Prevention of sudden death using beta-blockers. Review of possible contributory actions.

Coronary artery disease is the most serious complication of hypertension; therefore, the treatment of hypertension should be directed toward reducing the mortality from this disease. Since the majority of deaths occurring in post-myocardial infarction patients and hypertensive patients are sudden, the key objective is coronary artery disease treatment that will reduce the risk of sudden death. Several pharmacological interventions have been tested to determine whether they reduce the risk of sudden death. So far, only treatment with beta-adrenoceptor antagonists has been proven effective. Since most sudden cardiac deaths are due to ventricular fibrillation, an antifibrillatory effect on beta-adrenoceptor blockade has been invoked and demonstrated in clinical as well as animal experimental studies. Apart from an antifibrillatory effect, other effects of beta-blockade may also be involved. In the present review, different effects of beta-blockers that may contribute to the observed beneficial effects are discussed. The reduction in the risk of sudden death during active beta-adrenoceptor blockade reported in clinical studies is probably related to the summation of different effects, since cardiovascular drugs with a more limited mode of action (i.e., pure anti-ischemic effect or pure antiarrhythmic effect) have not shown similar impressive results.