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Bates AP, Paisey J, Yue A, Banks P, Roberts PR, Ullah W. Comparison of voltages between atria: differences in sinus rhythm and atrial fibrillation. J Interv Card Electrophysiol 2024; 67:649-656. [PMID: 37875609 PMCID: PMC11016007 DOI: 10.1007/s10840-023-01671-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 10/12/2023] [Indexed: 10/26/2023]
Abstract
BACKGROUND Ultra high-density mapping systems allow for comparison of atrial electroanatomical maps in unprecedented detail. Atrial scar determined by voltages and surface area between atria, rhythm and atrial fibrillation (AF) types was assessed. METHODS Left (LA) and right atrial (RA) maps were created using Rhythmia HDx in patients listed for ablation for paroxysmal (PAF, sinus rhythm (SR) maps only) or persistent AF (PeAF, AF and SR maps). Electrograms on corresponding SR/AF maps were paired for direct comparison. Percentage surface area of scar was assigned low- (LVM, ≤ 0.05 mV), intermediate- (IVM, 0.05-0.5 mV) or normal voltage myocardium, (NVM, > 0.5 mV). RESULTS Thirty-eight patients were recruited generating 96 maps using 913,480 electrograms. Paired SR-AF bipolar electrograms showed fair correlation in LA (Spearman's ρ = 0.32) and weak correlation in RA (ρ = 0.19) and were significantly higher in SR in both (LA: 0.61 mV (0.20-1.67) vs 0.31 mV (0.10-0.74), RA: 0.68 mV (0.19-1.88) vs 0.47 mV (0.14-1.07), p < 0.0005 both). Voltages were significantly higher in patients with PAF over PeAF, (LA: 1.13 mV (0.39-2.93) vs 0.52 mV (0.16-1.49); RA: 0.93 mV (0.24-2.46) vs 0.57 mV (0.17-1.69)). Minimal differences were seen in electrogram voltages between atria. Significantly more IVM/LVM surface areas were seen in AF over SR (LA only, p < 0005), and PeAF over PAF (LA: p = 0.01, RA: p = 0.04). There was minimal difference between atria within patients. CONCLUSIONS Ultra high-density mapping shows paired electrograms correlate poorly between SR and AF. SR electrograms are typically (but not always) larger than those in AF. Patients with PeAF have a lower global electrogram voltage than those with PAF. Electrogram voltages are similar between atria within individual patients.
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Affiliation(s)
- Alexander P Bates
- Department of Cardiology, University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, UK.
- Faculty of Medicine, School of Human Development and Health, University of Southampton, Southampton, UK.
| | - John Paisey
- Department of Cardiology, University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, UK
| | - Arthur Yue
- Department of Cardiology, University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, UK
| | - Phil Banks
- Department of Cardiology, University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, UK
| | - Paul R Roberts
- Department of Cardiology, University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, UK
- Faculty of Medicine, School of Human Development and Health, University of Southampton, Southampton, UK
| | - Waqas Ullah
- Department of Cardiology, University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, UK
- Faculty of Medicine, School of Human Development and Health, University of Southampton, Southampton, UK
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Yamaguchi J, Takigawa M, Goya M, Martin CA, Negishi M, Yamamoto T, Ikenouchi T, Goto K, Shigeta T, Kawamura I, Nishimura T, Takamiya T, Tao S, Miyazaki S, Sasano T. Impact of contact force on the lesion characteristics of very high-power short-duration ablation using a QDOT-MICRO catheter. J Arrhythm 2024; 40:247-255. [PMID: 38586837 PMCID: PMC10995585 DOI: 10.1002/joa3.12992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 01/05/2024] [Accepted: 01/06/2024] [Indexed: 04/09/2024] Open
Abstract
Background Lesion size is reported to become larger as contact force (CF) increases. However, this has not been systematically evaluated in temperature-guided very high-power short-duration (vHPSD) ablation, which was therefore the purpose of this study. Methods Radiofrequency applications (90 W/4 s, temperature-control mode) were performed in excised porcine myocardium with four different CFs of 5, 15, 25, and 35 g using QDOT-MICRO™ catheter. Ten lesions for each combination of settings were created, and lesion metrics and steam-pops were compared. Results A total of 320 lesions were analyzed. Lesion depth, surface area, and volume were smallest for CF of 5 g than for 15, 25, and 35 g (depth: 2.7 mm vs. 2.9 mm, 3.0 mm, 3.15 mm, p < .01; surface area: 38.4 mm2 vs. 41.8 mm2, 43.3 mm2, 41.5 mm2, p < .05; volume: 98.2 mm3 vs. 133.3 mm3, 129.4 mm3, 126.8 mm3, p < .01 for all pairs of groups compared to CF = 5 g). However, no significant differences were observed between CFs of 15-35 g. Average power was highest for CF of 5 g, followed by 15, 25, and 35 g (83.2 W vs. 82.1 W vs. 77.1 W vs. 66.1 W, p < .01 for all pairs), reflecting the higher incidence of temperature-guided power titration with greater CFs (5 g:8.8% vs. 15 g:52.5% vs. 25 g:77.5% vs. 35 g:91.2%, p < .01 for all pairs except for 25 g vs. 35 g). The incidence of steam-pops did not significantly differ between four groups (5 g:3.8% vs. 15 g:10% vs. 25 g:6.2% vs. 35 g:2.5%, not significant for all pairs). Conclusions For vHPSD ablation, lesion size does not become large once the CF reaches 15 g, and the risk of steam-pops may be mitigated through power titration even in high CFs.
