Reduction of ventricular ectopic beats with oral acebutolol: A double-blind, randomized crossover study

Abstract

The antiarrhythmic efficacy of oral acebutolol, a new cardioselective β-blocking agent, was assessed in a randomized double-blind, placebo-controlled study. Twenty-five patients with ≥30 ventricular ectopic beats (VEB) per hour on three control ambulatory monitorings were studied. Mean VEB reduction from the control period was 35% with placebo and 45% and 50% with the use of acebutolol 200 mg and 400 mg, respectively. Eleven patients had ≥70% reduction in VEB with acebutolol and nine of them had ≥90 VEB reduction. Among these 11 patients, the mean VEB suppression was 51% after placebo but significantly higher following the two doses of acebutolol at 71% ( p < 0.05) and 86% ( p < 0.01). The mean reduction of paired VEB compared to placebo was 71% ( p < 0.05) and 75% ( p < 0.01) following 200 mg and 400 mg of acebutolol and only 49% after placebo. Complete suppression of paroxysmal ventricular tachycardia was also noted in five patients. Mean PR interval only increased slightly when patients took 400 mg of acebutolol, but there was no significant change in either the QRS or QTc intervals. A significant decrease in heart rate from that during control periods was noted after acebutolol. No significant adverse reactions were noted during the study. Acebutolol appears to be an effective and well-tolerated antiarrhythmic agent in the treatment of VEB and higher grades of ventricular ectopy.