Propranolol in the Treatment and Prevention of Cardiac Arrhythmias

Abstract

Propranolol, a specific beta-adrenergic blocker, was given to 44 patients with a variety of cardiac arrhythmias. Twenty-seven patients received it intravenously in a dose of 100 [mu]g/Kg. Twenty patients, 3 of whom were treated with the intravenous preparation, were given oral propranolol, 30-120 mg/day. In each of 19 patients with atrial fibrillation or atrial flutter intravenous propranolol slowed the ventricular rate by means of an increase in the degree of atrioventricular block. In each of eight patients with paroxysmal atrial or nodal tachycardia intravenous propranolol abruptly stopped the attack or slowed the cardiac rate, and in 6 of 10 patients treated with oral propranolol recurrences were markedly reduced or eliminated. Digitalis and/or quinidine had been used unsuccessfully in all patients with supraventricular tachycardias. In 2 cases of digitalis-induced atrial tachycardia intravenous propranolol reduced the cardiac rate and brought the patients out of severe congestive heart failure. Two patients with Wolff-Parkins on-White syndrome and paroxysmal atrial tachycardia were greatly benefited by oral propranolol prophylaxis. One patient with repetitive ventricular tachycardia and four with multiple ventricular premature contractions were not helped by propranolol. Propranolol is a useful anti-arrhythmic agent. In digitalis-induced arrhythmias, it may be the drug of choice, provided hypokalemia is not present. It may be helpful in supraventricular tachycardias, particularly when digitalis or quinidine is ineffective. It may also control ventricular rate in patients who are being prepared for electrical cardioversion.