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Affiliation(s)
- Junji Yamaguchi
- Department of Cardiovascular MedicineTokyo Medical and Dental University HospitalTokyoJapan
- Department of Clinical and Diagnostic Laboratory ScienceTokyo Medical and Dental UniversityTokyoJapan
| | - Masateru Takigawa
- Department of Cardiovascular MedicineTokyo Medical and Dental University HospitalTokyoJapan
| | - Masahiko Goya
- Department of Cardiovascular MedicineTokyo Medical and Dental University HospitalTokyoJapan
| | | | - Miho Negishi
- Department of Cardiovascular MedicineTokyo Medical and Dental University HospitalTokyoJapan
| | - Tasuku Yamamoto
- Department of Cardiovascular MedicineTokyo Medical and Dental University HospitalTokyoJapan
| | - Takashi Ikenouchi
- Department of Cardiovascular MedicineTokyo Medical and Dental University HospitalTokyoJapan
| | - Kentaro Goto
- Department of Cardiovascular MedicineTokyo Medical and Dental University HospitalTokyoJapan
| | - Takatoshi Shigeta
- Department of Cardiovascular MedicineTokyo Medical and Dental University HospitalTokyoJapan
| | - Iwanari Kawamura
- Department of Cardiovascular MedicineTokyo Medical and Dental University HospitalTokyoJapan
| | - Takuro Nishimura
- Department of Cardiovascular MedicineTokyo Medical and Dental University HospitalTokyoJapan
| | - Tomomasa Takamiya
- Department of Cardiovascular MedicineTokyo Medical and Dental University HospitalTokyoJapan
| | - Susumu Tao
- Department of Cardiovascular MedicineTokyo Medical and Dental University HospitalTokyoJapan
| | - Shinsuke Miyazaki
- Department of Cardiovascular MedicineTokyo Medical and Dental University HospitalTokyoJapan
| | - Tetsuo Sasano
- Department of Cardiovascular MedicineTokyo Medical and Dental University HospitalTokyoJapan
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3
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Issa ZF. Radiofrequency lesion formation prediction with contact force versus local impedance. Curr Opin Cardiol 2024; 39:6-14. [PMID: 37820074 DOI: 10.1097/hco.0000000000001095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
PURPOSE OF REVIEW Safe and effective radiofrequency (RF) myocardial ablation requires real-time monitoring of lesion formation. Here, we review conventional and novel approaches proposed to guide titration of RF energy application. RECENT FINDINGS Conventional monitoring modalities, such as ablation electrode temperature, generator impedance, and tissue electrophysiological properties have been of limited value in predicting efficacy and safety of ablation. Therefore, several input-driven indices have been proposed to improve the quality and durability of RF ablation lesion while maintaining safety. These metrics predominantly incorporate RF power output, duration of RF application, and firmness and stability of electrode-tissue contact. More recently, novel catheters have enabled measuring local impedance at the catheter-tissue interface, which has been found valuable for real-time monitoring of RF lesion formation. SUMMARY It is likely that using the combination of multiple metrics would be required to improve the quality and safety of RF lesions, but further investigation is still required.
