An antiarrhythmic drug experience in 941 patients resuscitated from an initial cardiac arrest between 1970 and 1985

Survival rates and antiarrhythmic drug use were determined in 941 consecutive patients resuscitated from prehospital cardiac arrest due to ventricular fibrillation between March 7, 1970, and March 6, 1985. Of these patients, 18.7% were treated for at least a portion of the period with quinidine, 17.5% with procainamide, and 39.4% received no antiarrhythmic agent. Beta blockers were prescribed for 28.3% of the patients. Unadjusted comparisons of survival estimates showed dramatically lower survival rates for patients who received antiarrhythmic drugs independent of beta-blocker therapy and significantly improved survival for patients receiving beta-blocker therapy independent of antiarrhythmic use. Patients for whom antiarrhythmic therapy was prescribed also had more adverse baseline risk factors, whereas patients taking beta blockers had fewer such risk factors. After adjustment for these baseline risk factors, the use of antiarrhythmics was weakly (p less than 0.09) associated with worsened survival; 2-year survival for procainamide-treated patients was 30% and quinidine-treated patients 55% (p = 0.003). Beta-blocker therapy was associated with improved (p less than 0.001) survival. Thus, although neither procainamide nor quinidine appear to have had a benefit on mortality, the effect of procainamide appears to be significantly worse than that of quinidine. The use of antiarrhythmic drug therapy in patients resuscitated from prehospital ventricular fibrillation should be regarded as not only unproved, but potentially hazardous, and should probably be restricted to testing in randomized clinical trials.