Clinical efficacy of CARTOSound-guided radiofrequency ablation for hypertrophic obstructive cardiomyopathy

Abstract

Objective To investigate the clinical efficacy of CARTOSound-guided radiofrequency ablation on hypertrophic obstructive cardiomyopathy. Methods The consecutive patients with hypertrophic obstructive cardiomyopathy accompanied with systolic anterior mitral valve movement (SAM) confirmed by echocardiography in our hospital from June to December 2019 were enrolled in this study. A retrospective study was carried out on the clinical features, ablative strategies and ablative effects. According to the ablation effects, the patients were divided into response group and non-response group, and the factors affecting the ablation effect were analyzed. Results There were 11 enrolled patients (3 males and 8 females, aged 58.36±10.82 years, ranging from 44 to 77 years) with a history of hypertrophic obstructive cardiomyopathy for 6 months to 2 years. The left ventricular outflow tract gradient (LVOTG) at rest (20.00±31.12 vs 57.09±33.44 mmHg, P=0.01) and at ventricular premature beat stimulation (24.09±19.34 vs 139.60±44.52 mmHg, P < 0.01) were significantly decreased immediately in the patients after ablation. After 3 months follow-up, echocardiography showed no significant difference in ventricular septal thickness compared with that before ablation (18.15±92.84 vs 19.50±2.67 mm, P=0.35), and the LVOGT was decreased slightly and had no statistical difference (71.09±31.40 vs 52.38±35.76 mmHg, P=0.28). Similiar results were seen after 6 months follow-up, but the NYHA grade was significantly improved (1.64±0.15 vs 2.36±0.20, P < 0.01). The ventricular septal thickness was thinner, the left ventricular diameter was smaller, and B-type natriuretic peptide (BNP) level was lower in the response group (n=6) than those in the non-response group (n=5). Conclusion CARTOsound-guided radiofrequency ablation can improve cardiac function and alleviate short-term left ventricular outflow tract obstruction in the patients with hypertrophic obstructive cardiomyopathy.

Keywords

• hypertrophic obstructive cardiomyopathy
• intracardiac echocardiography
• radiofrequency ablation
• clinical efficacy