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Affiliation(s)
- Ziad F Issa
- Prairie Heart Institute, Springfield, Illinois, USA
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4
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Yamaguchi J, Takigawa M, Goya M, Yamamoto T, Ikenouchi T, Iwakawa H, Negishi M, Goto K, Shigeta T, Nishimura T, Takamiya T, Tao S, Miyazaki S, Sasano T. Safety verification of a novel irrigation catheter with flexible tip of laser-cut kerfs and contact force sensor. Pacing Clin Electrophysiol 2023; 46:1536-1545. [PMID: 37957924 DOI: 10.1111/pace.14868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/27/2023] [Accepted: 10/29/2023] [Indexed: 11/15/2023]
Abstract
BACKGROUND AND AIMS The safety evaluation of TactiFlex, a novel contact-force sensing catheter with a flexible 4-mm tip irrigated through laser-cut kerfs, has been ongoing. This study aimed to verify the safety of this type of catheter. METHODS Study 1: Radiofrequency (RF) applications at a range of powers (30-50 W), contact forces (10-20 g), and durations (10-60 s) using perpendicular/parallel catheter orientation with half-normal (HNS) or normal saline irrigation were compared between TactiFlex (4-mm tip) and TactiCath (3.5-mm tip) with temperature-controlled mode in excised porcine hearts. Study 2: The relation between RF applications using TactiFlex and the incidence of steam-pops in the real clinical cases were examined. RESULTS Study-1: 576 RF lesions were examined. TactiFlex demonstrated a significantly lower risk of steam-pops (5[1.7%] vs. 59[20.5%], p < .0001). Compared to 3.5-mm-tip catheter (TactiCath), 4-mm-tip catheter (TactiFlex) produced smaller lesion volume at perpendicular (193[98-554]mm3 vs. 263[139-436]mm3 , p < .0001), but relatively similar lesion volume at parallel contact (243[105-443]mm3 vs. 278[180-440]mm3 , p = .06). HNS-irrigation tended to increase the lesion volume in both catheters and to increase the incidence of steam-pops with TactiCath, but not with TactiFlex. The cut-off value of %impedance-drop ( = absolute impedance-drop/initial impedance) of 20% predicted steam-pops with a sensitivity = 100% and specificity = 89.6% in TactiFlex. Study-2: 5496 RF applications in 84 patients (51AFs/8ATs/3AVNRTs/4AVRTs/17PVCs/4VTs) using TactiFlex were analyzed. Four steam-pops (0.07%) in three patients with pericardial effusion were observed (%impedance-drop = 24%/26%/29%/35%, respectively). The cut-off value of %impedance-drop = 20%, derived from ex-vivo study, showed sensitivity = 100% and specificity = 90.1% in detecting steam-pops. CONCLUSION TactiFlex reduced the risk of steam-pops than TactiCath. %impedance-drop ≤ 20% may be reasonable for safely use with a sufficient safety margin. For 4-mm-tip catheter, parallel-contact may be recommended for larger lesion creation.
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Affiliation(s)
- Junji Yamaguchi
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University Hospital, Tokyo, Japan
- Department of Clinical and Diagnostic Laboratory Science, Tokyo Medical and Dental University, Tokyo, Japan
| | - Masateru Takigawa
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University Hospital, Tokyo, Japan
| | - Masahiko Goya
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University Hospital, Tokyo, Japan
| | - Tasuku Yamamoto
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University Hospital, Tokyo, Japan
| | - Takashi Ikenouchi
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University Hospital, Tokyo, Japan
| | - Hidehiro Iwakawa
- Department of Cardiovascular Medicine, Akita University Graduate School of Medicine, Akita, Japan
| | - Miho Negishi
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University Hospital, Tokyo, Japan
| | - Kentaro Goto
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University Hospital, Tokyo, Japan
| | - Takatoshi Shigeta
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University Hospital, Tokyo, Japan
| | - Takuro Nishimura
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University Hospital, Tokyo, Japan
| | - Tomomasa Takamiya
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University Hospital, Tokyo, Japan
| | - Susumu Tao
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University Hospital, Tokyo, Japan
| | - Shinsuke Miyazaki
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University Hospital, Tokyo, Japan
| | - Tetsuo Sasano
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University Hospital, Tokyo, Japan
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5
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Di C, Wang Q, Wu Y, Li L, Lin W. Monitoring Spike Potential and Abrupt Impedance Rise with Concomitant Temperature/Contact Force Change for Timely Detection of the Occurrence of “Silent” or “Nonaudible” Steam Pop. J Interv Cardiol 2023; 2023:8873404. [PMID: 37064642 PMCID: PMC10098411 DOI: 10.1155/2023/8873404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 03/14/2023] [Accepted: 03/28/2023] [Indexed: 04/08/2023] Open
Abstract
Aim. Steam pop (SP) during radiofrequency catheter ablation (RFCA) for pulmonary vein isolation (PVI) may cause cardiac perforation, which may require drainage and emergent thoracotomy or even lead to death. Data investigating the timely detection of the occurrence of “silent” or “nonaudible” SP events are limited. Methods and Results. A total of 516 consecutive atrial fibrillation (AF) patients who underwent index PVI were included in this retrospective observational study. The duration, power, impedance, temperature, and contact force (CF) of RFCA were continually monitored and recorded throughout the procedure. A total of 15 (2.9%) audible SP events occurred in 14 patients; 2 of the patients developed pericardial tamponade, 1 patient underwent drainage, and 1 patient underwent emergent thoracotomy. The time from RFCA initiation to the occurrence of audible SP was 19.4 ± 6.9 s. Abrupt temperature change occurred in 13 (86.7%) of the 15 SP events, of which 8 (53.3%) exhibited an abrupt temperature rise of 2.3 ± 1.0°C, 5 (33.3%) exhibited an abrupt temperature drop of 2.3 ± 1.3°C, and 2 (13.3%) exhibited no discernible temperature change. Conclusions. In conclusion, simultaneously recorded spike potentials and abrupt impedance rise with concomitant temperature and/or CF change could be a feasible method for the timely detection of the occurrence of audible, “silent,” or “nonaudible” SP events, particularly in regions where the risk of perforation may be of concern.
