Efficacy of catheter ablation of atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy

BACKGROUND Although pulmonary vein (PV) antrum isolation is effective in curing atrial fibrillation (AF) in a variety of heart diseases, results in patients with hypertrophic obstructive cardiomyopathy (HOCM) have not been reported. OBJECTIVES The purpose of this study was to report the results and outcome of PV antrum isolation in patients with AF and HOCM. METHODS Data from patients with AF and HOCM who underwent PV antrum isolation between February 2002 and May 2004 were analyzed retrospectively. An intracardiac echocardiographic-guided ablation technique with an 8-mm-tip catheter was used in all patients. Patients were followed in the outpatient clinic at 3, 6, and 12 months after ablation. RESULTS Twenty-seven patients with AF and HOCM (mean age 55 +/- 10 years) underwent PV antrum isolation. Mean AF duration was 5.4 +/- 3.6 years. AF was paroxysmal in 14 (52%), persistent in 9 (33%), and permanent in 4 (15%). During a mean follow-up of 341 +/- 237 days, 13 patients (48%) had AF recurrence. Of these patients, five maintained sinus rhythm (SR) with antiarrhythmic drugs, one patient remained in persistent AF, and seven patients underwent a second PV antrum isolation. After the second PV antrum isolation, five patients remained in SR, giving a final success rate of 70% (19/27). Two patients had recurrence after second PV antrum isolation; one maintained SR with antiarrhythmic drugs and one remained in persistent AF. CONCLUSION Compared with previously reported results in patients with lone AF, AF recurrence after the first PV antrum isolation is higher in patients with HOCM. However, after repeated ablation procedures, long-term cure can be achieved in a sizable number of patients. PV antrum isolation is a feasible therapeutic option in patients with AF and HOCM.