PMID- 38045455 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20231205 IS - 1880-4276 (Print) IS - 1883-2148 (Electronic) IS - 1880-4276 (Linking) VI - 39 IP - 6 DP - 2023 Dec TI - Landiolol, an intravenous beta1-selective blocker, is useful for dissociating a fusion of atrial activation via accessory pathway and atrioventricular node. PG - 937-946 LID - 10.1002/joa3.12934 [doi] AB - INTRODUCTION: During ventricular pacing, a fusion of atrial activation may occur owing to the simultaneous retrograde conduction of the atrioventricular (AV) node and accessory pathway (AP), potentially leading to an inaccurate mapping of the atrial AP insertion site. OBJECTIVE: We tested the hypothesis that landiolol, an ultra-short-acting intravenous beta1-blocker, could dissociate a fusion of atrial activation. METHODS: We conducted a prospective before-and-after study to investigate the effect of landiolol on retrograde conduction via the AV node and AP. We enrolled 21 consecutive patients with orthodromic AV reciprocating tachycardia who underwent electrophysiological studies at our hospital between January 1, 2018, and August 31, 2020. RESULTS: Six patients exhibited a fusion of atrial activation. After landiolol administration (10 mug/kg/min), the effective refractory period was unchanged in AP (280 [240-290] ms vs. 280 [245-295] ms, p = .91), whereas that of the AV node was prolonged (275 [215-380] ms vs. 332 [278-445] ms, p = .03). The Wenckebach pacing rate via retrograde AV node decreased after landiolol administration (180 [140-200] beats per minute [bpm] vs. 140 [120-180] bpm, p = .02). Thus, landiolol decreased the minimum ventricular pacing rate required to dissociate a fusion of atrial activation (180 [160-200] bpm vs. 140 [128-155] bpm, p = .007). Radiofrequency catheter ablation under landiolol administration successfully eliminated AP in all patients during ventricular pacing without complications or recurrence. CONCLUSION: Landiolol inhibited the AV node without affecting the AP and helped dissociate a fusion of atrial activation at a lower ventricular pacing rate. CI - (c) 2023 The Authors. Journal of Arrhythmia published by John Wiley & Sons Australia, Ltd on behalf of Japanese Heart Rhythm Society. FAU - Kinjo, Takahiko AU - Kinjo T AUID- ORCID: 0000-0003-4363-0259 AD - Department of Cardiology and Nephrology Hirosaki University Graduate School of Medicine Hirosaki Japan. FAU - Kimura, Masaomi AU - Kimura M AUID- ORCID: 0000-0003-0229-0569 AD - Department of Advanced Management of Cardiac Arrhythmias Hirosaki University Graduate School of Medicine Hirosaki Japan. FAU - Kaname, Noriyoshi AU - Kaname N AD - Department of Cardiology and Nephrology Hirosaki University Graduate School of Medicine Hirosaki Japan. FAU - Horiuchi, Daisuke AU - Horiuchi D AD - Department of Cardiology and Nephrology Hirosaki University Graduate School of Medicine Hirosaki Japan. FAU - Itoh, Taihei AU - Itoh T AUID- ORCID: 0000-0002-8473-0320 AD - Department of Advanced Management of Cardiac Arrhythmias Hirosaki University Graduate School of Medicine Hirosaki Japan. FAU - Ishida, Yuji AU - Ishida Y AUID- ORCID: 0000-0002-2365-0968 AD - Department of Cardiac Remote Management System Hirosaki University Graduate School of Medicine Hirosaki Japan. FAU - Nishizaki, Kimitaka AU - Nishizaki K AUID- ORCID: 0000-0003-4597-1508 AD - Department of Cardiology and Nephrology Hirosaki University Graduate School of Medicine Hirosaki Japan. FAU - Toyama, Yuichi AU - Toyama Y AUID- ORCID: 0000-0001-8403-8839 AD - Department of Cardiology and Nephrology Hirosaki University Graduate School of Medicine Hirosaki Japan. FAU - Sasaki, Shingo AU - Sasaki S AUID- ORCID: 0000-0001-9866-2325 AD - Department of Cardiology and Nephrology Hirosaki University Graduate School of Medicine Hirosaki Japan. AD - Department of Advanced Management of Cardiac Arrhythmias Hirosaki University Graduate School of Medicine Hirosaki Japan. AD - Department of Cardiac Remote Management System Hirosaki University Graduate School of Medicine Hirosaki Japan. FAU - Tomita, Hirofumi AU - Tomita H AUID- ORCID: 0000-0001-8149-3043 AD - Department of Cardiology and Nephrology Hirosaki University Graduate School of Medicine Hirosaki Japan. AD - Department of Advanced Management of Cardiac Arrhythmias Hirosaki University Graduate School of Medicine Hirosaki Japan. AD - Department of Cardiac Remote Management System Hirosaki University Graduate School of Medicine Hirosaki Japan. AD - Department of the Advanced Therapeutics for Cardiovascular Diseases Hirosaki University Graduate School of Medicine Hirosaki Japan. LA - eng PT - Journal Article DEP - 20231003 PL - Japan TA - J Arrhythm JT - Journal of arrhythmia JID - 101263026 PMC - PMC10692861 OTO - NOTNLM OT - accessory pathway OT - atrioventricular node OT - beta-blocker OT - fusion of atrial activation COIS- Dr. Masaomi Kimura is an associate professor, and Dr. Taihei Itoh is an associate professor/lecturer of the Department of Advanced Management of Cardiac Arrhythmias, which is an endowment department supported by Medtronic Japan Co., Ltd., Japan Lifeline Co., Ltd, and Fukuda Denshi Kita-Tohoku Hanbai Co., Ltd. Dr. Yuji Ishida is an assistant professor of the Department of Cardiac Remote Management System, which is an endowment department supported by BIOTRONIK Japan Co., Ltd. Dr. Shingo Sasaki received research grant from Boston Scientific Japan Co., Ltd. and is a concurrent associate professor of the Department of Advanced Management of Cardiac Arrhythmias and the Department of Cardiac Remote Management System. Dr. Hirofumi Tomita is a concurrent professor of the Department of Advanced Management of Cardiac Arrhythmias, the Department of Cardiac Remote Management System, and the Department of the Advanced Therapeutics for Cardiovascular Diseases, which is an endowment department supported by Boston Scientific Japan Co., Ltd. Dr. Tomita also received research grant from Abbott Medical Japan LLC. Other authors have no relevant disclosures. EDAT- 2023/12/04 06:41 MHDA- 2023/12/04 06:42 PMCR- 2023/10/03 CRDT- 2023/12/04 04:37 PHST- 2023/08/07 00:00 [received] PHST- 2023/08/30 00:00 [revised] PHST- 2023/09/17 00:00 [accepted] PHST- 2023/12/04 06:42 [medline] PHST- 2023/12/04 06:41 [pubmed] PHST- 2023/12/04 04:37 [entrez] PHST- 2023/10/03 00:00 [pmc-release] AID - JOA312934 [pii] AID - 10.1002/joa3.12934 [doi] PST - epublish SO - J Arrhythm. 2023 Oct 3;39(6):937-946. doi: 10.1002/joa3.12934. eCollection 2023 Dec.