-FDG was injected after completing SPECT imaging and allowed to accumulate for 40 min before killing the animals. Flow was assessed with radiolabeled microspheres. Myocardial metabolism was evaluated independently by selective coronary arterial and venous sampling. Serial IPPA SPECT images showed an initial defect in the ischemic region (0.70% plus minus 0.03% ischemic-to-nonischemic ratio), which normalized within 48 min because of the slower IPPA clearance from the ischemic region (t(1/2) = 54.2 plus minus 3.3 min) relative to the nonischemic region (t(1/2) = 36.7 plus minus 5.6 min) (P < 0.05). Delayed myocardial IPPA and (18)F-FDG activities were correlated (r = 0.70; n = 576 segments), and both were maximally increased in segments with a moderate flow reduction (IPPA, 151% of nonischemic; (18)F-FDG, 450% of nonischemic; P < 0.05). Serial SPECT imaging showed delayed myocardial clearance of IPPA in ischemic regions with moderate flow reduction, which lead to increased late myocardial retention of IPPA. Retention of IPPA correlated with (18)F-FDG accumulation, supporting the potential of IPPA as a noninvasive marker of ischemic myocardium.

Time course of regional myocardial glucose metabolism after transient ischemia assessed by positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Hoshizaki, Hiroshi (Gunma Univ., Maebashi (Japan). School of Medicine)

1992-11-01

The purpose of this study was to examine the significance of glucose metabolism in ischemic canine myocardium after reperfusion. Transient ischemia was induced by 90 or 180 minutes occlusion of the left anterior descending coronary artery. Twelve hours and 4 weeks after reperfusion, myocardial blood flow (MBF) and glucose metabolism were assessed (with H[sub 2][sup 15]O and [sup 18]F-FDG, respectively) by positron emission tomography (PET) under the fasting state, and the metabolic findings were compared with the histologic examination. Glucose metabolism in ischemic regions was inversely related to the amount of tissue necrosis 12 hours and 4 weeks after reperfusion (r=-0.89 and r=-0.82, respectively). The perfusion-metabolism mismatch pattern was seen in the area with less than 10 percent necrosis 12 hours after reperfusion, but this pattern disappeared after 4 weeks. The area with 10 to 50 percent necrosis showed the mismatch pattern until 4 weeks after reperfusion, and in the area with more than 50 percent necrosis, perfusion-metabolism concordantly decreased. Thus, metabolic index assessed early after reperfusion by PET identified myocardial viability, and the perfusion-metabolism mismatch pattern sustained in relation to the degree of ischemic injury. Since some regions estimated to be irreversible by PET were viable by the histologic examination, PET study might underestimate the myocardial viability. (author).

Effect of exercise supplementation on dipyridamole thallium-201 image quality

International Nuclear Information System (INIS)

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

1991-01-01

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

The past, the present and the future of experimental research on myocardial ischemia and protection

Czech Academy of Sciences Publication Activity Database

Ošťádal, Bohuslav

2009-01-01

Roč. 61, č. 1 (2009), s. 3-12 ISSN 1734-1140 R&D Projects: GA MŠk(CZ) 1M0510 Institutional research plan: CEZ:AV0Z50110509 Keywords : myocardial ischemia * protection * cell death Subject RIV: FA - Cardiovascular Disease s incl. Cardiotharic Surgery Impact factor: 2.086, year: 2009

Usefulness of 201Tl myocardial scintigraphy after dipyridamole infusion in patients with atherosclerotic vascular disease

International Nuclear Information System (INIS)

Toyama, Takuji; Nishimura, Tsunehiko; Uehara, Toshiisa

1992-01-01

To determine the utility for detecting ischemic heart disease (IHD), dipyridamole thallium myocardial images (DIP-Tl) have been performed in 103 patients with atherosclerotic vascular disease who can't exercise fully. Of the 103 patients, there were 36 patients with arteriosclerosis obliterans (ASO), 31 patients with aneurysm of the abdominal aorta (AAA), 24 patients with aneurysm of the thoracic aorta (TAA) and 12 patients with dissecting aortic aneurysm (DAA). Clinical evidence of IHD was found in 20 patients with ASO, 10 with AAA, 7 with TAA and 4 with DAA. Positive evidence of DIP-Tl was identified in 66% of 41 patients who had clinical evidence of IHD, and particularly in the patients with AAA (80%) and ASO (65%). On the other hand, in the patients without clinical evidence of IHD, positive evidence of DIP-Tl was identified in 19% of 62 patients and particularly in the patients with AAA (39%). In all patients, the percentage of the positive DIP-Tl ratio was 38%. And, when the 38% patients of the positive DIP-Tl were added to the patients of the negative DIP-Tl who had clinical evidence of IHD, almost half patients (51%) were considered to be complicated with IHD. This study suggests that the atherosclerotic vascular disease is highly complicated with IHD and DIP-Tl is useful to detect IHD. (author)

Detection of exercise induced ischemia in the asymptomatic recent post myocardial infarction patient: comparison of stress electrocardiography and radionuclide angiography

International Nuclear Information System (INIS)

Jengo, J.A.; Brizendine, M.; Dykstra, L.; Sweet, J.; Bruno, M.; Garcia, A.

1982-01-01

The purpose of this study was to compare the techniques of low level stress electrocardiography and radionuclide angiographic wall motion analysis for the detection of new areas of myocardial ischemia in the asymptomatic recent post-myocardial infarction patient. The protocol consisted of obtaining a resting, RAO upright first pass radionuclide angiocardiogram using 15 mCi of 99m technetium-DTPA. The study suggests that assessment of segmental wall motion during low level stress can detect areas of myocardium at high risk either intermixed with or in addition to recently infarcted areas in the asymptomatic post-infarction patient, which are not detected by ECG. This high risk subset of patients can then be observed or treated in a more vigorous manner. This technique allows for not only the identification of additional areas of myocardium at jeopardy but also provides information regarding the severity of ischemic dysfunction, an important prognostic and therapeutic factor

Isoflurane administration before ischemia and during reperfusion attenuates ischemia/reperfusion-induced injury of isolated rabbit lungs.

Science.gov (United States)

Liu, R; Ishibe, Y; Ueda, M; Hang, Y

1999-09-01

To investigate the effects of isoflurane on ischemia/ reperfusion (IR)-induced lung injury, we administered isoflurane before ischemia or during reperfusion. Isolated rabbit lungs were divided into the following groups: control (n = 6), perfused and ventilated for 120 min without ischemia; ISO-control (n = 6), 1 minimum alveolar anesthetic concentration (MAC) isoflurane was administered for 30 min before 120 min continuous perfusion; IR (n = 6), ischemia for 60 min, followed by 60 min reperfusion; IR-ISO1 and IR-ISO2, ischemia followed by reperfusion and 1 MAC (n = 6) or 2 MAC (n = 6) isoflurane for 60 min; ISO-IR (n = 6), 1 MAC isoflurane was administered for 30 min before ischemia, followed by IR. During these maneuvers, we measured total pulmonary vascular resistance (Rt), coefficient of filtration (Kfc), and lung wet to dry ratio (W/D). The results indicated that administration of isoflurane during reperfusion inhibited an IR-induced increase in Kfc and W/D ratio. Furthermore, isoflurane at 2 MAC, but not 1 MAC, significantly inhibited an IR-induced increase in Rt. The administration of isoflurane before ischemia significantly attenuated the increase in IR-induced Kfc, W/D, and Rt. Our results suggest that the administration of isoflurane before ischemia and during reperfusion protects against ischemia-reperfusion-induced injury in isolated rabbit lungs.

Fisetin Confers Cardioprotection against Myocardial Ischemia Reperfusion Injury by Suppressing Mitochondrial Oxidative Stress and Mitochondrial Dysfunction and Inhibiting Glycogen Synthase Kinase 3β Activity

Directory of Open Access Journals (Sweden)

Karthi Shanmugam

2018-01-01

Full Text Available Acute myocardial infarction (AMI is the leading cause of morbidity and mortality worldwide. Timely reperfusion is considered an optimal treatment for AMI. Paradoxically, the procedure of reperfusion can itself cause myocardial tissue injury. Therefore, a strategy to minimize the reperfusion-induced myocardial tissue injury is vital for salvaging the healthy myocardium. Herein, we investigated the cardioprotective effects of fisetin, a natural flavonoid, against ischemia/reperfusion (I/R injury (IRI using a Langendorff isolated heart perfusion system. I/R produced significant myocardial tissue injury, which was characterized by elevated levels of lactate dehydrogenase and creatine kinase in the perfusate and decreased indices of hemodynamic parameters. Furthermore, I/R resulted in elevated oxidative stress, uncoupling of the mitochondrial electron transport chain, increased mitochondrial swelling, a decrease of the mitochondrial membrane potential, and induction of apoptosis. Moreover, IRI was associated with a loss of the mitochondrial structure and decreased mitochondrial biogenesis. However, when the animals were pretreated with fisetin, it significantly attenuated the I/R-induced myocardial tissue injury, blunted the oxidative stress, and restored the structure and function of mitochondria. Mechanistically, the fisetin effects were found to be mediated via inhibition of glycogen synthase kinase 3β (GSK3β, which was confirmed by a biochemical assay and molecular docking studies.

Fisetin Confers Cardioprotection against Myocardial Ischemia Reperfusion Injury by Suppressing Mitochondrial Oxidative Stress and Mitochondrial Dysfunction and Inhibiting Glycogen Synthase Kinase 3β Activity.

Science.gov (United States)

Shanmugam, Karthi; Ravindran, Sriram; Kurian, Gino A; Rajesh, Mohanraj

2018-01-01

Acute myocardial infarction (AMI) is the leading cause of morbidity and mortality worldwide. Timely reperfusion is considered an optimal treatment for AMI. Paradoxically, the procedure of reperfusion can itself cause myocardial tissue injury. Therefore, a strategy to minimize the reperfusion-induced myocardial tissue injury is vital for salvaging the healthy myocardium. Herein, we investigated the cardioprotective effects of fisetin, a natural flavonoid, against ischemia/reperfusion (I/R) injury (IRI) using a Langendorff isolated heart perfusion system. I/R produced significant myocardial tissue injury, which was characterized by elevated levels of lactate dehydrogenase and creatine kinase in the perfusate and decreased indices of hemodynamic parameters. Furthermore, I/R resulted in elevated oxidative stress, uncoupling of the mitochondrial electron transport chain, increased mitochondrial swelling, a decrease of the mitochondrial membrane potential, and induction of apoptosis. Moreover, IRI was associated with a loss of the mitochondrial structure and decreased mitochondrial biogenesis. However, when the animals were pretreated with fisetin, it significantly attenuated the I/R-induced myocardial tissue injury, blunted the oxidative stress, and restored the structure and function of mitochondria. Mechanistically, the fisetin effects were found to be mediated via inhibition of glycogen synthase kinase 3 β (GSK3 β ), which was confirmed by a biochemical assay and molecular docking studies.

Prognostic significance of silent myocardial ischemia on a thallium stress test

International Nuclear Information System (INIS)

Heller, L.I.; Tresgallo, M.; Sciacca, R.R.; Blood, D.K.; Seldin, D.W.; Johnson, L.L.

1990-01-01

The clinical significance of silent ischemia is not fully known. The purpose of this study was to determine whether the presence or absence of angina during a thallium stress test positive for ischemia was independently predictive of an adverse outcome. Two hundred thirty-four consecutive patients with ischemia on a thallium stress test were identified. Ischemia was defined as the presence of defect(s) on the immediate postexercise scans not in the distribution of prior infarctions that redistributed on 4-hour scans. During the test 129 patients had angina, defined as characteristic neck, jaw, arm, back or chest discomfort, while the remaining 105 patients had no angina. Follow-up ranged from 2 to 8.2 years (mean 5.2 +/- 2.1) and was successfully obtained in 156 patients. Eighty-two of the 156 patients had angina (group A) and 74 had silent ischemia (group S). Group A patients were significantly older (62 +/- 8 vs 59 +/- 8 years, p less than 0.05). There was no significant difference between the 2 groups in terms of sex, history of prior infarction or presence of left main/3-vessel disease. A larger percentage of patients in group A were receiving beta blockers (60 vs 41%, p less than 0.05) and nitrates (52 vs 36%, 0.05 less than p less than 0.10). There was a large number of cardiac events (myocardial infarction, revascularization and death) in both groups (37 of 82 [45%] in group A; 28 of 72 [38%] in group S) but no statistically significant difference between the groups. Similarly, life-table analysis revealed no difference in mortality between the 2 groups

Myocardial perfusion SPECT imaging in patients with myocardial bridging

International Nuclear Information System (INIS)

Fang Wei; Qiu Hong; Yang Weixian; Wang Feng; He Zuoxiang

2008-01-01

Objective: Stress myocardial perfusion SPECT imaging was used to assess myocardial ischemia in patients with myocardial bridging. Methods: Ninety-six patients with myocardial bridging of the left anterior descending artery documented by coronary angiography were included in this study. All under- went exercise or pharmacological stress myocardial perfusion SPECT assessing myocardial ischemia. None had prior myocardial infarction. One year follow-up by telephone interview was performed in all patients. Results The mean stenotic severity of systolic phase on angiography was (65 ± 19)%. In the SPECT study, 20 of 96 (20.8%) patients showed abnormal perfusion. This percentage was significantly higher than that of stress electrocardiogram (ECG). The higher positive rate of SPECT perfusion images was showed in the group of patients with severe systolic narrowing (≥75%) than that with mild-to-moderate systolic narrowing (50% vs 6.3%, P<0.001). The prevalence of abnormal image was significantly higher in ELDERLY PEOPLE; patients with STT change on rest ECG than in those with normal rest ECG (54.2% vs 9.7%, P<0.001). During follow-up, one patient with abnormal SPECT perfusion image sustained angina and accepted percutaneous coronary intervention, and no cardiac event occurred in patients with normal images. Conclusions: Stress myocardial perfusion SPECT imaging can be used effectively for assessing myocardial ischemia and has potential prognostic value for patients with myocardial bridging. (authors)

Dobutamine cardiovascular magnetic resonance for the detection of myocardial ischemia with the use of myocardial tagging.

Science.gov (United States)

Kuijpers, Dirkjan; Ho, Kai Yiu J A M; van Dijkman, Paul R M; Vliegenthart, Rozemarijn; Oudkerk, Matthijs

2003-04-01

The purpose of this study was to assess the value of high-dose dobutamine cardiovascular magnetic resonance (CMR) with myocardial tagging for the detection of wall motion abnormalities as a measure of myocardial ischemia in patients with known or suspected coronary artery disease. Two hundred eleven consecutive patients with chest pain underwent dobutamine-CMR 4 days after antianginal medication was stopped. Dobutamine-CMR was performed at rest and during increasing doses of dobutamine. Cine-images were acquired during breath-hold with and without myocardial tagging at 3 short-axis levels. Regional wall motion was assessed in a 16-segment short-axis model. Patients with new wall motion abnormalities (NWMA) were examined by coronary angiography. Dobutamine-CMR was successfully performed in 194 patients. Dobutamine-CMR without tagging detected NWMA in 58 patients, whereas NWMA were detected in 68 patients with tagging (P=0.002, McNemar). Coronary angiography showed coronary artery disease in 65 (96%) of these 68 patients. All but 3 of the 65 patients needed revascularization. In the 112 patients with a negative dobutamine-CMR study, without baseline wall motion abnormalities, the cardiovascular occurrence-free survival rate was 98.2% during the mean follow-up period of 17.3 months (range, 7 to 31). Dobutamine-CMR with myocardial tagging detected more NWMA compared with dobutamine-CMR without tagging and reliably separated patients with a normal life expectancy from those at increased risk of major adverse cardiac events.

Reduction of myocardial blood flow reserve in idiopathic dilated cardiomyopathy without overt heart failure and its relation with functional indices: an echo-Doppler and positron emission tomography study.

