{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,27]],"date-time":"2026-04-27T03:55:52Z","timestamp":1777262152394,"version":"3.51.4"},"reference-count":37,"publisher":"BMJ","issue":"11","license":[{"start":{"date-parts":[[2022,11,21]],"date-time":"2022-11-21T00:00:00Z","timestamp":1668988800000},"content-version":"unspecified","delay-in-days":20,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000266","name":"Engineering and Physical Sciences Research Council","doi-asserted-by":"publisher","award":["112538"],"award-info":[{"award-number":["112538"]}],"id":[{"id":"10.13039\/501100000266","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2022,11,8]]},"published-print":{"date-parts":[[2022,11]]},"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Long COVID (LC), also known as post-COVID-19 syndrome, refers to symptoms persisting 12 weeks after COVID-19 infection. It affects up to one in seven people contracting the illness and causes a wide range of symptoms, including fatigue, breathlessness, palpitations, dizziness, pain and brain fog. Many of these symptoms can be linked to dysautonomia or dysregulation of the autonomic nervous system after SARS-CoV2 infection. This study aims to test the feasibility and estimate the efficacy, of the heart rate variability biofeedback (HRV-B) technique via a standardised slow diaphragmatic breathing programme in individuals with LC.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods and analysis<\/jats:title>\n                    <jats:p>30 adult LC patients with symptoms of palpitations or dizziness and an abnormal NASA Lean Test will be selected from a specialist Long COVID rehabilitation service. They will undergo a 4-week HRV-B intervention using a Polar chest strap device linked to the Elite HRV phone application while undertaking the breathing exercise technique for two 10\u2009min periods everyday for at least 5\u2009days a week. Quantitative data will be gathered during the study period using: HRV data from the chest strap and wrist-worn Fitbit, the modified COVID-19 Yorkshire Rehabilitation Scale, Composite Autonomic Symptom Score, WHO Disability Assessment Schedule and EQ-5D-5L health-related quality of life measures. Qualitative feedback on user experience and feasibility of using the technology in a home setting will also be gathered. Standard statistical tests for correlation and significant difference will be used to analyse the quantitate data.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Ethics and dissemination<\/jats:title>\n                    <jats:p>The study has received ethical approval from Health Research Authority (HRA) Leicester South Research Ethics Committee (21\/EM\/0271). Dissemination plans include academic and lay publications.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Trial registration number<\/jats:title>\n                    <jats:p>\n                      <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"clintrialgov\" xlink:href=\"NCT05228665\">NCT05228665<\/jats:ext-link>\n                      .\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2022-066044","type":"journal-article","created":{"date-parts":[[2022,11,21]],"date-time":"2022-11-21T11:26:47Z","timestamp":1669030007000},"page":"e066044","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":15,"title":["HEART rate variability biofeedback for long COVID symptoms (HEARTLOC): protocol for a feasibility study"],"prefix":"10.1136","volume":"12","clinical-trial-number":[{"clinical-trial-number":"nct05228665","registry":"10.18810\/clinical-trials-gov"}],"author":[{"given":"Joanna","family":"Corrado","sequence":"first","affiliation":[{"name":"Academic Department of Rehabilitation Medicine, University of Leeds, Leeds, UK"},{"name":"National Demonstration Centre in Rehabilitation, Leeds Teaching Hospitals NHS Trust, Leeds, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0417-8928","authenticated-orcid":false,"given":"Stephen","family":"Halpin","sequence":"additional","affiliation":[{"name":"Academic Department of Rehabilitation Medicine, University of Leeds, Leeds, UK"},{"name":"Long COVID Rehabilitation Service, Leeds Community Healthcare NHS Trust, Leeds, UK"},{"name":"The University of Manchester, Manchester, Manchester, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8429-7320","authenticated-orcid":false,"given":"Nick","family":"Preston","sequence":"additional","affiliation":[{"name":"Academic Department of Rehabilitation Medicine, University of Leeds, Leeds, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Diana","family":"Whiteside","sequence":"additional","affiliation":[{"name":"Long COVID Rehabilitation Service, Leeds Community Healthcare NHS