{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T09:17:31Z","timestamp":1789377451851,"version":"build-2803163510"},"reference-count":47,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2015,3,2]],"date-time":"2015-03-02T00:00:00Z","timestamp":1425254400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004442","name":"National Science Centre, Poland","doi-asserted-by":"publisher","award":["UMO: 2012\/06\/M\/ST2\/00480"],"award-info":[{"award-number":["UMO: 2012\/06\/M\/ST2\/00480"]}],"id":[{"id":"10.13039\/501100004442","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Foundation for Polish Science with European Union funds from the European Social Fund","award":["No. 172\/UD\/SKILLS\/2012"],"award-info":[{"award-number":["No. 172\/UD\/SKILLS\/2012"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Sample entropy (SampEn) was reported to be useful in the assessment of the complexity of heart rate dynamics. Permutation entropy (PermEn) is a new measure based on the concept of order and was previously shown to be accurate for short, non-stationary datasets. The aim of the present study is to assess if SampEn and PermEn obtained from baseline recordings might differentiate patients with various outcomes of the head-up tilt test (HUTT). Time-domain heart rate variability (HRV) indices and several nonlinear parameters were calculated using 500 RR interval-long ECG recordings done before tilting in patients with a history suggesting vasovagal syncope. Groups of patients with so-called cardiodepressive vasovagal syncope (VVS_2) during HUTT and patients who did not faint during the test were compared. Two types of HUT tests were analyzed: with spontaneous (SB) or controlled breathing (CB). In our study, SampEn was higher in VVS_2 patients during SB, and PermEn was higher in VVS_2 patients during CB. Irrespective of the type of breathing during the test, SampEn and PermEn were similar in patients with the same type of reaction during HUTT. The use of several entropy-based parameters seems to be useful in HRV assessment in patients with vasovagal fainting.<\/jats:p>","DOI":"10.3390\/e17031007","type":"journal-article","created":{"date-parts":[[2015,3,2]],"date-time":"2015-03-02T10:45:12Z","timestamp":1425293112000},"page":"1007-1022","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":22,"title":["Entropy Measures in the Assessment of Heart Rate Variability in Patients with Cardiodepressive Vasovagal Syncope"],"prefix":"10.3390","volume":"17","author":[{"given":"Beata","family":"Graff","sequence":"first","affiliation":[{"name":"Hypertension Unit, Department of Hypertension and Diabetology, Medical University of Gda\u0144sk, D\u0119binki 7c, 80-952 Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Grzegorz","family":"Graff","sequence":"additional","affiliation":[{"name":"Faculty of Applied Physics and Mathematics, Gda\u0144sk University of Technology, Narutowicza 11\/12,80-233 Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Danuta","family":"Makowiec","sequence":"additional","affiliation":[{"name":"Institute of Theoretical Physics and Astrophysics, University of Gda\u0144sk, Wita Stwosza 57, 80-952Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Agnieszka","family":"Kaczkowska","sequence":"additional","affiliation":[{"name":"Faculty of Applied Physics and Mathematics, Gda\u0144sk University of Technology, Narutowicza 11\/12,80-233 Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dorota","family":"Wejer","sequence":"additional","affiliation":[{"name":"Institute of Theoretical Physics and Astrophysics, University of Gda\u0144sk, Wita Stwosza 57, 80-952Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Szymon","family":"Budrejko","sequence":"additional","affiliation":[{"name":"Department of Cardiology and Electrotherapy, Medical University of Gda\u0144sk, D\u0119binki 7, 80-952Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dariusz","family":"Koz\u0142owski","sequence":"additional","affiliation":[{"name":"Department of Cardiology and Electrotherapy, Medical University of Gda\u0144sk, D\u0119binki 7, 80-952Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Krzysztof","family":"Narkiewicz","sequence":"additional","affiliation":[{"name":"Hypertension Unit, Department of Hypertension and Diabetology, Medical University of Gda\u0144sk, D\u0119binki 7c, 80-952 Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2015,3,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Alboni, P., and Furlan, R. (2015). Vasovagal Syncope, Springer.","DOI":"10.1007\/978-3-319-09102-0"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1824","DOI":"10.1172\/JCI3050","article-title":"Yohimbine in neurally mediated syncope. Pathophysiological implications","volume":"102","author":"Tank","year":"1998","journal-title":"J. Clin. Invest."