Percutaneous Radiofrequency Septal Reduction for Hypertrophic Obstructive Cardiomyopathy in Children

OBJECTIVES: The aim of this study was to assess the efficacy of radiofrequency catheter ablation (RFCA) in the treatment of hypertrophic obstructive cardiomyopathy in children. BACKGROUND: Hypertrophic obstructive cardiomyopathy is an uncommon cause of left ventricular outflow tract obstruction in children. In symptomatic patients, open heart surgical myectomy has hitherto been the only therapeutic option. METHODS: In 32 children, at a median age of 11.1 (range 2.9 to 17.5) years and weight of 31 (15 to 68) kg, ablation of the hypertrophied septum was performed using a cool-tip ablation catheter via a femoral arterial approach. The median number of lesions was 27 (10 to 63) and fluoroscopic time was 24 (12 to 60) min. RESULTS: The majority of patients demonstrated an immediate decrease in the catheter pullback gradient (mean 78.5 ± 26.2 mm Hg pre-RFCA versus mean 36.1 ± 16.5 mm Hg post-RFCA, p < 0.01) and a further reduction in the Doppler echocardiographic gradient (mean 96.9 ± 27.0 mm Hg pre-RFCA versus 32.7 ± 27.1 mm Hg post-RFCA, p < 0.01) at follow-up. One patient died due to a paradoxical increase in left ventricular outflow tract obstruction, and another had persistent atrioventricular block that required permanent pacing. Six patients required further procedures (surgery, pacing, or further RFCA) during a median follow-up of 48 (3 to 144) months. CONCLUSIONS: The preliminary results of RFCA for septal reduction in children with hypertrophic cardiomyopathy are promising and merit further evaluation.