{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T14:22:52Z","timestamp":1777386172638,"version":"3.51.4"},"reference-count":51,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2022,9,8]],"date-time":"2022-09-08T00:00:00Z","timestamp":1662595200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004837","name":"Spanish Government","doi-asserted-by":"publisher","award":["DPI2017-83952-C3"],"award-info":[{"award-number":["DPI2017-83952-C3"]}],"id":[{"id":"10.13039\/501100004837","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004837","name":"Spanish Government","doi-asserted-by":"publisher","award":["PID2021-00X128525-IV0"],"award-info":[{"award-number":["PID2021-00X128525-IV0"]}],"id":[{"id":"10.13039\/501100004837","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004837","name":"Spanish Government","doi-asserted-by":"publisher","award":["PID2021-123804OB-I00"],"award-info":[{"award-number":["PID2021-123804OB-I00"]}],"id":[{"id":"10.13039\/501100004837","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004837","name":"Spanish Government","doi-asserted-by":"publisher","award":["SBPLY\/17\/180501\/000411"],"award-info":[{"award-number":["SBPLY\/17\/180501\/000411"]}],"id":[{"id":"10.13039\/501100004837","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004837","name":"Spanish Government","doi-asserted-by":"publisher","award":["AICO\/2021\/286"],"award-info":[{"award-number":["AICO\/2021\/286"]}],"id":[{"id":"10.13039\/501100004837","id-type":"DOI","asserted-by":"publisher"}]},{"name":"European Regional Development Fund (EU)","award":["DPI2017-83952-C3"],"award-info":[{"award-number":["DPI2017-83952-C3"]}]},{"name":"European Regional Development Fund (EU)","award":["PID2021-00X128525-IV0"],"award-info":[{"award-number":["PID2021-00X128525-IV0"]}]},{"name":"European Regional Development Fund (EU)","award":["PID2021-123804OB-I00"],"award-info":[{"award-number":["PID2021-123804OB-I00"]}]},{"name":"European Regional Development Fund (EU)","award":["SBPLY\/17\/180501\/000411"],"award-info":[{"award-number":["SBPLY\/17\/180501\/000411"]}]},{"name":"European Regional Development Fund (EU)","award":["AICO\/2021\/286"],"award-info":[{"award-number":["AICO\/2021\/286"]}]},{"DOI":"10.13039\/501100011698","name":"Junta de Comunidades de Castilla-La Mancha","doi-asserted-by":"publisher","award":["DPI2017-83952-C3"],"award-info":[{"award-number":["DPI2017-83952-C3"]}],"id":[{"id":"10.13039\/501100011698","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100011698","name":"Junta de Comunidades de Castilla-La Mancha","doi-asserted-by":"publisher","award":["PID2021-00X128525-IV0"],"award-info":[{"award-number":["PID2021-00X128525-IV0"]}],"id":[{"id":"10.13039\/501100011698","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100011698","name":"Junta de Comunidades de Castilla-La Mancha","doi-asserted-by":"publisher","award":["PID2021-123804OB-I00"],"award-info":[{"award-number":["PID2021-123804OB-I00"]}],"id":[{"id":"10.13039\/501100011698","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100011698","name":"Junta de Comunidades de Castilla-La Mancha","doi-asserted-by":"publisher","award":["SBPLY\/17\/180501\/000411"],"award-info":[{"award-number":["SBPLY\/17\/180501\/000411"]}],"id":[{"id":"10.13039\/501100011698","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100011698","name":"Junta de Comunidades de Castilla-La Mancha","doi-asserted-by":"publisher","award":["AICO\/2021\/286"],"award-info":[{"award-number":["AICO\/2021\/286"]}],"id":[{"id":"10.13039\/501100011698","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003359","name":"Generalitat Valenciana","doi-asserted-by":"publisher","award":["DPI2017-83952-C3"],"award-info":[{"award-number":["DPI2017-83952-C3"]}],"id":[{"id":"10.13039\/501100003359","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003359","name":"Generalitat Valenciana","doi-asserted-by":"publisher","award":["PID2021-00X128525-IV0"],"award-info":[{"award-number":["PID2021-00X128525-IV0"]}],"id":[{"id":"10.13039\/501100003359","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003359","name":"Generalitat Valenciana","doi-asserted-by":"publisher","award":["PID2021-123804OB-I00"],"award-info":[{"award-number":["PID2021-123804OB-I00"]}],"id":[{"id":"10.13039\/501100003359","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003359","name":"Generalitat Valenciana","doi-asserted-by":"publisher","award":["SBPLY\/17\/180501\/000411"],"award-info":[{"award-number":["SBPLY\/17\/180501\/000411"]}],"id":[{"id":"10.13039\/501100003359","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003359","name":"Generalitat Valenciana","doi-asserted-by":"publisher","award":["AICO\/2021\/286"],"award-info":[{"award-number":["AICO\/2021\/286"]}],"id":[{"id":"10.13039\/501100003359","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Atrial fibrillation (AF) is the most common cardiac arrhythmia, and in response to increasing clinical demand, a variety of signals and indices have been utilized for