{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,17]],"date-time":"2026-03-17T15:26:27Z","timestamp":1773761187497,"version":"3.50.1"},"reference-count":41,"publisher":"Oxford University Press (OUP)","issue":"3","license":[{"start":{"date-parts":[[2026,2,26]],"date-time":"2026-02-26T00:00:00Z","timestamp":1772064000000},"content-version":"vor","delay-in-days":1,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,3,4]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Aims<\/jats:title>\n                    <jats:p>Chronic heart failure (CHF) is characterized by impaired autonomic regulation and disrupted sleep\u2013wake cycles, limiting recovery and daily function. CircAlign-HF, a wearable-guided circadian biofeedback tool providing personalized timing recommendations on activity, naps, and sleep, was developed. This study evaluated its physiological and clinical value in CHF.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods and results<\/jats:title>\n                    <jats:p>Twenty-one patients with stable CHF (median age 68 years, 90.5% male, NYHA II\u2013III) completed a 3-week crossover protocol. Week 1 served as baseline, in Week 2 participants received general advice (30\u2005min daily walk, 20\u2005min nap, sleep hygiene), and in Week 3, participants were guided to align their walk, nap, sleep, and wake times with their circadian rhythm. Autonomic regulation was assessed using HRV over 24\u2005h, and within 15\u2005min windows centred on each participant\u2019s peak daytime activity (diurnal acrophase) and deepest nocturnal rest (nocturnal nadir), capturing activity-related and sleep-related autonomic function. Patient-centred outcomes and adherence were evaluated using a structured questionnaire.<\/jats:p>\n                    <jats:p>General advice improved 24\u2005h autonomic regulation: the root mean square of successive differences (rMSSD) increased from baseline to Week 2 (+18.2\u2005ms, P = 0.037), with concurrent gains in standard deviation of normal-to-normal intervals (SDNN) and rMSSD during exertion windows (+47.3\u2005ms and +56.8\u2005ms, both P = 0.037). Adding circadian alignment yielded specific nocturnal benefits: SDNN (+56.7\u2005ms, P = 0.039), rMSSD (+47.6\u2005ms, P = 0.0078), low-frequency (LF) power (+6236\u2005ms\u00b2, P = 0.039), and high-frequency (HF) power (+6812\u2005ms\u00b2, P = 0.0078) during sleep increased from Week 1 to Week 3. Adherence was 68% for walks, 74% for naps, and 47% for circadian timing; over half perceived better sleep quality and steadier energy levels.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>General advice improved overall autonomic regulation, whereas circadian-aligned recommendations specifically enhanced nocturnal autonomic function. These short-term physiological and perceived gains support the potential relevance of circadian biofeedback as a behavioural strategy in chronic heart failure.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/ehjdh\/ztag036","type":"journal-article","created":{"date-parts":[[2026,2,26]],"date-time":"2026-02-26T11:29:55Z","timestamp":1772105395000},"source":"Crossref","is-referenced-by-count":0,"title":["The clinical value of circadian biofeedback in chronic heart failure"],"prefix":"10.1093","volume":"7","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4946-6288","authenticated-orcid":false,"given":"Valerie A A","family":"van Es","sequence":"first","affiliation":[{"name":"Department of Cardiology, M\u00e1xima Medical Centre , Veldhoven\/Eindhoven ,","place":["the Netherlands"]},{"name":"Department of Industrial Design, Eindhoven University of Technology , Eindhoven ,","place":["the Netherlands"]},{"name":"MoMiLab Research Unit, IMT School for Advanced Studies , Lucca ,","place":["Italy"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ignace L J","family":"De Lathauwer","sequence":"additional","affiliation":[{"name":"Department of Cardiology, M\u00e1xima Medical Centre , Veldhoven\/Eindhoven ,","place":["the Netherlands"]},{"name":"Department of Industrial Design, Eindhoven University of Technology , Eindhoven ,","place":["the Netherlands"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Freek J C","family":"van Blerck","sequence":"additional","affiliation":[{"name":"Department of Cardiology, M\u00e1xima Medical Centre , Veldhoven\/Eindhoven ,","place":["the Netherlands"]},{"name":"Department of Industrial Design, Eindhoven University of Technology , Eindhoven ,","place":["the Netherlands"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mayke M C J","family":"van Leunen","sequence":"additional","affiliation":[{"name":"Department of Cardiology, M\u00e1xima Medical Centre , Veldhoven\/Eindhoven ,","place":["the Netherlands"]},{"name":"Department of Industrial Design, Eindhoven University of Technology , Eindhoven ,","place":["the Netherlands"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Danny A J P","family":"van de Sande","sequence":"additional","affiliation":[{"name":"Department of Cardiology, M\u00e1xima Medical Centre , Veldhoven\/Eindhoven ,","place":["the Netherlands"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rutger W M","family":"Brouwers","sequence":"additional","affiliation":[{"name":"Department of Industrial Design, Eindhoven University of Technology , Eindhoven ,","place":["the Netherlands"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mathias","family":"Funk","sequence":"additional","affiliation":[{"name":"Department of Industrial Design, Eindhoven University of Technology , Eindhoven ,","place":["the 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