[Efficacy of propafenone in supraventricular arrhythmias]

We evaluated the results of intravenous administration of propafenone in 44 patients with rapid symptomatic supraventricular arrhythmia of less than 1 month duration. Mean age was 54 years and 22 were females. Propafenone, 2 mg/kg was given over 15 min and blood pressure and heart rate were monitored in the following hour. Sixteen out of 19 (84%) episodes of paroxysmal supraventricular tachycardia in 15 patients reverted to sinus rhythm at a mean interval of 11 min. None of 14 patients with atrial flutter reverted to sinus rhythm, but the ventricular rate decreased from 143 +/- 38 to 110 +/- 41 (p less than 0.02). The mechanism involved was slowing of the atrial cycle with associated increase A-V block in 7 patients. One patient experienced 1:1 conduction at a rate of 214 per min. Twenty seven % of 15 patients with atrial fibrillation reverted to sinus rhythm; ventricular rate decreased from 134 +/- 40 to 98 +/- 22 (p less than 0.05) in the remaining cases. There were no significant side effects of the drug and systolic blood pressure decreased from 109 +/- 27 to 99 +/- 30 beats per min (p less than 0.05) with no change in diastolic pressure.