Experience with “cardioversion” of atrial fibrillation and flutter

Abstract

Synchronized direct current countershock, “cardioversion,” was used in 70 patients on 94 occasions for reversion of atrial fibrillation or flutter. The method and anesthetic technics are described. A modification of the size and location of the electrode has decreased the incidence of minor discomfort resulting from the procedure and lowered the amount of energy necessary for successful cardioversion.

In 90 of 94 episodes, or in 66 of 70 patients, the arrhythmia was restored to sinus rhythm. With a follow-up period of from 1 to 9 months, 52 of 66 patients (79%) remained in sinus rhythm. Fourteen patients (21%) reverted to atrial fibrillation despite multiple cardioversions and maximally tolerated quinidine therapy.

Certain factors appear to decrease the chances of maintaining sinus rhythm: duration of fibrillation, type of valvular lesion, functional classification and previous quinidine failure.

The advantages anticipated with the restoration of sinus rhythm are discussed. The emergency indication and contraindications are outlined. A broad policy of selection of patients for cardioversion is suggested. The reasons for this approach are the high degree of acute success (94%), the low incidence of complications (5%) and success in maintaining sinus rhythm (79%) for a short follow-up Period.