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Affiliation(s)
- Chengye Di
- Cardiac Electrophysiology Unit, First Department of Cardiology, TEDA International Cardiovascular Hospital, Tianjin, China
- College of Clinical Cardiology, Tianjin Medical University, Tianjin, China
- Cardiovascular Institute, Tianjin University, Tianjin, China
| | - Qun Wang
- Cardiac Electrophysiology Unit, First Department of Cardiology, TEDA International Cardiovascular Hospital, Tianjin, China
- College of Clinical Cardiology, Tianjin Medical University, Tianjin, China
- Cardiovascular Institute, Tianjin University, Tianjin, China
| | - Yanxi Wu
- Cardiac Electrophysiology Unit, First Department of Cardiology, TEDA International Cardiovascular Hospital, Tianjin, China
- College of Clinical Cardiology, Tianjin Medical University, Tianjin, China
- Cardiovascular Institute, Tianjin University, Tianjin, China
| | - Longyu Li
- Cardiac Electrophysiology Unit, First Department of Cardiology, TEDA International Cardiovascular Hospital, Tianjin, China
- College of Clinical Cardiology, Tianjin Medical University, Tianjin, China
- Cardiovascular Institute, Tianjin University, Tianjin, China
| | - Wenhua Lin
- Cardiac Electrophysiology Unit, First Department of Cardiology, TEDA International Cardiovascular Hospital, Tianjin, China
- College of Clinical Cardiology, Tianjin Medical University, Tianjin, China
- Cardiovascular Institute, Tianjin University, Tianjin, China
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Fukaya H, Mori H, Oikawa J, Kawano D, Nakamura H, Ishizue N, Kishihara J, Hojo R, Tsutsui K, Ikeda Y, Kato R, Fukamizu S. Optimal local impedance parameters for successful pulmonary vein isolation in patients with atrial fibrillation. J Cardiovasc Electrophysiol 2023; 34:71-81. [PMID: 36378816 DOI: 10.1111/jce.15748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/24/2022] [Accepted: 11/07/2022] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Local impedance (LI) parameters of IntellaNav STABLEPOINT for successful pulmonary vein isolation (PVI) of atrial fibrillation (AF) remain unclear. The purpose of this study was to seek LI data achieving successful PVI. METHODS Consecutive AF patients who underwent catheter ablation with STABLEPOINT were prospectively enrolled in two centers. PVI was performed under a constant 35-or 40-watt power, 20-s duration, and >5-g contact force. The operators were blinded to the LI data. The characteristics of all ablation points with/without conduction gaps (Unsuccess or Success tags) after the first-attempt PVI were evaluated for the right/left PVs and anterior/posterior wall (RPV/LPV and AW/PW, respectively), and cutoff values of LI data were calculated for successful lesion formation. RESULTS A total of 5257 ablation points in 102 patients (65 [58-72] years old, 65.7% male) were evaluated. The LI drop values were higher in the Success tags than Unsuccess tags on the LPV-AW and RPV-AW/PW (p < .001), except for the LPV-PW (p = .105). The %LI drop values (LI drop/initial LI) were higher for the Success tags in all areas (15.8 [12.2%-19.6%] vs. 11.6 [9.7%-15.6%] in LPV-AW: p < .001, 15.0 [11.5%-19.3%] vs. 11.4 [8.7%-17.3%] in LPV-PW: p = .035, 15.3 [11.5%-19.4%] vs. 9.9 [8.1%-13.7%] in RPV-AW: p < .001, and 13.3 [10.1%-17.4%] vs. 8.1 [6.3%-9.5%] in RPV-PW, p < .001). The LI drop and %LI drop cutoff values were 20.0 ohms and 11.6%, respectively. CONCLUSIONS An insufficient LI drop with STABLEPOINT was associated with a gap formation during PVI, and the best cutoff values for the LI drop and %LI drop were 20.0 ohms and 11.6%, respectively.