Science.gov (United States)

Morales, Maria-Aurora; Neglia, Danilo; L'Abbate, Antonio

2008-08-01

Myocardial blood flow during pharmacological vasodilatation is depressed in patients with idiopathic dilated cardiomyopathy even the in absence of overt heart failure; the extent of myocardial blood flow abnormalities is not predictable by left ventricular ejection fraction (LVEF) and diastolic dimensions. To assess whether myocardial blood flow impairment in idiopathic dilated cardiomyopathy without overt heart failure can be related to Doppler-derived dP/dt and to echocardiographically determined left ventricular end systolic stress - which is linked to myocardial blood flow reserve in advanced disease. Twenty-six patients, New York Heart Association Class I-II, (LVEF 37.4 +/- 1.4%, left ventricular diastolic dimensions 62.6 +/- 0.9 mm) underwent resting/dipyridamole [13N]NH3 flow positron emission tomography and an ultrasonic study. Regional myocardial blood flow values (ml/min per g) were computed from positron emission tomography data in 13 left ventricular (LV) myocardial regions and averaged to provide mean myocardial blood flow and myocardial blood flow reserve, defined as dipyridamole/resting mean myocardial blood flow ratio. Resting myocardial blood flow was 0.686 +/- 0.045, dipyridamole myocardial blood flow 1.39 +/- 0.15 and myocardial blood flow reserve 2.12 +/- 0.2, lower than in controls (P < 0.01). The ratio dP/dt was directly related to dipyridamole myocardial blood flow and myocardial blood flow reserve (r = 0.552 and 0.703, P < 0.005 and P < 0.0001); no relation was found between myocardial blood flow and LVEF left ventricular diastolic dimensions, and left ventricular end systolic stress. In idiopathic dilated cardiomyopathy patients without overt heart failure, the extent of myocardial blood flow reserve impairment is related to dP/dt but not to more classical indices of left ventricular function.

Low-Level Tragus Stimulation for the Treatment of Ischemia and Reperfusion Injury in Patients With ST-Segment Elevation Myocardial Infarction: A Proof-of-Concept Study.

Science.gov (United States)

Yu, Lilei; Huang, Bing; Po, Sunny S; Tan, Tuantuan; Wang, Menglong; Zhou, Liping; Meng, Guannan; Yuan, Shenxu; Zhou, Xiaoya; Li, Xuefei; Wang, Zhuo; Wang, Songyun; Jiang, Hong

2017-08-14

The aim of this study was to investigate whether low-level tragus stimulation (LL-TS) treatment could reduce myocardial ischemia-reperfusion injury in patients with ST-segment elevation myocardial infarction (STEMI). The authors' previous studies suggested that LL-TS could reduce the size of myocardial injury induced by ischemia. Patients who presented with STEMI within 12 h of symptom onset, treated with primary percutaneous coronary intervention, were randomized to the LL-TS group (n = 47) or the control group (with sham stimulation [n = 48]). LL-TS, 50% lower than the electric current that slowed the sinus rate, was delivered to the right tragus once the patients arrived in the catheterization room and lasted for 2 h after balloon dilatation (reperfusion). All patients were followed for 7 days. The occurrence of reperfusion-related arrhythmia, blood levels of creatine kinase-MB, myoglobin, N-terminal pro-B-type natriuretic peptide and inflammatory markers, and echocardiographic characteristics were evaluated. The incidence of reperfusion-related ventricular arrhythmia during the first 24 h was significantly attenuated by LL-TS. In addition, the area under the curve for creatine kinase-MB and myoglobin over 72 h was smaller in the LL-TS group than the control group. Furthermore, blood levels of inflammatory markers were decreased by LL-TS. Cardiac function, as demonstrated by the level of N-terminal pro-B-type natriuretic peptide, the left ventricular ejection fraction, and the wall motion index, was markedly improved by LL-TS. LL-TS reduces myocardial ischemia-reperfusion injury in patients with STEMI. This proof-of-concept study raises the possibility that this noninvasive strategy may be used to treat patients with STEMI undergoing primary percutaneous coronary intervention. Copyright © 2017. Published by Elsevier Inc.

Acute myocardial ischemia after aortic valve replacement: A comprehensive diagnostic evaluation using dynamic multislice spiral computed tomography

Energy Technology Data Exchange (ETDEWEB)

Lembcke, Alexander [Department of Radiology, Charite-Universitaetsmedizin Berlin, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Berlin (Germany)]. E-mail: alexander.lembcke@gmx.de; Hein, Patrick A. [Department of Radiology, Charite-Universitaetsmedizin Berlin, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Berlin (Germany); Enzweiler, Christian N.H. [Department of Radiology, Charite-Universitaetsmedizin Berlin, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Berlin (Germany); Hoffmann, Udo [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Klessen, Christian [Department of Radiology, Charite-Universitaetsmedizin Berlin, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Berlin (Germany); Dohmen, Pascal M. [Department of Cardiovascular Surgery, Charite-Universitaetsmedizin Berlin, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Berlin (Germany)

2006-03-15

We describe the case of a 72-year-old man presenting with endocarditis and clinical signs of acute myocardial ischemia after biological aortic valve replacement. A comprehensive cardiac dynamic multislice spiral computed tomography demonstrated: (1) an endocarditic vegetation of the aortic valve; (2) a subvalvular leakage feeding a paravalvular pseudoaneurysm based on an aortic root abscess with subsequent compromise of the systolic blood flow in the left main coronary artery and the resulting myocardial perfusion deficit.

Acute myocardial ischemia after aortic valve replacement: A comprehensive diagnostic evaluation using dynamic multislice spiral computed tomography

International Nuclear Information System (INIS)

Lembcke, Alexander; Hein, Patrick A.; Enzweiler, Christian N.H.; Hoffmann, Udo; Klessen, Christian; Dohmen, Pascal M.

2006-01-01

We describe the case of a 72-year-old man presenting with endocarditis and clinical signs of acute myocardial ischemia after biological aortic valve replacement. A comprehensive cardiac dynamic multislice spiral computed tomography demonstrated: (1) an endocarditic vegetation of the aortic valve; (2) a subvalvular leakage feeding a paravalvular pseudoaneurysm based on an aortic root abscess with subsequent compromise of the systolic blood flow in the left main coronary artery and the resulting myocardial perfusion deficit

Assessment of myocardial fatty acid metabolism in patients with angina pectoris and diabetes mellitus using 123I-BMIPP myocardial scintigraphy

International Nuclear Information System (INIS)

Ito, Kazuki; Tanabe, Takuji; Yuba, Tatsuya; Doue, Tomoki; Adachi, Yoshihiko; Katoh, Shuuji; Sugihara, Hiroki; Azuma, Akihiro; Nakagawa, Masao

2001-01-01

We studied the effect of myocardial ischemia and diabetes mellitus (DM) on the myocardial fatty acid metabolism using 123 I-BMIPP myocardial scintigraphy. We performed 123 I-BMIPP myocardial scintigraphy in 50 patients with myocardial ischemia and without DM (AP), in 30 patients with myocardial ischemia and DM (AP+DM), 12 patients with DM and without myocardial ischemia (DM), and in 10 normal subjects (N). Myocardial uptake rate of 123 I-BMIPP was obtained using the time activity curve. Myocardial washout rate of 123 I-BMIPP was calculated using the polar images of early and delayed SPECT images. Myocardial uptake rate of 123 I-BMIPP (%) were AP: 4.9±0.6, AP+DM: 5.5±0.5, DM 5.7±0.5 and N: 5.0±0.4. 123 I-BMIPP myocardial uptake rate was increased in AP+DM and DM. 123 I-BMIPP myocardial washout rate (%) were AP: 30.2±4.3, AP+DM: 24.5±3.9, DM: 16.1±2.8 and N: 19.4±3.2. 123 I-BMIPP myocardial washout rate was increased in AP and AP+DM. 123 I-BMIPP myocardial washout rate was increased particularly in patients with multi-vessels disease. 123 I-BMIPP myocardial washout rate was decreased in DM. The present study suggested that diabetes mellitus increased myocardial fatty acid uptake and decreased myocardial fatty acid washout, and that myocardial ischemia increased myocardial fatty acid washout. (author)

Fenofibrate Therapy Restores Antioxidant Protection and Improves Myocardial Insulin Resistance in a Rat Model of Metabolic Syndrome and Myocardial Ischemia: The Role of Angiotensin II

Directory of Open Access Journals (Sweden)

Luz Ibarra-Lara

2016-12-01

Full Text Available Renin-angiotensin system (RAS activation promotes oxidative stress which increases the risk of cardiac dysfunction in metabolic syndrome (MetS and favors local insulin resistance. Fibrates regulate RAS improving MetS, type-2 diabetes and cardiovascular diseases. We studied the effect of fenofibrate treatment on the myocardic signaling pathway of Angiotensin II (Ang II/Angiotensin II type 1 receptor (AT1 and its relationship with oxidative stress and myocardial insulin resistance in MetS rats under heart ischemia. Control and MetS rats were assigned to the following groups: (a sham; (b vehicle-treated myocardial infarction (MI (MI-V; and (c fenofibrate-treated myocardial infarction (MI-F. Treatment with fenofibrate significantly reduced triglycerides, non-high density lipoprotein cholesterol (non-HDL-C, insulin levels and insulin resistance index (HOMA-IR in MetS animals. MetS and MI increased Ang II concentration and AT1 expression, favored myocardial oxidative stress (high levels of malondialdehyde, overexpression of nicotinamide adenine dinucleotide phosphate (NADPH oxidase 4 (NOX4, decreased total antioxidant capacity and diminished expression of superoxide dismutase (SOD1, SOD2 and catalase and inhibited expression of the insulin signaling cascade: phosphatidylinositol 3-kinase (PI3K/protein kinase B (PkB, also known as Akt/Glut-4/endothelial nitric oxide synthase (eNOS. In conclusion, fenofibrate treatment favors an antioxidant environment as a consequence of a reduction of the Ang II/AT1/NOX4 signaling pathway, reestablishing the cardiac insulin signaling pathway. This might optimize cardiac metabolism and improve the vasodilator function during myocardial ischemia.

Myocardial perfusion and left ventricular function during exercise evaluated by 201Tl myocardial scintigraphy and 99mTc radionuclide ventriculography in patients treated with PTCA

International Nuclear Information System (INIS)

Honda, Toshio; Jo, Tadafumi; Doiuchi, Junji

1992-01-01

To evaluate the effects of percutaneous transluminal coronary angioplasty (PTCA), we investigated myocardial ischemia and left ventricular function during exercise before and after successful PTCA in 30 patients. We used extent and severity scores of 201 thallium ( 201 Tl) exercise myocardial scintigraphy to assess myocardial ischemia and determined global and regional left ventricular ejection fraction (EF and REF) of 99m Tc-RBC exercise radionuclide ventriculography to assess left ventricular function. The extent and severity scores of stress images were significantly less after PTCA than before PTCA. The scores of the redistribution images were unchanged before and after PTCA. Global EF during exercise was significantly higher after PTCA than before PTCA. There was no difference in resting global EF between before and after PTCA. Myocardial ischemia induced by exercise was semi-quantitatively analyzed as transient perfusion defect with severity score. Severity score was significantly less after PTCA than before PTCA. ΔEF, which was obtained by subtraction of resting global EF from exercise one, was significantly higher after PTCA than before PTCA. However, the degree of improvement in myocardial ischemia and left ventricular function varied from patient to patient. In 17 patients with one-vessel left anterior descending artery disease, ΔREF, which was determined by subtracting resting regional EF from exercise one, was significantly higher in septal and apical segments after PTCA than before PTCA. Myocardial ischemia and left ventricular function under exercise were alleviated by PTCA. However, the degree of improvement varied from patient to patient and it might have been affected by various factors including coronary dissection, edema, thrombus, restenosis, spasm, side branch stenosis or occlusion, distal thrombus, and myocardial hibernation. (author)

Relation of N-terminal pro B-type natriuretic peptide levels after symptom-limited exercise to baseline and ischemia levels.

Science.gov (United States)

van der Zee, P Marc; Verberne, Hein J; van Spijker, Rianne C; van Straalen, Jan P; Fischer, Johan C; Sturk, Augueste; van Eck-Smit, Berthe L F; de Winter, Robbert J

2009-03-01

Circulating levels of B-type natriuretic peptide (BNP) and the amino-terminal portion of the prohormone (NT-proBNP) have been reported to increase immediately after myocardial ischemia. The association between extent of exercise-induced myocardial ischemia measured using myocardial perfusion scintigraphy and the magnitude and time course of changes in NT-proBNP was studied. One hundred one patients underwent symptom-limited exercise myocardial perfusion scintigraphy. Myocardial ischemia was assessed semiquantitatively. Serum samples were obtained before the start of exercise (baseline), at maximal exercise, and every hour up to 6 hours after maximal exercise. Myocardial ischemia was present in 37 patients (37%). NT-proBNP rapidly increased during exercise (to 113%, interquartile range 104 to 144, and 118%, interquartile range 106 to 142, of baseline, respectively), with a second peak at 4 (141%, interquartile range 119 to 169) and 5 hours (136%, interquartile range 93 to 188), respectively. Absolute changes between NT-proBNP at baseline and at maximum exercise in patients with versus without ischemia were similar (median, 30 pg/ml, interquartile range 7 to 45 vs 15, interquartile range 4 to 46, respectively, p = 0.230), but absolute change between baseline and the secondary peak was higher in patients with ischemia than in patients without ischemia (median 64 pg/ml, interquartile range 32 to 172 vs 34, interquartile range 19 to 85, respectively, p = 0.024). In multivariate linear stepwise regression analysis of determinants of changes in NT-proBNP after exercise, baseline NT-proBNP was the only independent determinant of absolute changes at maximum exercise, whereas the presence of ischemia was not predictive. Baseline NT-proBNP, cystatin C, and end-systolic volume were independent determinants of the absolute increase to secondary peak levels. In conclusion, myocardial ischemia per se did not lead to additional increases in NT-proBNP within 6 hours after exercise.

Technetium 99m SESTAMIBI myocardial perfusion imaging: Comparison between treadmill, dipyridamole and trans-oesophageal atrial pacing 'stress' tests in normal subjects

International Nuclear Information System (INIS)

Primeau, M.; Taillefer, R.; Lambert, R.; Essiambre, R.; Honos, G.

1991-01-01

The purpose of this study was to determine the blood clearance, myocardial uptake and heart/lung and heart/liver ratios of technetium 99m methoxyisobutylisonitrile ( 99m Tc-SESTAMIBI) following 3 different types of cardiac stimulation in normal subjects: Treadmill stress (STRESS), intravenous administration of dipyridamole (DIP) and trans-oesophageal atrial pacing (TAP). Ten normal volunteers were submitted to 3 injections of 99m Tc-SESTAMIBI (10 mCi/70 kg, separated by an interval of 7 days) following STRESS (standard Bruce protocol), DIP (0.142 mg/kg.min during 4 min) and TAP procedures. Blood samples were collected from 1 to 60 min after each 99m Tc-SESTAMIBI injection. Planar imaging was performed at 5, 30 and 60 min. Blood retention (percentage of injected dose at 1 min) was 56%±4%, 24%±4% and 38%±6% for STRESS, DIP and TAP, respectively (P 99m Tc-SESTAMIBI. (orig.)

