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)

Among the clinical manifestations of ischemic heart disease, right coronary artery (RCA) disease offers a wide variety of right and left ventricular ischemic involvement, including prevalent right ventricular dysfunction and severe cardiac failure. Whether the right ventricular impairment is dependent primarily on ischemia of the right ventricle or requires a concomitant left ventricular dysfunction remains debatable. To assess the pathophysiology and clinical relevance of RCA-related ischemia, a systematic study of patients with single RCA disease (either vasospastic angina at rest or typical stable angina) was undertaken by radionuclide ventriculography. A high incidence of ischemia-induced right ventricular dysfunction was observed (93% and 95% in angina at rest and on effort, respectively), either alone or associated with left ventricular impairment. These results were compared with those obtained in a control population with isolated left anterior descending artery disease and either primary or secondary angina pectoris. We infer that the impairment of the right ventricle was related primarily to right ventricular ischemia and that left ventricular dysfunction alone did not cause an important depression of right ventricular systolic function. In conclusion, the clinical manifestations of RCA disease can be protean; the right ventricle can be the target of ischemia, and recognition of its impairment poses diagnostic problems. Radionuclide ventriculography and two-dimensional echocardiography, together with stressors of coronary flow reserve, are reliable techniques for assessing RCA-related ischemia.
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PMID:Right coronary artery disease. Pathophysiology, clinical relevance, and methods for recognition. 202 49

Provocative testing has provided a method of evaluating the important role of vasomotor tone in coronary artery disease. The most sensitive test is the ergonovine (Methergin) test. This is a specific and reliable method of defining the clinical situations in which coronary spasm is common: --focal coronary artery spasm is mainly observed in resting angina alone or in association with effort angina. The prognosis of spasm is excellent with calcium antagonist therapy provided there is no other associated pathology such as left ventricular failure or triple vessel disease; --in the six weeks following myocardial infarction, focal coronary artery spasm is a common event: 20% of coronary angiographies. After six weeks, spasm is much less frequent. It does not influence the prognosis. This type of spasm is probably related to the scarring process; --coronary artery spasm is frequently associated with restenosis after coronary angioplasty, a process which is histologically related to proliferation of smooth muscle; --diffuse increase in coronary vasomotor tone is a much rarer pathology, perhaps related to global changes in vascular tone as its association with the Raynaud syndrome and with migraine would suggest. It presents clinically with resting angina and sometimes by typical Prinzmetal angina; --finally, vosomotor tone plays an important role in the daily life of coronary patients. Holter recordings for the detection of silent myocardial ischemia have shown episodes of myocardial ischemia at lower myocardial oxygen consumption levels than those usually recorded during exercise stress testing, which suggests a reduction in oxygen supply, that is to say coronary vasoconstriction. Changes in coronary vasomotor tone can modify the diameter of healthy coronary arteries by 100%.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Vasomotor activity and coronary insufficiency]. 205 36

Coronary vasoconstriction may play a relevant role in the pathogenesis of exercise-induced myocardial ischemia, not only in patients with Prinzmetal's angina, but also in patients with chronic stable angina. In these patients the use of calcium antagonists, namely, dihydropyridine derivatives, may be beneficial. Hyperventilation is a simple and sensitive test to discriminate patients with effort angina who will improve their exercise capacity after administration of these drugs.
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PMID:Increased coronary tone in exertional angina: the beneficial effects of calcium antagonists. 207 96

Spontaneous angina is an ideal condition in which to study left ventricular (LV) dysfunction induced by acute myocardial ischemia. In 6 patients with Prinzmetal's angina, LV diastolic function during 16 episodes of spontaneous angina was studied by simultaneous recordings of electrocardiographic (ECG), echocardiographic and hemodynamic parameters. In particular, pulsed Doppler echocardiography measured peak velocity of early (E) and late (A) transmitral flow and E/A ratio, as indexes of relative early versus late LV filling. During the ischemic attacks, the time sequence of pulsed Doppler echocardiographic and ECG changes showed 3 distinct phases: (1) "waxing phase: transmitral flow changes with minimal ECG modifications (E/A = 0.85 +/- 0.1); (2) "steady" phase: maximal ECG changes (E/A = 0.9 +/- 0.1); and (3) "waning" phase: regression of the ECG changes (E/A = 1.26 +/- 0.15). In each phase, E/A ratio showed a significant difference from the baseline value (E/A = 1.17 +/- 0.2) as a result of changes in E, suggesting that myocardial ischemia affects mainly the early phase of diastole. In the waxing phase, LV diastolic dysfunction preceded systolic abnormalities, as documented by a significant reduction of E/A ratio in the absence of alterations in LV ejection fraction, as well as in systemic arterial and pulmonary wedge pressures. Finally, all the recorded parameters were consistent with LV "contractile rebound" occurring in the waning phase and affecting both diastole and systole.
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PMID:Doppler assessment of left ventricular filling pattern in silent ischemia in patients with Prinzmetal's angina. 222 Jun 31

Coronary artery disease may present as silent ischemia, chronic typical angina pectoris, unstable angina, Prinzmetal angina, acute myocardial infarction, and sudden cardiac death. These manifestations can usually be differentiated by the clinical history. Each of them has its own pathophysiology and, accordingly, therapy and prognosis are different. Myocardial ischemia is common to all of the manifestations and this can be assessed by history taking, ECG stress-testing, ambulatory monitoring, myocardial perfusion scanning, or radionuclide angiography (RNA). The diagnostic accuracy of these diagnostic procedures varies from 70% (history) to 81% (RNA).
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PMID:[Clinical presentation and diagnosis of coronary heart disease]. 231 79

