PMID- 33516959 OWN - NLM STAT- MEDLINE DCOM- 20210702 LR - 20210702 IS - 1879-0534 (Electronic) IS - 0010-4825 (Linking) VI - 130 DP - 2021 Mar TI - Spatial phase discontinuity at the center of moving cardiac spiral waves. PG - 104217 LID - S0010-4825(21)00011-1 [pii] LID - 10.1016/j.compbiomed.2021.104217 [doi] AB - BACKGROUND: Precise analysis of cardiac spiral wave (SW) dynamics is essential for effective arrhythmia treatment. Although the phase singularity (PS) point in the spatial phase map has been used to determine the cardiac SW center for decades, quantitative detection algorithms that assume PS as a point fail to trace complex and rapid PS dynamics. Through a detailed analysis of numerical simulations, we examined our hypothesis that a boundary of spatial phase discontinuity induced by a focal conduction block exists around the moving SW center in the phase map. METHOD: In a numerical simulation model of a 2D cardiac sheet, three different types of SWs (short wavelength; long wavelength; and low excitability) were induced by regulating ion channels. Discontinuities of all boundaries among adjacent cells at each instance were evaluated by calculating the phase bipolarity (PB). The total amount of phase transition (PTA) in each cell during the study period was evaluated. RESULTS: Pivoting, drifting, and shifting SWs were observed in the short-wavelength, low-excitability, and long-wavelength models, respectively. For both the drifting and shifting cases, long high-PB edges were observed on the SW trajectories. In all cases, the conduction block (CB) was observed at the same boundaries. These were also identical to the boundaries in the PTA maps. CONCLUSIONS: The analysis of the simulations revealed that the conduction block at the center of a moving SW induces discontinuous boundaries in spatial phase maps that represent a more appropriate model of the SW center than the PS point. CI - Copyright (c) 2021 Elsevier Ltd. All rights reserved. FAU - Tomii, Naoki AU - Tomii N AD - Faculty of Medicine, The University of Tokyo, 7 -3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. Electronic address: tomii@g.ecc.u-tokyo.ac.jp. FAU - Yamazaki, Masatoshi AU - Yamazaki M AD - School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan. FAU - Ashihara, Takashi AU - Ashihara T AD - Shiga University of Medical Science, Setatsukinowa-cho, Otsu-city, Shiga, 520-2192, Japan. FAU - Nakazawa, Kazuo AU - Nakazawa K AD - Morinomiya University of Medical Sciences, 1-26-16 Minami-Kohoku, Suminoe-ku, Osaka City, 559-8611, Japan. FAU - Shibata, Nitaro AU - Shibata N AD - Shinjuku Mitsui Building Clinic, 2-1-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo, 163-0404, Japan. FAU - Honjo, Haruo AU - Honjo H AD - Research Institute of Environmental Medicine, Nagoya University, Furo-cho Chikusa-ku, Nagoya City, Aichi, 464-8601, Japan. FAU - Sakuma, Ichiro AU - Sakuma I AD - School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20210119 PL - United States TA - Comput Biol Med JT - Computers in biology and medicine JID - 1250250 SB - IM MH - Action Potentials MH - Algorithms MH - Arrhythmias, Cardiac MH - Computer Simulation MH - *Heart MH - Humans MH - *Models, Cardiovascular OTO - NOTNLM OT - Electrophysiological simulation OT - Phase singularity OT - Reaction diffusion system OT - Spiral wave OT - Tachyarrhythmia EDAT- 2021/02/01 06:00 MHDA- 2021/07/03 06:00 CRDT- 2021/01/31 20:28 PHST- 2020/09/09 00:00 [received] PHST- 2021/01/10 00:00 [revised] PHST- 2021/01/10 00:00 [accepted] PHST- 2021/02/01 06:00 [pubmed] PHST- 2021/07/03 06:00 [medline] PHST- 2021/01/31 20:28 [entrez] AID - S0010-4825(21)00011-1 [pii] AID - 10.1016/j.compbiomed.2021.104217 [doi] PST - ppublish SO - Comput Biol Med. 2021 Mar;130:104217. doi: 10.1016/j.compbiomed.2021.104217. Epub 2021 Jan 19.