Comparison of Flecainide with Quinidine for Suppression of Chronic Stable Ventricular Ectopic Depolarizations

Abstract

In a randomized placebo-controlled double-blind trial, flecainide was compared to quinidine for treatment of ventricular ectopic depolarizations in 19 patients. The mean percent suppression of total ventricular ectopic depolarizations was 95% for flecainide and 56% for quinidine (P < 0.05). A greater than 80% reduction of total ventricular ectopic depolarizations was obtained in 8 of 9 patients given flecainide and in 5 of 10 patients given quinidine (P = 0.09). After the randomized protocol, the patients who had received quinidine were given flecainide; 9 of the 10 patients had greater than 80% reduction of total ventricular ectopic depolarizations. Flecainide produced 100% suppression of nonsustained ventricular tachycardia and 99.5% suppression of paired ventricular depolarizations. Flecainide prolonged the PR and QRS intervals; quinidine prolonged the PR and JTc intervals. Side-effects were more common with quinidine than flecainide (P = 0.06). Three other patients failed to complete the protocol because of serious adverse experiences.