[Comparison of the anti-arrhythmic effects of propafenone and aprindine in the treatment of refractory chronic ventricular arrhythmias. A randomized double-blind crossover study controlled with placebo].

A placebo-controlled, randomized, double-blind, crossover study was performed in 14 patients with chronic, resistant, ventricular arrhythmias in order to evaluate the efficacy and safety of two new antiarrhythmic agents, propafenone and aprindine. After an initial placebo phase, patients received orally either propafenone (600 mg daily) or aprindine (150 mg daily for the first two days and 50 mg every 12 hours successively) for five days. This treatment was followed by a drug-free period (placebo II); patients were then crossed over to the alternative drug. A 24-hour Holter recording was performed during the last 48 hours of the initial placebo phase and on the final day of each phase of the crossover period. Analysis of Holter recordings revealed that the mean hourly PVCs frequency, for the group, was similar during the two control periods. Significant reduction in the mean hourly frequency of PVCs from control levels was observed in 78% of the patients during propafenone therapy and in 42% during aprindine therapy. For the whole group, propafenone induced a significant reduction of the average PVCs/h frequency (p less than 0.05), whereas the aprindine was ineffective. Finally no patient experienced side effects with propafenone, whereas aprindine caused side effects in three patients (dizziness, tremor, ataxy).