title: Septal ablation induced by transthoracic high-intensity focused ultrasound in canines.
abstract: BACKGROUND
  High-intensity focused ultrasound (HIFU) can achieve accurate and focused deep tissue ablation through an extracorporeal emission. Cardiac ablation using HIFU applied transthoracically must overcome potential interference from intervening thoracic structures. The aim of this study was to explore the efficacy and safety of septal ablation that was induced using transthoracic HIFU.
  
  
  METHODS
  Twenty-one canines were pretreated to improve acoustic transmission. Single ablations were induced by targeting transthoracic HIFU with acoustic power of 400 W for 3 sec at the middle and basal septum in eight canines. Extended ablations were performed to create larger lesions at the basal septum in eight more canines. The three-dimensional morphology of a basal septum lesion induced by a single ablation was analyzed. The temperature at the ablative targets was measured in the other five canines.
  
  
  RESULTS
  The cardiomyocytes in the lesions underwent necrosis with a clear boundary. The three-dimensional morphology of the lesions appeared approximately as ellipsoids with a flatter endocardial side. The peak temperature at a power of 400 W for 3 sec was 93.27 ± 2.54°C, and it remained >50°C for nearly 10 sec. No procedure-related complications were observed.
  
  
  CONCLUSIONS
  Ultrasound-guided transthoracic HIFU has the potential to safely create small dot or large mass lesions in the septum without a thoracotomy or a catheter.
authors.affiliation: Department of Cardiology, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China; State Key Laboratory of Ultrasound Engineering in Medicine Cofounded by Chongqing and the Ministry of Science and Technology, and the National Engineering Research Center of Ultrasound Medicine, Chongqing, China.
authors.forename: Shunkang
authors.initials: S
authors.lastname: Rong
authors.affiliation: Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Kamsang
authors.initials: K
authors.lastname: Woo
authors.affiliation: Department of Cardiology, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China; State Key Laboratory of Ultrasound Engineering in Medicine Cofounded by Chongqing and the Ministry of Science and Technology, and the National Engineering Research Center of Ultrasound Medicine, Chongqing, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Department of Cardiology, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China; State Key Laboratory of Ultrasound Engineering in Medicine Cofounded by Chongqing and the Ministry of Science and Technology, and the National Engineering Research Center of Ultrasound Medicine, Chongqing, China.
authors.forename: Que
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: Department of Cardiology, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China; State Key Laboratory of Ultrasound Engineering in Medicine Cofounded by Chongqing and the Ministry of Science and Technology, and the National Engineering Research Center of Ultrasound Medicine, Chongqing, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Ultrasound Engineering in Medicine Cofounded by Chongqing and the Ministry of Science and Technology, and the National Engineering Research Center of Ultrasound Medicine, Chongqing, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Cardiology, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Changming
authors.initials: C
authors.lastname: Deng
authors.affiliation: Department of Cardiology, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Dichuan
authors.initials: D
authors.lastname: Liu
authors.affiliation: Department of Cardiology, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Yang
authors.affiliation: Department of Cardiology, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Ultrasound Engineering in Medicine Cofounded by Chongqing and the Ministry of Science and Technology, and the National Engineering Research Center of Ultrasound Medicine, Chongqing, China.
authors.forename: Zhibiao
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Cardiology, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China; State Key Laboratory of Ultrasound Engineering in Medicine Cofounded by Chongqing and the Ministry of Science and Technology, and the National Engineering Research Center of Ultrasound Medicine, Chongqing, China. Electronic address: huangjing@cqmu.edu.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Huang
mesh_terms: D000818:Animals; D004285:Dogs; D019560:Echocardiography, Three-Dimensional; D005240:Feasibility Studies; D006346:Heart Septum / Q000166:cytology / Q000601:surgery*; D057086:High-Intensity Focused Ultrasound Ablation / Q000379:methods; D032383:Myocytes, Cardiac / Q000473:pathology; D009336:Necrosis
keywords: 3D; HIFU; High-intensity focused ultrasound; IVS; Interventricular septum; Septal ablation; Three-dimensional; Transthoracic