Intravenous metoprolol for the treatment of acute supraventricular tachyarrhythmias.

The antiarrhythmic effect of the cardioselective beta-adrenoreceptor blocking agent metoprolol, given intravenously, was studied in 20 patients with acute supraventricular tachyarrhythmias, including patients with congestive heart failure, acute myocardial infarction and complete bundle branch block. Six patients out of 9 with atrial fibrillation reverted to sinus rhythm. In all patients with atrial tachycardia and 3 out of 4 patients with atrial flutter restoration of sinus rhythm occurred. The drug was well tolerated and is of clinical value for the treatment of supraventricular tachyarrhythmias even in an elderly patient group.