Antiarrhythmic therapy for ventricular arrhythmias.

Treatment of ventricular arrhythmias has received great attention during the past 20 years. However, results of recent trials with class I antiarrhythmic drugs in patients after myocardial infarction have raised many questions about the risk-benefit ratio of antiarrhythmic therapy, at least in asymptomatic subjects. Theoretically, the only two reasons to treat ventricular arrhythmias are (a) the presence of symptoms related to the arrhythmia, and (b) the presence of an increased risk of sudden death. The prognostic significance of a ventricular arrhythmia depends on the type of underlying cardiac disease, on the extent of left ventricular dysfunction, on arrhythmia-related symptoms, and on specific characteristics of the ventricular arrhythmia itself. All these factors should be assessed to allow an adequate selection of patients who really need antiarrhythmic therapy (including nonpharmacological modes of treatment), and to allow the identification of patients for whom antiarrhythmic therapy is clearly unnecessary. Such a risk stratification strategy is essential, because many if not all antiarrhythmic agents have potentially serious adverse effects such as proarrhythmic or negative inotropic effects.