Management of ventricular arrhythmias occurring in patients after myocardial infarction

Some of the problems facing clinicians in the management of patients with ventricular ectopy occurring during the convalescent phase of myocardial infarction (MI) are discussed, and the permtinent literature is surveyed. The outstanding problem is identification of the patient at high risk for developing sustained ventricular tachycardia or fibrillation. Decisions on administration of antiarrhythmic agents to post-MI patients have long been based solely on detection of ventricular ectopy. By now, however, it has become apparent that this approach has not favorably altered the incidence of sudden cardiac death and has exposed many asymptomatic patients needlessly to potentially toxic antiarrhythmic agents. At present, assessment of the benefit/risk ratio favors treating asymptomatic complex ventricular ectopy only in patients with significant left ventricular dysfunction, provided that treatment results in the adequate suppression of complex forms of the ventricular ectopy and does not produce deleterious effects. The benefit/risk ratio does not favor treatment of asymptomatic ventricular ectopy in other groups of post-(MI) patients. Improved methods of identifying patients requiring treatment are needed. Programmed ventricular stimulation and noninvasive interrogation of signal-averaged electrocardiograms are designed to detect the presence of an arryhthmogenic substrate and offer promise for improved identification of patients at risk for sudden cardiac death.