[Efficacy and safety of transthoracic echocardiography-guided percutaneous intramyocardial septal radiofrequency ablation for the treatment of patients with obstructive hypertrophic cardiomyopathy].

Objective: To investigate the safety and efficacy of transthoracic echocardiography-guided percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) in patients with hypertrophic obstructive cardiomyopathy (HOCM). Methods: Nine HOCM patients with interventricular septal thickness ≥15 mm and ≤25 mm who were treated with PIMSRA between October 2016 to March 2017 in the Hypertrophic Cardiomyopathy Center of Xijing Hospital of Air Force Military Medical University were enrolled,and the clinical data were retrospectively analyzed.Interventricular septum thickness, left ventricular outflow tract diameter and maximum gradient were measured by transthoracic echocardiography immediately after procedure, at 1 month, 3 months and 6 months after operation.Symptoms and New York Heart Association (NYHA) functional class were assessed, and provoked left ventricular outflow tract gradient and exercise time were measured after 6 months. Results: The anterior interventricular septum ((21.5±2.6) mm vs. (24.7±2.7) mm, P<0.05) and posterior interventricular septum (21.1±2.5) mm vs. (22.6±3.3) mm, P<0.05) were significantly increased,left ventricular outflow tract diameter was widened ((8.2±3.4) mm vs. (4.8±2.2) mm, P<0.05), left ventricular outflow tract gradient ((26.8±19.6) mmHg (1 mmHg=0.133 kPa) vs. (83.3±32.4) mmHg, P<0.05) and mitral regurgitation (2.0±1.9) ml vs. (3.2±3.0) ml, P<0.05) were significantly decreased immediately after ablation compared with pre-operation values. Anterior interventricular septum, posterior interventricular septum and left ventricular outflow tract gradient further decreased after 1 month ((17.5±2.0) mm vs. (24.7±2.7) mm, P<0.05; (16.9±2.1) mm vs. (22.6±3.3) mm, P<0.05; (11.6±4.0) mmHg vs. (26.8±19.6) mmHg, P<0.05, respectively) compared with values immediately after ablation. Anterior interventricular septum and posterior interventricular septum decreased after 3 and 6 months ((14.8±1.7) mm and (13.4±2.0) mm vs. (17.5±2.0) mm, all P<0.05; (12.9±1.9) mm and (12.3±2.4) mm vs. (16.9±2.1) mm, all P<0.05, respectively) compared with values at 1 month after ablation.There were no significantly difference in left ventricular outflow tract gradient at 3 and 6 months post procedure compared with 1 month after ablation (all P>0.05). Compared with pre-operation, provoked left ventricular outflow tract gradient decreased ((25.5±11.4) mmHg vs. (147.8±58.0) mmHg, P<0.01), and total exercise time increased ((9.3±1.6) minutes vs. (6.7±1.6) minutes, P=0.03) at 6 months after operation.The symptoms were disappeared in 5 patients. There were 2 cases with NYHA class Ⅱ and 7 cases with NYHA class Ⅲ before operation,while there were 6 patients with NYHA classⅠ and 3 patients with NYHA class Ⅱ at 6 months after operation (P<0.01). Conclusion: Transthoracic echocardiography-guided PIMSRA is a safe and effective new treatment approach for patients with obstructive hypertrophic cardiomyopathy.目的：评价经胸超声心动图引导下经皮心肌内室间隔射频消融术（PIMSRA）治疗梗阻性肥厚型心肌病的安全性和有效性。 方法：纳入2016年10月至2017年3月在空军军医大学西京医院肥厚型心肌病诊治中心接受PIMSRA治疗的梗阻性肥厚型心肌病患者9例（室间隔厚度≥15 mm且≤25 mm），对其临床资料进行回顾性分析。采用经胸超声心动图评价术后即刻、1、3和6个月室间隔厚度、左心室流出道内径和峰值压力阶差等，并评估术后6个月症状、纽约心脏协会（NYHA）心功能分级、运动负荷左心室流出道峰值压力阶差和运动总时间。 结果：与术前比较，术后即刻前间隔厚度和后间隔厚度均增加[分别为（24.7±2.7）mm比（21.5±2.6）mm，P<0.05；（22.6±3.3）mm比（21.1±2.5）mm，P<0.05]，左心室流出道内径增宽[（8.2±3.4）mm比（4.8±2.2）mm，P<0.05]，左心室流出道峰值压力阶差和二尖瓣反流量均减小[分别为（26.8±19.6）mmHg（1 mmHg=0.133 kPa）比（83.3±32.4）mmHg，P<0.05；（2.0±1.9）ml比（3.2±3.0）ml，P<0.05]。与术后即刻比较，术后1个月前间隔厚度、后间隔厚度和左心室流出道峰值压力阶差均减小[分别为（17.5±2.0）mm比（24.7±2.7）mm，P<0.05；（16.9±2.1）mm比（22.6±3.3）mm，P<0.05；（11.6±4.0）mmHg比（26.8±19.6）mmHg，P<0.05]。与术后1个月比较，术后3和6个月前间隔和后间隔厚度均减小[分别为（14.8±1.7）mm和（13.4±2.0）mm比（17.5±2.0）mm，P均<0.05；（12.9±1.9）mm和（12.3±2.4）mm比（16.9±2.1）mm，P均<0.05]。术后3和6个月的左心室流出道峰值压力阶差与术后1个月比较差异均无统计学意义（P均>0.05）。与术前比较，术后6个月激发左心室流出道峰值压力阶差减小[（25.5±11.4）mmHg比（147.8±58.0）mmHg，P<0.01]，运动总时间增长[（9.3±1.6）min比（6.7±1.6）min，P=0.03]。术后6个月，5例患者症状消失。术前NYHA心功能分级Ⅱ级2例，Ⅲ级7例，术后6个月NYHA心功能分级Ⅰ级为6例，Ⅱ级3例，两者差异有统计学意义（P<0.01）。 结论：PIMSRA是一种安全、有效治疗梗阻性肥厚型心肌病的新技术。.