Fang Liu1,2,3, Jianli Fu1,2,4, David Hsi5, Chao Sun1,2, Guangbin He1, Rui Hu1,2, Jun Zhang1, Liwen Liu6,7. 1. Department of Ultrasound Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, China. 2. Multidisciplinary Clinic and Genetic Counseling Center of Hypertrophic Cardiomyopathy, Xijing Hospital, Fourth Military Medical University, Xi'an, China. 3. Department of Ultrasound Medicine, Affiliated Children's Hospital of Xi'an Jiaotong University, Xi'an, China. 4. Ultrasound Department, Shaan Xi Province People's Hopital, Xi'an, China. 5. Heart and Vascular Institute, Stamford Hospital, Stamford, Connecticut, USA. 6. Department of Ultrasound Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, China, liuliwen@fmmu.edu.cn. 7. Multidisciplinary Clinic and Genetic Counseling Center of Hypertrophic Cardiomyopathy, Xijing Hospital, Fourth Military Medical University, Xi'an, China, liuliwen@fmmu.edu.cn.
Abstract
BACKGROUND: Percutaneous intramyocardial (PIM) septal radiofrequency ablation (SRA) is a novel treatment approach for hypertrophic obstructive cardiomyopathy patients, but there has been lack of a large animal model to study PIM-SRA. We aimed to validate the long-term safety and efficacy of PIM-SRA and to observe pathological changes of the ablated interventricular septum (IVS) in a healthy sheep model. METHODS AND RESULTS: Twelve sheep were randomized to the PIM-SRA group (n = 6) and the sham group (n = 6). In the PIM-SRA group, a radiofrequency (RF) electrode was inserted into the IVS with a maximum power of 80 W for 5 min. In the sham group, the RF electrode tip was positioned in the IVS segment but without RF power delivery. Septal hypokinesis was seen in all PIM-SRA group animals immediately after the procedure; the systolic wall thickening rate and motion amplitude of the ablated region decreased (p < 0.01), and the diastolic IVS thickness also decreased significantly over time (p < 0.01). ECG showed that all the sheep had normal sinus rhythm during the follow-up. Pathological examinations revealed scar tissue in the ablated region as expected. CONCLUSIONS: PIM-SRA produced precisely ablated myocardial tissue, reduced the IVS thickness significantly, preserved the global LV function, and avoided the incidence of conduction system damage in the long term. PIM-SRA was found to be a safe and effective minimally invasive septal reduction therapy.
BACKGROUND: Percutaneous intramyocardial (PIM) septal radiofrequency ablation (SRA) is a novel treatment approach for hypertrophic obstructive cardiomyopathypatients, but there has been lack of a large animal model to study PIM-SRA. We aimed to validate the long-term safety and efficacy of PIM-SRA and to observe pathological changes of the ablated interventricular septum (IVS) in a healthy sheep model. METHODS AND RESULTS: Twelve sheep were randomized to the PIM-SRA group (n = 6) and the sham group (n = 6). In the PIM-SRA group, a radiofrequency (RF) electrode was inserted into the IVS with a maximum power of 80 W for 5 min. In the sham group, the RF electrode tip was positioned in the IVS segment but without RF power delivery. Septal hypokinesis was seen in all PIM-SRA group animals immediately after the procedure; the systolic wall thickening rate and motion amplitude of the ablated region decreased (p < 0.01), and the diastolic IVS thickness also decreased significantly over time (p < 0.01). ECG showed that all the sheep had normal sinus rhythm during the follow-up. Pathological examinations revealed scar tissue in the ablated region as expected. CONCLUSIONS: PIM-SRA produced precisely ablated myocardial tissue, reduced the IVS thickness significantly, preserved the global LV function, and avoided the incidence of conduction system damage in the long term. PIM-SRA was found to be a safe and effective minimally invasive septal reduction therapy.
Authors: Mengyao Zhou; Shengjun Ta; Rebecca T Hahn; David H Hsi; Martin B Leon; Rui Hu; Jun Zhang; Lei Zuo; Jing Li; Jing Wang; Bo Wang; Xiaoli Zhu; Jiani Liu; Yupeng Han; Xiaojuan Li; Bo Xu; Lei Zhang; Lihong Hou; Chao Han; Jincheng Liu; Liwen Liu Journal: JAMA Cardiol Date: 2022-05-01 Impact factor: 30.154