Sustained atrial fibrillation after conversion of paroxysmal reciprocating junctional tachycardia by intravenous verapamil

Intravenous verapamil is a very effective therapy for terminating paroxysmal reciprocating junctional tachycardia (PRJT).¹ Ventricular arrhythmias, usually ventricular premature complexes¹ and, rarely, short runs of ventricular tachycardia,² have been observed after conversion of PRJT by verapamil. In contrast, verapamil-induced atrial tachyarrhythmias are rare. To our knowledge, there have been only 2 previous reports of atrial fibrillation (AF) after administration of verapamil during PRJT: in 1 patient just before conversion³ and in another when verapamil failed to convert PRJT to sinus rhythm.⁴ We describe 2 patients who developed sustained AF shortly after conversion of PRJT to sinus rhythm by intravenous verapamil during electrophysiologic study.