its analysis, which include complex fractionated atrial electrograms (CFAEs). New methodologies have been developed to characterize the atrial substrate, along with straightforward classification models to discriminate between paroxysmal and persistent AF (ParAF vs. PerAF). Yet, most previous works have missed the mark for the assessment of CFAE signal quality, as well as for studying their stability over time and between different recording locations. As a consequence, an atrial substrate assessment may be unreliable or inaccurate. The objectives of this work are, on the one hand, to make use of a reduced set of nonlinear indices that have been applied to CFAEs recorded from ParAF and PerAF patients to assess intra-recording and intra-patient stability and, on the other hand, to generate a simple classification model to discriminate between them. The dominant frequency (DF), AF cycle length, sample entropy (SE), and determinism (DET) of the Recurrence Quantification Analysis are the analyzed indices, along with the coefficient of variation (CV) which is utilized to indicate the corresponding alterations. The analysis of the intra-recording stability revealed that discarding noisy or artifacted CFAE segments provoked a significant variation in the CV(%) in any segment length for the DET and SE, with deeper decreases for longer segments. The intra-patient stability provided large variations in the CV(%) for the DET and even larger for the SE at any segment length. To discern ParAF versus PerAF, correlation matrix filters and Random Forests were employed, respectively, to remove redundant information and to rank the variables by relevance, while coarse tree models were built, optimally combining high-ranked indices, and tested with leave-one-out cross-validation. The best classification performance combined the SE and DF, with an accuracy (Acc) of 88.3%, to discriminate ParAF versus PerAF, while the highest single Acc was provided by the DET, reaching 82.2%. This work has demonstrated that due to the high variability of CFAEs data averaging from one recording place or among different recording places, as is traditionally made, it may lead to an unfair oversimplification of the CFAE-based atrial substrate characterization. Furthermore, a careful selection of reduced sets of features input to simple classification models is helpful to accurately discern the CFAEs of ParAF versus PerAF.<\/jats:p>","DOI":"10.3390\/e24091261","type":"journal-article","created":{"date-parts":[[2022,9,8]],"date-time":"2022-09-08T04:18:32Z","timestamp":1662610712000},"page":"1261","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Practical Considerations for the Application of Nonlinear Indices Characterizing the Atrial Substrate in Atrial Fibrillation"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6253-6260","authenticated-orcid":false,"given":"Emanuela","family":"Finotti","sequence":"first","affiliation":[{"name":"BioMIT.org, Electronic Engineering Department, Universitat Politecnica de Valencia, 46022 Valencia, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4709-1993","authenticated-orcid":false,"given":"Aurelio","family":"Quesada","sequence":"additional","affiliation":[{"name":"Arrhythmia Unit, Cardiology Department, General University Hospital Consortium of Valencia, 46014 Valencia, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5552-6366","authenticated-orcid":false,"given":"Edward J.","family":"Ciaccio","sequence":"additional","affiliation":[{"name":"Department of Medicine, Division of Cardiology, Columbia University Medical Center, New York, NY 10032, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6742-3660","authenticated-orcid":false,"given":"Hasan","family":"Garan","sequence":"additional","affiliation":[{"name":"Department of Medicine, Division of Cardiology, Columbia University Medical Center, New York, NY 10032, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7560-2781","authenticated-orcid":false,"given":"Fernando","family":"Hornero","sequence":"additional","affiliation":[{"name":"Cardiovascular Surgery Department, Hospital Cl\u00ednico Universitario de Valencia, 46010 Valencia, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0942-3638","authenticated-orcid":false,"given":"Ra\u00fal","family":"Alcaraz","sequence":"additional","affiliation":[{"name":"Research Group in Electronic, Biomedical and Telecommunication Engineering, University of Castilla-La Mancha, 16071 Cuenca, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3364-6380","authenticated-orcid":false,"given":"Jos\u00e9 J.","family":"Rieta","sequence":"additional","affiliation":[{"name":"BioMIT.org, Electronic Engineering Department, Universitat Politecnica de Valencia, 46022 Valencia, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,9,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"373","DOI":"10.1093\/eurheartj\/ehaa612","article-title":"2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS): The Task Force for the diagnosis and management of atrial fibrillation of the European Society of Cardiology (ESC) Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC","volume":"42","author":"Hindricks","year":"2021","journal-title":"Eur. Heart J."