Efficacy and safety of transvenous atrial cardioversion in patients with mitral valve disease and long-standing atrial fibrillation

Background: Transvenous infernal cardioversion (ICV) of atrial fibrillation (AF) may be successful after unsuccessful external CV. However, the safety and efficacy of ICV in patients with significant mitral valve disease and AF of long duration have not been evaluated prospectively. Methods: This st udy included 22 consecutive patients (mean age = 59 +/- 14 years, 12 women) with mitral regurgitation grade = II (n = 14) or after mitral valve replac ement (n = 8), who underwent ICV with 3/3 ms biphasic shocks delivered via two defibrillation catheters placed in the right atrium and the coronary si nus, respectively. The mean left atrial diameter was 53 +/- 7 mm (range 45- 68), and AF had been diagnosed for a median of 24 months. All patients rece ived oral amiodarone pretreatment followed by a maintenance dose of 200 mg/ day. Results: Sinus rhythm (SR) was restored by ICV in 15/20 patients (75%) , and returned spontaneously in two patients during amiodarone pretreatment . The mean threshold for ICV was 6.2 +/- 3.5 J. Sinus node disease was pres ent in one patient after ICV, and two patients developed amiodarone-induced hyperthyroidism. During a follow-up of 11 +/- 5 months, 8 patients had rec urrent AF. The remaining 11 patients who were successfully cardioverted rem ained in stable SR. Conclusion: SR can be safely and successfully restored by ICV in patients with MVD and long-standing AF. During intermediate-term follow-up, a significant proportion of patients remained in SR with oral am iodarone therapy.