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1016\/j.ijcard.2006.03.093","article-title":"Modulations of autonomic activity leading to tilt-mediated syncope","volume":"120","author":"Folino","year":"2007","journal-title":"Int. J. Cardiol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1053\/eupc.1999.0050","article-title":"Impaired arterial baroreceptor sensitivity before tilt-induced syncope","volume":"1","author":"Freitas","year":"1999","journal-title":"Europace"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2411","DOI":"10.1111\/j.1540-8159.1998.tb01192.x","article-title":"Heart rate variability during head-up tilt testing in patients with suspected neurally mediated syncope","volume":"21","author":"Grimm","year":"1998","journal-title":"Electrophysiology"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"591","DOI":"10.1016\/S0002-9149(99)80623-7","article-title":"Failure to decrease parasympathetic tone during upright tilt predicts a positive tilt-table test","volume":"75","author":"Lippman","year":"1995","journal-title":"Am. J. Cardiol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1258","DOI":"10.1016\/0002-9149(94)90559-2","article-title":"Time and frequency domain analyses of heart rate variability during orthostatic stress in patients with neurally mediated syncope","volume":"74","author":"Morillo","year":"1994","journal-title":"Am. J. Cardiol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"H1081","DOI":"10.1152\/ajpheart.2001.280.3.H1081","article-title":"Effects of exercise and passive head-up tilt on fractal and complexity properties of heart rate dynamics","volume":"280","author":"Tulppo","year":"2001","journal-title":"Am. J. Physiol. Heart Circ. Physiol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1332","DOI":"10.1111\/j.1540-8159.1997.tb06788.x","article-title":"Autonomic nervous system activity during tilt testing in syncopal patients, estimated by power spectral analysis of heart rate variability","volume":"20","author":"Kochiadakis","year":"1997","journal-title":"Pacing. Clin. Electrophysiol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"459","DOI":"10.1016\/S0002-8703(97)70082-6","article-title":"Assessment of autonomic function at rest and during tilt testing in patients with vasovagal syncope","volume":"134","author":"Kochiadakis","year":"1997","journal-title":"Am. Heart J."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1053\/eupc.1999.0064","article-title":"New classification of haemodynamics of vasovagal syncope: Beyond the VASIS classification. Analysis of the pre-syncopal phase of the tilt test without and with nitroglycerin challenge. Vasovagal Syncope International Study","volume":"2","author":"Brignole","year":"2000","journal-title":"Europace"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1016\/S0188-0128(99)00022-6","article-title":"Differences in heart rate variability between cardioinhibitory and vasodepressor responses to head-up tilt table testing","volume":"30","author":"Hermosillo","year":"1999","journal-title":"Arch. Med. Res."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/S0167-5273(98)00039-4","article-title":"Spectral analysis of heart rate variability during tilt-table testing in patients with vasovagal syncope","volume":"64","author":"Kochiadakis","year":"1998","journal-title":"Int. J. Cardiol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"312","DOI":"10.1136\/hrt.82.3.312","article-title":"Inadequate sympathovagal balance in response to orthostatism in patients with unexplained syncope and a positive head up tilt test","volume":"82","author":"Kouakam","year":"1999","journal-title":"Heart"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1042\/CS20030327","article-title":"Heart rate and blood pressure variability in subjects with vasovagal syncope","volume":"107","author":"Piccirillo","year":"2004","journal-title":"Clin. Sci. (Lond.)"