{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,9,12]],"date-time":"2026-09-12T12:12:20Z","timestamp":1789215140457,"version":"build-2803163510"},"posted":{"date-parts":[[2026,9,9]]},"group-title":"Pharmacology and Toxicology","reference-count":20,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,9,9]],"date-time":"2026-09-09T00:00:00Z","timestamp":1788912000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"award":["R01DK131524"],"award-info":[{"award-number":["R01DK131524"]}],"id":[{"id":"https:\/\/ror.org\/00adh9b73","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,9,9]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>While Heart Rate Variability (HRV) is a cornerstone of non-invasive autonomic assessment, the sensitivity and sustainability of specific HRV parameters remain debated. This study introduces a \u201csustainability score\u201d to systematically validate which metrics best reflect autonomic nervous system (ANS) modulation following pharmacological blockade.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>Ten male Sprague-Dawley rats were implanted with ECG electrodes. After recovery, rats underwent randomized atropine (1 mg\/kg, intraperitoneal) and propranolol (10 mg\/kg, intraperitoneal) sessions separated by at least 3 days. Baseline ECG was recorded for 30 min before each session, followed by 90-min post-drug ECG recording. HRV parameters were analyzed in sequential 15-min and 30-min segments. Reliability was assessed using average p-values across post-drug segments and a sustainability score, defined as the number of segments significantly different from baseline.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>After atropine, HF Power showed the strongest rapid parasympathetic-related response in 15-min segments, with the lowest average p-value (0.1476) and highest sustainability score (4), followed by RSA (p=0.16148; score=4). HFn was less reliable in 15-min segments (p=0.23147; score=2) but became the most reliable parasympathetic-related metric in 30-min segments (p=0.0001; score=3). After propranolol, SI was the most reliable sympathetic-related metric in both 15-min (p=0.18225; score=2) and 30-min segments (p=0.0393; score=2), while SD2\/SD1 showed the strongest 30-min sympathovagal-balance response (p=0.0200; score=3).<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Conclusion<\/jats:title>\n                  <jats:p>HF Power is recommended for rapid parasympathetic-related assessment in short windows, HFn for longer-window parasympathetic assessment, SI for sympathetic-assessment, and SD2\/SD1 for 30-min sympathovagal-balance analysis. Sustainability scoring provides a structured framework for selecting ECG-derived autonomic markers.<\/jats:p>\n                <\/jats:sec>","DOI":"10.64898\/2026.09.04.748642","type":"posted-content","created":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T00:45:21Z","timestamp":1789001121000},"source":"Crossref","is-referenced-by-count":0,"title":["A Temporal Reliability and Sustainability Score Framework for Ranking Heart Rate Variability Metrics During Pharmacological Autonomic Blockade in Rats"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8120-3218","authenticated-orcid":false,"given":"M. Khawar","family":"Ali","sequence":"first","affiliation":[{"name":"Division of Gastroenterology and Hepatology, Department of Internal Medicine, School of Medicine, University of Michigan, Ann Arbor, MI, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shuangshuang","family":"Ji","sequence":"additional","affiliation":[{"name":"Division of Gastroenterology and Hepatology, Department of Internal Medicine, School of Medicine, University of Michigan, Ann Arbor, MI, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Siden","family":"Long","sequence":"additional","affiliation":[{"name":"Division of Gastroenterology and Hepatology, Department of Internal Medicine, School of Medicine, University of Michigan, Ann Arbor, MI, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shiyuan","family":"Gong","sequence":"additional","affiliation":[{"name":"Division of Gastroenterology and Hepatology, Department of Internal Medicine, School of Medicine, University of Michigan, Ann Arbor, MI, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiande D.Z.","family":"Chen","sequence":"additional","affiliation":[{"name":"Division of Gastroenterology and Hepatology, Department of Internal Medicine, School of Medicine, University of Michigan, Ann Arbor, MI, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2026091204500889000_2026.09.04.748642v1.1","doi-asserted-by":"publisher","DOI":"10.3390\/diagnostics13020293"},{"key":"2026091204500889000_2026.09.04.748642v1.2","doi-asserted-by":"publisher","DOI":"10.3390\/s23198128"},{"key":"2026091204500889000_2026.09.04.748642v1.3","doi-asserted-by":"publisher","DOI":"10.3389\/fphys.2021.619722"},{"key":"2026091204500889000_2026.09.04.748642v1.4","doi-asserted-by":"publisher","DOI":"10.4103\/sja.SJA_33_18"},{"key":"2026091204500889000_2026.09.04.748642v1.5","doi-asserted-by":"publisher","DOI":"10.12710\/cardiometry.2017.10.6676"},{"key":"2026091204500889000_2026.09.04.748642v1.6","doi-asserted-by":"publisher","DOI":"10.3390\/60300142"},{"key":"2026091204500889000_2026.09.04.748642v1.7","doi-asserted-by":"publisher","DOI":"10.1016\/B978-0-12-801238-3.09248-5"},{"key":"2026091204500889000_2026.09.04.748642v1.8","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.3.5725.731"},{"key":"2026091204500889000_2026.09.04.748642v1.9","doi-asserted-by":"publisher","DOI":"10.4330\/wjc.v7.i4.204"},{"key":"2026091204500889000_2026.09.04.748642v1.10","doi-asserted-by":"publisher","DOI":"10.1016\/B978-0-323-40053-4.00010-X"},{"key":"2026091204500889000_2026.09.04.748642v1.11","unstructured":"McLendon, Kevin , and Charles V. Preuss . 2024. \u201cAtropine.\u201d In StatPearls. Treasure Island (FL): StatPearls Publishing. http:\/\/www.ncbi.nlm.nih.gov\/books\/NBK470551\/."},{"key":"2026091204500889000_2026.09.04.748642v1.12","doi-asserted-by":"publisher","DOI":"10.1007\/BF00420338"},{"key":"2026091204500889000_2026.09.04.748642v1.13","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-017-15632-x"},{"key":"2026091204500889000_2026.09.04.748642v1.14","doi-asserted-by":"publisher","DOI":"10.1007\/s11517-006-0119-0"},{"key":"2026091204500889000_2026.09.04.748642v1.15","doi-asserted-by":"publisher","DOI":"10.1159\/000336498"},{"key":"2026091204500889000_2026.09.04.748642v1.16","doi-asserted-by":"publisher","DOI":"10.3389\/fpubh.2017.00258"},{"key":"2026091204500889000_2026.09.04.748642v1.17","unstructured":"Shahrokhi, Mahsa , and Vikas Gupta . 2024. \u201cPropranolol.\u201d In StatPearls. 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