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

International Nuclear Information System (INIS)

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

1987-01-01

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

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

Science.gov (United States)

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

2018-05-01

This study sought to compare the diagnostic accuracy of visual and quantitative analyses of myocardial perfusion cardiovascular magnetic resonance against a reference standard of quantitative coronary angiography. Visual analysis of perfusion cardiovascular magnetic resonance studies for assessing myocardial perfusion has been shown to have high diagnostic accuracy for coronary artery disease. However, only a few small studies have assessed the diagnostic accuracy of quantitative myocardial perfusion. This retrospective study included 128 patients randomly selected from the CE-MARC (Clinical Evaluation of Magnetic Resonance Imaging in Coronary Heart Disease) study population such that the distribution of risk factors and disease status was proportionate to the full population. Visual analysis results of cardiovascular magnetic resonance perfusion images, by consensus of 2 expert readers, were taken from the original study reports. Quantitative myocardial blood flow estimates were obtained using Fermi-constrained deconvolution. The reference standard for myocardial ischemia was a quantitative coronary x-ray angiogram stenosis severity of ≥70% diameter in any coronary artery of >2 mm diameter, or ≥50% in the left main stem. Diagnostic performance was calculated using receiver-operating characteristic curve analysis. The area under the curve for visual analysis was 0.88 (95% confidence interval: 0.81 to 0.95) with a sensitivity of 81.0% (95% confidence interval: 69.1% to 92.8%) and specificity of 86.0% (95% confidence interval: 78.7% to 93.4%). For quantitative stress myocardial blood flow the area under the curve was 0.89 (95% confidence interval: 0.83 to 0.96) with a sensitivity of 87.5% (95% confidence interval: 77.3% to 97.7%) and specificity of 84.5% (95% confidence interval: 76.8% to 92.3%). There was no statistically significant difference between the diagnostic performance of quantitative and visual analyses (p = 0.72). Incorporating rest myocardial

Objective evidence of myocardial ischemia in patients with posttraumatic stress disorder.

Science.gov (United States)

Turner, Jesse H; Neylan, Thomas C; Schiller, Nelson B; Li, Yongmei; Cohen, Beth E

2013-12-01

Patients with posttraumatic stress disorder (PTSD) are at increased risk for cardiovascular disease (CVD), but few studies have included objective measures of CVD and how PTSD causes CVD remains unknown. We sought to determine the association between PTSD and objectively assessed CVD and examine potential underlying mechanisms. Outpatients from two Veterans Affairs Medical Centers were enrolled from 2008 to 2010. Posttraumatic stress disorder was identified using the Clinician Administered PTSD Scale, and standardized exercise treadmill tests were performed to detect myocardial ischemia. Of the 663 participants with complete data, ischemia was present in 17% of patients with PTSD versus 10% of patients without PTSD (p = .006). The association between PTSD and ischemia remained significant after adjusting for potential confounders (age, sex, prior CVD) and mediators (traditional cardiac risk factors, C-reactive protein, obesity, alcohol use, sleep quality, social support, and depression), adjusted odds ratio (OR) 2.42, 95% confidence interval (CI) 1.39 to 4.22, p = .002. Findings remained significant when those with prior CVD were excluded (fully adjusted OR 2.24, 95% CI 1.20-4.18, p = .01) and when continuous PTSD symptom score was used as the predictor (fully adjusted OR per 10-point change in Clinician Administered PTSD Scale score 1.12, 95% CI 1.03-1.22, p = .01). Posttraumatic stress disorder was associated with ischemic changes on exercise treadmill tests independent of traditional cardiac risk factors, C-reactive protein, and several health behaviors and psychosocial risk factors, suggesting additional mechanisms linking PTSD and ischemia should be explored. The association of PTSD and ischemia among patients without known CVD highlights an opportunity for early interventions to prevent progression of cardiovascular disease. Published by Elsevier Inc on behalf of Society of Biological Psychiatry.

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

Energy Technology Data Exchange (ETDEWEB)

Cortinas, Inés Vidal, E-mail: invi@montevideo.com.uy; Beretta, Mario; Alonso, Omar; Mut, Fernando [Departamento de Medicina Nuclear do Hospital ‘Asociación Española’, Br. Artigas 1515, Montevideo (Uruguay)

2015-08-15

Myocardial perfusion scintigraphy (MPS) in patients not reaching 85% of the maximum predicted heart rate (MPHR) has reduced sensitivity. 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. 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. 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). 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.

Quantification of the total Na,K-ATPase concentration in atria and ventricles from mammalian species by measuring 3H-ouabain binding to intact myocardial samples. Stability to short term ischemia reperfusion

DEFF Research Database (Denmark)

Schmidt, Thomas A; Svendsen, J H; Haunsø, S

1990-01-01

,K-ATPase may be less than 1% due to loss during purification. A higher Na,K-ATPase concentration is found in small animals than in large animals. A relationship between higher concentration of Na,K-ATPase and larger pressure work in ventricles compared to atria is suggested. Myocardial 3H-ouabain binding sites...... were found to be stable for 20 min of ischemia, followed by 1 h of reperfusion, supporting the concept that myocyte injury induced by short term ischemia may be reversible and that reperfusion may result in normalization....

Quantification of the total Na,K-ATPase concentration in atria and ventricles from mammalian species by measuring 3H-ouabain binding to intact myocardial samples. Stability to short term ischemia reperfusion

DEFF Research Database (Denmark)

Schmidt, T A; Svendsen, Jesper Hastrup; Haunsø, S

2011-01-01

,K-ATPase may be less than 1% due to loss during purification. A higher Na,K-ATPase concentration is found in small animals than in large animals. A relationship between higher concentration of Na,K-ATPase and larger pressure work in ventricles compared to atria is suggested. Myocardial 3H-ouabain binding sites...... were found to be stable for 20 min of ischemia, followed by 1 h of reperfusion, supporting the concept that myocyte injury induced by short term ischemia may be reversible and that reperfusion may result in normalization....

The Effect of Lidocaine Enriched Cardioplegia on Myocardial Ischemia-Reperfusion Injury

Directory of Open Access Journals (Sweden)

Emin Ata

2016-07-01

Full Text Available Aim: Most of the complications after open heart surgery is usually associated with ischemia reperfusion injury that develops during cardiopulmoner bypass. In ischemia and reperfusion periods lidocaine blocks intracelluler sodium and calcium channels and protect cell membrane against reactive oxygen metabolites. In this study, lidocaine added to cardioplegia solution and its effects on myocardial ischemia-reperfusion injury was examined. Material and Method: 36 patients who underwent elective coronary artery bypass surgery in our clinic between September 2005 and April 2006 was studied. Patients included into two groups. In study group patients (groupe I 2 mg/kg lidocaine was added into cardioplegia solution that is used during aortic cross clamp period; standart cardioplegia solution was used in control group patients (group II. Postoperative 6. and 24. hours cardiac enzyme levels, inotropic support requirement and atrial fibrilation incidence were compared in both groups. Results: In this study, 36 patients (13 women, 23 man whose average age was 63(±5,5, age range 50-70 years and ventriculer functions were not deformed (EF>40% were involved. There were no significantly differences in demographic datas between towo groups. There were no significantly differences in postoperative 6. and 24. hours troponin-I and CK-MB levels, inotropic support or defibrilation requirement and postoperative atrial fibrilation incidence between two groups. Discussion: Addition of 2 mg/kg dosage lidocaine into cardioplegia solution dont effect cardiac enzyme levels, inotropic support requirement and postoperative atrial fibrilation insidence and it doesnt prevent ischemia-reperfusion injury.

Preemptive, but not reactive, spinal cord stimulation mitigates transient ischemia-induced myocardial infarction via cardiac adrenergic neurons

NARCIS (Netherlands)

Southerland, E. M.; Milhorn, D. M.; Foreman, R. D.; Linderoth, B.; DeJongste, M. J. L.; Armour, J. A.; Subramanian, V.; Singh, M.; Singh, K.; Ardell, J. L.

2007-01-01

Our objective was to determine whether electrical neuromodulation using spinal cord stimulation ( SCS) mitigates transient ischemia-induced ventricular infarction and, if so, whether adrenergic neurons are involved in such cardioprotection. The hearts of anesthetized rabbits, subjected to 30 min of

Suv39h1 Protects from Myocardial Ischemia-Reperfusion Injury in Diabetic Rats

Directory of Open Access Journals (Sweden)

Bo Yang

2014-04-01

Full Text Available Background: Patients with diabetes are at increased risk of ischemic events. Suv39h1 is a histone methyltransferase that catalyzes the methylation of histone 3 lysine 9, which is associated with the suppression of inflammatory genes in diabetes. However, the role of Suv39h1 in myocardial ischemia/reperfusion (I/R injury under diabetic condition has not been evaluated. Methods: To generate diabetic model, male SD rats were fed with 60% fat diet followed by intraperitoneal injection with 40mg/kg streptozotocin. Adenovirus encoding Suv39h1 gene was used for Suv39h1 overexpression. Each rat received injections of adenovirus at five myocardial sites. Three days after gene transfection, each rat was subjected to left main coronary artery occlusion and reperfusion. After 30 min ischemia and reperfusion for 4 h, the rats were euthanized for real-time PCR, Western blot, immunohistochemical staining, and morphometric analysis. Results: Delivery of Ad-Suv39h1 into the hearts of diabetic rats could markedly increase Suv39h1 expression. Up-regulation of Suv39h1 significantly reduced infarct size and tissue damage after I/R injury, which was associated with protection from apoptosis of cardiac myocytes and reduction of inflammatory response. In addition, compared with injury group, Ad-Suv39h1 led to a decreased activity of mitogen-activated protein kinase family and its down-steam transcriptional factor NF-κB. Conclusion: Overexpression of Suv39h1 results in the de-activation of proinflammatory pathways and reduced apoptosis and myocardial injury. Therefore, Suv39h1 might represent a novel therapeutic strategy to reduce I/R injury under diabetic condition.

Noninvasive detection of regional myocardial ischemia using rubidium-81 and scintillation camera. Comparison with stress electrocardiography in patients with arteriographically documented coronary stenosis

International Nuclear Information System (INIS)

Berman, D.S.; Salel, A.F.; DeNardo, G.L.; Mason, D.T.

1975-01-01

The sensitivity of rest and stress myocardial perfusion studies using scintillation camera imaging of intravenously administered rubidium-81 ( 81 Rb) in the detection of myocardial ischemia was compared to that of stress electrocardiography by relating results in 40 patients to the degree of stenosis delineated by coronary arteriography. Of 33 patients with greater than 75 percent stenosis of at least one of the three major coronary vessels (significant stenosis), rest and stress 81 Rb imaging detected ventricular ischemia in 29 (88 percent), whereas simultaneous stress electrocardiography was positive (1 mm or greater horizontal ST-segment depression) in only 19 (58 percent) of the same patients. Five of the 29 patients who developed stress-induced scintigraphic evidence of ischemia did not develop angina or a positive electrocardiogram with stress. In 31 of the 33 patients with significant coronary stenosis, either the stress scintigram or the stress electrocardiogram was positive. In seven patients with less than 50 percent narrowing of a major coronary vessel on coronary arteriography, the stress scintigrams were negative, whereas the stress electrocardiograms were positive in the two of these patients with the syndrome of angina with normal coronary arteriograms. It is concluded that high resolution images of the myocardium can be obtained with 81 Rb using the scintillation camera with special shielding, and that rest and stress 81 Rb scintigraphy appears to provide greater sensitivity and specificity when compared to stress electrocardiography in the noninvasive identification of significant coronary stenosis

Myocardial capillary permeability for small hydrophilic indicators during normal physiological conditions and after ischemia and reperfusion

DEFF Research Database (Denmark)

Svendsen, Jesper Hastrup

1991-01-01

Myocardial capillary permeability for small hydrophilic solutes (51Cr-EDTA or 99mTc-DTPA) has been measured using intracoronary indicator bolus injection and external radioactivity registration (the single injection, residue detection method). The method is based on kinetic separation of the inje......Myocardial capillary permeability for small hydrophilic solutes (51Cr-EDTA or 99mTc-DTPA) has been measured using intracoronary indicator bolus injection and external radioactivity registration (the single injection, residue detection method). The method is based on kinetic separation...... including microvascular alterations. In open chest dogs transitory increases in capillary extraction fraction and PdS for small hydrophilic solutes were seen following 20 minutes of regional myocardial ischemia and reperfusion. This response could be inhibited by treatment directed against superoxide...

[Spectrum-Effect Relationship of GualouXiebai Dropping Pills on Myocardial Ischemia].

Science.gov (United States)

Yan, Hai-yan; Zou, Chun-cai; Wei, Mei-ling; Yang, You-yun; Fei, Fu-qi; Xu, Xin-ying

2015-09-01

To study the relationship between HPLC characteristic spectrum and pharmacodynamics on anti-myocardial ischemia of GualouXiebai dropping pills. HPLC characteristic spectrum of GualouXiebai dropping pills was established, dropping pills were divided into five dose groups (3.75, 11.25, 22.5, 33.75 and 45 g/kg, equivalent to the crude herb g/kg), the mice were orally administered dropping pills once daily for 7 d, 90 min after the mice were given by intraperitoneal injection of isoprenaline to establish myocardial ischemia models, the level of CK in blood plasma were detected; Then, the correlation between characteristic spectrum and biochemical index CK was studied by grey relational analysis method. The correlation between each common peak and CK had gradually increased with the dose increased from 3.73 g/kg to 33.75 g/kg, but when the dose reached to 45 g/kg, the correlation between each common peak and CK had decreased. The variation trends of correlation of spectrum-effect relationship for different dose were similar,but the correlation variation trend of the efficacy on the No. 8 peak in 33.75 g/kg group with the other four groups in the opposite, the change trends of the No. 11 peak in 22.5 g/kg group, the No. 24 peak in 33. 75 g/kg group and the No. 37 peak in 45 g/ kg group with 3.75 g/kg group and 11.25 g/kg group on the contrary. The relational orders of spectrum-effect relationship were not consistent, respectively( the first 15 peaks) :11 > 37 > 24 > 30 > 8 > 21 > 2 > 16 > 1 > 3 > 20 > 15 > 12 > 19 > 7;11 > 37 > 30 > 8 > 21 > 24 > 2 > 1 > 16 > 3 > 27 > 12 > 22 > 20 >10; 8 > 30 > 1 > 2 > 21 > 27 > 31 > 22 > 16 > 12 > 3 > 10 > 9 > 20 > 4; 1 > 2 > 27 > 21 > 31 > 22 > 12 > 16 > 9 > 3 > 10 > 4 > 17 > 30 > 20; 8 > 30 > 1 > 2 > 2 > 2 > 7 > 31 > 22 > 16 > 12 > 3 > 9 > 10 > 20 > 17. Anti-myocardial ischemia effect of GualouXiebai dropping pills comes from the synergistic or antagonistic effect among various active ingredients related to the dose. With the

DIAGNOSIS AND THERAPY IN TRANSITORY MYOCARDIAL ISCHEMIA

Directory of Open Access Journals (Sweden)

Anica Pavlovic

2008-01-01

Full Text Available Cardiac dysfunction occurring within subarachnoid hemorrhage named neurogenic stunned myocardium have great impact on intensive care of patients with SAH. Timely diagnosis and treatment of such condition can provide better haemodynamics of damaged brain. The standard follow-up was performed in 30 patients with SAH during two years at the Clinic of Neurosurgery (2005,2006. Serial electrocardiography, echocardiography, as well as laboratory findings of special biomarkers of left ventricular wall motion abnormalities were performed. All patients were treated with Urapidil, Metoprolol, MgSO4 by cheme and ACE inhibitors. Ninety EKG were analyzed in the study, as well as 16 electrocardiographies. The highest levels of CPK, CK-MB and TnI before and after the therapy were also recoded. EKG showed the signs of ischemia in 9 of 30 patients on 1st day and 7 of 30 patients on 3rd day of the therapy. The highest level of CK-MB was present during the 1st day with mean value of 67,80±1,83 IU/L that decreased on 3rd day of therapy with mean value of 66,8±1,83 IU/L, TnI was positive in 16 cases. It showed statistically significant decrease from 0,29 ng/ml till 0,187 ng/ml and p < 0,01. Myocardial ischaemia has been proven to be a very significant complication in SAH. Appropriate treatment of myocardial ischaemia seems to improve systemic haemodynamics, as well as haemodynamics of the damaged brain.

