Termination of refractory ventricular tachycardia by a combination of intravenous sotalol and overdrive ventricular pacing.

Right ventricular overdrive pacing is an effective method for termination of ventricular tachycardia. This may be due to alteration in conduction rate, conduction pathways, or refractory periods of myocardial tissue. The procedure can be facilitated by antiarrhythmic drugs which increase tachycardia cycle length. Sotalol possesses beta-blocking action, has been shown to increase duration of action potentials and refractory periods throughout myocardial tissue and accessory pathways, and can suppress and prevent recurrent malignant ventricular arrhythmias. We describe two cases with ventricular tachycardia which were terminated transiently by cardioversion, but were resistant to various antiarrhythmic drugs. Right ventricular overdrive pacing was used in both cases, but was only effective after the administration of intravenous sotalol. We conclude that the unique properties of sotalol may make it especially effective in this context. Caution is required because of the hypotensive and negative inotropic actions of beta blockers, and possible acceleration of ventricular tachycardia by overdrive pacing.