Evaluation of Countershock Treatment of Atrial Flutter:  With Special Reference to Arrhythmias Related to This Procedure

ELECTRICAL countershock has been found to be a useful method of terminating ventricular fibrillation since the end of the last century.¹ However, there are still aspects related to this procedure that are not well known,² especially in reference to the prevention of recurrence of the original arrhythmia. AC current was originally used by Zoll and co-workers³ primarily for the emergency treatment of ectopic ventricular rhythms.^4,5 More recently, DC current has been employed successfully by Lown et al not only for emergency ventricular fibrillation but also for abolishing susupra-ventricular arrhythmias.^6,8 Several other workers have performed elective defibrillation of the atria.^9,13 In a previous report from our department dealing with problems related to conversion of atrial fibrillation,² it was observed that a significant number of patients reverted to the original arrhythmia shortly after sinus rhythm was established. The number of recurrences of atrial fibrillation was decreased by premedication with quinidine sulfate.