{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,28]],"date-time":"2026-07-28T04:41:07Z","timestamp":1785213667375,"version":"3.55.0"},"reference-count":60,"publisher":"AIP Publishing","issue":"5","funder":[{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Network Joint Research Center for Materials and Devices"}],"content-domain":{"domain":["pubs.aip.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2020,5,1]]},"abstract":"<jats:p>Complex dynamical systems can shift abruptly from a stable state to an alternative stable state at a tipping point. Before the critical transition, the system either slows down in its recovery rate or flickers between the basins of attraction of the alternative stable states. Whether the heart critically slows down or flickers before it transitions into and out of paroxysmal atrial fibrillation (PAF) is still an open question. To address this issue, we propose a novel definition of cardiac states based on beat-to-beat (RR) interval fluctuations derived from electrocardiogram data. Our results show the cardiac state flickers before PAF onset and termination. Prior to onset, flickering is due to a \u201ctug-of-war\u201d between the sinus node (the natural pacemaker) and atrial ectopic focus\/foci (abnormal pacemakers), or the pacing by the latter interspersed among the pacing by the former. It may also be due to an abnormal autonomic modulation of the sinus node. This abnormal modulation may be the sole cause of flickering prior to termination since atrial ectopic beats are absent. Flickering of the cardiac state could potentially be used as part of an early warning or screening system for PAF and guide the development of new methods to prevent or terminate PAF. The method we have developed to define system states and use them to detect flickering can be adapted to study critical transition in other complex systems.<\/jats:p>","DOI":"10.1063\/1.5130524","type":"journal-article","created":{"date-parts":[[2020,5,26]],"date-time":"2020-05-26T10:45:10Z","timestamp":1590489910000},"update-policy":"https:\/\/doi.org\/10.1063\/aip-crossmark-policy-page","source":"Crossref","is-referenced-by-count":7,"title":["Flickering of cardiac state before the onset and termination of atrial fibrillation"],"prefix":"10.1063","volume":"30","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7585-7362","authenticated-orcid":false,"given":"Boon Leong","family":"Lan","sequence":"first","affiliation":[{"name":"Electrical and Computer Systems Engineering & Advanced Engineering Platform, School of Engineering, Monash University 1 , 47500 Bandar Sunway,","place":["Malaysia"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8245-1048","authenticated-orcid":false,"given":"Yew Wai","family":"Liew","sequence":"additional","affiliation":[{"name":"Electrical and Computer Systems Engineering & Advanced Engineering Platform, School of Engineering, Monash University 1 , 47500 Bandar Sunway,","place":["Malaysia"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0913-3438","authenticated-orcid":false,"given":"Mikito","family":"Toda","sequence":"additional","affiliation":[{"name":"Laboratory of Non-equilibrium Dynamics, Research Group of Physics, Faculty Division of Natural Sciences, Nara Women's University 2 , Nara 630-8506,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Suraya Hani","family":"Kamsani","sequence":"additional","affiliation":[{"name":"National Heart Institute 3 , 50400 Kuala Lumpur,","place":["Malaysia"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"317","published-online":{"date-parts":[[2020,5,26]]},"reference":[{"key":"2025100317120082400_c1","doi-asserted-by":"publisher","first-page":"033501","DOI":"10.1063\/1.5027718","article-title":"Multistability and tipping: From mathematics and physics to climate and brain-minireview and preface to the focus issue","volume":"28","year":"2018","journal-title":"Chaos"},{"key":"2025100317120082400_c2","doi-asserted-by":"publisher","first-page":"53","DOI":"10.1038\/nature08227","article-title":"Early-warning signals for critical transitions","volume":"461","year":"2009","journal-title":"Nature"},{"key":"2025100317120082400_c3","doi-asserted-by":"publisher","first-page":"591","DOI":"10.1038\/35098000","article-title":"Catastrophic shifts in ecosystems","volume":"413","year":"2001","journal-title":"Nature"},{"key":"2025100317120082400_c4","doi-asserted-by":"publisher","first-page":"344","DOI":"10.1126\/science.1225244","article-title":"Anticipating critical transitions","volume":"338","year":"2012","journal-title":"Science"},{"key":"2025100317120082400_c5","doi-asserted-by":"publisher","first-page":"17546","DOI":"10.1073\/pnas.1406326111","article-title":"Critical slowing down as early warning for the onset of collapse in mutualistic communities","volume":"111","year":"2014","journal-title":"Proc. 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