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.