Suppression of ventricular arrhythmia by acebutolol.

Abstract

AbstractTo study the efficacy of acebutolol in suppressing ventricular arrhythmia, 20 consecutive patients with more than 10 premature ventricular contractions (PVCs) per hour (averaged over 24 hours) were studied. Arrhythmias were not precipitated either by remediable clinical conditions or acute myocardial infarction. Digitalis and antiarrhythmic drugs were discontinued at least 5 days prior to entry into the trial. Besides routine clinical, laboratory, and ECG examinations, all patients also underwent serial 24‐h Holter monitoring every 10 days and echocardiographic examinations before and 20 days after treatment. The total duration of the trial was 30 days. The dosage of acebutolol was 400 mg/d during the first 10 days and was increased to 600 mg/d in the next 10 days as necessary, provided also that no significant side effects occurred. The drug was withdrawn for the last 10 days in order to establish drug withdrawal effects. Drug efficacy was assessed quantitatively by calculating the number of PVCs per day, and qualitatively by using the Lown grading system. There were 3 dropouts. Of the 17 patients who completed the trial, 10 (59%) showed a reduction of PVCs of at least 65%, and in 9 (53%) this occurred on a dosage of 400 mg/d. Elimination of grade 4A or 4B arrhythmia was observed in 6 (67%) of 9 patients. Although most patients were normotensive before entry into trial, none developed a drop in systolic blood pressure to 100 mmHg or less. The heart rate decreased slightly but significant bradycardia was not noted. Acebutolol did not adversely affect left ventricular function as assessed echocardiographically. We conclude that acebutolol is safe and effective for the treatment of PVCs And in most patients may be administered in a dosage of 200 mg twice daily.