Myocardial capillary permeability after regional ischemia and reperfusion in the in vivo canine heart. Effect of superoxide dismutase

DEFF Research Database (Denmark)

Svendsen, J H; Bjerrum, P J; Haunsø, S

1991-01-01

This study assesses the effect of the superoxide anion scavenger superoxide dismutase on myocardial capillary permeability-surface area (PS) products for small hydrophilic molecules after ischemia and reperfusion. Open-chest dogs underwent a 20-minute occlusion of the left anterior descending...... the start of reperfusion. In 13 dogs, no scavenger treatment was given (nonprotected control group), whereas eight dogs were treated systemically with 15,000 units/kg superoxide dismutase during 1 hour, starting 20 minutes before ischemia. In the control group, three dogs developed reperfusion ventricular...

Safety and diagnostic accuracy of dipyridamole-thallium imaging in the elderly

International Nuclear Information System (INIS)

Lam, J.Y.; Chaitman, B.R.; Glaenzer, M.; Byers, S.; Fite, J.; Shah, Y.; Goodgold, H.; Samuels, L.

1988-01-01

The noninvasive diagnosis of coronary artery disease in the elderly can occasionally be difficult. Intravenous dipyridamole-thallium imaging is a potentially useful diagnostic test to determine presence and severity of coronary disease; however, the safety of the procedure has not been determined in an older population. The side effect profile and frequency of severe ischemic responses after 0.56 mg/kg of intravenous dipyridamole were compared in 101 patients greater than or equal to 70 years old and 236 patients less than 70 years old. There were no side effects in 64% and 62% of patients greater than or equal to 70 and less than 70 years old, respectively (p = NS). Among the 337 patients tested, there were no complications of myocardial infarction or death. The most common cardiac side effect was chest pain, which occurred in 21 (21%) of the 101 patients aged greater than or equal to 70 years and in 64 (27%) of the 236 patients less than 70 years (p = NS). Aminophylline was required to reverse cardiac or noncardiac side effects in 15 (15%) and 36 (15%) of the patients greater than or equal to 70 and less than 70 years old, respectively (p = NS). A severe ischemic response occurred in 2% and 2.5% of patients greater than or equal to 70 and less than 70 years old, respectively (p = NS). The sensitivity of intravenous dipyridamole-thallium imaging for obstructive coronary artery disease was 86% (25 of 29) and 83% (68 of 82) in older and younger patients, respectively (p = NS); the specificity was 75% (6 of 8) and 70% (16 of 23), respectively (p = NS). Thus, intravenous dipyridamole-thallium imaging is a safe noninvasive method for assessment of older patients with obstructive coronary disease; its side effect profile and diagnostic accuracy are similar to those seen in younger patients. The technique is associated with severe ischemic responses in only a small minority of patients

Dipyridamole thallium imaging for detecting cardiac involvement in patients with systemic sclerosis (scleroderma)

Energy Technology Data Exchange (ETDEWEB)

Ishida, Yoshio; Matsubara, Noboru; Tani, Akihiro; Morozumi, Takakazu; Hori, Masatsugu; Kitabatake, Akira; Kamada, Takenobu; Kimura, Kazufumi; Kozuka, Takahiro (Osaka Univ. (Japan). Faculty of Medicine)

1990-02-01

Dipyridamole thallium-201 imaging was carried out in 21 patients with progressive systemic sclerosis (PSS) to assess its value in detecting impaired myocardium and coronary microcirculation associated with PSS. Depending upon the degree of cardiac function, the patients were classified as having either ejection fraction of 50% or more (Group I, n=17) or less than 50% (Group II, n=4). In Group I, four patients had transient defect in which perfusion defects were seen on early images but not seen on delayed images; three had reverse redistribution in which defects were not seen on early images but seen on delayed images; and three had persistent defects which were seen on both early and delayed images. A decreased washout of thallium-201 was seen in 9 patients. In an analysis of both perfusion defects and washout rate, 13 patients (76%) in Group I were found to have abnormal findings. This suggests that disturbed coronary microcirculation or impaired myocardium may frequently develop even when EF is normal. All of the patients categorized as having a decreased cardiac function (Group II) had perfusion defect, suggesting the presence of myocardial fibrosis. In PSS, deterioration of cardiac function seemed to be associated with progression of myocardial fibrosis. Dipyridamole thallium imaging may be a sensitive method for detecting cardiac lesions in PSS. It also has the potential for detecting decreased coronary flow reserve or slightly impaired myocardium even without decreased EF. (N.K.).

Gαi2- and Gαi3-Deficient Mice Display Opposite Severity of Myocardial Ischemia Reperfusion Injury

Science.gov (United States)

Köhler, David; Devanathan, Vasudharani; Bernardo de Oliveira Franz, Claudia; Eldh, Therese; Novakovic, Ana; Roth, Judith M.; Granja, Tiago; Birnbaumer, Lutz; Rosenberger, Peter; Beer-Hammer, Sandra; Nürnberg, Bernd

2014-01-01

G-protein-coupled receptors (GPCRs) are the most abundant receptors in the heart and therefore are common targets for cardiovascular therapeutics. The activated GPCRs transduce their signals via heterotrimeric G-proteins. The four major families of G-proteins identified so far are specified through their α-subunit: Gαi, Gαs, Gαq and G12/13. Gαi-proteins have been reported to protect hearts from ischemia reperfusion injury. However, determining the individual impact of Gαi2 or Gαi3 on myocardial ischemia injury has not been clarified yet. Here, we first investigated expression of Gαi2 and Gαi3 on transcriptional level by quantitative PCR and on protein level by immunoblot analysis as well as by immunofluorescence in cardiac tissues of wild-type, Gαi2-, and Gαi3-deficient mice. Gαi2 was expressed at higher levels than Gαi3 in murine hearts, and irrespective of the isoform being knocked out we observed an up regulation of the remaining Gαi-protein. Myocardial ischemia promptly regulated cardiac mRNA and with a slight delay protein levels of both Gαi2 and Gαi3, indicating important roles for both Gαi isoforms. Furthermore, ischemia reperfusion injury in Gαi2- and Gαi3-deficient mice exhibited opposite outcomes. Whereas the absence of Gαi2 significantly increased the infarct size in the heart, the absence of Gαi3 or the concomitant upregulation of Gαi2 dramatically reduced cardiac infarction. In conclusion, we demonstrate for the first time that the genetic ablation of Gαi proteins has protective or deleterious effects on cardiac ischemia reperfusion injury depending on the isoform being absent. PMID:24858945

Gαi2- and Gαi3-deficient mice display opposite severity of myocardial ischemia reperfusion injury.

Directory of Open Access Journals (Sweden)

David Köhler

Full Text Available G-protein-coupled receptors (GPCRs are the most abundant receptors in the heart and therefore are common targets for cardiovascular therapeutics. The activated GPCRs transduce their signals via heterotrimeric G-proteins. The four major families of G-proteins identified so far are specified through their α-subunit: Gαi, Gαs, Gαq and G12/13. Gαi-proteins have been reported to protect hearts from ischemia reperfusion injury. However, determining the individual impact of Gαi2 or Gαi3 on myocardial ischemia injury has not been clarified yet. Here, we first investigated expression of Gαi2 and Gαi3 on transcriptional level by quantitative PCR and on protein level by immunoblot analysis as well as by immunofluorescence in cardiac tissues of wild-type, Gαi2-, and Gαi3-deficient mice. Gαi2 was expressed at higher levels than Gαi3 in murine hearts, and irrespective of the isoform being knocked out we observed an up regulation of the remaining Gαi-protein. Myocardial ischemia promptly regulated cardiac mRNA and with a slight delay protein levels of both Gαi2 and Gαi3, indicating important roles for both Gαi isoforms. Furthermore, ischemia reperfusion injury in Gαi2- and Gαi3-deficient mice exhibited opposite outcomes. Whereas the absence of Gαi2 significantly increased the infarct size in the heart, the absence of Gαi3 or the concomitant upregulation of Gαi2 dramatically reduced cardiac infarction. In conclusion, we demonstrate for the first time that the genetic ablation of Gαi proteins has protective or deleterious effects on cardiac ischemia reperfusion injury depending on the isoform being absent.

[Anaesthetic-induced myocardial preconditioning: fundamental basis and clinical implications].

Science.gov (United States)

Chiari, P; Bouvet, F; Piriou, V

2005-04-01

Volatile halogenated anaesthetics offer a myocardial protection when they are administrated before a myocardial ischaemia. Cellular mechanisms involved in anaesthetic preconditioning are now better understood. The objectives of this review are to understand the anaesthetic-induced preconditioning underlying mechanisms and to know the clinical implications. References were obtained from PubMed data bank (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi) using the following keywords: volatile anaesthetic, isoflurane, halothane, sevoflurane, desflurane, preconditioning, protection, myocardium. Ischaemic preconditioning (PC) is a myocardial endogenous protection against ischaemia. It has been described as one or several short ischaemia before a sustained ischemia. These short ischaemia trigger a protective signal against this longer ischaemia. An ischemic organ is able to precondition a remote organ. It is possible to replace the short ischaemia by a preadministration of halogenated volatile anaesthetic with the same protective effect, this is called anaesthetic PC (APC). APC and ischaemic PC share similar underlying biochemical mechanisms including protein kinase C, tyrosine kinase activation and mitochondrial and sarcolemnal K(ATP) channels opening. All halogenated anaesthetics can produce an anaesthetic PC effect. Myocardial protection during reperfusion, after the long ischaemia, has been shown by successive short ischaemia or volatile anaesthetic administration, this is called postconditioning. Ischaemic PC has been described in humans in 1993. Clinical studies in human cardiac surgery have shown the possibility of anaesthetic PC with volatile anaesthetics. These studies have shown a decrease of postoperative troponin in patient receiving halogenated anaesthetics.

A novel clinically relevant segmentation method and corresponding maximal ischemia score to risk-stratify patients undergoing myocardial perfusion scintigraphy.

Science.gov (United States)

Nudi, Francesco; Pinto, Annamaria; Procaccini, Enrica; Neri, Giandomenico; Vetere, Maurizio; Tomai, Fabrizio; Gaspardone, Achille; Biondi-Zoccai, Giuseppe; Schillaci, Orazio

2014-08-01

Myocardial perfusion scintigraphy (MPS) represents a key prognostic tool, but its predictive yield is far from perfect. We developed a novel clinically relevant segmentation method and a corresponding maximal ischemia score (MIS) in order to risk-stratify patients undergoing MPS. Patients referred for MPS were identified, excluding those with evidence of myocardial necrosis or prior revascularization. A seven-region segmentation approach was adopted for left ventricular myocardium, with a corresponding MIS distinguishing five groups (no, minimal, mild, moderate, or severe ischemia). The association between MIS and clinical events was assessed at 1 year and at long-term follow-up. A total of 8,714 patients were included, with a clinical follow-up of 31 ± 20 months. Unadjusted analyses showed that subjects with a higher MIS were significantly different for several baseline and test data, being older, having lower ejection fraction, and achieving lower workloads (P < .05 for all). Adverse outcomes were also more frequent in patients with higher levels of ischemia, including cardiac death, myocardial infarction (MI), and their composites (P < .05 for all). Differences in adverse events remained significant even after extensive multivariable adjustment (hazard ratio for each MIS increment = 1.57 [1.29-1.90], P < .001 for cardiac death; 1.19 [1.04-1.36], P = .013 for MI; 1.23 [1.09-1.39], P = .001 for cardiac death/MI). Our novel segmentation method and corresponding MIS efficiently yield satisfactory prognostic information.

Ischemia modified albumin as laboratory marker of acute

Directory of Open Access Journals (Sweden)

Goran Miličević

2009-02-01

Full Text Available Daily clinical practice still lacks a marker of acute myocardial ischemia as compared with markers ofmyocardial necrosis. Ischemia modifed albumin (IMA has recently been proposed as a useful biochemicaltool for detection of ischemia – it is a test which determines the inability of N-terminal end ofalbumin to bind cobalt during ischemia. A strong relation between IMA and early myocardial ischemiahas been shown by several studies, in most of which percutaneous coronary intervention was used asa model of myocardial ischemia, where this test showed high sensitivity. IMA values raise during nextfew minutes after the ischemia has occured, and return back to normal levels within next six hours, butthe precise dynamics of its rise and fall are still unknown. Beside defining etiology of acute or sub-acutechest pain in patients with inconclusive electrocardiogram (ECG, in patients with “silent” myocardialischemia with ischemic changes in ECG or in patients with non-ischemic ECG changes during cardiacstress test, this promising marker could also be used as the earliest biochemical indicator of early developmentof myocardial infarction. Relatively low organ-specificity is a limitation of this test, becauseIMA levels are also raised during different ischemic conditions and diseases of other organs. If thisproblem is taken into consideration, IMA test shows good results in diagnosing myocardial ischemiadue to its high sensitivity.

Ginsenoside Rb1 for Myocardial Ischemia/Reperfusion Injury: Preclinical Evidence and Possible Mechanisms

Directory of Open Access Journals (Sweden)

Qun Zheng

2017-01-01

Full Text Available Ginseng is an important herbal drug that has been used worldwide for many years. Ginsenoside Rb1 (G-Rb1, the major pharmacological extract from ginseng, possesses a variety of biological activities in the cardiovascular systems. Here, we conducted a preclinical systematic review to investigate the efficacy of G-Rb1 for animal models of myocardial ischemia/reperfusion injury and its possible mechanisms. Ten studies involving 211 animals were identified by searching 6 databases from inception to May 2017. The methodological quality was assessed by using the CAMARADES 10-item checklist. All the data were analyzed using RevMan 5.3 software. As a result, the score of study quality ranged from 3 to 7 points. Meta-analyses showed that G-Rb1 can significantly decrease the myocardial infarct size and cardiac enzymes (including lactate dehydrogenase, creatine kinase, and creatine kinase-MB when compared with control group (P<0.01. Significant decrease in cardiac troponin T and improvement in the degree of ST-segment depression were reported in one study (P<0.05. Additionally, the possible mechanisms of G-Rb1 for myocardial infarction are antioxidant, anti-inflammatory, antiapoptosis, promoting angiogenesis and improving the circulation. Thus, G-Rb1 is a potential cardioprotective candidate for further clinical trials of myocardial infarction.

CD4+ Foxp3+ T-cells contribute to myocardial ischemia-reperfusion injury.

Science.gov (United States)

Mathes, Denise; Weirather, Johannes; Nordbeck, Peter; Arias-Loza, Anahi-Paula; Burkard, Matthias; Pachel, Christina; Kerkau, Thomas; Beyersdorf, Niklas; Frantz, Stefan; Hofmann, Ulrich

2016-12-01

The present study analyzed the effect of CD4 + Forkhead box protein 3 negative (Foxp3 - ) T-cells and Foxp3 + CD4 + T-cells on infarct size in a mouse myocardial ischemia-reperfusion model. We examined the infarct size as a fraction of the area-at-risk as primary study endpoint in mice after 30minutes of coronary ligation followed by 24hours of reperfusion. CD4 + T-cell deficient MHC-II KO mice showed smaller histologically determined infarct size (34.5±4.7% in MHCII KO versus 59.4±4.9% in wildtype (WT)) and better preserved ejection fraction determined by magnetic resonance tomography (56.9±2.8% in MHC II KO versus 39.0±4.2% in WT). MHC-II KO mice also displayed better microvascular perfusion than WT mice after 24hours of reperfusion. Also CD4 + T-cell sufficient OT-II mice, which express an in this context irrelevant T-cell receptor, revealed smaller infarct sizes compared to WT mice. However, MHC-II blocking anti-I-A/I-E antibody treatment was not able to reduce infarct size indicating that autoantigen recognition is not required for the activation of CD4 + T-cells during reperfusion. Flow-cytometric analysis also did not detect CD4 + T-cell activation in heart draining lymph nodes in response to 24hours of ischemia-reperfusion. Adoptive transfer of CD4 + T-cells in CD4 KO mice increased the infarct size only when including the Foxp3 + CD25 + subset. Depletion of CD4 + Foxp3 + T-cells in DEREG mice enabling specific conditional ablation of this subset by treatment with diphtheria toxin attenuated infarct size as compared to diphtheria toxin treated WT mice. CD4 + Foxp3 + T-cells enhance myocardial ischemia-reperfusion injury. CD4 + T-cells exert injurious effects without the need for prior activation by MHC-II restricted autoantigen recognition. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Directory of Open Access Journals (Sweden)

Inés Vidal Cortinas

2015-08-01

Full Text Available AbstractBackground: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.