Trust, Leeds, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rachel","family":"Tarrant","sequence":"additional","affiliation":[{"name":"Long COVID Rehabilitation Service, Leeds Community Healthcare NHS Trust, Leeds, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jennifer","family":"Davison","sequence":"additional","affiliation":[{"name":"Long COVID Rehabilitation Service, Leeds Community Healthcare NHS Trust, Leeds, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alexander D","family":"Simms","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Leeds Teaching Hospitals NHS Trust, Leeds, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4643-9794","authenticated-orcid":false,"given":"Rory J","family":"O'Connor","sequence":"additional","affiliation":[{"name":"Academic Department of Rehabilitation Medicine, University of Leeds, Leeds, UK"},{"name":"National Demonstration Centre in Rehabilitation, Leeds Teaching Hospitals NHS Trust, Leeds, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1408-1190","authenticated-orcid":false,"given":"Alexander","family":"Casson","sequence":"additional","affiliation":[{"name":"Academic Department of Rehabilitation Medicine, University of Leeds, Leeds, UK"},{"name":"The University of Manchester, Manchester, Manchester, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0334-2968","authenticated-orcid":false,"given":"Manoj","family":"Sivan","sequence":"additional","affiliation":[{"name":"Academic Department of Rehabilitation Medicine, University of Leeds, Leeds, UK"},{"name":"National Demonstration Centre in Rehabilitation, Leeds Teaching Hospitals NHS Trust, Leeds, UK"},{"name":"Long COVID Rehabilitation Service, Leeds Community Healthcare NHS Trust, Leeds, UK"},{"name":"The University of Manchester, Manchester, Manchester, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2022,11,21]]},"reference":[{"key":"2025120521165124000_12.11.e066044.1","unstructured":"National Institute for Health and Care Excellence (NICE), Scottish Intercollegiate Guidelines Network (SIGN), Royal College of General Practitioners (RCGP) . COVID-19 rapid guideline: managing the long- term effects of COVID-19. London: NICE, 2022."},{"key":"2025120521165124000_12.11.e066044.2","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.n1648"},{"key":"2025120521165124000_12.11.e066044.3","unstructured":"World Health Organisation . Support for rehabilitation: self-management after COVID-19-related illness. Copenhagen: WHO Regional Office for Europe, 2021."},{"key":"2025120521165124000_12.11.e066044.4","unstructured":"Office of National Statistics . Prevalence of ongoing symptoms following coronavirus (COVID-19) infection in the UK. London: ONS, 2022."},{"key":"2025120521165124000_12.11.e066044.5","unstructured":"OoN S . Coronavirus and the social impacts of \u2018long COVID\u2019 on people\u2019s lives in Great Britain, 2021. Available: https:\/\/www.ons.gov.uk\/peoplepopulationandcommunity\/healthandsocialcare\/conditionsanddiseases\/articles\/coronavirusandthesocialimpactsoflongcovidonpeopleslivesingreatbritain\/7aprilto13june2021 [Accessed 02 May 2022]."},{"key":"2025120521165124000_12.11.e066044.6","doi-asserted-by":"publisher","DOI":"10.7861\/clinmed.2020-0896"},{"key":"2025120521165124000_12.11.e066044.7","doi-asserted-by":"publisher","DOI":"10.1007\/s10286-021-00803-8"},{"key":"2025120521165124000_12.11.e066044.8","doi-asserted-by":"publisher","DOI":"10.1093\/bmb\/ldy036"},{"key":"2025120521165124000_12.11.e066044.9","doi-asserted-by":"publisher","DOI":"10.1093\/oxfordjournals.eurheartj.a014868"},{"key":"2025120521165124000_12.11.e066044.10","doi-asserted-by":"publisher","DOI":"10.1016\/j.ctim.2021.102750"},{"key":"2025120521165124000_12.11.e066044.11","doi-asserted-by":"publisher","DOI":"10.1186\/s12967-019-02184-z"},{"key":"2025120521165124000_12.11.e066044.12","doi-asserted-by":"publisher","DOI":"10.1007\/s10484-006-9028-0"},{"key":"2025120521165124000_12.11.e066044.13","doi-asserted-by":"publisher","DOI":"10.1378\/chest.126.2.352"},{"key":"2025120521165124000_12.11.e066044.14","doi-asserted-by":"publisher","DOI":"10.1017\/S0033291717001003"},{"key":"2025120521165124000_12.11.e066044.15","doi-asserted-by":"crossref","first-page":"98","DOI":"10.5298\/1081-5937-41.3.08","article-title":"Protocol for heart rate variability biofeedback training","volume":"41","author":"Lehrer","year":"2013","journal-title":"Biofeedback"},{"key":"2025120521165124000_12.11.e066044.16","doi-asserted-by":"crossref","first-page":"110","DOI":"10.5298\/1081-5937-41.3.01","article-title":"The promise of heart rate variability biofeedback: evidence-based