Feasibility of catheter ablation of mitral annular flutter in patients with prior mitral valve surgery
Background: Mitral annular flutter (MAF) may occur after ablation of atrial fibrillation in patients with prior mitral valve (MV) replacement or repair. Percutaneous catheter ablation may be challenging owing to the presence of surgical scar and a prosthetic MV. Objective: We examined the feasibility of and outcome after mitral isthmus ablation in patients with prior MV surgery. Methods: Twenty-one consecutive patients (18 males, age 61 ±10 years) with a history of MV surgery (nine replacement, 12 repair with annuloplasty ring) underwent catheter ablation of clinical (n = 17) or easily inducible (n = 4) MAF (group 1). Patients were matched for age, gender, and ejection fraction, with 21 patients undergoing MAF ablation without prior MV surgery (group 2). Irrigated ablation was delivered endocardially in a linear fashion from the MV to the left inferior and/or to the right superior pulmonary vein and, when required, epicardially inside the coronary sinus. Isolation of all pulmonary veins was also performed. Results: There was no difference in termination of tachycardia during ablation (group 1 vs. group 2; 86% vs. 71%; P = .454), achieving mitral isthmus block (71% vs. 71%; P = 1.000), or need for epicardial ablation (43% vs. 62%; P = .354) between groups. No complications occurred in either group. After a mean follow-up of 7 ± 4 months, 15 (71%) patients in group 1 and 14 (67%) in group 2 had no recurrence of atrial arrhythmias. Conclusions: Percutaneous mitral isthmus ablation is feasible and safe in patients with prior MV replacement or repair and has comparable outcomes to patients without prior MV surgery. © 2011 Heart Rhythm Society.