We investigated 303 (men: women = 2:1) cases who suffered sudden heart arrest in Yamagata city since 1984 to 1987. The incidence rate was 41.0/100,000/year, and increased markedly with increasing age. There was a tendency for sudden death to occur in the winter season, evening and early morning. Two major causes were cardiac disease (especially ischemic heart disease) (46.4%) and intracranial hemorrhages (18.6%). 20% of all the heart-arrest cases were able to be saved, but, depending on the kind of heart disease the survival rate varied greatly (18.8% in acute myocardial infarction and 71.4% in vasospastic angina), (40.0% in ventricular fibrillation and 13.3% in the bradycardic arrhythmias). Survival rate was also effected by the time interval from the onset till the beginning of cardio-pulmonary resuscitation. About one half of the cases had histories of cardiac disease. Premonitory symptoms were observed in at least one third of the cases.
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PMID:[Sudden cardiac death in the emergency hospital]. 240 68

The peak incidence of ventricular fibrillation in acute myocardial infarction usually occurs during the first hours after the onset. Electrophysiological changes immediately after the onset have been studied in animal models, but are still incompletely understood in humans. For clarification of the characteristic features of ventricular arrhythmias during acute myocardial ischemia, ventricular arrhythmias were studied in 81 patients with vasospastic angina pectoris induced by ergonovine. Ventricular arrhythmias occurred in 45 of these patients, including ventricular tachycardia in 15, and ventricular fibrillation requiring repeated DC defibrillation in two patients. Most ventricular extrasystoles occurred before the ST segment reached maximum elevation, while reperfusion arrhythmias were less common. In many patients the coupling intervals varied, and the configuration was multiform. It is concluded that ventricular arrhythmias occurring during ergonovine-induced coronary spasm show different characteristics from those occurring during chronic ischemia. As the arrhythmias in this study seem, in some ways, to resemble arrhythmias occurring at the onset of myocardial infarction, the results might provide useful information on ventricular arrhythmias in myocardial ischemia in humans.
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PMID:The nature of ventricular arrhythmias during ergonovine-induced vasospastic angina pectoris. 244 15

Heart rhythm and conductivity disorders, developing during anginal attacks, and their relation to the pattern of myocardial ischemia have been studied, using 24-hour ECG monitoring, in 60 patients with stable angina, and in 67 patients with unstable angina. Heart rhythm and conductivity disorders at the ventricular level were much more common in Prinzmetal's angina (73%), as compared to the attacks involving ST depression (10%). Their incidence depended both on the direction and magnitude of ST displacement. The probability of supraventricular arrhythmias was unrelated to the magnitude and direction of ST displacement. They tended to develop during the attacks, accompanied by slanting ST depressions (43%) rather than flat ones (8%). Arrhythmias were considerably more common as a complication of the attacks of unstable angina (42%) rather that stable angina (15%) owing to more severe myocardial ischemia.
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PMID:[Disorders of cardiac rhythm and conduction during attacks of stenocardia]. 247 Sep 49

Stress T1-201 myocardial SPECT was performed and evaluated quantitatively by Bull's eye method in 54 patients with single vessel coronary artery disease (33 angina pectoris, 21 myocardial infarction) who underwent successful PTCA. As the index of myocardial ischemia and viable muscle that was not affected by work load and others, relative washout rate (rW-R) was calculated from the formula: washout rate (W-R) of ischemic area was divided W-R of normal area. The purpose of this study was to examine the significance and usefulness of rW-R. Good correlation was recognized between grade of coronary artery stenosis, severity score (Sv-S) and rW-R in 28 patients with effort angina pectoris (EAP). Therefore, rW-R was regulated with coronary flow in EAP. On the other hand, in 5 patients with vasospastic angina (VSA), there was a tendency that rW-R showed low value compared with Sv-S. It was suggested that rW-R in patients with VSA was regulated not only coronary flow but also other factors. As a result of study before and after successful PTCA, rW-R foresaw the improvement of coronary perfusion and work load capacity by successful PTCA exactly. It was concluded that W-R reflected myocardial ischemia and myocardial viability accurately, and rW-R was a useful clinical index.
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PMID:[Assessment of relative washout rate (rW-R) in stress T1-201 myocardial SPECT]. 252 66

Calcium antagonists are among the most potent and efficacious drugs used in the treatment of angina pectoris. Amlodipine, a new member of this family of dihydropyridines, has a unique pharmacokinetic profile with high bioavailability and an extended period of pharmacodynamic activity. In formal randomized, double-blind, placebo-controlled trials with exercise tests carried out 24 hours after administration, amlodipine was significantly more effective than the placebo and comparable in efficacy with the calcium antagonist diltiazem and the beta-blocking drug nadolol. In addition to extending exercise capacity in patients with angina pectoris, amlodipine significantly reduces ECG evidence of myocardial ischemia. Amlodipine has also been found to be effective in reducing the anginal attack rate in patients with vasospastic angina. From the evidence available, it is concluded that once-daily treatment with amlodipine in the dose range of 5 to 10 mg is effective in improving exercise capacity and reducing anginal attack rate in patients with chronic stable angina pectoris and also those with vasospastic angina.
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PMID:The efficacy of amlodipine in myocardial ischemia. 257 66


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