Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The clinical manifestations of symptomatic coronary arterial spasm were analyzed in 30 patients whose coronary arteriograms demonstrated no fixed severe obstructions. The study group consisted of 14 men and 16 women (average age, 47 years). Angina at rest was invariable and it was usually typical in quality, location, duration and response to nitroglycerin. Exertional angina occurred in 23 percent and syncope with angina in 33 percent. Spontaneous remission of angina for at least 1 month occurred in 57 percent of patients. Prinzmetal's variant angina occurred in 77 percent of patients and only S-T segment depression or T wave changes during angina occurred in 23 percent. Major arrhythmias during ischemia developed in 47 percent. Exericse tests were positive in 24 percent. Myocardial infarction, probably due to coronary spasm, occurred in 7 percent of patients. Isosorbide dinitrate and propranolol were effective therapy in only 39 percent and 6 percent of patients, respectively. Nifedipine, a calcium flux antagonist, was effective in 80 percent of patients. Patients with normal coronary arteriograms who have clinical features suggestive of coronary arterial spasm should be considered for further investigation, including long-term electrocardiographic monitoring and provocative testing for spasm.
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PMID:Syndrome of symptomatic coronary arterial spasm with nearly normal coronary arteriograms. 698 57

The calcium channel blocking agents have multiple hemodynamic effects that make them potentially valuable in treating many cardiovascular disorders. They are potent dilators of coronary and peripheral arteries and in isolated tissue preparations exert potent negative inotropic, chronotropic, and dromotropic effects. In intact animals the peripheral arterial vasodilatation induces reflex-mediated adrenergic activity, which opposes the direct negative inotropic, chronotropic, dromotropic, and hypotensive effects. The individual calcium channel blockers have different relative potencies on various cardiovascular functions. The net hemodynamic and electrophysiologic effect of each agent, therefore, results from a complex interplay of direct and reflex phenomena. The clinical efficacy of these agents in classic angina pectoris relates to their ability to decrease afterload, myocardial contractility, and heart rate and increase coronary blood flow. The agents have been used to prevent coronary spasm in Prinzmetal's variant angina. The negative inotropic effects of verapamil are valuable in improving the symptoms and hemodynamic disturbances of hypertrophic cardiomyopathy. The role of these agents in treating arterial hypertension, unstable angina pectoris, acute myocardial infarction, and ischemia during cardiopulmonary bypass needs to be determined.
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PMID:Calcium channel blocking agents in the treatment of cardiovascular disorders. Part II: Hemodynamic effects and clinical applications. 700 93

Substantial evidence indicates that T wave alternans is an intrinsic property of ischemic myocardium. The electrophysiologic basis appears to be spatial and temporal heterogeneity of repolarization resulting from changes in action potential morphology rather than in activation sequence. Ischemia-induced changes in postrepolarization refractoriness and depressed electrical restitution of action potential duration have also been implicated. The main underlying ionic basis for T wave alternans during coronary occlusion appears to be derangements in intracellular cycling of calcium. Accumulation of potassium in the extracellular space adjoining ischemic cells and disruption in electrogenic sodium-calcium exchange may also be involved. In humans, T wave alternans has been observed in Prinzmetal's and classical angina, angioplasty, and bypass graft occlusion. Under these conditions associated with acute myocardial ischemia, alternans is restricted to the ischemic zone, and alternation in action potential morphology is an underlying factor. Recently, repolarization alternans has been shown to be a statistically significant predictor of the results of electrophysiologic testing and arrhythmia-free survival in individuals with and without organic heart disease. Collectively, these observations provide a rationale for quantitation of T wave alternans magnitude for assessment of vulnerability to life-threatening ventricular arrhythmias both in response to and independent of the effects of myocardial ischemia.
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PMID:Electrophysiologic basis for T wave alternans as an index of vulnerability to ventricular fibrillation. 805 49

We report a rare case, the second in the literature, of Prinzmetal's Variant Angina (VA) caused by cis-diamminodichloroplatinum (CDDP) infusion. We also discuss the possible underlying mechanism of ischemia.
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PMID:Prinzmetal's Variant Angina during cis-diamminodichloroplatinum (CDDP) administration: case report. 1267 22

Physiological and pathophysiological roles of K(ATP) channels have been clarified recently in genetically engineered mice. The Kir6.2-containing K(ATP) channels in pancreatic ss-cells and the hypothalamus are essential in the regulation of glucose-induced insulin secretion and hypoglycemia-induced glucagon secretion, respectively, and are involved in glucose uptake in skeletal muscles, thus playing a key role in the maintenance of glucose homeostasis. Disruption of Kir6.1-containing K(ATP) channels in mice leads to spontaneous vascular spasm mimicking vasospastic (Prinzmetal) angina in humans, indicating that the Kir6.1-containing K(ATP) channels in vascular smooth muscles participate in the regulation of vascular tonus, especially in coronary arteries. Together with protective roles of K(ATP) channels against cardiac ischemia and hypoxia-induced seizure propagation, it is now clear that K(ATP) channels, as metabolic sensors, are critical in the maintenance of homeostasis against acute metabolic changes.
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PMID:Roles of KATP channels as metabolic sensors in acute metabolic changes. 1591 Aug 76

Prinzmetal's variant angina (VA) and cardiac syndrome X (CSX) are two distinct, usually easily recognizable, forms of angina syndromes, caused by epicardial spasm, usually responsible for transient transmural myocardial ischemia at rest and by coronary microvascular dysfunction (CMVD), usually responsible for effort induced subendocardial ischemia, respectively. In this article we report clinical evidence in three patients of the simultaneous occurrence of angina episodes typical of both VA and CSX, suggesting that common pathogenetic factors may be responsible for clinical manifestations both of functional macrovascular and microvascular coronary artery abnormalities in some angina patients.
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PMID:Combination of variant and microvascular angina. 1961 Jan 23


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