Titrated energy cardioversion of patients on digitalis

Elective cardioversion with titrated energy was carried out under diazepam anaesthesia (38 procedures) in 26 patients on digitalis who presented with supraventricular or ventricular arrhythmias. Low energy shocks were given to establish the absence of latent digitalis intoxication, not unmasked by previous carotid sinus massage, and to restore sinus rhythm with the lowest possible energy discharge. In the absence of digitalis overdosage, titrated energy cardioversion restored sinus rhythm, at least temporarily, without dangerous ventricular arrhythmias. In one patient this precaution was neglected: a shock of 200 Ws provoked ventricular tachycardia. We present experimental and clinical evidence for the safety and effectiveness of titrated energy cardioversion in patients on digitalis.