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2746","DOI":"10.1093\/eurheartj\/eht280","article-title":"Projections on the number of individuals with atrial fibrillation in the European Union, from 2000 to 2060","volume":"34","author":"Krijthe","year":"2013","journal-title":"Eur. Heart J."},{"key":"ref_3","first-page":"ii9","article-title":"What are the costs of atrial fibrillation?","volume":"13","author":"Lip","year":"2011","journal-title":"EP Eur."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"e019412","DOI":"10.1161\/JAHA.120.019412","article-title":"National Trends in the Burden of Atrial Fibrillation During Hospital Admissions for Heart Failure","volume":"10","author":"Reinhardt","year":"2021","journal-title":"J. Am. Heart Assoc."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Lee, E., Choi, E.K., Han, K.D., Lee, H., Choe, W.S., Lee, S.R., Cha, M.J., Lim, W.H., Kim, Y.J., and Oh, S. (2018). Mortality and causes of death in patients with atrial fibrillation: A nationwide population-based study. PLoS ONE, 13.","DOI":"10.1371\/journal.pone.0209687"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"e125","DOI":"10.1161\/CIR.0000000000000665","article-title":"2019 AHA\/ACC\/HRS Focused Update of the 2014 AHA\/ACC\/HRS Guideline for the Management of Patients with Atrial Fibrillation: A Report of the American College of Cardiology\/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society in Collaboration With the Society of Thoracic Surgeons","volume":"140","author":"January","year":"2019","journal-title":"Circulation"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"97","DOI":"10.2459\/JCM.0b013e32834f23e1","article-title":"Medical treatment of atrial fibrillation","volume":"13","author":"Camm","year":"2012","journal-title":"J. Cardiovasc. Med."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"659","DOI":"10.1056\/NEJM199809033391003","article-title":"Spontaneous Initiation of Atrial Fibrillation by Ectopic Beats Originating in the Pulmonary Veins","volume":"339","author":"Shah","year":"1998","journal-title":"N. Engl. J. Med."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1055\/s-0040-1708476","article-title":"Catheter Ablation in the Treatment of Atrial Fibrillation","volume":"29","author":"Hesselson","year":"2020","journal-title":"Int. J. Angiol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"278","DOI":"10.1001\/jama.2015.7505","article-title":"Treatment of Atrial Fibrillation","volume":"314","author":"Prystowsky","year":"2015","journal-title":"JAMA"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"862","DOI":"10.1016\/j.hrthm.2021.02.014","article-title":"Individualized ablation strategy to treat persistent atrial fibrillation: Core-to-boundary approach guided by charge-density mapping","volume":"18","author":"Shi","year":"2021","journal-title":"Heart Rhythm."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1016\/j.jacc.2014.10.034","article-title":"Catheter ablation of atrial fibrillation: How to modify the substrate?","volume":"65","author":"Kottkamp","year":"2015","journal-title":"J. Am. Coll. Cardiol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1147","DOI":"10.1111\/jce.14987","article-title":"Atrial fibrosis and substrate based characterization in atrial fibrillation: Time to move forwards","volume":"32","author":"Quah","year":"2021","journal-title":"J. Cardiovasc. Electrophysiol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"573","DOI":"10.1536\/ihj.15-476","article-title":"Discrimination of Paroxysmal and Persistent Atrial Fibrillation in Patients With New-Onset Atrial Fibrillation","volume":"57","author":"Igarashi","year":"2016","journal-title":"Int. Heart J."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"223","DOI":"10.1016\/j.hfc.2015.08.018","article-title":"Catheter Ablation of Atrial Fibrillation","volume":"12","author":"Latchamsetty","year":"2016","journal-title":"Heart Fail. Clin."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"470","DOI":"10.1161\/CIRCEP.110.960153","article-title":"Differences in repeating patterns of complex fractionated left atrial electrograms in longstanding persistent atrial fibrillation as compared with paroxysmal atrial fibrillation","volume":"4","author":"Ciaccio","year":"2011","journal-title":"Circ. Arrhythm. Electrophysiol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2044","DOI":"10.1016\/j.jacc.2003.12.054","article-title":"A new approach for catheter ablation of atrial fibrillation: Mapping of the electrophysiologic substrate","volume":"43","author":"Nademanee","year":"2004","journal-title":"J. Am. Coll. Cardiol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3007","DOI":"10.1161\/01.CIR.0000130645.95357.97","article-title":"Changes in atrial fibrillation cycle length and inducibility during