Sandeep Panikker1, Renu Virmani2, Kenichi Sakakura2, Frank Kolodgie2, Darrel P Francis1, Vias Markides1, Greg Walcott3, H Tom McElderry3, Tom Wong4. 1. Heart Rhythm Centre, NIHR Cardiovascular Research Unit, Royal Brompton & Harefield Hospitals and National Heart and Lung Institute, Imperial College, London, United Kingdom. 2. CV Path, Gaithersburg, Maryland. 3. University of Alabama at Birmingham, Birmingham, Alabama. 4. Heart Rhythm Centre, NIHR Cardiovascular Research Unit, Royal Brompton & Harefield Hospitals and National Heart and Lung Institute, Imperial College, London, United Kingdom. Electronic address: tom.wong@imperial.ac.uk.
Abstract
BACKGROUND: Left atrial appendage (LAA) electrical isolation is reported to improve atrial fibrillation ablation outcomes. However, loss of mechanical function may increase thromboembolic risk. OBJECTIVE: The aim of this study was to evaluate the feasibility and safety of LAA occlusion after electrical isolation in a canine model. METHODS: Nine canines underwent LAA isolation with irrigated radiofrequency ablation after pulmonary vein (PV) isolation. Entrance and exit block were confirmed with intravenous adenosine after 30 minutes. The LAA was then occluded with a Watchman device. Device position was assessed at 10 days by using transthoracic echocardiography. At 45 days, LAA isolation was assessed epicardially. Hearts were then examined macroscopically and histologically. RESULTS: All 36 PVs and 8 of 9 LAAs (89%) were electrically isolated. Acute LAA reconnection occurred in 4 of 8 LAAs (50%). All were reisolated. The mean ablation time was 51 ± 19 minutes, including 24 ± 18 minutes for LAA isolation. LAA occlusion was successful in all cases. One animal died of a primary intracranial bleed due to anticoagulant hypersensitivity 36 hours after the procedure. Transthoracic echocardiography at 10 days confirmed satisfactory device positions and no pericardial effusion. At 45 days, 7 of 8 (88%) had persistent LAA electrical isolation. All devices were stable without evidence of erosion. Microscopy revealed complete device-tissue apposition and a mature connective tissue layer overlying the device surface in all cases. CONCLUSION: LAA electrical isolation and mechanical occlusion can be performed concomitantly in this animal model, with no displacement or mechanical erosion of the appendage at 45 days. This technique can potentially improve success rates and obviate the need for chronic anticoagulation. Future studies should address efficacy, safety, and feasibility in humans.
BACKGROUND: Left atrial appendage (LAA) electrical isolation is reported to improve atrial fibrillation ablation outcomes. However, loss of mechanical function may increase thromboembolic risk. OBJECTIVE: The aim of this study was to evaluate the feasibility and safety of LAA occlusion after electrical isolation in a canine model. METHODS: Nine canines underwent LAA isolation with irrigated radiofrequency ablation after pulmonary vein (PV) isolation. Entrance and exit block were confirmed with intravenous adenosine after 30 minutes. The LAA was then occluded with a Watchman device. Device position was assessed at 10 days by using transthoracic echocardiography. At 45 days, LAA isolation was assessed epicardially. Hearts were then examined macroscopically and histologically. RESULTS: All 36 PVs and 8 of 9 LAAs (89%) were electrically isolated. Acute LAA reconnection occurred in 4 of 8 LAAs (50%). All were reisolated. The mean ablation time was 51 ± 19 minutes, including 24 ± 18 minutes for LAA isolation. LAA occlusion was successful in all cases. One animal died of a primary intracranial bleed due to anticoagulant hypersensitivity 36 hours after the procedure. Transthoracic echocardiography at 10 days confirmed satisfactory device positions and no pericardial effusion. At 45 days, 7 of 8 (88%) had persistent LAA electrical isolation. All devices were stable without evidence of erosion. Microscopy revealed complete device-tissue apposition and a mature connective tissue layer overlying the device surface in all cases. CONCLUSION: LAA electrical isolation and mechanical occlusion can be performed concomitantly in this animal model, with no displacement or mechanical erosion of the appendage at 45 days. This technique can potentially improve success rates and obviate the need for chronic anticoagulation. Future studies should address efficacy, safety, and feasibility in humans.
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Authors: Hugh Calkins; Karl Heinz Kuck; Riccardo Cappato; Josep Brugada; A John Camm; Shih-Ann Chen; Harry J G Crijns; Ralph J Damiano; D Wyn Davies; John DiMarco; James Edgerton; Kenneth Ellenbogen; Michael D Ezekowitz; David E Haines; Michel Haissaguerre; Gerhard Hindricks; Yoshito Iesaka; Warren Jackman; José Jalife; Pierre Jais; Jonathan Kalman; David Keane; Young-Hoon Kim; Paulus Kirchhof; George Klein; Hans Kottkamp; Koichiro Kumagai; Bruce D Lindsay; Moussa Mansour; Francis E Marchlinski; Patrick M McCarthy; J Lluis Mont; Fred Morady; Koonlawee Nademanee; Hiroshi Nakagawa; Andrea Natale; Stanley Nattel; Douglas L Packer; Carlo Pappone; Eric Prystowsky; Antonio Raviele; Vivek Reddy; Jeremy N Ruskin; Richard J Shemin; Hsuan-Ming Tsao; David Wilber Journal: Heart Rhythm Date: 2012-03-01 Impact factor: 6.343
Authors: Hugh Calkins; Gerhard Hindricks; Riccardo Cappato; Young-Hoon Kim; Eduardo B Saad; Luis Aguinaga; Joseph G Akar; Vinay Badhwar; Josep Brugada; John Camm; Peng-Sheng Chen; Shih-Ann Chen; Mina K Chung; Jens Cosedis Nielsen; Anne B Curtis; D Wyn Davies; John D Day; André d'Avila; N M S Natasja de Groot; Luigi Di Biase; Mattias Duytschaever; James R Edgerton; Kenneth A Ellenbogen; Patrick T Ellinor; Sabine Ernst; Guilherme Fenelon; Edward P Gerstenfeld; David E Haines; Michel Haissaguerre; Robert H Helm; Elaine Hylek; Warren M Jackman; Jose Jalife; Jonathan M Kalman; Josef Kautzner; Hans Kottkamp; Karl Heinz Kuck; Koichiro Kumagai; Richard Lee; Thorsten Lewalter; Bruce D Lindsay; Laurent Macle; Moussa Mansour; Francis E Marchlinski; Gregory F Michaud; Hiroshi Nakagawa; Andrea Natale; Stanley Nattel; Ken Okumura; Douglas Packer; Evgeny Pokushalov; Matthew R Reynolds; Prashanthan Sanders; Mauricio Scanavacca; Richard Schilling; Claudio Tondo; Hsuan-Ming Tsao; Atul Verma; David J Wilber; Teiichi Yamane Journal: Europace Date: 2018-01-01 Impact factor: 5.214
Authors: Olga Lazoura; Tevfik F Ismail; Christopher Pavitt; Alistair Lindsay; Mona Sriharan; Michael Rubens; Simon Padley; Alison Duncan; Tom Wong; Edward Nicol Journal: Int J Cardiovasc Imaging Date: 2015-09-29 Impact factor: 2.357
Authors: C Lavalle; M Straito; E Chourda; S Poggi; G Frati; W Saade; A G M Marullo; M V Mariani; M Magnocavallo; F Miraldi Journal: Cardiol Res Pract Date: 2021-08-02 Impact factor: 1.866