Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0151744 (myocardial ischemia)
 31,282 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A method for the diagnosis of stunned myocardium has not yet been established, although it has been retrospectively demonstrated in patients after intracoronary thrombolysis, unstable angina, and coronary revascularization. In this study, radionuclide cardiac imaging was carried out to evaluate the existence of stunned myocardium. 1) Gated blood pool scanning was performed in patients undergoing intracoronary thrombolysis both at the time of reperfusion (Rp) and 10 days later. In the Rp less than 4 h group, about half of the initially abnormal segments showed complete improvement on quantitative wall motion analysis, which was more than in the Rp greater than 4 h and control groups. 2) In patients with acute myocardial ischemia, the correlation between thallium perfusion and regional wall motion was assessed semiquantitatively. In unstable angina, 5.8% of the ventricular wall segments showed dissociation between perfusion and wall motion (well-perfused asynergy). These segments had abnormal wall motion although perfusion was maintained, and were thought to be areas of stunned myocardium. 3) Fourteen dogs were studied using thallium and 123I-beta-methyliodophenyl pentadecanoic acid (BMIPP) fatty acid imaging to evaluate the relationship of perfusion to metabolism. In the reperfusion model, mismatching of the pattern of thallium and BMIPP uptake was observed. Reperfused myocardium probably has an increased triglyceride content, which is related to the degree of myocardial viability. In conclusion, stunned myocardium may be correctly diagnosed acutely on the basis of alterations in its perfusion, metabolism, and function by using radionuclide cardiac imaging.
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PMID:Radionuclide assessment of stunned myocardium by alterations in perfusion, metabolism and function. 194 96

A case is presented of rate-dependent left bundle branch block associated with chest pain in a patient with angiographically normal coronary arteries. Lactate extraction showed no evidence of myocardial ischemia. It appears that in this case, chest pain was associated with sudden ventricular asynergy rather than myocardial ischemia.
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PMID:Rate-related left bundle branch block as a cause of non-ischemic chest pain. 199 74

The purpose of this study is to increase understanding of the prognosis of coronary artery disease (CAD) patients whose anginal symptoms have been removed by medical therapy, and to evaluate the prognostic and clinical significance of silent myocardial ischemia (SMI). Cardiac events including cardiac death, acute myocardial infarction, PTCA/CABG and unstable angina were examined in 253 CAD patients who underwent ambulatory Holter monitoring, treadmill exercise testing and coronary angiography. The subjects were classified into two groups: 93 patients with exertional angina (AP) without previous myocardial infarction and 160 patients with old myocardial infarction (MI). SMI was diagnosed by Holter monitoring. Cox's proportional hazard regression model and the survival curves using the Kaplan-Meier method were used to analyze 9 variables in patients with AP, including Holter monitoring parameters, exercise parameters and angiographic findings, and 12 variables in patients with MI, including the same parameters as in AP patients. The cardiac event rate was 19% in patients with AP and 18% in patients with MI. The independent and common predictors of unfavorable outcome in both groups were severe coronary lesion and SMI. The incidence of SMI was 30% in AP patients and 38% in MI patients, the same incidence as reported in previous studies. The cardiac event rate in patients with SMI was higher than in those without SMI for both groups (28% vs 9% and 32% vs 9%; p less than 0.05). However, the most frequent cardiac event was different in the groups with SMI: PTCA/CABG in AP patients and re-infarction in MI patients. The significant predictors of cardiac events in patients with SMI were severe coronary lesion, short exercise duration, severe asynergy and exercise-induced angina in patients with AP and lower ejection fraction and maximum ST depression on Holter monitoring in patients with MI. In conclusion, it was ascertained that SMI is a significant and independent marker of unfavorable outcome in patients with CAD and that the cardiac event rate in patients with SMI was significantly higher than in those without SMI. However, severe complications such as acute myocardial infarction were more frequent in MI patients than in AP patients. Therefore, it was suggested that the use of re-vascularization procedure (PTCA/CABG) should be considered as soon as possible in patients with SMI, regardless of whether anginal symptoms are present or not.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[A study on the prognostic significance of silent myocardial ischemia in angina pectoris and myocardial infarction patients]. 201 42

