Cardiac function during heat stress: impact of short-term passive heat acclimation
Trachsel LD, Barry H, Gravel H, Behzadi P, Henri C, Gagnon D
American journal of physiology. Heart and circulatory physiology · 17 citations
How it was studied
- Design
- Controlled clinical trial (classified by our AI screen)
- Studied in
- People
- Main outcome
- Health markers and function
Who paid for it
- Funding
- Independent funding
- Government
- Government of Canada
- Government
- Canada Foundation for Innovation
- Nonprofit
- Fondation Institut de Cardiologie de Montréal
- Government
- Natural Sciences and Engineering Research Council of Canada
- Government
- Gouvernement du Canada | Natural Sciences and Engineering Research Council of Canada
- Nonprofit
- Montreal Heart Institute Foundation
- Grants
- Government of Canada (RGPIN-2017-04243); Natural Sciences and Engineering Research Council of Canada (rgpin-2017-04243); Canada Foundation for Innovation (35775)
Based on 6 listed funder(s).
Publication
- Published
- 2020-08-21 · Am J Physiol Heart Circ Physiol · vol. 319 · issue 4 · pp. H753–H764
- Publisher
- American Physical Society
- Cited
- 34 citations · more than 91% of similar papers · 2.7× the field average
- Impact
- Top 10% most cited in its field
- References
- 45 works
- Access
- Paywalled
- Research areas
- Thermoregulation and physiological responses · Climate Change and Health Impacts · Infrared Thermography in Medicine
- Keywords
- Heat stress, Acclimatization, Cardiac function curve, Cardiology, Internal medicine, Diastole, Heart rate, Function (biology), Diastolic function, Medicine, Animal science, Biology, Heart failure, Cell biology, Ecology, Blood pressure
- MeSH
- humans, heat stress disorders, echocardiography, doppler, cardiac output, skin temperature, heart rate, ventricular function, left, time factors, adult, female, male, hot temperature, thermotolerance
6 authors
From CH, CA
- Lukas D. TrachselUniversity of Bern; Montreal Heart Institute; University Hospital of Bern; Université de Montréal
- Hadiatou BarryMontreal Heart Institute; Université de Montréal
- Hugo GravelMontreal Heart Institute; Université de Montréal
- Parya BehzadiMontreal Heart Institute; Université de Montréal
- Christine HenriMontreal Heart Institute; Université de Montréal
- Daniel Gagnon · correspondingMontreal Heart Institute; Université de Montréal
Abstract
A lower heart rate (HR) during heat exposure is a classic marker of heat acclimation (HA), although it remains unclear whether this adaptation occurs secondary to reduced thermal strain and/or improvements in cardiac function. We evaluated the hypothesis that short-term passive HA reduces HR and improves cardiac function during passive heating. Echocardiography was performed under thermoneutral and hyperthermic conditions in 10 healthy adults (9 men/1 woman, 29 ± 6 yr old), pre and post 7 days of controlled hyperthermia. HR (P = 0.61), stroke volume (P = 0.99), and cardiac output (P = 0.99), were similar on days 1 and 7 of HA. Core (pre: 38.17 ± 0.42, post: 38.15 ± 0.27°C, P = 0.95) and mean skin (pre: 38.24 ± 0.41, post: 38.51 ± 0.29°C, P = 0.17) temperatures were similar during hyperthermic echocardiographic assessments. Cardiac systolic function was unaffected by HA (P ≥ 0.10). HA attenuated the decrease in end-diastolic volume (pre: -18 ± 18, post: -12 ± 19 mL, P = 0.05), accentuated the greater atrial contribution to diastolic filling (pre: +11 ± 5, post: +14 ± 5%, P = 0.02), and attenuated the increase in left atrial reservoir strain rate (pre: +1.5 ± 1.2, post: +0.8 ± 0.8 1/s, P = 0.02) during heating. Nonetheless, there were no differences in HR (pre: 106 ± 12, post: 104 ± 12 beats/min, P = 0.50), stroke volume (pre: 65 ± 15, post: 68 ± 13 mL, P = 0.55), or cardiac output (pre: 6.9 ± 2.0, post: 7.1 ± 1.7 L/min, P = 0.70) during passive heating. Short-term controlled hyperthermia HA results in limited adaptations of cardiac function during passive heating.NEW & NOTEWORTHY A lower heart rate during heat exposure is a classic marker of heat acclimation (HA). It remains unknown if improved cardiac function contributes to this response. A 7-day passive HA protocol did not alter cardiac systolic function during passive heating, whereas it improved some indexes of diastolic function in young adults. Nonetheless, heart rate during heating was unaffected by HA. These results suggest that passive HA induces limited adaptations in cardiac function during passive heating.
Abstract via Europe PMC. Copyright remains with the authors or publisher.
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