Elective cardioversion in the presence of conduction disturbances.

Elective cardioversion of supraventricular arrhythmias has been demonstrated to be an effective procedure which can be performed with minimal risk. The risks of cardioversion are increased in the presence of digoxin intoxication, failure of synchronization, conversion in the presence of high energies, long standing atrial fibrillation, atrial fibrillation with slow ventricular rates, and dysrhythmias in association with ischemic heart disease or cardiomyopathy. However, the risk of cardioversion of supraventricular arrhythmias in the presence of conduction disturbances, although thought to be increased, has never been carefully studied. This study was designed to examine the effects of conduction disturbances (CD) on the success and risk of elective cardioversion of supraventricular arrhythmias (atrial fibrillation and atrial flutter) and to define the role of temporary pacemakers prior to cardioversion in these patients.