Primary ventricular fibrillation continues to be a major complication of acute myocardial infarction occurring in 5-9% of patients in the coronary care unit and in a higher percentage of pre-hospital admissions. Prophylactic antiarrhythmic drugs can prevent primary ventricular fibrillation. Lidocaine has been used for this purpose and can be administered safely and effectively in most patients by following well-established programs based on pharmacokinetic and pharmacodynamic data. The in-hospital mortality for patients with primary ventricular fibrillation exceeds that of matched controls not having the arrhythmia, and many studies show a higher 1-, 3-, and 5-year mortality. Other studies have failed to confurm these long-term results and have produced controversy among cardiologists. I continue to recommend prophylactic antiarrhythmic drugs for all patients with acute infarction, especially in those undergoing early interventional therapy.
KEY WORDS. lidocaine, prophylactic antiarrhythmics, primary ventricular fibrillation, treatment of acute myocardial infarction
Although coronary care units have existed for almost 25 years, and ventricular arrhythmias during acute myocardial infarction have been recognized as a leading cause of death in these units, the question of the routine administration of antiarrhythmic drugs as prophylaxis for ventricular arrhythmias continues to be controversial. In 1978, in an editorial published in Circulation, "Should Lidocaine Be Administered Routinely to All Patients After Acute Myocardial Infarction?", I recommended routine prophylaxis with lidocaine for all patients with acute myocardial infarction and described programs of administration based on pharmacokinetic and pharmacodynamic principles that had been developed for lidocaine [1]. In addition, I suggested the need for a carefully controlled clinical trial to determine the validity of the recommendation and to learn more about the natural history of patients experiencing arrhythmias during acute myocardial infarction. To date, this definitive study has not been performed.
Ten years later, I still defend the recommendations, while utilizing new data that have been developed and taking into account better pharmacokinetic data allowing the safer administration of lidocaine [2,3]. However, during the past decade a number of other authors have taken both sides of this controversy [4-9].