Conversion of paroxysmal atrial fibrillation to sinus rhythm by intravenous pirmenol.

The acute effects of pirmenol on atrial fibrillation were investigated in 40 patients with paroxysm of atrial fibrillation. Patients were randomized to receive either pirmenol, 50 or 100 mg intravenously, or placebo. Patients with congestive heart failure or a history of sinus node disorder were excluded. Sinus rhythm was achieved in 12 of 20 patients in 2 to 16 minutes after pirmenol administration and in 3 of 20 patients in the control group within 1 hour. A nodal escape rhythm during sinus slowing was observed in 1 patient. No sinus arrest, atrioventricular conduction disturbance or hypotension appeared. Pirmenol has an antifibrillatory effect on the atria. Sinus rhythm is restored rapidly after intravenous administration. Treatment of atrial fibrillation of recent onset was well tolerated in patients accepted for the study.