},{"key":"ref_16","first-page":"45","article-title":"Syncope in an elderly, institutionalised population: Prevalence, incidence, and associated risk","volume":"55","author":"Lipsitz","year":"1985","journal-title":"Q. J. Med."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2079","DOI":"10.1161\/01.CIR.100.20.2079","article-title":"Altered Complexity and Correlation Properties of R-R Interval Dynamics Before the Spontaneous Onset of Paroxysmal Atrial Fibrillation","volume":"100","author":"Vikman","year":"1999","journal-title":"Circulation"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"398","DOI":"10.1093\/europace\/eul031","article-title":"Decrease in the heart rate complexity prior to the onset of atrial fibrillation","volume":"8","author":"Tuzcu","year":"2006","journal-title":"Europace"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"94","DOI":"10.1253\/circj.70.94","article-title":"Prediction of Paroxysmal Atrial Fibrillation Using Nonlinear Analysis of the R-R Interval Dynamics Before the Spontaneous Onset of Atrial Fibrillation","volume":"70","author":"Shin","year":"2006","journal-title":"Circ. J."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"565","DOI":"10.1097\/SHK.0b013e3181a993dc","article-title":"Rapid prediction of trauma patient survival by analysis of heart rate complexity: Impact of reducing data set size","volume":"32","author":"Batchinsky","year":"2009","journal-title":"Shock"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"429","DOI":"10.1161\/01.CIR.98.5.429","article-title":"RR interval dynamics before atrial fibrillation in patients after coronary artery bypass graft surgery","volume":"98","author":"Hogue","year":"1998","journal-title":"Circulation"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"3431","DOI":"10.1109\/IEMBS.2006.259744","article-title":"Prediction of Paroxysmal Atrial Fibrillation Using Nonlinear Analysis of the R-R Interval Dynamics Before the Spontaneous Onset of Atrial Fibrillation","volume":"1","author":"Signorini","year":"2006","journal-title":"Conf. Proc. IEEE Eng. Med. Biol. Soc."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1109\/TBME.2005.859809","article-title":"Comparison of Entropy-Based Regularity Estimators: Application to the Fetal Heart Rate Signal for the Identification of Fetal Distress","volume":"53","author":"Ferrario","year":"2006","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Amig\u00f3, J.M. (2010). Permutation Complexity in Dynamical Systems, Springer.","DOI":"10.1007\/978-3-642-04084-9"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"153","DOI":"10.5506\/APhysPolBSupp.5.153","article-title":"Entropy Measures of Heart Rate Variability for Short ECG Datasets in Patients with Congestive Heart Failure","volume":"5","author":"Graff","year":"2012","journal-title":"Acta Physica Polonica B Proc. Suppl."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1016\/j.compbiomed.2011.03.017","article-title":"Classifying cardiac biosignals using ordinal pattern statistics and symbolic dynamics","volume":"42","author":"Parlitz","year":"2012","journal-title":"Comput. Biol. Med."},{"key":"ref_27","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. Am. J. Physiol","volume":"278","author":"Richman","year":"2000","journal-title":"Heart Circ. Physiol."},{"key":"ref_28","unstructured":"Takens, F. (1981). Dynamical Systems and Turbulence, Springer."},{"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":"2297","DOI":"10.1073\/pnas.88.6.2297","article-title":"Approximate entropy as a measure of system complexity","volume":"88","author":"Pincus","year":"1991","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"R789","DOI":"10.1152\/ajpregu.00069.2002","article-title":"Sample entropy analysis of neonatal heart rate variability","volume":"283","author":"Lake","year":"2002","journal-title":"Am. J. Physiol. Regul. Integr. Comp. Physiol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"013123","DOI":"10.1063\/1.3081406","article-title":"Influence of noise on the sample entropy algorithm","volume":"19","author":"Ramdani","year":"2009","journal-title":"Chaos"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Bandt, C., and Pompe, B. (2002). Permutation Entropy: A Natural Complexity Measure for Time Series. Phys. Rev. Lett., 88.","DOI":"10.1103\/PhysRevLett.88.174102"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1706","DOI":"10.1053\/euhj.2002.3166","article-title":"Reproducibility of sequential head-up tilt testing in patients with recent syncope, normal ECG and no structural heart disease","volume":"23","author":"Romero","year":"2002","journal-title":"Eur. Heart J."