{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,20]],"date-time":"2026-09-20T02:17:12Z","timestamp":1789870632389,"version":"4.0.1"},"reference-count":20,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2024,12,13]],"date-time":"2024-12-13T00:00:00Z","timestamp":1734048000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background\/Objectives: Thermotherapy is expected to assist in the prevention of arteriosclerosis and cardiovascular disease in individuals with spinal cord injuries. This study aimed to investigate the impact and underlying mechanisms of whole-body heat stress on cardiac function in patients with cervical spinal cord injury (CSCI) and healthy controls using head-out hot water immersion (HHWI). Methods: Eight male patients with complete motor CSCI and nine healthy controls were recruited. Participants were immersed for 60 min in water set at 2 \u00b0C above the resting esophageal temperature. Esophageal temperature, heart rate, and arterial pressure were monitored throughout the experiment. Before and after HHWI, echocardiography was used to measure indices of left ventricular diastolic capacity (E, E\u2032, and A), left atrial contractility (A and A\u2032), and left ventricular contractility [S\u2032 and isovolumic acceleration (IVA)]. Results: Both groups exhibited an increase in body temperature and heart rate, while blood pressure remained stable. In the control group, there was a significant increase in E (67.0 \u00b1 22.6 to 89.1 \u00b1 13.6), E\u2032 (9.5 \u00b1 3.8 to 15.1 \u00b1 4.1), A (50.0 \u00b1 15.2 to 75.8 \u00b1 18.2), A\u2032 (8.1 \u00b1 1.6 to 14.8 \u00b1 5.9), S\u2032 (8.7 \u00b1 1.4 to 15.1 \u00b1 4.5) and isovolumic acceleration (IVA) (104.2 \u00b1 14.7 to 151.1 \u00b1 20.6). In the CSCI group, only A (49.5 \u00b1 9.9 to 56.9 \u00b1 10.9) and IVA (94.4 \u00b1 27.2 to 134.7 \u00b1 27.7) showed a significant change. Conclusions: In the control group, heat stress increased left atrial contractility, left ventricular dilatation, and left ventricular contractility, while in patients with CSCI, left atrial contractility and left ventricular contractility improved, but there was no improvement in left ventricular diastolic function. This discrepancy in the impact of HHWI on cardiac function suggests that the sympathetic nervous system predominantly influences left ventricular dilatation during whole-body heat stress. However, other factors may also contribute to left atrial and ventricular contractility.<\/jats:p>","DOI":"10.3390\/jcm13247593","type":"journal-article","created":{"date-parts":[[2024,12,13]],"date-time":"2024-12-13T05:55:45Z","timestamp":1734069345000},"page":"7593","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["The Acute Effect of Hot Water Immersion on Cardiac Function in Individuals with Cervical Spinal Cord Injury"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9050-0460","authenticated-orcid":false,"given":"Ken","family":"Kouda","sequence":"first","affiliation":[{"name":"Department of Rehabilitation Medicine, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-8510, Japan"},{"name":"Research Center of Sports Medicine and Balneology, Nachikatsuura Balneologic Town Hospital, Wakayama 649-5331, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Motohiko","family":"Banno","sequence":"additional","affiliation":[{"name":"Department of Rehabilitation Medicine, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-8510, Japan"},{"name":"Research Center of Sports Medicine and Balneology, Nachikatsuura Balneologic Town Hospital, Wakayama 649-5331, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8005-9154","authenticated-orcid":false,"given":"Yasunori","family":"Umemoto","sequence":"additional","affiliation":[{"name":"Department of Rehabilitation Medicine, Yokohama City University School of Medicine, Kanagawa 236-0004, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tokio","family":"Kinoshita","sequence":"additional","affiliation":[{"name":"Department of Rehabilitation Medicine, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-8510, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5365-1347","authenticated-orcid":false,"given":"Yukihide","family":"Nishimura","sequence":"additional","affiliation":[{"name":"Department of Rehabilitation Medicine, Iwate Medical University School of Medicine, Iwate 028-3694, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yukio","family":"Mikami","sequence":"additional","affiliation":[{"name":"Department of Rehabilitation Medicine, Hiroshima University Hospital, Hiroshima 734-8551, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Toshikazu","family":"Kubo","sequence":"additional","affiliation":[{"name":"Department of Rehabilitation Medicine, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-8510, Japan"},{"name":"School of Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fumihiro","family":"Tajima","sequence":"additional","affiliation":[{"name":"Department of Rehabilitation Medicine, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-8510, Japan"},{"name":"Chuzan Hospital, Okinawa 904-2151, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,12,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"919","DOI":"10.1016\/S0929-6646(08)60062-5","article-title":"Circulating levels of markers of inflammation and en-dothelial activation are increased in men with chronic spinal cord injury","volume":"106","author":"Wang","year":"2007","journal-title":"J. Formos. Med. Assoc."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"616","DOI":"10.1038\/sc.2008.32","article-title":"C-reactive protein in adults with chronic spinal cord injury: Increased chronic inflammation in tetraplegia vs. paraplegia","volume":"46","author":"Gibson","year":"2008","journal-title":"Spinal Cord"},{"key":"ref_3","unstructured":"Rowell, L.B. (1986). Human Circulation Regulation During Physical Stress, Oxford University Press."