The impact of mode of cardioversion on recovery of atrial function following cardioversion for atrial fibrillation

A variable delay in recovery of effective mechanical atrial function (EMAF) is observed following cardioversion (CV) for atrial fibrillation (AF), To identify clinical variables that affect EMAF, we studied 55 patients (pts) with AF undergoing CV (43 electrical; 12 pharmacologic). Serial transmitral Doppler patterns were obtained following CV on days 0 (i.e. I-6 hours after CV), I, 3, and 7 until EMAF [defined as A (atrial filling) velocity > 0.50 m/sec] was seen. Two outcomes were prospectively defined: recovery of EMAF by day 3 and recovery of EMAF by day 7. Independent clinical variables (age, left atrial diameter, duration of atrial fibrillation, left ventricular ejection fraction, use of anti-arrhythmic drug therapy, presence of cardiovascular disease, and mode of cardioversion) were tested in bivariate and multivariate analyses for an association with each of the outcomes. With respect to the outcome of EMAF by day 3, only mode of cardioversion was significant in bivariate and multivariate analyses. Thus, pts undergoing electrical cardioversion had an odds ratio of 0.12 (95% confidence interval 0.01 - 1.0) for achieving EMAF by day 3. None of the variables assessed had a significant relation with EMAF by day 7. The proportion of all pts, as well as electrically and pharmacologically cardioverted pts who achieved EMAF, was plotted against a time scale. Earlier recovery of EMAF was observed in the pharmacologic compared to the electrical group (p=00.01). The results are shown in the table. All patients Electrical Cardioversion Pharmacologic Cardioversion (n=55) (n=43) (n=12) EMAF by Day 0 22% 13% 50% EMAF by Day 1 52% 45% 75% EMAF by Day 3 68% 61% 92% EMAF by Day 7 83% 79% 92% Conclusions and Implications: Two-thirds of patients undergoing CV for AF recover EMAF by day 3 after CV, and more than 80% do so by day 7. Patients undergoing electrical CV show a significant delay in recovery of AF compared to those that cardiovert pharmacologically. These findings may have significant implications for future trials that will address the duration of post-cardioversion anticoagulation.