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Affiliation(s)
- Hidehira Fukaya
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Hitoshi Mori
- Department of Cardiovascular Medicine, Saitama Medical University International Medical Center, Hidaka, Japan
| | - Jun Oikawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Daisuke Kawano
- Department of Cardiovascular Medicine, Saitama Medical University International Medical Center, Hidaka, Japan
| | - Hironori Nakamura
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Naruya Ishizue
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Jun Kishihara
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Rintaro Hojo
- Department of Cardiology, Tokyo Metropolitan Hiroo Hospital, Tokyo, Japan
| | - Kenta Tsutsui
- Department of Cardiovascular Medicine, Saitama Medical University International Medical Center, Hidaka, Japan
| | - Yoshifumi Ikeda
- Department of Cardiovascular Medicine, Saitama Medical University International Medical Center, Hidaka, Japan
| | - Ritsushi Kato
- Department of Cardiovascular Medicine, Saitama Medical University International Medical Center, Hidaka, Japan
| | - Seiji Fukamizu
- Department of Cardiology, Tokyo Metropolitan Hiroo Hospital, Tokyo, Japan
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Requirement of larger local impedance reduction for successful lesion formation at carinal area during pulmonary vein isolation. J Interv Card Electrophysiol 2022; 65:509-518. [PMID: 35794439 DOI: 10.1007/s10840-022-01282-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 06/15/2022] [Indexed: 10/17/2022]
Abstract
PURPOSE Local impedance (LI) measurement from an ablation catheter is useful in predicting lesion size and acute success of pulmonary vein isolation (PVI). The LI variation can be described by absolute LI drop (ΔLID) or ΔLID/initial LI (%LID). We evaluated the utility of these parameters in predicting acute lesion durability during PVI using a novel catheter capable of measuring both LI and contact force (CF). METHODS PVI with a targeted CF, power, and duration was performed in 23 consecutive patients with paroxysmal atrial fibrillation. LI was blinded to operators during ablation. Parameters for each RF application were collected and compared for acute successful lesions and gaps. RESULTS A total of 1633 RF applications including 97 (5.9%) gap lesions were analyzed. Successful lesions were more frequently observed at non-carinal sites and those with higher contact force, FTI, initial LI, and larger variation of LI and generator impedance (GI). Multivariate analysis demonstrated that absolute GI drop (ΔGID) [OR 1.09 (1.04-1.15), p < 0.001], ΔLID [1.12 (1.09-1.16), p < 0.001], ΔGID/initial GI (%GID) [OR 1.04 (1.01-1.07), p = 0.01], and %LID [OR 1.15 (1.12-1.28), p < 0.001] were significantly associated with successful lesions, and carinal site [OR 0.15(0.09-0.24), p < 0.001] was significantly related to gaps. Both ΔLID and %LID equally predicted the acute durability of lesions during PVI. ΔLID ≥ 24Ω and %LID ≥ 15% at the carina, and ΔLID ≥ 21Ω and %LID ≥ 14% at non-carinal sites significantly predicted acute successful lesions with negative predictive values of 93-99%. CONCLUSIONS Both ΔLID and %LID were equally useful in predicting acute successful lesions during PVI. Larger cut-off values should be applied to carinal sites.
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Yasumoto K, Egami Y, Kawanami S, Sugae H, Ukita K, Kawamura A, Nakamura H, Matsuhiro Y, Tsuda M, Okamoto N, Matsunaga-Lee Y, Yano M, Nishino M, Tanouchi J. The correlation between local impedance drop and catheter contact in clinical pulmonary vein isolation use. Pacing Clin Electrophysiol 2022; 45:984-992. [PMID: 35363376 DOI: 10.1111/pace.14500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 02/27/2022] [Accepted: 03/18/2022] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Local impedance (LI) drop during radiofrequency (RF) application is monitored to assess the lesion formation. Recently, a novel ablation catheter has been introduced to clinical setting, which is capable of monitoring LI and catheter contact parameters including contact force (CF) and contact angle (CA). This study aimed to clarify the correlation between LI drop and catheter contact parameters. METHODS AND RESULTS This prospective study included 15 paroxysmal atrial fibrillation (AF) patients who underwent initial pulmonary vein isolation (PVI). First-pass encircling point-by-point PV ablation was performed by using a 4.5-mm irrigated ablation catheter, with monitoring LI, CF, and CA. RF energy was applied for 30 sec at each site with 30W. Stable ablation points were analyzed to examine the correlation between LI drop and catheter contact parameters. Among 903 ablation points, 499 stable ablation points (55.2%) were analyzed. CA showed good correlation with LI drop (ρ = 0.418, P<0.001). Maximum CF, minimum CF, average CF, and initial CF all showed weak correlation with LI drop (ρ = 0.201, P<0.001; ρ = 0.224, P<0.001; ρ = 0.258, P<0.001; and ρ = 0.212, P<0.001, respectively). Multivariate analysis demonstrated that CA was an independent factor of LI drop among the catheter contact parameters (β = 0.139, 95%CI = 0.111-0.167, P<0.001). The LI drop in the blocked segments was significantly higher than that in the electrical conduction gap segments (27.3 ± 9.8 Ω vs. 19.6 ± 6.4 Ω, P<0.001) CONCLUSION: In clinical PVI use, both CF and CA were correlated with LI drop. More parallel CA could induce higher LI drop, which may lead to effective lesion formation. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Koji Yasumoto
- Division of Cardiology, Osaka Rosai Hospital, Sakai, Osaka, Japan
| | - Yasuyuki Egami
- Division of Cardiology, Osaka Rosai Hospital, Sakai, Osaka, Japan
| | - Shodai Kawanami