Circadian variation of transient myocardial ischemia in the early out-of-hospital period after first acute myocardial infarction

DEFF Research Database (Denmark)

Mickley, H; Pless, P; Nielsen, J R

1991-01-01

with a peak activity occurring in the evening hours (p less than 0.01). Thus, 43% of ischemic episodes and 42% of ischemic time occurred between 6 P.M. and 12 midnight. The characteristics of morning and evening episodes were similar, except for the heart rate at maximal ST-segment depression, which...... was significantly higher during morning episodes (p less than 0.02). Patients with transient myocardial ischemia had a diurnal distribution similar to the circadian variation displayed during ischemic activity. Thus, 16 of the 21 patients had ischemic episodes from 6 P.M. to 12 midnight versus 10 patients from 6 A...

The effects of epidural bupivacaine on ischemia/reperfusion-induced liver injury.

Science.gov (United States)

Sarikus, Z; Bedirli, N; Yilmaz, G; Bagriacik, U; Bozkirli, F

2016-01-01

Several animal studies showed beneficial effects of thoracic epidural anesthesia (TEA) in hippocampal, mesenteric and myocardial IR injury (2-4). In this study, we investigated the effects of epidural bupivacaine on hepatic ischemia reperfusion injury in a rat model. Eighteen rats were randomly divided into three groups each containing 6 animals. The rats in Group C had sham laparotomy. The rats in the Group S were subjected to liver IR through laparotomy and 20 mcg/kg/h 0.9% NaCl was administered to these rats via an epidural catheter. The rats in the Group B were subjected to liver IR and were given 20 mcg/kg/h bupivacaine via an epidural catheter. Liver tissue was harvested for MDA analysis, apoptosis and histopathological examination after 60 minutes of ischemia followed by 360 minutes of reperfusion. Blood samples were also collected for TNF-α, IL-1β, AST and ALT analysis. The AST and ALT levels were higher in ischemia and reperfusion group, which received only normal saline via the thoracic epidural catheter, compared to the sham group. In the ischemia reperfusion group, which received bupivacaine via the epidural catheter, IL-1 levels were significantly higher than in the other groups. TNF-α levels were higher in the Groups S and B compared to the sham group. Bupivacaine administration induced apoptosis in all animals. These results showed that thoracic epidural bupivacaine was not a suitable agent for preventing inflammatory response and lipid peroxidation in experimental hepatic IR injury in rats. Moreover, epidural bupivacaine triggered apoptosis in hepatocytes. Further research is needed as there are no studies in literature investigate the effects of epidural bupivacaine on hepatic ischemia reperfusion injury (Tab. 3, Fig. 3, Ref. 34).

The significance of a dipyridamole induced [sup 99m]Tc-MIBI perfusion abnormality on single photon emission tomography: A quantiative validation with labelled water and positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Rechavia, E.; Galassi, A.R.; Araujo, L.I.; Halson, P.; Lammertsma, A.; Jones, T.; Lavender, J.P.; Maseri, A. (Royal Postgraduate Medical School, London (United Kingdom). Nuclear Medicine Dept. Medical Research Council, London (United Kingdom). Cyclotron Unit Medical Research Council, London (United Kingdom). Cardiovascular Unit)

1992-12-01

To relate [sup 99m]Tc-MIBI uptake to regional myocardial blood flow (rMBF), [sup 99m]Tc-MIBI SPET and H[sub 2] [sup 15]O PET scans were obtained at rest and after dipyridamole infusion in six patients with single vessel coronary artery disease. [sup 99m]Tc-MIBI-H[sub 2] [sup 15]O data sets were created for each segment perfused by the stenotic vessel and for a normal reference area, assigning regions on the SPET tomograms to comparable regions on the PET by similar transaxial image reconstructions. All patients demonstrated post-dipyridamole [sup 99m]Tc-MIBI perfusion defects in the territories supplied by the stenotic arteries; Resting rMBF in these regions was slightly lower than that in the normal areas. A 43% [+-] 14% reduction in [sup 99m]Tc-MIBI activity in the area at risk was coupled with on average a 60% [+-] 9% reduction in post-dipyridamole rMBF compared with control regions. Thus, SPET assessment of [sup 99m]Tc-MIBI uptake tends to underestimate the perfusion contrast between areas with normal and areas with low coronary vasodilatory reserve when compared to PET. However, these findings may still not affect the clinical usefulness of [sup 99m]Tc-MIBI and more extensive studies are required to confirm these results in the clinical environment (orig./MG).

Evaluation of myocardial abnormalities in collagen diseases by thallium-201 myocardial scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Yamano, Shigeru; Kagoshima, Tadashi; Sugihara, Kiyotaka (Nara Medical Univ., Kashihara (Japan)) (and others)

1993-12-01

This study was performed to evaluate myocardial abnormalities in patients with collagen diseases by exercise and rest thallium-201 myocardial scintigrams. A total of 65 patients without ischemic ECG changes, consisting of 18 with systemic lupus erythematosus (SLE), 18 with polymyositis (PM), 8 with progressive systemic sclerosis (PSS), and 21 with Sjoegren's syndrome (SjS), was enrolled in this study. Reversible exercise-induced defects scintigraphically suggesting myocardial ischemia were noted in 8 cases of SLE, 4 cases of PM, 4 cases of PSS, and 3 cases of SjS. Nineteen patients had exercise-induced defects and underwent cardiac catheterization, 8 of whom had normal coronary angiograms. Fixed hypoperfusion areas were observed in one case of SLE, 6 cases of PM and 3 cases of SjS. Rest thallium-201 myocardial scintigram disclosed hypoperfusion areas which were not induced by exercise in 2 cases of SLE, 3 cases of PM, one case of PSS and 5 cases of SjS. Echocardiogram showed no significant differences in ejection fraction and % fractional shortening between the disease groups and healthy control group. These findings suggest that patients with collagen diseases have abnormalities of coronary circulation at the level of the intramural vasculature before cardiac function impairment, myocardial fibrosis and functional abnormalities at the cell membrane. (author).

Melatonin ameliorates myocardial ischemia reperfusion injury through SIRT3-dependent regulation of oxidative stress and apoptosis.

Science.gov (United States)

Zhai, Mengen; Li, Buying; Duan, Weixun; Jing, Lin; Zhang, Bin; Zhang, Meng; Yu, Liming; Liu, Zhenhua; Yu, Bo; Ren, Kai; Gao, Erhe; Yang, Yang; Liang, Hongliang; Jin, Zhenxiao; Yu, Shiqiang

2017-09-01

Sirtuins are a family of highly evolutionarily conserved nicotinamide adenine nucleotide-dependent histone deacetylases. Sirtuin-3 (SIRT3) is a member of the sirtuin family that is localized primarily to the mitochondria and protects against oxidative stress-related diseases, including myocardial ischemia/reperfusion (MI/R) injury. Melatonin has a favorable effect in ameliorating MI/R injury. We hypothesized that melatonin protects against MI/R injury by activating the SIRT3 signaling pathway. In this study, mice were pretreated with or without a selective SIRT3 inhibitor and then subjected to MI/R operation. Melatonin was administered intraperitoneally (20 mg/kg) 10 minutes before reperfusion. Melatonin treatment improved postischemic cardiac contractile function, decreased infarct size, diminished lactate dehydrogenase release, reduced the apoptotic index, and ameliorated oxidative damage. Notably, MI/R induced a significant decrease in myocardial SIRT3 expression and activity, whereas the melatonin treatment upregulated SIRT3 expression and activity, and thus decreased the acetylation of superoxide dismutase 2 (SOD2). In addition, melatonin increased Bcl-2 expression and decreased Bax, Caspase-3, and cleaved Caspase-3 levels in response to MI/R. However, the cardioprotective effects of melatonin were largely abolished by the selective SIRT3 inhibitor 3-(1H-1,2,3-triazol-4-yl)pyridine (3-TYP), suggesting that SIRT3 plays an essential role in mediating the cardioprotective effects of melatonin. In vitro studies confirmed that melatonin also protected H9c2 cells against simulated ischemia/reperfusion injury (SIR) by attenuating oxidative stress and apoptosis, while SIRT3-targeted siRNA diminished these effects. Taken together, our results demonstrate for the first time that melatonin treatment ameliorates MI/R injury by reducing oxidative stress and apoptosis via activating the SIRT3 signaling pathway. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons

Relationships between the lung-heart ratio assessed from post-exercise thallium-201 myocardial tomograms, myocardial ischemia and the extent of coronary artery disease

International Nuclear Information System (INIS)

Ilmer, B.; Reijs, A.E.; Reiber, J.H.; Bakker, W.; Fioretti, P.

1990-01-01

Uptake of thallium (Tl)-201 in the lungs has been proposed as a measure of left ventricular dysfunction. In this study we were interested in pursuing two goals: (1) to assess possible relationships between the post-exercise Tl-201 lung-heart (LH)-ratio determined from the anterior view during SPECT-acquisition, myocardial ischemia and the extent of coronary artery disease; and (2) to explore the effects of coronary revascularisation procedures on the LH-ratio. The study group consisted of 145 patients with early and late postexercise Tl-201 tomograms, including 32 PTCA-patients with pre- and post-PTCA studies and 20 patients who underwent coronary artery bypass surgery (CABG) with corresponding pre- and post-CABG studies. Ischemia was defined as evoked angina during the exercise test in combination with greater than or equal to 1 mm horizontal or downsloping ST-depression on the ECG. The severity of coronary obstructions was assessed from coronary angiograms with a PC-based digital caliper technique; a stenosis was defined to be significant when its severity exceeded 50% diameter stenosis. The LH-ratio was defined by the ratio of the mean pulmonary counts and the mean myocardial counts assessed from corresponding regions of interest (ROI's) positioned over the left lung and the heart, respectively in the anterior view of a tomographic data acquisition procedure. Our results made clear that the LH-ratio was not significantly different between patients with and without ischemia during exercise, and between patients with single vs. multiple vessel disease

The relationship between myocardial blood flow and myocardial viability after reperfusion. Myocardial viability assessed by 15O-water-PET

International Nuclear Information System (INIS)

Tsukagoshi, Joichi

1994-01-01

The purpose of this study was to examine the relationship between myocardial blood flow and myocardial viability in the ischemic canine myocardium after reperfusion. Transient ischemia was induced by 60-, 90-, and 180-minute occlusion of the left anterior descending coronary artery. Myocardial blood flow (MBF) was measured in the areas in which regional contractility was severely impaired (ehocardiographically akinetic or dyskinetic) in the early reperfusion period by 15 O-water positron emission tomography (PET) 12 hours and 4 weeks after reperfusion. An MBF ratio of ischemic to nonischemic regions 12 hours after reperfusion was inversely correlated with the amount of histologically determined tissue necrosis (r=-0.74). The regional contractility recovered 4 weeks later in the areas where an MBF ratio was 0.48 or greater, but did not recover in the areas with a lower MBF ratio. Thus, myocardial viability can be appropriately predicted in the early phase of myocardial perfusion by PET with 15 O-water even in the absence of metabolic imaging. (author)

The use of coronary vasodilators in myocardial imaging with 43K

International Nuclear Information System (INIS)

Markov, A.K.; Smith, R.O.; Oglethorpe, N.C.; Lehan, P.H.; Hellems, H.K.

1980-01-01

As an alternative procedure to the exercise stress test used in myocardial scanning, vasoactive drugs were employed to elicit deficits in blood flow to myocardial regions supplied by stenotic arteries. The data were collected from 35 dogs, some of which had partial stenosis on either major branch of the left coronary artery, and others which had Ameroid constrictor implants. The effects of lidoflazine, dipyridamole, and nitroglycerin on coronary hemodynamics and myocardial dispersion of 43 K in animals with partial stenosis were evaluated in ten acute experiments. In the pilot studies, four rapid serial rectilinear control scans from 43 K (750 μCi) were reported; dipyridamole, lidoflazine, or nitroglycerin were then administered intravenously. When the selected drug reached a peak vasodilatative effect, a second equal bolus of 43 K was given and four additional scans recorded. The control scans from dogs with partial stenosis or an Ameroid constrictor showed homogeneous distribution of the myocardial 43 K. When drugs were used, the region supplied by compromised circulation became apparent because of lower counts when compared to the normally perfused ones. Coronary vasodilators, as opposed to postexercise in myocardial imaging, have a lesser effect on cardiac dynamics, peripheral hemodynamics, and also double the 43 K uptake in normally perfused myocardium. (orig.) [de

Dobutamine stress MRI. Part I. Safety and feasibility of dobutamine cardiovascular magnetic resonance in patients suspected of myocardial ischemia

International Nuclear Information System (INIS)

Kuijpers, Dirkjan; Janssen, Caroline H.C.; Oudkerk, Matthijs; Dijkman, Paul R.M. van

2004-01-01

The aim of the study was to evaluate safety and feasibility of dobutamine cardiovascular magnetic resonance (CMR) in patients with proven or suspected coronary artery disease. Dobutamine CMR was evaluated retrospectively in 400 consecutive patients with suspicion of myocardial ischemia. Dobutamine was infused using an incremental protocol up to 40 μg/kg body weight per minute. All anti-anginal medication was stopped 4 days before the CMR study and infusion time of dobutamine was 6 min per stage. Hemodynamic data, CMR findings and side effects were reported. Patients with contraindications to CMR (metallic implants and claustrophobia) were excluded from analysis. Dobutamine CMR was successfully performed in 355 (89%) patients. Forty-five (11%) patients could not be investigated adequately because of non-cardiac side effects in 29 (7%) and cardiac side effects in 16 (4%) patients. Hypotension (1.5%) and arrhythmias (1%) were the most frequent cardiac side effects. One patient developed a severe complication (ventricular fibrillation) at the end of the study. There were no myocardial infarctions or fatal complications of the stress test. The most frequent non-cardiac side effects were nausea, vomiting and claustrophobia. Age >70 years, prior myocardial infarction and rest wall motion abnormalities showed no significant differences with side effects (P>0.05). Dobutamine CMR is safe and feasible in patients with suspicion of myocardial ischemia. (orig.)

Dobutamine stress MRI. Part I. Safety and feasibility of dobutamine cardiovascular magnetic resonance in patients suspected of myocardial ischemia.

