Management of the Patient with Severe Angina Pectoris

Abstract

Severe angina pectoris may be reduced to tolerable levels by suppressing below the pain threshold those factors elevating systolic blood pressure and heart rate and prolonging systolic ejection period. Their product parallels myocardial oxygen consumption (MVO 2 ) as noted in several excellent reviews. The level of this product associated with angina, the "angina index," defines the individual threshold for onset of angina. Prevention of angina-inducing physical and psychic stress is desirable, but often impractical, and the use of nitroglycerin preceding or following stress may lead to years of acceptable life. Prolonged, spontaneous, or readily induced angina, especially with a change in pattern, may be due to an acute coronary occlusive episode, whether defined as a prodromal period or an actual myocardial infarct. This form of attack requires close observation and appropriate care. The psychic stress-prone patient may repeatedly present a benign duplicate of such pain production, producing a diagnostic challenge. Routine protection of the angina patient, especially against arrhythmias, is discussed. Different therapeutic modalities for control of intractable angina are presented, many with promise, but those currently giving the best results are: (1) elimination of precipitating conditions, i.e. (a) brady- and tachyarrhythmias, (b) hypertension, (c) hyperthyroidism, (d) mechanical obstruction of ventricular outflow, and (e) heart failure (2) beta-adrenergic blocking agents, i.e. propranolol, with or without nitrates or nitroglycerin; and (3) surgical revascularization preceded by selective coronary angiography. The aortocoronary saphenous vein bypass has been effective in prompt relief of angina in patients with viable myocardium and potentially good flow in the distal artery, with acceptably low operative mortality from skilled teams. Mechanical efficiency and thus congestive failure may improve, and there is hope for increased longevity. Contraindications are poorly defined, especially as related to its performance in recent infarction of varying magnitude. With only 3 years' experience in determining long-term benefits, it seems rational to repeatedly redefine indications for surgery, but currently not to operate on every patient with "significant" coronary disease.