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1016\/j.amjcard.2011.08.014","article-title":"Effect of repeated sauna treatment on exercise tolerance and endothelial function in patients with chronic heart failure","volume":"109","author":"Ohori","year":"2012","journal-title":"Am. J. Cardiol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"827","DOI":"10.1253\/circj.CJ-16-0051","article-title":"Waon Therapy for Managing Chronic Heart Failure\u2014Results From a Multicenter Prospective Randomized WAON-CHF Study","volume":"80","author":"Tei","year":"2016","journal-title":"Circ. J."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"348","DOI":"10.1007\/s12603-023-1895-1","article-title":"The Interplay between Systolic Blood Pressure, Sauna Bathing, and Cardiovascular Mortality in Middle-Aged and Older Finnish Men: A Cohort Study","volume":"27","author":"Laukkanen","year":"2023","journal-title":"J. Nutr. Health Aging"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1080\/23328940.2023.2300623","article-title":"The multifaceted benefits of passive heat therapies for extending the healthspan: A comprehensive review with a focus on Finnish sauna","volume":"11","author":"Laukkanen","year":"2024","journal-title":"Temperature"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1113\/jphysiol.2007.143057","article-title":"Effects of passive heating on central blood volume and ventricular dimensions in humans","volume":"586","author":"Crandall","year":"2008","journal-title":"J. Physiol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"673","DOI":"10.1152\/jappl.1969.27.5.673","article-title":"Cardiovascular responses to sustained high skin temperature in resting man","volume":"27","author":"Rowell","year":"1969","journal-title":"J. Appl. Physiol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"H1150","DOI":"10.1152\/ajpheart.01069.2008","article-title":"Cardiac systolic and diastolic function during whole body heat stress","volume":"296","author":"Brothers","year":"2009","journal-title":"Am. J. Physiol. Heart Circ. Physiol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1113\/jphysiol.2007.137901","article-title":"Effects of heat and cold stress on central vascular pressure relationships during orthostasis in humans","volume":"585","author":"Wilson","year":"2007","journal-title":"J. Physiol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"488","DOI":"10.1016\/0002-8703(70)90254-1","article-title":"The effects of exercise and changes in body temperature on the intrinsic heart rate in man","volume":"79","author":"Jose","year":"1970","journal-title":"Am. Heart J."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"860","DOI":"10.1085\/jgp.201812243","article-title":"Microscopic heat pulses activate cardiac thin filaments","volume":"151","author":"Ishii","year":"2019","journal-title":"J. Gen. Physiol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"H1336","DOI":"10.1152\/ajpheart.00911.2014","article-title":"The role of cardiac sympathetic innervation and skin thermoreceptors on cardiac responses during heat stress","volume":"308","author":"Shibasaki","year":"2015","journal-title":"Am. J. Physiol. Heart Circ. Physiol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1629","DOI":"10.1016\/j.amjcard.2007.01.050","article-title":"The effects of aging and physical activity on Doppler measures of diastolic function","volume":"99","author":"Prasad","year":"2007","journal-title":"Am. J. Cardiol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1131","DOI":"10.1113\/jphysiol.2008.165118","article-title":"Acute volume expansion preserves orthostatic tolerance during whole-body heat stress in humans","volume":"587","author":"Keller","year":"2009","journal-title":"J. Physiol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3333","DOI":"10.1113\/jphysiol.2010.191981","article-title":"Effect of volume loading on the Frank-Starling relation during reductions in central blood volume in heat-stressed humans","volume":"588","author":"Wilson","year":"2010","journal-title":"J. Physiol."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Nakahama-Matsushima, M., Kamijyo, Y.I., Umemoto, Y., Hashizaki, T., Nishimura, Y., Furusawa, K., Furotani, Y., Tajima, F., and Kouda, K. (2023). Increase in Serum Interleukin-1 Receptor Antagonist (IL-1ra) Levels after Wheelchair Half Marathon Race in Male Athletes with Spinal Cord Injury. J. Clin. Med., 12.","DOI":"10.3390\/jcm12227098"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Yoon, H.M., Joo, S.J., Boo, K.Y., Lee, J.G., Choi, J.H., Kim, S.Y., and Lee, S.Y. (2024). Impact of cardiac rehabilitation on ventricular-arterial coupling and left ventricular function in patients with acute myocardial infarction. PLoS ONE, 19.","DOI":"10.1371\/journal.pone.0300578"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"102210","DOI":"10.1016\/j.cpcardiol.2023.102210","article-title":"Exercise-based cardiac rehabilitation for left ventricular function in patients with heart failure: A systematic review and meta-analysis","volume":"49","author":"Qi","year":"2024","journal-title":"Curr. Probl. Cardiol."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/13\/24\/7593\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:54:20Z","timestamp":1760115260000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/13\/24\/7593"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,12,13]]},"references-count":20,"journal-issue":{"issue":"24","published-online":{"date-parts":[[2024,12]]}},"alternative-id":["jcm13247593"],"URL":"https:\/\/doi.org\/10.3390\/jcm13247593","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,12,13]]}}}