{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T19:09:55Z","timestamp":1783451395639,"version":"3.55.0"},"reference-count":23,"publisher":"BMJ","issue":"7","license":[{"start":{"date-parts":[[2025,8,1]],"date-time":"2025-08-01T00:00:00Z","timestamp":1754006400000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"name":"China Heart House-Chinese Cardiovascular Association HX fund","award":["2022-CCA-HX-009"],"award-info":[{"award-number":["2022-CCA-HX-009"]}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2025,7,15]]},"published-print":{"date-parts":[[2025,8]]},"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Patients with heart failure with reduced ejection fraction (HFrEF) and heart failure with mildly reduced ejection fraction (HFmrEF) are at high risk for developing atrial fibrillation (AF) due to significantly impaired cardiac pump function, heightened sympathetic nervous system activity and the frequent coexistence of cardiovascular comorbidities such as hypertension and coronary artery disease. Reduced heart rate variability (HRV), a key marker of autonomic nervous system balance, is an independent predictor of AF. Recently, ultra-short-term HRV (usHRV) has emerged as a promising method for rapid HRV assessment. UsHRV, operationally defined through \u226410\u2009s ECG analyses, represents a methodological divergence from conventional short-term HRV measurements requiring \u22655\u2009min recordings. This paradigm shift permits continuous autonomic surveillance while specifically capturing parasympathetic modulation indices as opposed to composite sympathetic\u2013parasympathetic metrics. Such temporal optimisation establishes a novel framework for expedited autonomic evaluation in time-sensitive clinical environments. Evidence on the link between usHRV and AF in heart failure patients remains limited. This study aims to investigate the association between usHRV and AF risk in this population.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Method and analysis<\/jats:title>\n                    <jats:p>This is a prospective, single-centre cohort study in patients with heart failure and reduced left ventricular ejection fraction (LVEF&lt;50%). Eligible patients will be enrolled based on predefined inclusion and exclusion criteria. The primary endpoints are AF, atrial flutter and subclinical AF. Secondary outcomes include all-cause mortality and first major cardiovascular events. Kansas City Cardiomyopathy Questionnaire (KCCQ-12) scores at baseline, 6 and 12 months as patient-centred secondary outcomes. LVEF will be assessed via standard transthoracic ECG, and AF will be identified through 12-lead ECG or long-term wearable ECG monitoring. Patient enrolment began on 1 January 2025, and is expected to conclude by 31 March 2026.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Ethics and dissemination<\/jats:title>\n                    <jats:p>The study protocol received approval from the Ethics Committee of Beijing Tsinghua Changgung Hospital on 14 November 2024 (review no. 24674-4-01). The findings will be submitted for publication in a peer-reviewed journal. Additionally, this protocol has been registered with the Chinese Clinical Trial Registry.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Trial registration number<\/jats:title>\n                    <jats:p>ChiCTR2400092516).<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2025-101170","type":"journal-article","created":{"date-parts":[[2025,8,1]],"date-time":"2025-08-01T09:00:31Z","timestamp":1754038831000},"page":"e101170","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":2,"title":["Association between ultra-short-term heart rate variability and atrial fibrillation in heart failure population: a protocol for a prospective observational cohort study"],"prefix":"10.1136","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5071-498X","authenticated-orcid":false,"given":"Xiaodi","family":"Tang","sequence":"first","affiliation":[{"name":"Department of Cardiology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua Medicine, Tsinghua University, Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rong","family":"He","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua Medicine, Tsinghua University, Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5843-1108","authenticated-orcid":false,"given":"Ping","family":"Zhang","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua Medicine, Tsinghua University, Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2025,8,1]]},"reference":[{"key":"2025121510254084000_15.7.e101170.1","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1002\/ehf2.14593","article-title":"Time-domain heart rate variability features for automatic congestive heart failure prediction","volume":"11","author":"Moses","year":"2024","journal-title":"ESC Heart Fail"},{"key":"2025121510254084000_15.7.e101170.2","doi-asserted-by":"crossref","DOI":"10.1186\/s12916-022-02273-9","article-title":"Heart rate variability is associated with left ventricular systolic, diastolic function and incident heart failure in the general population","volume":"20","author":"Arshi","year":"2022","journal-title":"BMC Med"},{"key":"2025121510254084000_15.7.e101170.3","first-page":"306","article-title":"Evaluation of heart rate variability in patients with coronary artery ectasia and coronary artery