catheter ablation and their relation to outcome","volume":"109","author":"Sanders","year":"2004","journal-title":"Circulation"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"7493","DOI":"10.3390\/e17117493","article-title":"Characterization of Complex Fractionated Atrial Electrograms by Sample Entropy: An International Multi-Center Study","volume":"17","author":"Novak","year":"2015","journal-title":"Entropy"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1207","DOI":"10.1016\/j.hrthm.2010.06.018","article-title":"Different characteristics of complex fractionated atrial electrograms in acute paroxysmal versus long-standing persistent atrial fibrillation","volume":"7","author":"Ciaccio","year":"2010","journal-title":"Heart Rhythm"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1016\/j.cmpb.2019.04.018","article-title":"Application of nonlinear methods to discriminate fractionated electrograms in paroxysmal versus persistent atrial fibrillation","volume":"175","author":"Acharya","year":"2019","journal-title":"Comput. Methods Programs Biomed."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"525","DOI":"10.1046\/j.1540-8167.2002.00525.x","article-title":"Characterization of paroxysmal and persistent atrial fibrillation in the human left atrium during initiation and sustained episodes","volume":"13","author":"Ndrepepa","year":"2002","journal-title":"J. Cardiovasc. Electrophysiol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"S66","DOI":"10.1111\/j.1540-8159.2008.02229.x","article-title":"Electrocardiographic measurements of regional atrial fibrillation cycle length","volume":"32","author":"Ravi","year":"2009","journal-title":"Pacing Clin. Electrophysiol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"789","DOI":"10.1161\/CIRCULATIONAHA.104.517011","article-title":"Spectral analysis identifies sites of high-frequency activity maintaining atrial fibrillation in humans","volume":"112","author":"Sanders","year":"2005","journal-title":"Circulation"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"327","DOI":"10.2174\/157340312803760802","article-title":"Current hot potatoes in atrial fibrillation ablation","volume":"8","author":"Roten","year":"2012","journal-title":"Curr. Cardiol. Rev."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"075003","DOI":"10.1088\/1361-6579\/ab2cb8","article-title":"The stationary wavelet transform as an efficient reductor of powerline interference for atrial bipolar electrograms in cardiac electrophysiology","volume":"40","author":"Rieta","year":"2019","journal-title":"Physiol. Meas."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1109\/TAU.1967.1161901","article-title":"The use of fast Fourier transform for the estimation of power spectra: A method based on time averaging over short, modified periodograms","volume":"15","author":"Welch","year":"1967","journal-title":"IEEE Trans. Audio Electroacoust."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"H2039","DOI":"10.1152\/ajpheart.2000.278.6.H2039","article-title":"Physiological time-series analysis using approximate entropy and sample entropy","volume":"278","author":"Richman","year":"2000","journal-title":"Am. J. Physiol. Heart Circ. Physiol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1016\/j.cmpb.2010.02.009","article-title":"Optimal parameters study for sample entropy-based atrial fibrillation organization analysis","volume":"99","author":"Alcaraz","year":"2010","journal-title":"Comput. Methods Programs Biomed."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1016\/j.physrep.2006.11.001","article-title":"Recurrence plots for the analysis of complex systems","volume":"438","author":"Marwan","year":"2007","journal-title":"Phys. Rep."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"026702","DOI":"10.1103\/PhysRevE.66.026702","article-title":"Recurrence-plot-based measures of complexity and their application to heart-rate-variability data","volume":"66","author":"Marwan","year":"2002","journal-title":"Phys. Rev. E Stat. Nonlin Soft Matter Phys."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"867","DOI":"10.1142\/S0218127491000634","article-title":"The takens embedding theorem","volume":"1","author":"Noakes","year":"1991","journal-title":"Int. J. Bifurc. Chaos"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"S1149","DOI":"10.1016\/S0098-1354(97)00204-4","article-title":"The false nearest neighbors algorithm: An overview","volume":"21","author":"Rhodes","year":"1997","journal-title":"Comput. Chem. Eng."},{"key":"ref_34","first-page":"325","article-title":"Non-linear time series analysis: Methods and applications to atrial fibrillation","volume":"37","author":"Hoekstra","year":"2001","journal-title":"Ann. Dell\u2019Ist. Super. Sanit."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1140\/epjst\/e2008-00833-5","article-title":"Selection of recurrence threshold for signal detection","volume":"164","author":"Schinkel","year":"2008","journal-title":"Eur. Phys. J. Spec. Top."