Value of Cardioversion in Chronic Atrial Fibrillation

CARDIOVERSION, the Lown technique of direct current capacitor discharge through the chest wall, has converted chronic atrial fibrillation to sinus rhythm in approximately four fifths of reported cases.1-6Hemodynamic improvement has been reported to follow restoration of regular rhythm, with an increase in cardiac output and coronary blood flow.7-11Serious detrimental effects, such as embolism, have infrequently been noted.6,12,13 Nearly half of the reported cases reverted to atrial fibrillation in one month, in some, despite the continuance of a maintenance dose of quinidine.2-6The procedure was of little or no value in this group. In those patients remaining in sinus rhythm for longer periods, clinical benefit has been inferred but not well documented. Reported followup data after electroconversion are summarized in Table 1. These data suggest that: (1) fibrillation recurs in two thirds of the patients within one year, and in half of them within one year, and in half