Abstract 2194: Endocardial Radiofrequency Septal Reduction - The Other Treatment Option for Hypertrophic Obstructive Cardiomyopathy in Children
Objectives: To evaluate the efficacy and safety of endocardial radiofrequency septal reduction in the management of hypertrophic obstructive cardiomyopathy (HCM) in children.
Method: Retrospective analysis of patient records from two centres over a ten year period (1998 –2008).
Results: Thirty patients (18 male), median age 11.3 (range 2.9 – 17.2) years, and median weight 31.6 (range 15– 68.7) kg underwent 34 procedures. The mean (SD) peak echo gradient was 96.4 (20.7) mm Hg. A mean (SD) of 24(±11.2) lesions were applied under fluoroscopic and transesophageal echo guidance using a cooled tip ablation catheter, staying away from the His bundle. The lesions were applied starting distally moving towards the aortic valve. Median fluoroscopy time was 26 (range 15 – 38) minutes. Mean (SD) peak troponin-T level was 8.7(±5.5) microgram/litre (normal<0.1). One patient developed LV dysfunction (LVEDP 26 –34 mm Hg) with severe mitral regurgitation acutely and died despite ECMO. All but one reported symptomatic improvement. One patient developed AV block requiring pacing. The mean (95% CI) decrease in the peak systolic gradient in the LVOT was 36.9 (28.6 – 45.1) mm Hg in peri-procedure transcatheter measurement (p<0.001) and 65.8(57.4 – 74.2) mm Hg on the transthoracic echo performed in the follow-up out-patient visit at least 2 weeks after the procedure (p<0.001). Four patients have had a repeat procedure after a median period of 2 (range 0.5 – 6.2) years.
Conclusion: Endocardial radiofrequency septal reduction is an effective alternative to surgical myectomy and alcohol septal ablation in children with HOCM. It is repeatable, and can result in a significant reduction in gradient.