disease","volume":"44","author":"Y\u0131ld\u0131z","year":"2016","journal-title":"Turk Kardiyol Dern Ars"},{"key":"2025121510254084000_15.7.e101170.4","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCRESAHA.114.303772"},{"key":"2025121510254084000_15.7.e101170.5","doi-asserted-by":"publisher","DOI":"10.1016\/j.jacc.2016.10.059"},{"key":"2025121510254084000_15.7.e101170.6","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCEP.111.970095"},{"key":"2025121510254084000_15.7.e101170.7","doi-asserted-by":"publisher","DOI":"10.1161\/01.CIR.0000139841.42454.78"},{"key":"2025121510254084000_15.7.e101170.8","doi-asserted-by":"crossref","first-page":"644","DOI":"10.1002\/clc.23190","article-title":"The cardiac autonomic nervous system: A target for modulation of atrial fibrillation","volume":"42","author":"Qin","year":"2019","journal-title":"Clin Cardiol"},{"key":"2025121510254084000_15.7.e101170.9","doi-asserted-by":"crossref","DOI":"10.3389\/fpubh.2017.00258","article-title":"An Overview of Heart Rate Variability Metrics and Norms","volume":"5","author":"Shaffer","year":"2017","journal-title":"Front Public Health"},{"key":"2025121510254084000_15.7.e101170.10","doi-asserted-by":"crossref","DOI":"10.3389\/fnins.2020.594880","article-title":"A Critical Review of Ultra-Short-Term Heart Rate Variability Norms Research","volume":"14","author":"Shaffer","year":"2020","journal-title":"Front Neurosci"},{"key":"2025121510254084000_15.7.e101170.11","doi-asserted-by":"crossref","DOI":"10.1038\/s41598-023-45988-2","article-title":"Long-term association of ultra-short heart rate variability with cardiovascular events","volume":"13","author":"Orini","year":"2023","journal-title":"Sci Rep"},{"key":"2025121510254084000_15.7.e101170.12","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0138921","article-title":"Validity of (Ultra-)Short Recordings for Heart Rate Variability Measurements","volume":"10","author":"Munoz","year":"2015","journal-title":"PLoS One"},{"key":"2025121510254084000_15.7.e101170.13","doi-asserted-by":"publisher","DOI":"10.1089\/tmj.2014.0104"},{"key":"2025121510254084000_15.7.e101170.14","doi-asserted-by":"publisher","DOI":"10.1016\/j.jelectrocard.2004.04.004"},{"key":"2025121510254084000_15.7.e101170.15","doi-asserted-by":"crossref","DOI":"10.1038\/s41598-022-07783-3","article-title":"Higher heart rate variability as a predictor of atrial fibrillation in patients with hypertension","volume":"12","author":"Kim","year":"2022","journal-title":"Sci Rep"},{"key":"2025121510254084000_15.7.e101170.16","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejheart.2003.09.007"},{"key":"2025121510254084000_15.7.e101170.17","doi-asserted-by":"crossref","first-page":"4919","DOI":"10.2147\/IJGM.S435901","article-title":"Heart Rate Variability and Its Role in Predicting Atrial Fibrillation in Patients Undergoing Coronary Artery Bypass Graft","volume":"16","author":"Thanh","year":"2023","journal-title":"Int J Gen Med"},{"key":"2025121510254084000_15.7.e101170.18","doi-asserted-by":"crossref","DOI":"10.3390\/jcm12010089","article-title":"Ultra Short Heart Rate Variability Predicts Clinical Outcomes in Patients with a Clinical Presentation Consistent with Myocarditis: A Derivation Cohort Analysis","volume":"12","author":"Perek","year":"2022","journal-title":"J Clin Med"},{"key":"2025121510254084000_15.7.e101170.19","doi-asserted-by":"crossref","first-page":"1684","DOI":"10.1016\/j.amjcard.2019.08.025","article-title":"Resting Heart Rate, Short-Term Heart Rate Variability and Incident Atrial Fibrillation (from the Multi-Ethnic Study of Atherosclerosis (MESA))","volume":"124","author":"Habibi","year":"2019","journal-title":"Am J Cardiol"},{"key":"2025121510254084000_15.7.e101170.20","doi-asserted-by":"publisher","DOI":"10.1093\/eurheartj\/ehae176"},{"key":"2025121510254084000_15.7.e101170.21","doi-asserted-by":"crossref","unstructured":"Vandenberk B , Haemers P , Morillo C . The autonomic nervous system in atrial fibrillation\u2014pathophysiology and non-invasive assessment. Front Cardiovasc Med 2024;10. doi:10.3389\/fcvm.2023.1327387","DOI":"10.3389\/fcvm.2023.1327387"},{"key":"2025121510254084000_15.7.e101170.22","doi-asserted-by":"crossref","first-page":"747","DOI":"10.1007\/s00392-022-02072-5","article-title":"Heart rate variability and atrial fibrillation in the general population: a longitudinal and Mendelian randomization study","volume":"112","author":"Geurts","year":"2023","journal-title":"Clin Res Cardiol"},{"key":"2025121510254084000_15.7.e101170.23","doi-asserted-by":"publisher","DOI":"10.1111\/j.1540-8167.2007.01093.x"}],"container-title":["BMJ Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bmjopen-2025-101170","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,15]],"date-time":"2025-12-15T18:25:48Z","timestamp":1765823148000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmjopen.bmj.com\/lookup\/doi\/10.1136\/bmjopen-2025-101170"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,8]]},"references-count":23,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2025,8,1]]},"published-print":{"date-parts":[[2025,8]]}},"alternative-id":["10.1136\/bmjopen-2025-101170"],"URL":"https:\/\/doi.org\/10.1136\/bmjopen-2025-101170","relation":{},"ISSN":["2044-6055","2044-6055"],"issn-type":[{"value":"2044-6055","type":"print"},{"value":"2044-6055","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,8]]}}}