- Division of Cardiology, Osaka Rosai Hospital, Sakai, Osaka, Japan
| | - Hiroki Sugae
- Division of Cardiology, Osaka Rosai Hospital, Sakai, Osaka, Japan
| | - Kohei Ukita
- Division of Cardiology, Osaka Rosai Hospital, Sakai, Osaka, Japan
| | - Akito Kawamura
- Division of Cardiology, Osaka Rosai Hospital, Sakai, Osaka, Japan
| | - Hitoshi Nakamura
- Division of Cardiology, Osaka Rosai Hospital, Sakai, Osaka, Japan
| | - Yutaka Matsuhiro
- Division of Cardiology, Osaka Rosai Hospital, Sakai, Osaka, Japan
| | - Masaki Tsuda
- Division of Cardiology, Osaka Rosai Hospital, Sakai, Osaka, Japan
| | - Naotaka Okamoto
- Division of Cardiology, Osaka Rosai Hospital, Sakai, Osaka, Japan
| | | | - Masamichi Yano
- Division of Cardiology, Osaka Rosai Hospital, Sakai, Osaka, Japan
| | - Masami Nishino
- Division of Cardiology, Osaka Rosai Hospital, Sakai, Osaka, Japan
| | - Jun Tanouchi
- Division of Cardiology, Osaka Rosai Hospital, Sakai, Osaka, Japan
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9
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Chu GS, Calvert P, Futyma P, Ding WY, Snowdon R, Gupta D. Local impedance for the optimization of radiofrequency lesion delivery: A review of bench and clinical data. J Cardiovasc Electrophysiol 2021; 33:389-400. [PMID: 34921465 DOI: 10.1111/jce.15335] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 11/11/2021] [Accepted: 12/05/2021] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Radiofrequency catheter ablation is a cornerstone of treatment for many cardiac arrhythmias. Progression in three-dimensional mapping and contact-force sensing technologies have improved our capability to achieve success, but challenges still remain. METHODS In this article, we discuss the importance of overall circuit impedance in radiofrequency lesion formation. This is followed by a review of the literature regarding recently developed "local impedance" technology and its current and future potential applications and limitations, in the context of established surrogate markers currently used to infer effective ablation. RESULTS We discuss the role of local impedance in assessing myocardial substrate, as well as its role in clinical studies of ablation. We also discuss safety considerations, limitations and ongoing research. CONCLUSION Local impedance is a novel tool which has the potential to tailor ablation in a manner distinct from other established metrics.
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Affiliation(s)
- Gavin S Chu
- Department of Cardiology, Liverpool Heart and Chest Hospital NHS Foundation Trust, Liverpool, UK.,Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Peter Calvert
- Department of Cardiology, Liverpool Heart and Chest Hospital NHS Foundation Trust, Liverpool, UK.,Research Unit, Liverpool Centre for Cardiovascular Science, University of Liverpool, Liverpool, UK
| | - Piotr Futyma
- Department of Cardiology, Medical College of the University of Rzeszów, St. Joseph's Heart Rhythm Center, Rzeszów, Poland, Rzeszów, Poland
| | - Wern Yew Ding
- Department of Cardiology, Liverpool Heart and Chest Hospital NHS Foundation Trust, Liverpool, UK.,Research Unit, Liverpool Centre for Cardiovascular Science, University of Liverpool, Liverpool, UK
| | - Richard Snowdon
- Department of Cardiology, Liverpool Heart and Chest Hospital NHS Foundation Trust, Liverpool, UK
| | - Dhiraj Gupta
- Department of Cardiology, Liverpool Heart and Chest Hospital NHS Foundation Trust, Liverpool, UK.,Research Unit, Liverpool Centre for Cardiovascular Science, University of Liverpool, Liverpool, UK
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10
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Yazaki K, Ejima K, Kataoka S, Kanai M, Higuchi S, Yagishita D, Shoda M, Hagiwara N. Regional differences in the predictors of acute electrical reconnection following high-power pulmonary vein isolation for paroxysmal atrial fibrillation. J Arrhythm 2021; 37:1260-1269. [PMID: 34621424 PMCID: PMC8485794 DOI: 10.1002/joa3.12597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/04/2021] [Accepted: 06/25/2021] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Acute pulmonary vein reconnection (PVR) is associated with long procedure times and large radiofrequency (RF) energy delivery during pulmonary vein isolation (PVI). Although the efficacy of high-power PVI (HP-PVI) has been recently established, the determinants of acute PVR following HP-PVI remain unclear. METHODS We evaluated data on 62 patients with paroxysmal atrial fibrillation undergoing unipolar signal modification (USM)-guided HP-PVI. A 50-W RF wave was applied for 3-5 seconds after USM. In the segments adjacent to the esophagus (SAEs), the RF time was limited to 5 seconds. Each circle was subdivided into six regions (segments), and the possible predictors of acute PVR, including minimum contact force (CFmin), minimum force-time integral (FTImin), minimum ablation index (AImin), minimum impedance drop (Imp-min), and maximum inter-lesion distance (ILDmax), were assessed in each segment. RESULTS We investigated 1162 ablations in 744 segments (including 124 SAEs). Acute PVR was observed in 21 (17%) SAEs and 43 (7%) other segments (P = .001). The acute PVR segments were characterized by significantly lower CFmin, FTImin, AImin, and Imp-min values in the segments other than the SAEs and larger ILDmax values in the SAEs. Furthermore, lower Imp-min and larger ILDmax values independently predicted acute PVR in the segments other than the SAEs and SAEs (odds ratios 0.90 and 1.39 respectively). Acute PVR was not significantly associated with late atrial fibrillation recurrence. CONCLUSIONS Avoiding PVR remains a challenge in HP-PVI cases, but it might be resolved by setting the optimal target impedance drop and lesion distance values.
