Cardiac response to whole-body heating

Journal Article · Sun Apr 01 00:00:00 EST 1979 · Aviat., Space Environ. Med.; (United States)

OSTI ID:5818172

Frey, M A.B.; Kenney, R A

Systolic time interval analysis was used to assess changes in ventricular function during heat stress. Seven subjects (4 M + 3 F, 22-35 yr) participated in the experiments. The heating procedure was the following: both legs of seated subjects were immersed to the knees in stirred water maintained at 42-45 C. The subjects' upper legs and trunks were enclosed in nonpermeable plastic and covered with a sheet blanket to reduce heat loss. After 30 min of heating, the water and plastic were removed. The parameters measured were HR and R-R interval, LVET, and PEP. Results were compared by t test at the 0.05 significance level. The results pointed to a two-stage cardiac response to heat-vagal withdrawal followed by a strong sympathetic outflow to the heart affecting both inotropic and chronotropic characteristics.

• Research Organization: George Washington University, Washington, D.C.
• OSTI ID: 5818172
• Journal Information: Aviat., Space Environ. Med.; (United States), Vol. 50
• Country of Publication: United States
• Language: English

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