applications","volume":"41","author":"Gevirtz","year":"2013","journal-title":"Biofeedback"},{"key":"2025120521165124000_12.11.e066044.17","doi-asserted-by":"publisher","DOI":"10.1007\/s10484-006-9029-z"},{"key":"2025120521165124000_12.11.e066044.18","doi-asserted-by":"publisher","DOI":"10.1007\/s10484-006-9009-3"},{"key":"2025120521165124000_12.11.e066044.19","doi-asserted-by":"publisher","DOI":"10.3389\/fpsyg.2014.00756"},{"key":"2025120521165124000_12.11.e066044.20","doi-asserted-by":"publisher","DOI":"10.2478\/hukin-2020-0004"},{"key":"2025120521165124000_12.11.e066044.21","doi-asserted-by":"publisher","DOI":"10.1007\/s00421-019-04142-5"},{"key":"2025120521165124000_12.11.e066044.22","doi-asserted-by":"publisher","DOI":"10.1016\/j.jsams.2018.07.014"},{"key":"2025120521165124000_12.11.e066044.23","doi-asserted-by":"crossref","unstructured":"Sivan M , Preston N , Parkin A . The modified COVID-19 Yorkshire rehabilitation scale (C19-YRSm) patient-reported outcome measure for long Covid or Post-COVID-19 syndrome. J Med Virol 2022.doi:10.1002\/jmv.27878","DOI":"10.1101\/2021.06.28.21259613"},{"key":"2025120521165124000_12.11.e066044.24","first-page":"985","article-title":"Cardiovascular deconditioning during space flight and the use of saline as a countermeasure to orthostatic intolerance","volume":"56","author":"Bungo","year":"1985","journal-title":"Aviat Space Environ Med"},{"key":"2025120521165124000_12.11.e066044.25","doi-asserted-by":"publisher","DOI":"10.1186\/s12967-020-02481-y"},{"key":"2025120521165124000_12.11.e066044.26","first-page":"801","article-title":"Comparison of 70 degrees tilt, LBNP, and passive standing as measrues of orthostatic tolerance","volume":"46","author":"Hyatt","year":"1975","journal-title":"Aviat Space Environ Med"},{"key":"2025120521165124000_12.11.e066044.27","doi-asserted-by":"crossref","unstructured":"Sivan M , Corrado J , Mathias C . The adapted autonomic profile (aAP) home-based test for the evaluation of neuro-cardiovascular autonomic dysfunction. ACNR 2022.doi:10.47795\/QKBU6715","DOI":"10.20944\/preprints202206.0325.v1"},{"key":"2025120521165124000_12.11.e066044.28","doi-asserted-by":"crossref","unstructured":"Sivan M , Halpin S , Gees J , et al . The self-report version and digital format of the COVID-19 Yorkshire rehabilitation scale (C19-YRS) for long Covid or Post-COVID syndrome assessment and monitoring. ACNR 2021;20.doi:10.47795\/QROO4168","DOI":"10.47795\/QROO4168"},{"key":"2025120521165124000_12.11.e066044.29","doi-asserted-by":"crossref","first-page":"1027","DOI":"10.1002\/jmv.27415","article-title":"The COVID-19 Yorkshire rehabilitation scale (C19-YRS): application and psychometric analysis in a post-COVID-19 syndrome cohort","volume":"94","author":"O'Connor","year":"2022","journal-title":"J Med Virol"},{"key":"2025120521165124000_12.11.e066044.30","doi-asserted-by":"publisher","DOI":"10.1016\/j.mayocp.2012.10.013"},{"key":"2025120521165124000_12.11.e066044.31","doi-asserted-by":"publisher","DOI":"10.1186\/1477-7525-8-51"},{"key":"2025120521165124000_12.11.e066044.32","unstructured":"Ustun TB , Kostanjsek N , Chatterji S . Measuring health and disability : manual for WHO Disability Assessment Schedule (WHODAS 2.0), 2010. Available: https:\/\/www.who.int\/publications\/i\/item\/measuring-health-and-disability-manual-for-who-disability-assessment-schedule-(-whodas-2.0) [Accessed 19 June 2022]."},{"key":"2025120521165124000_12.11.e066044.33","doi-asserted-by":"publisher","DOI":"10.1007\/s11136-011-9903-x"},{"key":"2025120521165124000_12.11.e066044.34","doi-asserted-by":"publisher","DOI":"10.1016\/0168-8510(96)00822-6"},{"key":"2025120521165124000_12.11.e066044.35","doi-asserted-by":"publisher","DOI":"10.1016\/j.cct.2014.04.001"},{"key":"2025120521165124000_12.11.e066044.36","doi-asserted-by":"publisher","DOI":"10.1186\/1471-2288-13-104"},{"key":"2025120521165124000_12.11.e066044.37","doi-asserted-by":"publisher","DOI":"10.1136\/bmjopen-2022-063505"}],"container-title":["BMJ Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bmjopen-2022-066044","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,6]],"date-time":"2025-12-06T05:16:59Z","timestamp":1764998219000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmjopen.bmj.com\/lookup\/doi\/10.1136\/bmjopen-2022-066044"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,11]]},"references-count":37,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2022,11,21]]},"published-print":{"date-parts":[[2022,11]]}},"alternative-id":["10.1136\/bmjopen-2022-066044"],"URL":"https:\/\/doi.org\/10.1136\/bmjopen-2022-066044","relation":{"has-preprint":[{"id-type":"doi","id":"10.1101\/2022.06.23.22276821","asserted-by":"object"}]},"ISSN":["2044-6055","2044-6055"],"issn-type":[{"value":"2044-6055","type":"print"},{"value":"2044-6055","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,11]]}}}