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Affiliation(s)
- Kyoichiro Yazaki
- Department of Cardiology Tokyo Women's Medical University Tokyo Japan
| | - Koichiro Ejima
- Department of Cardiology Tokyo Women's Medical University Tokyo Japan
- Clinical Research Division for Heart Rhythm Management Department of Cardiology Tokyo Women's Medical University Tokyo Japan
| | - Shohei Kataoka
- Department of Cardiology Tokyo Women's Medical University Tokyo Japan
| | - Miwa Kanai
- Department of Cardiology Tokyo Women's Medical University Tokyo Japan
| | - Satoshi Higuchi
- Department of Cardiology Tokyo Women's Medical University Tokyo Japan
| | - Daigo Yagishita
- Department of Cardiology Tokyo Women's Medical University Tokyo Japan
| | - Morio Shoda
- Department of Cardiology Tokyo Women's Medical University Tokyo Japan
- Clinical Research Division for Heart Rhythm Management Department of Cardiology Tokyo Women's Medical University Tokyo Japan
| | - Nobuhisa Hagiwara
- Department of Cardiology Tokyo Women's Medical University Tokyo Japan
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11
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Szegedi N, Salló Z, Perge P, Piros K, Nagy VK, Osztheimer I, Merkely B, Gellér L. The role of local impedance drop in the acute lesion efficacy during pulmonary vein isolation performed with a new contact force sensing catheter-A pilot study. PLoS One 2021; 16:e0257050. [PMID: 34529678 PMCID: PMC8445471 DOI: 10.1371/journal.pone.0257050] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 08/22/2021] [Indexed: 11/24/2022] Open
Abstract
Introduction Our pilot study aimed to evaluate the role of local impedance drop in lesion formation during pulmonary vein isolation with a novel contact force sensing ablation catheter that records local impedance as well and to find a local impedance cut-off value that predicts successful lesion formation. Materials and methods After completing point-by-point radiofrequency pulmonary vein isolation, the success of the applications was evaluated by pacing along the ablation line at 10 mA, 2 ms pulse width. Lesions were considered successful if loss of local capture was achieved. Results Out of 645 applications, 561 were successful and 84 were unsuccessful. Compared to the unsuccessful ablation points, the successful applications were shorter (p = 0.0429) and had a larger local impedance drop (p<0.0001). There was no difference between successful and unsuccessful applications in terms of mean contact force (p = 0.8571), force-time integral (p = 0.0699) and contact force range (p = 0.0519). The optimal cut-point for the local impedance drop indicating successful lesion formation was 21.80 Ohms on the anterior wall [AUC = 0.80 (0.75–0.86), p<0.0001], and 18.30 Ohms on the posterior wall [AUC = 0.77 (0.72–0.83), p<0.0001]. A local impedance drop larger than 21.80 Ohms on the anterior wall and 18.30 Ohms on the posterior wall was associated with an increased probability of effective lesion creation [OR = 11.21, 95%CI 4.22–29.81, p<0.0001; and OR = 7.91, 95%CI 3.77–16.57, p<0.0001, respectively]. Conclusion The measurement of the local impedance may predict optimal lesion formation. A local impedance drop > 21.80 Ohms on the anterior wall and > 18.30 Ohms on the posterior wall significantly increases the probability of creating a successful lesion.
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Affiliation(s)
- Nándor Szegedi
- Heart and Vascular Center, Semmelweis University, Budapest, Hungary
- * E-mail:
| | - Zoltán Salló
- Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Péter Perge
- Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Katalin Piros
- Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | | | | | - Béla Merkely
- Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - László Gellér
- Heart and Vascular Center, Semmelweis University, Budapest, Hungary
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12
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Hashimoto K, Tsuzuki I, Seki Y, Ibe S, Yamashita T, Miyama H, Fujisawa T, Katsumata Y, Kimura T, Fukuda K, Takatsuki S. Change in the local impedance and electrograms recorded by a micro-electrode tip catheter during initial atrial fibrillation ablation. J Arrhythm 2021; 37:566-573. [PMID: 34141009 PMCID: PMC8207389 DOI: 10.1002/joa3.12535] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/04/2021] [Accepted: 03/18/2021] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND A novel measurement of the local impedance (LI) and electrograms recorded from micro-electrodes on catheter tip has been developed. However, the data during pulmonary vein (PV) ablation is not sufficient. We aimed to investigate the utility of this measurement during initial atrial fibrillation (AF) ablation. METHODS We investigated 111 representative radiofrequency applications in 7 AF patients without a history of prior ablation (6 males, age 68 [65-72] years, 2 persistent AF). The ablation strategy was PV isolation for paroxysmal AF and single ring box isolation for persistent AF, using MiFi catheter. The correlation of the generator impedance (GI) drop and LI drop after radiofrequency applications and the predictive value of the initial LI elevation before radiofrequency applications for LI drop were analyzed. Also, the LI and GI drop were investigated according to the location of RF applications. RESULTS The LI drop was higher than GI drop (23.7 [16.4-35.7] and 9.0 [6.0-12.0]; P < .01). There were correlations between the initial LI elevation and LI drop (R 2 = 0.466, P < .01) and between the LI and GI drop (R 2 = 0.263, P < .01). The LI drops significantly differed according to the different anatomical localizations by the Kruskal-Wallis test, although the GI drops did not differ (P < .01 and P = .49, respectively). CONCLUSION LI drop was associated with initial LI elevation and was larger than GI drop. LI drop was different according to locations, although GI drop was not. These findings might indicate that LI drop would be a more sensitive marker for lesion formation than GI drop.