Recently 123I-MIBG scintigraphy has been developed for evaluating the function of cardiac sympathetic nerve. To assess its ischemic damage, dual SPECT with 123I-MIBG and 201Tl-Cl were performed in 24 patients with ischemic heart disease and 8 normal subjects. In order to evaluate extent and severity of ischemic damage, Tl and MIBG abnormal scores were calculated by Bull's eye map. In patients with Non-Q wave myocardial infarction (NQMI), MIBG abnormal scores were significantly higher than Tl scores (p less than 0.01). In the regions where regional wall motion showed hypokinesis, MIBG abnormalities were detected in all cases whereas Tl abnormalities existed only in 42%. MIBG abnormality score in NQMI group with negative T wave and wall motion asynergy was significantly higher than that of NQMI group without T wave abnormality and asynergy (p less than 0.01). Ischemic damage of cardiac sympathetic nerve seemed to contribute to negative T wave and stunned myocardium. 123I-MIBG scintigraphy was thought to be a sensitive and useful method for clinical evaluation of ischemic heart disease.
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PMID:[Assessment of ischemic damage of the cardiac sympathetic nerve function by semiquantitative analysis of 123I-MIBG (metaiodobenzylguanidine)-SPECT--comparison with 201Tl-Cl-SPECT]. 223 50

Inappropriate discharge from the emergency room of patients with acute chest pain may have serious consequences. Regional asynergy is one of the first signs of myocardial ischemia and can be detected with 2-dimensional echocardiography (2-DE). This study determines the value of 2-DE in the emergency room for immediate detection of myocardial ischemia causing acute chest pain at the time the electrocardiogram was nondiagnostic. Forty-three patients (32 men and 11 women) with a normal or nondiagnostic electrocardiogram during acute chest pain were studied with 2-DE. Only patients without a previous myocardial infarction and without known coronary artery disease (CAD) were studied. The entire left ventricular wall was examined for presence of regional asynergy. Coronary angiography was performed within 3 weeks. Cardiac enzyme levels were measured serially to establish or rule out an acute myocardial infarction. Sensitivity of 2-DE for detection of myocardial ischemia was 88% (22 of 25), specificity 78% (14 of 18), negative predictive accuracy 82% (14 of 17) and positive predictive accuracy 85% (22 of 26). Sensitivity of 2-DE for detection of acute myocardial infarction was 92% (12 of 13), specificity 53% (16 of 30) and negative predictive accuracy 94% (16 of 17). Thus, 2-DE during pain and a nondiagnostic electrocardiogram can readily identify patients with CAD in the emergency room, and it can accurately rule out an acute myocardial infarction.
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PMID:Usefulness of two-dimensional echocardiography for immediate detection of myocardial ischemia in the emergency room. 231 47

To elucidate the clinical characteristics associated with advanced atrioventricular (AV) block that appears relatively late (more than 24 hours) after the onset of myocardial infarction (MI), 101 patients with acute Q wave inferior MI were studied. Fourteen patients had late-onset advanced AV block, and 87 patients were free of AV block. The hospital mortality rate was 11%. Multivariate analysis was performed to determine the important variables associated with the occurrence of late advanced AV block and hospital mortality rates based on 12 clinical variables. Colloid osmotic pressure, right atrial pressure, serum potassium level, and number of segments with advanced asynergy were the significant factors associated with the occurrence of late advanced AV block, whereas advanced asynergic segments and alveolar arterial oxygen difference were important in the consideration of hospital mortality rates. Therefore not only the extent of myocardial ischemia but also the increases in the extracellular potassium level and interstitial fluid are some of the factors that are associated with the occurrence of late advanced AV block in acute inferior MI. Late advanced AV block, in itself, has no significant influence on hospital mortality rates.
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PMID:Factors associated with late onset of advanced atrioventricular block in acute Q wave inferior infarction. 233 Aug 59

We have previously shown that cardiac cycle-dependent variation of integrated backscatter occurs in normal myocardium. To determine whether myocardial ischemia and reperfusion can be distinguished by real-time integrated backscatter imaging we performed 10 min balloon occlusion of the Left Anterior Descending (LAD) coronary artery followed by reperfusion in 10 closed-chest anesthetized dogs. Images were obtained at baseline, during occlusion, and up to 120 min after reperfusion. We measured the magnitude and delay of cyclic variation of integrated backscatter in segments with and without asynergy. Radiolabeled microspheres were used to verify both ischemia and reperfusion. Ischemic segments exhibited decreased magnitude and increased normalized delay of cyclic variation of integrated backscatter (from 3.3 +/- 0.3 dB to 1.4 +/- 0.2 dB, mean +/- SE; and from 0.95 +/- 0.03 to 1.67 +/- 0.15, respectively, all p less than or equal to 0.001). Reperfusion promptly restored the magnitude of cyclic variation toward normal. However, the delay of the cyclic variation was restored only partially. Wall motion analysis of the ischemic sites revealed persistent abnormalities throughout the reperfusion interval despite return to normal of the magnitude and delay of cyclic variation. Thus, real-time integrated backscatter imaging permits detection and differentiation of changes in myocardial acoustic properties indicative of ischemia and of subsequent reperfusion.
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PMID:Myocardial ultrasonic backscatter for characterization of ischemia and reperfusion: relationship to wall motion. 239 28