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"416","DOI":"10.1109\/JPROC.2015.2505318","article-title":"Quantitative-Electrogram-Based Methods for Guiding Catheter Ablation in Atrial Fibrillation","volume":"104","author":"Baumert","year":"2016","journal-title":"Proc. IEEE"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"579","DOI":"10.1109\/10.387197","article-title":"A Technique for Measurement of the Extent of Spatial Organization of Atrial Activation During Atrial Fibrillation in the Intact Human Heart","volume":"42","author":"Botteron","year":"1995","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Osorio, D., Vraka, A., Quesada, A., Hornero, F., Alcaraz, R., and Rieta, J.J. (2022). An Efficient Hybrid Methodology for Local Activation Waves Detection under Complex Fractionated Atrial Electrograms of Atrial Fibrillation. Sensors, 22.","DOI":"10.3390\/s22145345"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"911","DOI":"10.1093\/europace\/eul113","article-title":"Analysis of surface electrocardiograms in atrial fibrillation: Techniques, research, and clinical applications","volume":"8","author":"Bollmann","year":"2006","journal-title":"Europace"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1016\/j.hrthm.2008.10.024","article-title":"Real-time dominant frequency mapping and ablation of dominant frequency sites in atrial fibrillation with left-to-right frequency gradients predicts long-term maintenance of sinus rhythm","volume":"6","author":"Atienza","year":"2009","journal-title":"Heart Rhythm"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1176","DOI":"10.1109\/TBME.2004.827272","article-title":"Atrial activity extraction for atrial fibrillation analysis using blind source separation","volume":"51","author":"Rieta","year":"2004","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_42","first-page":"1235","article-title":"Use of coefficient of variation in assessing variability of quantitative assays","volume":"9","author":"Reed","year":"2002","journal-title":"Clin. Diagn. Lab. Immunol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"170","DOI":"10.2307\/1165320","article-title":"The Kruskal-Wallis Test and Stochastic Homogeneity","volume":"23","author":"Vargha","year":"1998","journal-title":"J. Educ. Behav. Stat."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"681","DOI":"10.2307\/2297739","article-title":"Testing the Error Components Model with Non-Normal Disturbances","volume":"52","author":"Honda","year":"1985","journal-title":"Rev. Econ. Stud."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"13","DOI":"10.20982\/tqmp.04.1.p013","article-title":"The Mann-Whitney U: A Test for Assessing Whether Two Independent Samples Come from the Same Distribution","volume":"4","author":"Nachar","year":"2008","journal-title":"Tutor. Quant. Methods Psychol."},{"key":"ref_46","first-page":"1157","article-title":"An Introduction of Variable and Feature Selection","volume":"3","author":"Guyon","year":"2003","journal-title":"J. Mach. Learn. Res. Spec. Issue Var. Feature Sel."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1198\/106186006X94072","article-title":"Unsupervised Learning With Random Forest Predictors","volume":"15","author":"Shi","year":"2006","journal-title":"J. Comput. Graph. Stat."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/j.eupc.2003.12.003","article-title":"How to perform pulmonary vein isolation","volume":"6","author":"Gill","year":"2004","journal-title":"Europace"},{"key":"ref_49","first-page":"1285","article-title":"Review of economic evaluations of radiofrequency catheter ablation for cardiac arrhythmias","volume":"19","author":"Marshall","year":"2003","journal-title":"Can. J. Cardiol."},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Rodgers, M., McKenna, C., Palmer, S., Chambers, D., Van Hout, S., Golder, S., Pepper, C., Todd, D., and Woolacott, N. (2008). Curative catheter ablation in atrial fibrillation and typical atrial flutter: Systematic review and economic evaluation. Health Technol. Assess., 12.","DOI":"10.3310\/hta12340"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"650","DOI":"10.1161\/CIRCEP.111.967992","article-title":"Spatiotemporal behavior of high dominant frequency during paroxysmal and persistent atrial fibrillation in the human left atrium","volume":"5","author":"Jarman","year":"2012","journal-title":"Circ. Arrhythmia Electrophysiol."}],"container-title":["Entropy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1099-4300\/24\/9\/1261\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T00:25:30Z","timestamp":1760142330000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1099-4300\/24\/9\/1261"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,9,8]]},"references-count":51,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2022,9]]}},"alternative-id":["e24091261"],"URL":"https:\/\/doi.org\/10.3390\/e24091261","relation":{},"ISSN":["1099-4300"],"issn-type":[{"value":"1099-4300","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,9,8]]}}}