Predictors of sudden death in coronary artery disease

Although advances in the management of acute myocardial infarction have res ulted in a decline in long-term risk of sudden death, it continues to be hi gh in certain subsets of patients. Thus, it is important to identify and tr eat these patients. Left ventricular ejection fraction less than 0.40, freq uent premature ventricular ectopy on Holter monitoring, late potentials on signal-averaged electrocardiogram, impaired heart rate variability, abnorma l baroreflex sensitivity and inducible sustained monomorphic ventricular ta chycardia during electrophysiological study are predictors of sudden death and arrhythmic events. Although the negative predictive value of each facto r is high, the positive predictive accuracy is low. Several tests can be co mbined to obtain higher positive predictive values. In fact, in some studie s combined noninvasive tests have been used to select patients for ventricu lar stimulation study. Some preventive treatment can be applied in these patients. Available data do not justify prophylactic therapy with amiodarone in high-risk survivors of acute myocardial infarction. Sudden death and total mortality have been significantly reduced in postinfarction patients by longterm beta blockade. Hence, beta blockers should be given to all patients with acute myocardial infarction who do not have contraindications to their use. The MADIT study has shown the beneficial effect of implantable cardioverter defibrillator in reducing mortality in patients with prior myocardial infarction, an ejec tion fraction less than 0.36, asymptomatic nonsustained ventricular tachyca rdia, and inducible sustained ventricular tachycardia, unsuppressable by pr ocainamide. Besides, several studies are under way to evaluate the prophyla ctic use of implantable defibrillator for improving survival in high-risk p atients.