Science.gov (United States)

Kuijpers, Dirkjan; Janssen, Caroline H C; van Dijkman, Paul R M; Oudkerk, Matthijs

2004-10-01

The aim of the study was to evaluate safety and feasibility of dobutamine cardiovascular magnetic resonance (CMR) in patients with proven or suspected coronary artery disease. Dobutamine CMR was evaluated retrospectively in 400 consecutive patients with suspicion of myocardial ischemia. Dobutamine was infused using an incremental protocol up to 40 microg/kg body weight per minute. All anti-anginal medication was stopped 4 days before the CMR study and infusion time of dobutamine was 6 min per stage. Hemodynamic data, CMR findings and side effects were reported. Patients with contraindications to CMR (metallic implants and claustrophobia) were excluded from analysis. Dobutamine CMR was successfully performed in 355 (89%) patients. Forty-five (11%) patients could not be investigated adequately because of non-cardiac side effects in 29 (7%) and cardiac side effects in 16 (4%) patients. Hypotension (1.5%) and arrhythmias (1%) were the most frequent cardiac side effects. One patient developed a severe complication (ventricular fibrillation) at the end of the study. There were no myocardial infarctions or fatal complications of the stress test. The most frequent non-cardiac side effects were nausea, vomiting and claustrophobia. Age >70 years, prior myocardial infarction and rest wall motion abnormalities showed no significant differences with side effects (P>0.05). Dobutamine CMR is safe and feasible in patients with suspicion of myocardial ischemia. Copyright 2004 Springer-Verlag

Dobutamine stress MRI. Part I. Safety and feasibility of dobutamine cardiovascular magnetic resonance in patients suspected of myocardial ischemia

Energy Technology Data Exchange (ETDEWEB)

Kuijpers, Dirkjan [State University and Academic Hospital Groningen, Department of Radiology, Groningen (Netherlands); Bronovo Hospital, Department of Radiology and Cardiology, Bronovolaan 1, P.O. Box 96900, The Hague (Netherlands); Janssen, Caroline H.C.; Oudkerk, Matthijs [State University and Academic Hospital Groningen, Department of Radiology, Groningen (Netherlands); Dijkman, Paul R.M. van [Bronovo Hospital, Department of Radiology and Cardiology, Bronovolaan 1, P.O. Box 96900, The Hague (Netherlands)

2004-10-01

The aim of the study was to evaluate safety and feasibility of dobutamine cardiovascular magnetic resonance (CMR) in patients with proven or suspected coronary artery disease. Dobutamine CMR was evaluated retrospectively in 400 consecutive patients with suspicion of myocardial ischemia. Dobutamine was infused using an incremental protocol up to 40 {mu}g/kg body weight per minute. All anti-anginal medication was stopped 4 days before the CMR study and infusion time of dobutamine was 6 min per stage. Hemodynamic data, CMR findings and side effects were reported. Patients with contraindications to CMR (metallic implants and claustrophobia) were excluded from analysis. Dobutamine CMR was successfully performed in 355 (89%) patients. Forty-five (11%) patients could not be investigated adequately because of non-cardiac side effects in 29 (7%) and cardiac side effects in 16 (4%) patients. Hypotension (1.5%) and arrhythmias (1%) were the most frequent cardiac side effects. One patient developed a severe complication (ventricular fibrillation) at the end of the study. There were no myocardial infarctions or fatal complications of the stress test. The most frequent non-cardiac side effects were nausea, vomiting and claustrophobia. Age >70 years, prior myocardial infarction and rest wall motion abnormalities showed no significant differences with side effects (P>0.05). Dobutamine CMR is safe and feasible in patients with suspicion of myocardial ischemia. (orig.)

Transient myocardial ischemia after a first acute myocardial infarction and its relation to clinical characteristics, predischarge exercise testing and cardiac events at one-year follow-up

DEFF Research Database (Denmark)

Mickley, H; Pless, P; Nielsen, J R

1993-01-01

recording 11 +/- 5 days after AMI 23 patients (19%) had 123 ischemic episodes (group 1), whereas 100 patients demonstrated no ischemia (group 2). Exercise-induced ST-segment depression was more prevalent in group 1 (83%) than in group 2 (47%) (p ... as judged from a shorter exercise duration before significant ST-segment depression (5.5 +/- 2.4 vs 7.7 +/- 4.1 minutes; p depression on exercise testing (4.1 +/- 2.6 vs 2.6 +/- 1.6 mm; p exercise test results revealed an impaired hemodynamic......The relation between early out-of-hospital ambulatory ST-segment monitoring, clinical characteristics, predischarge maximal exercise testing and cardiac events was determined in 123 consecutive men (age 55 +/- 8 years) with a first acute myocardial infarction (AMI). During 36 hours of ambulatory...

Myocardial injury and protection related to cardiopulmonary bypass

NARCIS (Netherlands)

de Hert, Stefan; Moerman, Anneliese

2015-01-01

During cardiac surgery with cardiopulmonary bypass, the heart is isolated from the circulation. This inevitably induces myocardial ischemia. In addition to this ischemic insult, an additional hit will occur upon reperfusion, which may worsen the extent of tissue damage and organ dysfunction. Over

Extracorporeal Shock Wave Therapy for Coronary Artery Disease: Relationship of Symptom Amelioration and Ischemia Improvement

Directory of Open Access Journals (Sweden)

Youko Takakuwa

2018-01-01

Full Text Available Objective(s: The current management of coronary artery disease (CAD relies on three major therapeutic options, namely medication, percutaneous coronary intervention (PCI, and coronary artery bypass grafting (CABG. However, severe CAD that is not indicated for PCI or CABG still bears a poor prognosis due to the lack of effective treatments. In 2006, extracorporeal cardiac shock wave (SW therapy reported on human for the first time. This treatment resulted in better myocardial perfusion as evaluated by dipyridamole stress thallium scintigraphy, angina symptoms, and exercise tolerance. The aim of the present study was to investigate myocardial perfusion images and evaluate the relationship between the ischemia improvement and symptom amelioration by SW therapy. Methods: We treated ten patients (i.e., nine males and one female with cardiac SW therapy who had CAD but not indicated for PCI or CABG and aged 63–89 years old. After the SW therapy, all patients were followed up for three months to evaluate any amelioration of the myocardial ischemia based on symptoms, adenosine stress thallium scintigraphy, transthoracic echocardiography, and blood biochemical examinations. Results: The changes in various parameters were evaluated before and after cardiac SW therapy. The cardiac SW therapy resulted in a significant improvement in the symptoms as evaluated by the Canadian Cardiovascular Society [CCS] class score (P=0.016 and a tendency to improve in summed stress score (SSS (P=0.068. However, no significant improvement was observed in the summed rest score (SRS, summed difference score (SDS, left ventricular wall motion score index (LVWMSI, N-terminal pro-brain natriuretic, and troponin I. The difference of CCS class score (ΔCCS was significantly correlated with those of SSS (ΔSSS and SDS (ΔSDS (r=0.69, P=0.028 and r=0.70, P=0.025, respectively. There was no significant correlation between ΔCCS and other parameters. Furthermore, no significant

The value of radionuclide angiography for risk assessment of patients following acute myocardial infarction

International Nuclear Information System (INIS)

Morris, K.G.

1985-01-01

Radionuclide angiography (RNA) is an accurate noninvasive method for the evaluation of left ventricular function at rest and exercise. Both the change in ejection fraction from rest to exercise and the exercise ejection fraction correlate with the severity of coronary artery disease and are more sensitive than ST-segment changes for detecting abnormalities due to exercise-induced myocardial ischemia. The amount of left ventricular dysfunction produced acutely by myocardial ischemia appears to vary linearly with the severity of ischemia produced. Thus rest and exercise RNA provide information noninvasively regarding both the severity of left ventricular dysfunction and the amount of potentially ischemic myocardium, two of the three major pathophysiologic mechanisms related to prognosis. It is reasonable to hypothesize that rest and exercise RNA may provide useful prognostic information concerning subsequent mortality and morbidity in survivors of acute myocardial infarction

Postoperative myocardial infarction documented by technetium pyrophosphate scan using single-photon emission computed tomography: Significance of intraoperative myocardial ischemia and hemodynamic control

International Nuclear Information System (INIS)

Cheng, D.C.; Chung, F.; Burns, R.J.; Houston, P.L.; Feindel, C.M.

1989-01-01

The aim of this prospective study was to document postoperative myocardial infarction (PMI) by technetium pyrophosphate scan using single-photon emission computed tomography (TcPPi-SPECT) in 28 patients undergoing elective coronary bypass grafting (CABG). The relationships of intraoperative electrocardiographic myocardial ischemia, hemodynamic responses, and pharmacological requirements to this incidence of PMI were correlated. Radionuclide cardioangiography and TcPPi-SPECT were performed 24 h preoperatively and 48 h postoperatively. A standard high-dose fentanyl anesthetic protocol was used. Twenty-five percent of elective CABG patients were complicated with PMI, as documented by TcPPi-SPECT with an infarcted mass of 38.0 +/- 5.5 g. No significant difference in demographic, preoperative right and left ventricular function, number of coronary vessels grafted, or aortic cross-clamp time was observed between the PMI and non-PMI groups. The distribution of patients using preoperative beta-adrenergic blocking drugs or calcium channel blocking drugs was found to have no correlation with the outcome of PMI. As well, no significant differences in hemodynamic changes or pharmacological requirements were observed in the PMI and non-PMI groups during prebypass or postbypass periods, indicating careful intraoperative control of hemodynamic indices did not prevent the outcome of PMI in these patients. However, the incidence of prebypass ischemia was 39.3% and significantly correlated with the outcome of positive TcPPi-SPECT, denoting a 3.9-fold increased risk of developing PMI. Prebypass ischemic changes in leads II and V5 were shown to correlate with increased CPK-MB release (P less than 0.05) and tends to occur more frequently with lateral myocardial infarction

Postoperative myocardial infarction documented by technetium pyrophosphate scan using single-photon emission computed tomography: Significance of intraoperative myocardial ischemia and hemodynamic control

Energy Technology Data Exchange (ETDEWEB)

Cheng, D.C.; Chung, F.; Burns, R.J.; Houston, P.L.; Feindel, C.M. (Toronto Hospital, Ontario (Canada))

1989-12-01

The aim of this prospective study was to document postoperative myocardial infarction (PMI) by technetium pyrophosphate scan using single-photon emission computed tomography (TcPPi-SPECT) in 28 patients undergoing elective coronary bypass grafting (CABG). The relationships of intraoperative electrocardiographic myocardial ischemia, hemodynamic responses, and pharmacological requirements to this incidence of PMI were correlated. Radionuclide cardioangiography and TcPPi-SPECT were performed 24 h preoperatively and 48 h postoperatively. A standard high-dose fentanyl anesthetic protocol was used. Twenty-five percent of elective CABG patients were complicated with PMI, as documented by TcPPi-SPECT with an infarcted mass of 38.0 +/- 5.5 g. No significant difference in demographic, preoperative right and left ventricular function, number of coronary vessels grafted, or aortic cross-clamp time was observed between the PMI and non-PMI groups. The distribution of patients using preoperative beta-adrenergic blocking drugs or calcium channel blocking drugs was found to have no correlation with the outcome of PMI. As well, no significant differences in hemodynamic changes or pharmacological requirements were observed in the PMI and non-PMI groups during prebypass or postbypass periods, indicating careful intraoperative control of hemodynamic indices did not prevent the outcome of PMI in these patients. However, the incidence of prebypass ischemia was 39.3% and significantly correlated with the outcome of positive TcPPi-SPECT, denoting a 3.9-fold increased risk of developing PMI. Prebypass ischemic changes in leads II and V5 were shown to correlate with increased CPK-MB release (P less than 0.05) and tends to occur more frequently with lateral myocardial infarction.

Hydroxytyrosol Protects against Myocardial Ischemia/Reperfusion Injury through a PI3K/Akt-Dependent Mechanism

Directory of Open Access Journals (Sweden)

Ying-hao Pei

2016-01-01

Full Text Available Objective. To investigate the effects and mechanisms of hydroxytyrosol (HT during the pathogenesis of myocardial ischemia reperfusion (I/R in rat hearts. Methods. The rats were randomized into five groups: sham group, I/R group, HT+I/R group, HT+LY294002+I/R group, and LY+I/R group. Myocardial infarct size, markers of oxidative stress, extent of myocardial apoptosis, echocardiographically assessed cardiac function, and expression of Akt and GSK 3β were measured in each group. Results. Prereperfusion administration of HT was associated with a significantly smaller area of myocardial infarction and remarkably decreased level of myocardial apoptosis and necrosis, as evidenced by a lower apoptotic index, reduced cleaved caspase-3, and the serum activities of lactate dehydrogenase and creatinine kinase MB. Moreover, HT also attenuated the impairment of cardiac systolic function. However, cotreatment with LY294002 and HT completely abolished the above cardioprotective effects of HT. A subsequent mechanistic study revealed that the cardioprotective effects of HT during the process of I/R of the myocardium were dependent on the activation of the Akt/GSK3β pathway. Conclusion. Pretreatment with HT may have antiapoptotic and cardioprotective effects against myocardial I/R injury, and these effects seem to be related to the activation of the Akt/GSK3β pathway in the myocardium.

Markers of Myocardial Ischemia in Patients with Obstructive Sleep Apnea and Coronary Artery Disease

Directory of Open Access Journals (Sweden)

Misa Valo

2015-01-01

Full Text Available Obstructive sleep apnea (OSA is characterized by intermittent hypoxia during sleep. We tested the hypothesis that nocturnal myocardial ischemia is detectable by ST segment depression and elevation of high sensitive troponin T (hsTrop T and B-type natriuretic peptide (NT-proBNP in patients with OSA and coexisting coronary artery disease (CAD. Twenty-one patients with OSA and CAD and 20 patients with OSA alone underwent in-hospital polysomnography. Blood samples for hsTrop T and NT-proBNP measurements were drawn before and after sleep. ST segment depression was measured at the time of maximum oxygen desaturation during sleep. The apnea-hypopnea-index (AHI, oxygen saturation nadir, and time in bed with oxygen saturation of ≤80% were similar in both groups. Levels of hsTrop T and NT-proBNP did not differ significantly before and after sleep but NT-proBNP levels were significantly higher in patients suffering from OSA and CAD compared to patients with OSA alone. No significant ST depression was found at the time of oxygen saturation nadir in either group. Despite the fact that patients with untreated OSA and coexisting CAD experienced severe nocturnal hypoxemia, we were unable to detect myocardial ischemia or myocyte necrosis based on significant ST segment depression or elevation of hsTrop T and NT-proBNP, respectively.

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

International Nuclear Information System (INIS)

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

1990-01-01

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

Cardioprotection of CAPE-oNO2 against myocardial ischemia/reperfusion induced ROS generation via regulating the SIRT1/eNOS/NF-κB pathway in vivo and in vitro

Directory of Open Access Journals (Sweden)

Dejuan Li

2018-05-01

Full Text Available Caffeic acid phenethyl ester (CAPE could ameliorate myocardial ischemia/reperfusion injury (MIRI by various mechanisms, but there hadn’t been any reports on that CAPE could regulate silent information regulator 1 (SIRT1 and endothelial nitric oxide synthase (eNOS to exert cardioprotective effect. The present study aimed to investigate the cardioprotective potential of caffeic acid o-nitro phenethyl ester (CAPE-oNO2 on MIRI and the possible mechanism based on the positive control of CAPE. The SD rats were subjected to left coronary artery ischemia /reperfusion (IR and the H9c2 cell cultured in hypoxia/reoxygenation (HR to induce the MIRI model. Prior to the procedure, vehicle, CAPE or CAPE-oNO2 were treated in the absence or presence of a SIRT1 inhibitor nicotinamide (NAM and an eNOS inhibitor Nω-nitro-L-arginine methyl ester (L-NAME. In vivo, CAPE and CAPE-oNO2 conferred a cardioprotective effect as shown by reduced myocardial infarct size, cardiac marker enzymes and structural abnormalities. From immunohistochemical and sirius red staining, above two compounds ameliorated the TNF-α release and collagen deposition of IR rat hearts. They could agitate SIRT1 and eNOS expression, and consequently enhance NO release and suppress NF-κB signaling, to reduce the malondialdehyde content and cell necrosis. In vitro, they could inhibit HR-induced H9c2 cell apoptosis and ROS generation by activating SIRT1/eNOS pathway and inhabiting NF-κB expression. Emphatically, CAPE-oNO2 presented the stronger cardioprotection than CAPE both in vivo and in vitro. However, NAM and L-NAME eliminated the CAPE-oNO2-mediated cardioprotection by restraining SIRT1 and eNOS expression, respectively. It suggested that CAPE-oNO2 ameliorated MIRI by suppressing the oxidative stress, inflammatory response, fibrosis and necrocytosis via the SIRT1/eNOS/NF-κB pathway.

