Effect of antiarrhythmic therapy on mortality after myocardial infarction.

In an attempt to improve survival of patients with coronary artery disease and high-grade ventricular ectopic activity, several studies using different antiarrhythmic drugs were undertaken. A meta-analysis of all randomized controlled trials using type I antiarrhythmic agents showed that the treatment effect was much more likely to be adverse than beneficial. In contrast to these studies, the pooled results of major secondary prevention trials using beta-blocking agents could demonstrate a significant reduction in the sudden death rate by an average of 24% during observation periods of 9-36 months. In the beta-blocker trials, however, patients with contraindications for this type of drug, such as overt congestive heart failure or chronic obstructive lung disease, were excluded. In these patients a type III antiarrhythmic drug, such as amiodarone, may have a place, and in fact, the Basel Antiarrhythmic Study of Infarct Survival, a prospective, controlled, randomized trial using low-dose amiodarone as an antiarrhythmic agent, could demonstrate a 60% reduction in sudden death rate and a 74% reduction in arrhythmic events incidence during the first year after myocardial infarction. Therefore, in patients with repetitive ventricular ectopic activity after myocardial infarction and adequate left ventricular function, a therapeutic attempt with beta-blockers without intrinsic sympathomimetic activity seems advisable. Beside beta-adrenergic blockade, low-dose amiodarone is an alternative, especially in patients with impaired left ventricular function or other contraindications for beta-blockers.