Immediate Effects of Intravenous Verapamil in Cardiac Arrhythmias

TLDR

Intravenous verapamil was administered to 181 patients with diverse cardiac arrhythmias. Intravenous verapamil slowed pacemaker automaticity in sinus, idioventricular, and idioventricular tachycardia, reduced ventricular response and regularized rhythm in atrial fibrillation, converted atrial flutter and paroxysmal supraventricular tachycardia to sinus rhythm, produced favorable responses in pre‑excitation syndromes, and caused no adverse clinical side effects.

Abstract

Verapamil was administered by intravenous injection to 181 patients with various cardiac arrhythmias. The automaticity of the cardiac pacemaker was slowed in sinus, idionodal, and idioventricular tachycardia. In atrial fibrillation the drug usually slowed the ventricular response and often made it regular. In some cases atrial flutter was converted to sinus rhythm, the ventricular response being reduced in the remainder. Conversion of paroxysmal supraventricular tachycardia to sinus rhythm was consistently achieved. A favourable response occurred in four patients in whom arrhythmias were associated with pre-excitation syndromes. There were no adverse clinical side effects.