ArticleAmerican journal of physiology. Heart and circulatory physiology2010
Insufficient cutaneous vasoconstriction leading up to and during syncopal symptoms in the heat stressed human.
Article in American journal of physiology. Heart and circulatory physiology, 2010. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 29 papers, 1 of them a synthesis that pooled it.
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Who cites it
29 citing papers in PubMed, 1 synthesis or guideline pooled it, 59 citations in OpenAlex.
- Meta-analysis of heat-induced changes in cardiac function from over 400 laboratory-based heat exposure studies.Nature communications · 2025Pooled it
- Hemodynamic Stability to Surface Warming and Cooling During Sustained and Continuous Simulated Hemorrhage in Humans.Shock (Augusta, Ga.) · 2016Trial
- Normothermic central hypovolemia tolerance reflects hyperthermic tolerance.Clinical autonomic research : official journal of the Clinical Autonomic Research Society · 2014Trial
- Acute volume expansion attenuates hyperthermia-induced reductions in cerebral perfusion during simulated hemorrhage.Journal of applied physiology (Bethesda, Md. : 1985) · 2013Trial
- Sweat loss during heat stress contributes to subsequent reductions in lower-body negative pressure tolerance.Experimental physiology · 2013Trial
- Colloid volume loading does not mitigate decreases in central blood volume during simulated haemorrhage while heat stressed.The Journal of physiology · 2012Trial
- A review of the DTS: Diathermic Syncope® system with a discussion regarding its use for kosher slaughter (Animal welfare (South Mimms, England) · 2023Review
- Cardiovascular responses to orthostasis during a simulated 3-day heatwave.Scientific reports · 2022Article
- Neural control of blood pressure is altered following isolated leg heating in aged humans.American journal of physiology. Heart and circulatory physiology · 2020Article
- Impact of environmental stressors on tolerance to hemorrhage in humans.American journal of physiology. Regulatory, integrative and comparative physiology · 2019Article
- Heat Adaptation in Military Personnel: Mitigating Risk, Maximizing Performance.Frontiers in physiology · 2019Review
- Limb Skin Temperature as a Tool to Predict Orthostatic Instability.Frontiers in physiology · 2018Article
- Effects of postural change from supine to head-up tilt on the skin sympathetic nerve activity component synchronised with the cardiac cycle in warmed men.The Journal of physiology · 2017Article
- Elevated skin and core temperatures both contribute to reductions in tolerance to a simulated haemorrhagic challenge.Experimental physiology · 2017Article
- Mechanisms of orthostatic intolerance during heat stress.Autonomic neuroscience : basic & clinical · 2016Review
- Fluid restriction during exercise in the heat reduces tolerance to progressive central hypovolaemia.Experimental physiology · 2015Article
- Human cardiovascular responses to passive heat stress.Comprehensive Physiology · 2015Review
- Active and passive heat stress similarly compromise tolerance to a simulated hemorrhagic challenge.American journal of physiology. Regulatory, integrative and comparative physiology · 2014Article
- Forehead versus forearm skin vascular responses at presyncope in humans.American journal of physiology. Regulatory, integrative and comparative physiology · 2014Article
- Blunted cutaneous vasoconstriction and increased frequency of presyncope during an orthostatic challenge under moderate heat stress in the morning.European journal of applied physiology · 2014Article
Corrections and comments
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Authors and funding
3 authors at 3 institutions in 2 countries.
Funding
Abstract
As much as 50% of cardiac output can be distributed to the skin in the hyperthermic human, and therefore the control of cutaneous vascular conductance (CVC) becomes critical for the maintenance of blood pressure. Little is known regarding the magnitude of cutaneous vasoconstriction in profoundly hypotensive individuals while heat stressed. This project investigated the hypothesis that leading up to and during syncopal symptoms associated with combined heat and orthostatic stress, reductions in CVC are inadequate to prevent syncope. Using a retrospective study design, we evaluated data from subjects who experienced syncopal symptoms during lower body negative pressure (N = 41) and head-up tilt (N = 5). Subjects were instrumented for measures of internal temperature, forearm skin blood flow, arterial pressure, and heart rate. CVC was calculated as skin blood flow/mean arterial pressure × 100. Data were obtained while subjects were normothermic, immediately before an orthostatic challenge while heat stressed, and at 5-s averages for the 2 min preceding the cessation of the orthostatic challenge due to syncopal symptoms. Whole body heat stress increased internal temperature (1.25 ± 0.3°C; P < 0.001) and CVC (29 ± 20 to 160 ± 58 CVC units; P < 0.001) without altering mean arterial pressure (83 ± 7 to 82 ± 6 mmHg). Mean arterial pressure was reduced to 57 ± 9 mmHg (P < 0.001) immediately before the termination of the orthostatic challenge. At test termination, CVC decreased to 138 ± 61 CVC units (P < 0.001) relative to before the orthostatic challenge but remained approximately fourfold greater than when subjects were normothermic. This negligible reduction in CVC during pronounced hypotension likely contributes to reduced orthostatic tolerance in heat-stressed humans. Given that lower body negative pressure and head-up tilt are models of acute hemorrhage, these findings have important implications with respect to mechanisms of compromised blood pressure control in the hemorrhagic individual who is also hyperthermic (e.g., military personnel, firefighters, etc.).
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.