Abstract 10553: Left Atrial Wall Thickness in Patients With Hypertrophic Cardiomyopathy Undergoing Catheter Ablation for Atrial Fibrillation
Background: Several studies reported the effectiveness of catheter ablation for atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM), but it remains unclear whether myocardial wall of the left atrium (LA) is also hypertrophied in HCM. We sought to compare the LA myocardial thickness and ablation outcomes between the patients with HCM and those without structural heart disease.
Methods: Seventeen consecutive HCM patients (12 men, 63±12 years, 47% paroxysmal) with drug-refractory AF and 34 controls without detectable heart disease, whose age, gender, type of AF, and left atrial dimension were matched to the HCM patients were enrolled. LA myocardial wall thickness of 11 distinct LA locations were measured using 64-slice computed tomography images obtained prior to the RFCA, and compared between the HCM and control patients.
Results: The LA wall thickness did not differ between the two groups at 9 of the 11 locations, and was significantly thinner in the HCM patients at the middle part of the mid-posterior wall (1.44±0.17 vs. 1.58±0.22, P=0.04) and the left side of the infero-posterior wall (1.62±0.20 vs. 1.74±0.18, P=0.03). The follow-up period was 26±14 months. Although antiarrhythmic drugs were used more frequently in the HCM patients (P=0.005), the rate of maintaining sinus rhythm did not differ between the HCM and control groups (53% vs. 56% after the initial RFCA [log-rank P=0.78], and 82% and 88% after the repeated procedure [log-lank P=0.35]).
Conclusions: The LA wall in HCM patients with AF was not thicker than matched patients without structural heart disease. Catheter ablation for drug-refractory AF in these patients showed favorable outcomes.
- © 2013 by American Heart Association, Inc.