Exploring ischemia-induced vascular lesions and potential pharmacological intervention strategies.

Science.gov (United States)

Aliev, G; Obrenovich, M E; Seyidova, D; de la Torre, J C

2005-01-01

Structural changes in vessels under the influence of ischemia play an important role in the pathogenesis of many diseases, most important of which are stroke and myocardial infarction or myocardial insult. Over the years, information has been gathered, which implicate a role for ischemic vascular changes in the pathogenesis of crush-syndrome, atherosclerosis and other vascular diseases. When blood vessels are damaged they become unresponsive to a stimulus, which normally elicits vasodilatation and can lead to intraluminal thrombosis and ischemic events. The aim of this review is to explore the structural changes seen in vessels affected by ischemia reperfusion injury. With ischemia, the development of observable changes to vascular structure is multifactorial. One key factor is reperfusion ischemic injury. Moreover, the duration of the ischemic event is an important factor when determining both the prognosis and the type of morphological change that is observable in affected vessel walls. In this regard, the deleterious progression of blood flow impairment and its severity depends on the specific organ involved and the type of tissue affected. Further, there are regional differences within affected tissues and the degree of microvascular injury is well correlated with differences in the nature and severity of the ischemic event. Any method aimed at preventing and treating ischemic reperfusion injuries in vessels, based on these investigations, should likewise be able to decrease the early signs of brain, cerebrovascular and heart injury and preserve normal cellular architecture.

Reliability of the exercise ECG in detecting silent ischemia in patients with prior myocardial infarction

International Nuclear Information System (INIS)

Yamagishi, Takashi; Matsuda, Yasuo; Satoh, Akira

1991-01-01

To assess the reliability of the exercise ECG in detecting silent ischemia, ECG results were compared with those of stress-redistribution thallium-201 single-photon emission computed tomography (SPECT) in 116 patients with prior myocardial infarction and in 20 normal subjects used as a control. The left ventricle (LV) was divided into 20 segmental images, which were scored blindly on a 5-point scale. The redistribution score was defined as thallium defect score of exercise subtracted by that of redistribution image and was used as a measure of amount of ischemic but viable myocardium. The upper limit of normal redistribution score (=4.32) was defined as mean+2 standard deviations derived from 20 normal subjects. Of 116 patients, 47 had the redistribution score above the normal range. Twenty-five (53%) of the 47 patients showed positive ECG response. Fourteen (20%) of the 69 patients, who had the normal redistribution score, showed positive ECG response. Thus, the ECG response had a sensitivity of 53% and a specificity of 80% in detecting transient ischemia. Furthermore, the 116 patients were subdivided into 4 groups according to the presence or absence of chest pain and ECG change during exercise. Fourteen patients showed both chest pain and ECG change and all these patients had the redistribution score above the normal range. Twenty-five patients showed ECG change without chest pain and 11 (44%) of the 25 patients had the abnormal redistribution. Three (43%) of 7 patients who showed chest pain without ECG change had the abnormal redistribution score. Of 70 patients who had neither chest pain nor ECG change, 19 (27%) had the redistribution score above the normal range. Thus, limitations exist in detecting silent ischemia by ECG in patients with a prior myocardial infarction, because the ECG response to the exercise test may have a low degree of sensitivity and a high degree of false positive and false negative results in detecting silent ischemia. (author)

A comparison between 99Tcm-tetrofosmin and 99Tcm-MIBI myocardial perfusion imaging in detection of silent myocardial ischemia

International Nuclear Information System (INIS)

Fu Wei; Tang Yi; Liu Xuemei; Fan Yan; Liu Tao

2012-01-01

Objective: To compare 99 Tc m -tetrofosmin (TF) and 99 Tc m -MIBI adenosine stress/resting MPI in detection of silent myocardial ischemia (SMI). Methods: According to the WHO diagnostic criteria for coronary heart disease (CHD), 306 SMI patients were classified to three groups as type Ⅰ (n=122), type Ⅱ (n=112) and type Ⅲ (n=72). The subjects of each type were randomly divided into 2 subgroups; one subgroup underwent adenosine stress/rest MPI with 99 Tc m -MIBI and another subgroup with 99 Tc m -TF. The clinical diagnosis of CHD was proven with electrocardiogram (46 cases), dynamic electrocardiogram (219 cases) or CAG (41 cases). Comparison factors between the two tracers included image quality and diagnostic efficacy. The image quality was graded into three classes:excellent, good and moderate. χ 2 test and analysis of variance were used to analyze data. Results: The sensitivities of detecting myocardial ischemia with 99 Tc m -MIBI MPI and 99 Tc m -TF MPI in group type Ⅰ were 57.38% (35/61) vs 60.66% (37/61) (χ 2 =0.136, P>0.05); in group type Ⅱ 69.64% (39/56) vs 64.29% (36/56) (χ 2 =0.363, P>0.05) and in group type Ⅲ 83.33% (30/36) vs 88.89% (32/36) (χ 2 =0.465, P>0.05), respectively. There was no significant difference between the sensitivities of the two imaging modalities in all three types of SMI patients.In image quality grading, 99 Tc m -MIBI and 99 Tc m -TF demonstrated excellent images with 41.18% (63/153) vs 48.37% (74/153) (χ 2 =1.599, P=0.206), good with 45.10% (69/153) vs 34.64% (53/153) (χ 2 =3.489, P=0.062) and moderate with 13.72% (21/153) vs 16.99%(26/153) (χ 2 =0.628, P=0.428). There was no unqualified image with either modality. 99 Tc m -TF displayed quicker radioactivity clearance in liver and lungs. Thereby there was less interference or pitfalls present in the ventricle base or interior wall that may result from higher liver radioactivity retention. The waiting time between the tracer injection and imaging was at least 1 h

Hypercholesterolemic myocardium is vulnerable to ischemia-reperfusion injury and refractory to sevoflurane-induced protection.

Directory of Open Access Journals (Sweden)

Yong Xu

Full Text Available Recent studies have demonstrated that volatile anesthetic postconditioning confers myocardial protection against ischemia-reperfusion (IR injury through activation of the reperfusion injury salvage kinase (RISK pathway. As RISK has been shown to be impaired in hypercholesterolemia. Therefore, we investigate whether anesthetic-induced cardiac protection was maintained in hypercholesterolemic rats. In the present study, normocholesteolemic or hypercholesterolemic rat hearts were subjected to 30 min of ischemia and 2 h of reperfusion. Animals received 2.4% sevoflurane for 5 min or 3 cycles of 10-s ischemia/10-s reperfusion. The hemodynamic parameters, including left ventricular developed pressure, left ventricular end-diastolic pressure and heart rate, were continuously monitored. The infarct size, apoptosis, p-Akt, p-ERK1/2, p-GSK3β were determined. We found that both sevoflurane and ischemic postconditioning significantly improved heart pump function, reduced infarct size and increased the phosphorylation of Akt, ERK1/2 and their downstream target of GSK3β in the healthy rats. In the hypercholesterolemic rats, neither sevoflurane nor ischemic postconditioning improved left ventricular hemodynamics, reduced infarct size and increased the phosphorylated Akt, ERK1/2 and GSK3β. In contrast, GSK inhibitor SB216763 conferred cardioprotection against IR injury in healthy and hypercholesterolemic hearts. In conclusions, hyperchoesterolemia abrogated sevoflurane-induced cardioprotection against IR injury by alteration of upstream signaling of GSK3β and acute GSK inhibition may provide a novel therapeutic strategy to protect hypercholesterolemic hearts against IR injury.

A New Therapeutic Modality for Acute Myocardial Infarction: Nanoparticle-Mediated Delivery of Pitavastatin Induces Cardioprotection from Ischemia-Reperfusion Injury via Activation of PI3K/Akt Pathway and Anti-Inflammation in a Rat Model.

Directory of Open Access Journals (Sweden)

Kazuhiro Nagaoka

Full Text Available There is an unmet need to develop an innovative cardioprotective modality for acute myocardial infarction (AMI, for which the effectiveness of interventional reperfusion therapy is hampered by myocardial ischemia-reperfusion (IR injury. Pretreatment with statins before ischemia is shown to reduce MI size in animals. However, no benefit was found in animals and patients with AMI when administered at the time of reperfusion, suggesting insufficient drug targeting into the IR myocardium. Here we tested the hypothesis that nanoparticle-mediated targeting of pitavastatin protects the heart from IR injury.In a rat IR model, poly(lactic acid/glycolic acid (PLGA nanoparticle incorporating FITC accumulated in the IR myocardium through enhanced vascular permeability, and in CD11b-positive leukocytes in the IR myocardium and peripheral blood after intravenous treatment. Intravenous treatment with PLGA nanoparticle containing pitavastatin (Pitavastatin-NP, 1 mg/kg at reperfusion reduced MI size after 24 hours and ameliorated left ventricular dysfunction 4-week after reperfusion; by contrast, pitavastatin alone (as high as 10 mg/kg showed no therapeutic effects. The therapeutic effects of Pitavastatin-NP were blunted by a PI3K inhibitor wortmannin, but not by a mitochondrial permeability transition pore inhibitor cyclosporine A. Pitavastatin-NP induced phosphorylation of Akt and GSK3β, and inhibited inflammation and cardiomyocyte apoptosis in the IR myocardium.Nanoparticle-mediated targeting of pitavastatin induced cardioprotection from IR injury by activation of PI3K/Akt pathway and inhibition of inflammation and cardiomyocyte death in this model. This strategy can be developed as an innovative cardioprotective modality that may advance currently unsatisfactory reperfusion therapy for AMI.

Fibroblast growth factor-1 improves cardiac functional recovery and enhances cell survival after ischemia and reperfusion: a fibroblast growth factor receptor, protein kinase C, and tyrosine kinase-dependent mechanism

NARCIS (Netherlands)

Palmen, Meindert; Daemen, Mat J. A. P.; de Windt, Leon J.; Willems, Jodil; Dassen, Willem R. M.; Heeneman, Sylvia; Zimmermann, Rene; van Bilsen, Marc; Doevendans, Pieter A.

2004-01-01

We sought to investigate the role of fibroblast growth factor (FGF)-1 during acute myocardial ischemia and reperfusion. The FGFs display cardioprotective effects during ischemia and reperfusion. We investigated FGF-1-induced cardioprotection during ischemia and reperfusion and the intracellular

Effect of programmed ventricular stimulation on myocardial lactate extraction in patients with and without coronary artery disease

International Nuclear Information System (INIS)

Morady, F.; DiCarlo, L.A. Jr.; Krol, R.B.; de Buitleir, M.; Nicklas, J.M.; Annesley, T.M.

1986-01-01

The arterial-coronary sinus lactate difference was measured in 17 patients after each step of a programmed ventricular stimulation protocol consisting of single, double, and triple extrastimuli, first at a basic drive cycle length of 600 msec, then at 400 msec, with an inter-train interval of 4 seconds. Four patients had no structural heart disease, four had an idiopathic dilated cardiomyopathy, and nine had coronary artery disease with a significant stenosis in at least one branch of the left coronary artery. Net myocardial lactate production during programmed ventricular stimulation was observed in three patients with coronary artery disease, but not in any patient without coronary artery disease. Among the patients who had coronary artery disease, net myocardial lactate production generally occurred in the patients who had more severe coronary artery disease. Exercise-induced ischemia, as demonstrated by a stress thallium-201 test, did not correlate with myocardial lactate production during programmed ventricular stimulation. Programmed ventricular stimulation, with a stimulation protocol typically used in many electrophysiology laboratories, is capable of inducing myocardial ischemia in at least some patients who have coronary artery disease. This finding suggests that myocardial ischemia may potentially influence the results of programmed ventricular stimulation in some patients with coronary artery disease

Fatty acid myocardial imaging using iodine-123-beta-methyl-para-iodophenyl pentadecanoic acid (BMIPP) in patients with hypertrophic cardiomyopathy (HCM)

International Nuclear Information System (INIS)

Wada, Toyofumi

1993-01-01

Myocardial ischemia has been shown to develop during exercise and to play an important role on the pathophysiology in patients with hypertrophic cardiomyopathy (HCM). However, it is known whether or not myocardial ischemia is present under basal condition. BMIPP myocardial imaging has been proven to be useful for the detection of regional abnormalities of fatty acid metabolism induced by myocardial ischemia. We therefore performed BMIPP and Tl myocardial imagings in 18 patients with HCM. Six patients with chest pain syndrome or idiopathic ventricular arrhythmia served as controls. BMIPP and Tl scintigraphies were performed at least five days apart for avoiding cross talk and after overnight fasting. Six control subjects presented BMIPP images similar to Tl images without appreciable discrepancy. Of 18 patients with HCM, 15 manifested segments of reduced BMIPP uptakes as compared with those of Tl images. These segments of reduced BMIPP in patients with HCM were mainly observed in segments of increased Tl uptake, and suggested that myocardial ischemia was present under basal condition. Since the reduction of BMIPP uptake were often localized to parts of segments of increased Tl uptake, small coronary disease seemed to be a mechanism responsible for myocardial ischemia developing during resting condition. Four patients with apical hypertrophy showed reduction of BMIPP uptake in the hypertrophied apical segments. The observation suggests that abnormal myocardial energy metabolism is in progress during resting state, although the condition is generally considered to be benign. (author)

Evaluation of potassium-43 scintillation images during early myocardial ischemia in an animal model

International Nuclear Information System (INIS)

Haider, B.; Oldewurtel, H.A.; Moschos, C.B.; Regan, T.J.

1976-01-01

To assess the validity of myocardial imaging with potassium-43 ( 43 K) early after the onset of ischemia, the left anterior descending artery was occluded with a balloon tip catheter in 32 intact anesthetized dogs. /sup 99m/Technetium ventriculograms localized the left ventricle. 43 K was administered intravenously and serial images were obtained in four views using an Anger camera with a pinhole collimator. The heart was arrested after 60 minutes and removed for imaging and tissue counts to ascertain extracardiac and geometric factors. In normals (group 1) left ventricular images were relatively homogeneous, except for the thin walled apex, both in vivo and in the isolated heart. Equilibration with 43 K prior to ischemia (group 2) gave similar images to group 1, associated with a small reduction in tissue counts after one hour of ischemia. Group 3 was infused with 43 K after initiation of ischemia. Despite a reduction of 43 K counts in the ischemic area to less than one-fourth of the nonischemic site (P < 0.001), demonstration of a ''cold area'' in vivo was inconstant, occurring in only 34 percent of studies. Lead shielding did not improve accuracy. In the isolated heart the ability to detect the cold area was improved to 73 percent. However, when the left ventricle was incised and spread flat, so that low and high activity areas were contiguous rather than superimposed, a widespread area of ischemia was present without exception in the anterior wall. Use of a rectilinear scanner in seven animals failed to improve diagnostic yield; areas of reduced radioactivity were seen at the apex in normals by both techniques. Thus, while detection of low flow areas in the isolated heart is feasible by isotopic imaging early after the onset of ischemia, both extracardiac and geometric factors can contribute to qualitative and quantitative errors in vivo

Zero Flow Global Ischemia-Induced Injuries in Rat Heart Are Attenuated by Natural Honey

Science.gov (United States)

Najafi, Moslem; Zahednezhad, Fahimeh; Samadzadeh, Mehrban; Vaez, Haleh

2012-01-01

Purpose: In the present study, effects of preischemic administration of natural honey on cardiac arrhythmias and myocardial infarction size during zero flow global ischemia were investigated in isolated rat heart. Methods: The isolated hearts were subjected to 30 min zero flow global ischemia followed by 120 min reperfusion then perfused by a modified drug free Krebs-Henseleit solution throughout the experiment (control) or the solution containing 0.25, 0.5, 1 and 2% of natural honey for 15 min before induction of global ischemia (treated groups), respectively. Cardiac arrhythmias were determined based on the Lambeth conventions and the infarct size was measured by computerized planimetry. Results: Myocardial infarction size was 55.8±7.8% in the control group, while preischemic perfusion of honey (0.25, 0.5, 1 and 2%) reduced it to 39.3±11, 30.6±5.5 (Phoney concentrations and infarction size reduction was observed (R2=0.9948). In addition, total number of ventricular ectopic beats were significantly decreased by all used concentrations of honey (PHoney (0.25, 0.5 and 1 %) also lowered incidence of irreversible ventricular fibrillation (Phoney treated groups. Conclusion: Preischemic administration of natural honey before zero flow global ischemia can protect isolated rat heart against ischemia/reperfusion injuries as reduction of infarction size and arrhythmias. Maybe, antioxidant and free radical scavenging activities of honey, reduction of necrotized tissue and providing energy sources may involve in these cardioprotective effects of honey. PMID:24312788

Cardioprotection against experimental myocardial ischemic injury using cornin

Directory of Open Access Journals (Sweden)

Y. Xu

2016-01-01

Full Text Available Phosphorylated-cyclic adenosine monophosphate response element-binding protein (Phospho-CREB has an important role in the pathogenesis of myocardial ischemia. We isolated the iridoid glycoside cornin from the fruit of Verbena officinalis L, investigated its effects against myocardial ischemia and reperfusion (I/R injury in vivo, and elucidated its potential mechanism in vitro. Effects of cornin on cell viability, as well as expression of phospho-CREB and phospho-Akt in hypoxic H9c2 cells in vitro, and myocardial I/R injury in vivo, were investigated. Cornin attenuated hypoxia-induced cytotoxicity significantly in H9c2 cells in a concentration-dependent manner. Treatment of H9c2 cells with cornin (10 µM blocked the reduction of expression of phospho-CREB and phospho-Akt in a hypoxic condition. Treatment of rats with cornin (30 mg/kg, iv protected them from myocardial I/R injury as indicated by a decrease in infarct volume, improvement in hemodynamics, and reduction of severity of myocardial damage. Cornin treatment also attenuated the reduction of expression of phospho-CREB and phospho-Akt in ischemic myocardial tissue. These data suggest that cornin exerts protective effects due to an increase in expression of phospho-CREB and phospho-Akt.

