Udi Nussinovitch1, Paul Wang1, Sanjiv Narayan1, Mohan Viswanathan1, Nitish Badhwar1, Lijun Zheng2, William H Sauer3, Duy T Nguyen1. 1. Section of Cardiac Electrophysiology, Division of Cardiovascular Medicine, Stanford University, Stanford, California, USA. 2. Section of Cardiac Electrophysiology, Division of Cardiology, University of Colorado, Aurora, Colorado, USA. 3. Section of Cardiac Electrophysiology, Division of Cardiology, Brigham and Women's Hospital, Boston, Massachusetts, USA.
Abstract
INTRODUCTION: Ablation of papillary muscles (PMs) for refractory ventricular arrhythmias can often be challenging. The catheter approach and orientation during ablation may affect optimal radiofrequency (RF) delivery. Yet, no previous study investigated the association between catheter orientation and PM lesion size. We evaluated ablation lesion characteristics with various catheter orientations relative to the PM tissue during open irrigated ablation, using a standardized, experimental setting. METHODS: Viable bovine PM was positioned on a load cell in a circulating saline bath. RF ablation was performed over PM tissue at 50 W, with the open irrigated catheter positioned either perpendicular or parallel to the PM surface. Applied force was 10 g. Ablation lesions were sectioned and underwent quantitative morphometric analysis. RESULTS: A catheter position oriented directly perpendicular to the PM tissue resulted in the largest ablation lesion volumes and depths compared with ablation with the catheter parallel to PM tissue (75.26 ± 8.40 mm3 vs. 34.04 ± 2.91 mm3 , p < .001) and (3.33 ± 0.18 mm vs. 2.24 ± 0.10 mm, p < .001), respectively. There were no significant differences in initial impedance, peak voltage, peak current, or overall decrease in impedance among groups. Parallel catheter orientation resulted in higher peak temperature (41.33 ± 0.28°C vs. 40.28 ± 0.24°C, p = .003), yet, there were no steam pops in either group. CONCLUSION: For PM ablation, catheter orientation perpendicular to the PM tissue achieves more effective and larger ablation lesions, with greater lesion depth. This may have implications for the chosen ventricular access approach, the type of catheter used, consideration for remote navigation, and steerable sheaths.
INTRODUCTION: Ablation of papillary muscles (PMs) for refractory ventricular arrhythmias can often be challenging. The catheter approach and orientation during ablation may affect optimal radiofrequency (RF) delivery. Yet, no previous study investigated the association between catheter orientation and PM lesion size. We evaluated ablation lesion characteristics with various catheter orientations relative to the PM tissue during open irrigated ablation, using a standardized, experimental setting. METHODS: Viable bovine PM was positioned on a load cell in a circulating saline bath. RF ablation was performed over PM tissue at 50 W, with the open irrigated catheter positioned either perpendicular or parallel to the PM surface. Applied force was 10 g. Ablation lesions were sectioned and underwent quantitative morphometric analysis. RESULTS: A catheter position oriented directly perpendicular to the PM tissue resulted in the largest ablation lesion volumes and depths compared with ablation with the catheter parallel to PM tissue (75.26 ± 8.40 mm3 vs. 34.04 ± 2.91 mm3 , p < .001) and (3.33 ± 0.18 mm vs. 2.24 ± 0.10 mm, p < .001), respectively. There were no significant differences in initial impedance, peak voltage, peak current, or overall decrease in impedance among groups. Parallel catheter orientation resulted in higher peak temperature (41.33 ± 0.28°C vs. 40.28 ± 0.24°C, p = .003), yet, there were no steam pops in either group. CONCLUSION: For PM ablation, catheter orientation perpendicular to the PM tissue achieves more effective and larger ablation lesions, with greater lesion depth. This may have implications for the chosen ventricular access approach, the type of catheter used, consideration for remote navigation, and steerable sheaths.
Authors: Miki Yokokawa; Eric Good; Benoit Desjardins; Thomas Crawford; Krit Jongnarangsin; Aman Chugh; Frank Pelosi; Hakan Oral; Fred Morady; Frank Bogun Journal: Heart Rhythm Date: 2010-07-14 Impact factor: 6.343
Authors: Takumi Yamada; H Thomas McElderry; Taro Okada; Yoshimasa Murakami; Harish Doppalapudi; Naoki Yoshida; James D Allred; Toyoaki Murohara; G Neal Kay Journal: J Cardiovasc Electrophysiol Date: 2009-02-27
Authors: Mark A Wood; Scott M Goldberg; Babar Parvez; Vishesh Pathak; Kristen Holland; Amy L Ellenbogen; Frederick T Han; Daniel Alexander; Melissa Lau; Leonid Reshko; Aneesh Goel Journal: J Cardiovasc Electrophysiol Date: 2009-06-30