Myocardial ischemia results in altered left ventricular (LV) diastolic compliance, reflected by an abnormal mitral inflow pattern on Doppler echocardiography. To investigate the relationship of Doppler echocardiography and regional myocardial systolic function during dipyridamole infusion, we evaluated transmitral flow changes detected by pulsed Doppler technique during a high-dose dipyridamole echocardiography test (DET, two-dimensional echo monitoring with dipyridamole infusion, up to 0.84 mg/kg over 10 min). The DET response produced two groups: group 1 (34 patients) with negative DET, and group 2 (35 patients) with positive DET, defined as the development of a newly onset LV regional asynergy. The E/A values overlapped at baseline (1.07 +/- .32 vs .92 +/- .22; p = NS) but differed at peak changes (.92 +/- .26 vs. 75 +/- .25; p less than .01). Heart rate changes could not account for the observed Doppler changes, since the values of R-R interval were similar in the groups, both basally (.927 +/- .226 vs .867 +/- .143 s; p = NS) and at peak dipyridamole (.754 +/- .100 vs. 681 +/- .112; p = NS). Transient myocardial ischemia induced by dipyridamole administration is accompanied by changes in transmitral flow, which consist of an increase in the relative atrial contribution to LV filling, possibly owing to an acute impairment in LV relaxation.
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PMID:Transmitral flow changes during dipyridamole-induced ischemia. A Doppler-echocardiographic study. 270 60

The diagnosis of ischemic heart disease by radionuclide ventriculography (RNV) is performed on the basis of an abnormal response of the left ventricular ejection fraction and the occurrence, or aggravation, of regional wall motion abnormality during exercise. However, the abnormal wall motion observed by RNV at rest is improved in some patients with coronary artery disease during exercise. We examined the clinical features of such patients who showed a paradoxical response of regional wall motion. The left ventricle was divided into 4 segments: anteroseptal, apical, inferior and posterolateral. The degree of wall motion of each segment was classified into 5 grades and scored according to a 5 point system: 4 = normokinesis, 3 = hypokinesis, 2 = severe hypokinesis, 1 = akinesis and 0 = dyskinesis. The wall motion score (WMS) was calculated as the sum of each segment score. If the WMS increased by 2 points or more during exercise, the case was defined as having shown significant improvement of wall motion. Improvement in WMS was found in 26 (12%) of 209 serial patients who underwent exercise RNV, exercise thallium myocardial scintigraphy and coronary angiography. Clinically, half of these patients had a variant form of angina pectoris. With respect to coronary lesions in the segments with reversible asynergy, 12 patients had 0 vessel disease, 8 had lesions with stenosis of less than 75% and 3 showed an adequate collateral circulation. Redistribution found on the exercise thallium myocardial scintigram at the same sites of improved wall motion was identified in only 1 patient. An analysis of patients with paradoxical improvement of wall motion during exercise suggests the involvement of coronary spasm, an improvement of coronary flow reserve, such as could be produced by regression or recanalization of the main lesions, or establishment of significant collateral circulation.
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PMID:Reversal of rest asynergy during exercise in patients with coronary artery disease. 281 Jul 64

We have shown improvement in collateral filling immediately after sudden controlled coronary occlusion in human subjects undergoing elective coronary angioplasty. It has been suggested but not proved that collateral circulation can limit myocardial ischemia. We prospectively studied 23 patients with isolated left anterior descending (n = 14) or right coronary (n = 9) disease and normal left ventriculograms during elective coronary angioplasty. A second arterial catheter was used for injection of the contralateral artery to assess collateral filling before balloon placement and during coronary occlusion by balloon inflation. Left ventriculography was performed during another inflation. Grading of collateral filling was as follows: 0 = none, 1 = filling of side branches only, 2 = partial filling of the epicardial segment, 3 = complete filling of the epicardial segment. Indexes of myocardial ischemia included percent of the left ventricular perimeter showing new hypocontractility and the sum of ST segment elevation measured on a simultaneous 12-lead electrocardiogram recorded during each inflation. Collateral filling during balloon occlusion and indexes of ischemia were assessed at 30 to 40 sec into inflation. Aortic pressure and heart rate did not correlate with the percent hypocontractile perimeter nor the sum of ST segment elevation. There was a significant correlation between the grade of collateral filling during inflation and both percent hypocontractile perimeter (r = -.85) and the sum of ST segment elevation (r = -.87). Anginal pain occurred in all patients with grade 0 or 1 collateral filling but in only 36% of patients with grade 2 or 3 collaterals. In conclusion, collateral circulation limits myocardial ischemia as assessed by the extent of new ventricular asynergy and electrocardiographic changes during coronary occlusion in patients.
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PMID:Limitation of myocardial ischemia by collateral circulation during sudden controlled coronary artery occlusion in human subjects: a prospective study. 294 29


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