Evaluation of acute ischemia in pre-procedure ECG predicts myocardial salvage after primary PCI in STEMI patients with symptoms >12hours

DEFF Research Database (Denmark)

Fakhri, Yama; Busk, Martin; Schoos, Mikkel Malby

2016-01-01

-presenters). The Anderson-Wilkin's score (AW-score) estimates the acuteness of myocardial ischemia from the electrocardiogram (ECG) in STEMI patients. We hypothesized that the AW-score is superior to symptom duration in identifying substantial salvage potential in late-presenters. METHODS: The AW-score (range 1......-4) was obtained from the pre-pPCI ECG in 55 late-presenters and symptoms 12-72 hours. Myocardial perfusion imaging was performed to assess area at risk before pPCI and after 30days to assess myocardial salvage index (MSI). We correlated both the AW-score and pain-to-balloon with MSI and determined the salvage...

Clinical significance of stress-induced ST segment changes in patients with previous myocardial infarction

International Nuclear Information System (INIS)

Futagami, Yasuo; Hamada, Masayuki; Makino, Katsutoshi; Ichikawa, Takehiko; Konishi, Tokuji

1984-01-01

To explain the clinical significance of stress(st)-induced ST-segment (ST) changes postinfarction, 93 patients with previous myocardial infarction (MI) were performed st- 201 Tl myocardial single photon emission computed tomography (SPECT) and compared ST changes with SPECT, coronary arteriographic and left ventriculographic findings. 30 out of 93 cases (32%) had ST depression, 20 (21.5%) had ST elevation, 9 (10%) had both ST depression and elevation and remaining 34 (36.5 %) had no significant ST changes. In single vessel disease, ST depression were noted in 29% (12/42), while in multivessel disease, 53% (27/51). 35 out of 39 cases (90%) with ST depression had transient perfusion defect but no apparent relation was noted between location of ST depression on ECG and region of transient perfusion defect in SPECT. All of 28 cases with ST elevation were noted in anterior MI cases, and 26 out of these showed severe LV wall motion abnormality in contrast left ventriculography and broad anterior permanent defect in SPECT. Only 15 cases (54%) showed slight redistribution. Thus, we conclude that in patients with previous MI, st-induced ST depression seems to reflect myocardial ischemia and ST elevation possibly related abnormal LV wall motion. (author)

Gastric injury induced by hemorrhage, local ischemia, and oxygen radical generation

International Nuclear Information System (INIS)

Wadhwa, S.S.; Perry, M.A.

1987-01-01

Gastric mucosal injury caused by local intra-arterial generation of oxygen-derived free radicals was compared with gastric injury caused by 30 min of hemorrhage-induced ischemia or local ischemia. The index of injury was the loss of 51 Cr-labeled red cells across the gastric mucosa. Generation of oxygen radicals in the celiac artery caused a rapid increase in mucosal blood loss during the period of radical generation, and this loss was maintained after radical production ceased. Local ischemia produced similar mucosal injury; however, this occurred after reperfusion of the stomach and not during the ischemic episode. Hemorrhage-induced ischemia produced a threefold greater mucosal blood loss than local ischemia. The results of this study indicate that (1) oxygen radicals generated enzymatically in the blood supply to the stomach cause mucosal bleeding of similar magnitude to that observed after local ischemia and (2) that gastric ischemia induced by systemic hypotension produces more severe gastric injury than the same level of local hypotension

Myocardial ischemia analysis based on electrocardiogram QRS complex

International Nuclear Information System (INIS)

Song, J.; Yan, H.; Xu, Z.; Yu, X.; Zhu, R.

2011-01-01

Full text: Electrocardiogram (ECG) is an economic, convenient, and non-invasive detecting tool in myocardial ischemia (MI), and its clinical appearance is mainly exhibited by the changes in ST-T complex. Recently, QRS complex characters were proposed to analyze MI by more and more researchers. In this paper, various QRS complex characters were extracted in ECG signals, and their relationship was analyzed systematically. As a result, these characters were divided into two groups, and there existed good relationship among them for each group, while the poor relationship between the groups. Then these QRS complex characters were applied for statistical analysis on MI, and five characters had significant differences after ECG recording verification, which were: QRS upward and downward slopes, transient heart rate, angle R and angle Q. On the other hand, these QRS complex characters were analyzed in frequency domain. Experimental results showed that the frequency features of RR interval series (Heart Rate Variability, HRV), and QRS barycenter sequence had signjficant differences between MI states and normal states. Moreover, QRS barycenter sequence performed better. (author)

Myocardial perfusion scintigraphy with exercise and pharmacological stress

Energy Technology Data Exchange (ETDEWEB)

Sundram, F X [General Hospital of Singapore, Dept. of Nuclear Medicine (Senegal)

1996-12-31

Cardiac studies including myocardial perfusion scintigraphy was begun in the Singapore General Hospital, nuclear medicine department in 1983. From a few patients per year using planar imaging, we have in 1994 studied 1500 patients for myocardial perfusion, using mainly SPECT (single-photon emission computerised tomography) and radionuclides such as Thallium-201, Technetium-99m sestamibi and Tc-99m tetrofosmin. Patients have been stressed using treadmill exercise or pharmacological agents; we have used dipyridamole, and dobutamine for pharmacological stress but have no experience with intravenous adenosine.

Myocardial perfusion scintigraphy with exercise and pharmacological stress

International Nuclear Information System (INIS)

Sundram, F.X.

1995-01-01

Cardiac studies including myocardial perfusion scintigraphy was begun in the Singapore General Hospital, nuclear medicine department in 1983. From a few patients per year using planar imaging, we have in 1994 studied 1500 patients for myocardial perfusion, using mainly SPECT (single-photon emission computerised tomography) and radionuclides such as Thallium-201, Technetium-99m sestamibi and Tc-99m tetrofosmin. Patients have been stressed using treadmill exercise or pharmacological agents; we have used dipyridamole, and dobutamine for pharmacological stress but have no experience with intravenous adenosine

Zero Flow Global Ischemia-Induced Injuries in Rat Heart Are Attenuated by Natural Honey

OpenAIRE

Najafi, Moslem; Zahednezhad, Fahimeh; Samadzadeh, Mehrban; Vaez, Haleh

2012-01-01

Purpose: In the present study, effects of preischemic administration of natural honey on cardiac arrhythmias and myocardial infarction size during zero flow global ischemia were investigated in isolated rat heart. Methods: The isolated hearts were subjected to 30 min zero flow global ischemia followed by 120 min reperfusion then perfused by a modified drug free Krebs-Henseleit solution throughout the experiment (control) or the solution containing 0.25, 0.5, 1 and 2% of natural honey...

Significance of increased lung thallium-201 activity on serial cardiac images after dipyridamole treatment in coronary heart disease

International Nuclear Information System (INIS)

Okada, R.D.; Dai, Y.H.; Boucher, C.A.; Pohost, G.M.

1984-01-01

Increased lung thallium-201 (Tl-201) activity occurs in patients with severe coronary artery disease (CAD) on initial postexercise images. To determine the significance of assessing lung Tl-201 on serial imaging after dipyridamole therapy, initial and delayed (2 to 3 hours) Tl-201 imaging was performed in 40 patients with CAD and 26 normal control subjects. Lung Tl-201 activity was quantitated as a percentage of maximal myocardial activity for each imaging time (lung Tl-201 index). The mean initial lung Tl-201 activity was 42 +/- 2% (+/- standard error of the mean) in 26 control subjects, 56 +/- 2% in 25 patients with 2- or 3-vessel CAD (p less than 0.001) and 53 +/- 2% in 15 patients with 1-vessel CAD (p less than 0.005 compared with control subjects) (difference not significant between 1-vessel and multivessel CAD). Dipyridamole lung Tl-201 activity decreased relative to the myocardium from initial to delayed images (p less than 0.001) in patients with CAD but not in control subjects. When a dipyridamole lung Tl-201 index of 58% (mean +/- 2 standard deviations for control subjects) was chosen as the upper limit of normal, 14 of 40 of the CAD patients (35%) had abnormal values and all control patients had values within normal limits. These 14 patients with CAD and abnormal initial lung Tl-201 indexes had rest ejection fractions that were not significantly different from those in patients with CAD, and normal initial dipyridamole lung Tl-201 index (58 +/- 4% and 63 +/- 2%, respectively)

The effect of levosimendan on myocardial ischemia–reperfusion injury in streptozotocin-induced diabetic rats

Science.gov (United States)

Kiraz, Hasan Ali; Poyraz, Fatih; Kip, Gülay; Erdem, Özlem; Alkan, Metin; Arslan, Mustafa; Özer, Abdullah; Şivgin, Volkan; Çomu, Faruk Metin

2015-01-01

Objective Ischemia/reperfusion (I/R) injury is an important cause of myocardial damage by means of oxidative, inflammatory, and apoptotic mechanisms. The aim of the present study was to examine the potential cardio protective effects of levosimendan in a diabetic rat model of myocardial I/R injury. Methods A total of 18 streptozotocin-induced diabetic Wistar Albino rats (55 mg/kg) were randomly divided into three equal groups as follows: the diabetic I/R group (DIR) in which myocardial I/R was induced following left thoracotomy, by ligating the left anterior descending coronary artery for 60 min, followed by 2 h of reperfusion; the diabetic I/R levosimendan group (DIRL), which underwent I/R by the same method while taking levosimendan intraperitoneal 12 µg kg−1; and the diabetic control group (DC) which underwent sham operations without tightening of the coronary sutures. As a control group (C), six healthy age-matched Wistar Albino rats underwent sham operations similar to the DC group. Two hours after the operation, the rats were sacrificed and the myocardial tissue samples were examined by light microscopy for evidence of myonecrosis and inflammatory cell infiltration. Results Myonecrosis findings were significantly different among groups (p=0.008). Myonecrosis was more pronounced in the DIR group compared with the C, DC, and DIRL groups (p=0.001, p=0.007 and p=0.037, respectively). Similarly, the degree of inflammatory cell infiltration showed significant difference among groups (p<0.0001). Compared with C, DC, and DIRL groups, the inflammatory cell infiltration was significantly higher among the DIR group (p<0.0001, p<0.0001, and p=0.020, respectively). Also, myocardial tissue edema was significantly different among groups (p=0.006). The light microscopic myocardial tissue edema levels were significantly higher in the DIR group than the C, DC, and DIRL groups (p=0.001, p=0.037, and p=0.014, respectively). Conclusion Taken together, our data indicate that

San-Huang-Xie-Xin-Tang Prevents Rat Hearts from Ischemia/Reperfusion-Induced Apoptosis through eNOS and MAPK Pathways

Directory of Open Access Journals (Sweden)

Shu-Fen Liou

2011-01-01

Full Text Available San-Huang-Xie-Xin-Tang (SHXT is a traditional Chinese medication consisting of three herbs, namely Coptidis rhizome, Scutellariae radix and Rhei rhizome. This study aimed to examine the cardioprotective effects of SHXT in a rat model of acute myocardial apoptosis induced by ischemia/reperfusion (I/R. Vehicle (intravenous saline or SHXT (intravenous or oral was administered prior to I/R (occlusion of left coronary artery for 45 min followed by reperfusion for 2 h. In the vehicle group, myocardial I/R caused myocardial infarction with increased plasma cardiac enzymes, severe arrhythmia and mortality. Myocardial apoptosis was induced by I/R as evidenced by DNA ladder and Bcl-2/Bax ratio. In the SHXT group, we found that SHXT significantly reduced plasma levels of cardiac enzymes, arrhythmia scores (from 5 ± 1 to 2 ± 1, P<.01 and mortality rate (from 53 to 0%, P<.01. In addition, pretreatment with intravenous SHXT reduced the infarct size dose-dependently when compared with the vehicle group (10 mg kg−1: 14.0 ± 0.2 versus 44.5 ± 5.0%, and 30 mg kg−1: 6.2 ± 1.2% versus 44.5 ± 5.0%, both P<.01. Similarly, oral administration of SHXT reduced the infarct size dose-dependently. Furthermore, SHXT markedly decreased the apoptosis induced by I/R with increased Bcl-2/Bax ratio. Finally, we found that SHXT counteracted the I/R-induced downstream signaling, resulting in increased myocardial eNOS expression and plasma nitrite, and decreased activation of ERK1/2, p38 and JNK. These data suggest that SHXT has cardioprotective effects against I/R-induced apoptosis, and that these effects are mediated, at least in part, by eNOS and MAPK pathways.

Beneficial effects of combined benazepril-amlodipine on cardiac nitric oxide, cGMP, and TNF-alpha production after cardiac ischemia.

Science.gov (United States)

Siragy, Helmy M; Xue, Chun; Webb, Randy L

2006-05-01

The aim of this study was to determine if myocardial inflammation is increased after myocardial ischemia and whether angiotensin-converting enzyme inhibitors, calcium channel blockers, or diuretics decrease mediators of inflammation in rats with induced myocardial ischemia. Changes in cardiac interstitial fluid (CIF) levels of nitric oxide metabolites (NOX), cyclic guanosine 3',5'-monophosphate (cGMP), angiotensin II (Ang II), and tumor necrosis factor-alpha (TNF-alpha) were monitored with/without oral administration of benazepril, amlodipine, combined benazepril-amlodipine, or hydrochlorothiazide. Using a microdialysis technique, levels of several mediators of inflammation were measured after sham operation or 30-minute occlusion of the left anterior descending coronary artery. Compared with sham animals, levels of CIF NOX and cGMP were decreased in animals with ischemia (P Benazepril or amlodipine significantly increased NOX levels (P benazepril significantly increased cGMP (P benazepril-amlodipine further increased CIF NOX and cGMP (P benazepril alone, or combined benazepril-amlodipine significantly reduced TNF-alpha (P benazepril-amlodipine may be beneficial for managing cardiac ischemia.