Does low-dose propranolol reduce the incidence of supraventricular tachyarrhythmias following myocardial revascularisation? A clinical study.

During 1986, 343 consecutive patients who underwent isolated coronary bypass grafting were given 10 mg of propranolol three times daily for six postoperative weeks to help prevent supraventricular tachyarrhythmias. The incidence of these arrhythmias in this group was compared to that in a similar group of 337 consecutive patients who underwent coronary surgery in 1984 at the same institution and did not receive propranolol. There was no significant difference in the overall incidence of such arrhythmias between the propranolol group (10.8%) and the control group (10.4%). In preoperatively beta-blocked patients, the arrhythmia incidence in the propranolol group (9.9%) was lower than that in the control group (13.8%) but the difference did not achieve statistical significance. The two groups were also similar with respect to the ventricular response rates at the onset of the arrhythmia and the effectiveness of therapeutic intervention. These results suggest that propranolol in the above dosage does not significantly reduce the incidence of supraventricular tachyarrhythmias after myocardial revascularisation.