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1143","DOI":"10.1152\/japplphysiol.00293.2007","article-title":"Progressive decrease of heart period variability entropy-based complexity during graded head-up tilt","volume":"103","author":"Porta","year":"2007","journal-title":"J. Appl. Physiol. (1985)"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1425","DOI":"10.1088\/0967-3334\/32\/9\/006","article-title":"The effect of orthostatic stress on multiscale entropy of heart rate and blood pressure","volume":"32","author":"Turianikova","year":"2011","journal-title":"Physiol. Meas."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1088\/0967-3334\/34\/1\/17","article-title":"K-nearest-neighbor conditional entropy approach for the assessment of short-term complexity of cardiovascular control","volume":"34","author":"Porta","year":"2013","journal-title":"Physiol. Meas."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"5698","DOI":"10.3390\/e16115698","article-title":"Sample Entropy and Traditional Measures of Heart Rate Dynamics Reveal Different Modes of Cardiovascular Control During Low Intensity Exercise","volume":"16","author":"Weippert","year":"2014","journal-title":"Entropy"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1553","DOI":"10.3390\/e14081553","article-title":"Permutation entropy and its main biomedical and econophysics applications: A review","volume":"14","author":"Zanin","year":"2012","journal-title":"Entropy"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"6212","DOI":"10.3390\/e16126212","article-title":"Ordinal Patterns, Entropy, and EEG","volume":"16","author":"Keller","year":"2014","journal-title":"Entropy"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"525","DOI":"10.1140\/epjst\/e2013-01857-4","article-title":"Ordinal pattern statistics for the assessment of heart rate variability","volume":"222","author":"Graff","year":"2013","journal-title":"Eur. Phys. J. Spec. Top."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"180","DOI":"10.1007\/BF02344774","article-title":"Information domain analysis of cardiovascular variability signals: Evaluation of regularity, synchronisation and co-ordination","volume":"38","author":"Porta","year":"2000","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"I\/9","DOI":"10.1007\/s10286-004-1003-3","article-title":"Epidemiology of reflex syncope","volume":"14","author":"Colman","year":"2004","journal-title":"Clin. Auton. Res."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"357","DOI":"10.1016\/j.pcad.2012.11.006","article-title":"Epidemiology of syncope\/collapse in younger and older Western patient populations","volume":"55","author":"Kenny","year":"2013","journal-title":"Prog. Cardiovasc. Dis."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1700","DOI":"10.1016\/0735-1097(94)90177-5","article-title":"Gender- and age-related differences in heart rate dynamics: Are women more complex than men?","volume":"24","author":"Ryan","year":"1994","journal-title":"J. Am. Coll. Cardiol."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"6686","DOI":"10.3390\/e16126686","article-title":"Effect of the Postural Challenge on the Dependence of the Cardiovascular Control Complexity on Age","volume":"16","author":"Catai","year":"2014","journal-title":"Entropy"},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Mueller, A., Bonnemeier, H., Malberg, H., Kurths, J., and Wessel, N. (2014, January 25\u201328). Age-dependent changes in the manifestations of gender-related differences in the cardiovascular regulation. Trento, Italy.","DOI":"10.1109\/ESGCO.2014.6847562"}],"container-title":["Entropy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1099-4300\/17\/3\/1007\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T20:43:01Z","timestamp":1760215381000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1099-4300\/17\/3\/1007"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,3,2]]},"references-count":47,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2015,3]]}},"alternative-id":["e17031007"],"URL":"https:\/\/doi.org\/10.3390\/e17031007","relation":{},"ISSN":["1099-4300"],"issn-type":[{"value":"1099-4300","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,3,2]]}}}