Short-term control of supraventricular tachycardia with verapamil infusion and calcium pretreatment.

Nineteen consecutive patients with atrial fibrillation/flutter or other types of supraventricular tachycardia were given intravenous (IV) calcium salts (1 g) followed by verapamil infusion at a rate of 1 mg/min. Successful treatment was defined as control of ventricular response to less than or equal to 100 beats per minute (bpm) or conversion to sinus mechanism in patients with atrial arrhythmias: 11 patients had atrial fibrillation; three had atrial flutter; four had reentrant supraventricular tachycardias (SVT); and one had paroxysmal SVT. Therapy was successful in all patients. The mean dose of verapamil required to achieve desired outcome was 20 mg. Heart rate showed no significant change as a result of calcium pretreatment (160 bpm v 151 bpm). However, heart rate was significantly decreased, to 95 bpm, after treatment with verapamil. Blood pressure showed no change from baseline with either calcium or verapamil therapy. Verapamil infusion following IV calcium successfully treats atrial fibrillation/flutter or SVTs without depressing systemic blood pressure.