Asynergy in coronary heart disease. Evolving clinical and pathophysiologic concepts.
The widespread use of cardiac ventriculography has focused interest on the frequency with which asynergy accompanies coronary heart disease as well as on its clinical and prognostic implications and dynamic nature. Recently, "intervention ventriculography" using nitroglycerin or postextrasystolic potentiation has indicated that asynergic zones may be more accurately classified as reversible (implying viable myocardium) or irreversible (nonviable or scarred myocardium), and thus the ventriculographic definition of aneurysm must reflect not only the severity of asynergy but its contractile reserve. Surface electrocardiogram Q waves, the severity of asynergy, and degree of coronary occlusion all adversely affect the potential for reversibility, whereas coronary collaterals enhance it. Important clinical applications include assessment of the potential utility of coronary bypass surgery in improving asynergy and of vasodilators in the treatment of patients with left ventricular failure. With refractory sequelae of aneurysms (heart failure, ventricular tachyarrhythmias, and systemic emboli) and a discrete aneurysm, surgical resection has been increasingly used with generally good results.
D001145:Arrhythmias, Cardiac / Q000503:physiopathology; D003097:Collateral Circulation; D001026:Coronary Artery Bypass; D003326:Coronary Circulation; D003327:Coronary Disease / Q000503:physiopathology* / Q000601:surgery; D003331:Coronary Vessels / Q000503:physiopathology; D004562:Electrocardiography; D006322:Heart Aneurysm / Q000209:etiology / Q000601:surgery; D006329:Heart Conduction System / Q000187:drug effects / Q000503:physiopathology*; D006333:Heart Failure / Q000209:etiology / Q000628:therapy; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D007511:Ischemia; D009200:Myocardial Contraction / Q000187:drug effects; D005996:Nitroglycerin / Q000494:pharmacology / Q000627:therapeutic use; D011379:Prognosis
D005996:Nitroglycerin