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Affiliation(s)
- Kenji Hashimoto
- Department of CardiologyKeio University School of MedicineTokyoJapan
| | - Ippei Tsuzuki
- Department of CardiologyKeio University School of MedicineTokyoJapan
| | - Yuta Seki
- Department of CardiologyKeio University School of MedicineTokyoJapan
| | - Susumu Ibe
- Department of CardiologyKeio University School of MedicineTokyoJapan
| | | | - Hiroshi Miyama
- Department of CardiologyKeio University School of MedicineTokyoJapan
| | - Taishi Fujisawa
- Department of CardiologyKeio University School of MedicineTokyoJapan
| | | | - Takehiro Kimura
- Department of CardiologyKeio University School of MedicineTokyoJapan
| | - Keiichi Fukuda
- Department of CardiologyKeio University School of MedicineTokyoJapan
| | - Seiji Takatsuki
- Department of CardiologyKeio University School of MedicineTokyoJapan
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13
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Miyazaki S, Hasegawa K, Mukai M, Aoyama D, Nodera M, Yamaguchi J, Shiomi Y, Tama N, Ikeda H, Ishida K, Uzui H, Tada H. Superior vena cava isolation using a novel ablation catheter incorporating local impedance monitoring. J Interv Card Electrophysiol 2021; 64:291-300. [PMID: 33755817 DOI: 10.1007/s10840-021-00980-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/15/2021] [Indexed: 11/24/2022]
Abstract
BACKGROUND A novel technology able to measure the local impedance (LI) during radiofrequency ablation has become available for clinical use. We investigated the change in the LI characteristics during superior vena cava isolations (SVCIs) using a novel catheter equipped with mini-electrodes. METHODS Twenty paroxysmal atrial fibrillation patients (68 ± 9 years; 14 males) underwent an SVCI by targeting breakthroughs. Subsequently, dormant conduction provoked by adenosine triphosphate (ATP) was evaluated. RESULTS Electrical SVCIs were successfully achieved in all with 7.2 ± 3.0 radiofrequency applications (RFA) without any complications. The procedure and fluoroscopic times were 13.1 ± 8.1 and 2.8 ± 2.3 min. No ablation was required at the anteroseptal SVC in 19 (95.0%) patients. The baseline LI and generator impedance (GI) were 125 ± 23 and 105 ± 14Ω. LI drops during RFA were significantly greater than GI drops (17 ± 12 vs. 4 ± 4Ω, p < 0.001). The correlation between the LI drops and GI drops was relatively high (R = 0.69, p < 0.001). LI drops were highest at the septal SVC and lowest at the lateral followed by antero-lateral SVC. The baseline electrogram amplitude between the mini-electrodes and tip-ring electrodes was 1.2 ± 1.4 and 0.8 ± 0.6 mV. The mini-electrode amplitude is more sharply attenuated with a greater magnitude than the tip-ring amplitude (p < 0.001). ATP-provoked dormant conduction was exposed in 10/17 (58.8%) patients and antero-lateral SVC gap locations in 7. Antero-lateral SVC LI drops were similar between patients with and without dormancy. CONCLUSIONS The LI drop magnitude during RFA significantly differed among the SVC segments. Antero-lateral SVC ATP-provoked dormant conduction was often exposed, and additional applications are recommended following the isolation for a robust SVCI.
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Affiliation(s)
- Shinsuke Miyazaki
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Shimo-aiduki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan.
| | - Kanae Hasegawa
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Shimo-aiduki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Moe Mukai
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Shimo-aiduki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Daisetsu Aoyama
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Shimo-aiduki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Minoru Nodera
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Shimo-aiduki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Junya Yamaguchi
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Shimo-aiduki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Yuichiro Shiomi
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Shimo-aiduki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Naoto Tama
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Shimo-aiduki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Hiroyuki Ikeda
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Shimo-aiduki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Kentaro Ishida
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Shimo-aiduki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Hiroyasu Uzui
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Shimo-aiduki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Hiroshi Tada
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Shimo-aiduki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
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