This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Cui, J. Articles by Crandall, C. G. Search for Related Content PubMed PubMed Citation Articles by Cui, J. Articles by Crandall, C. G. Related Collections Congestive Other Treatment Heart failure - basic studies

(Circulation. 2005;112:2286-2292.)
© 2005 American Heart Association, Inc.

Heart Failure

Effects of Heat Stress on Thermoregulatory Responses in Congestive Heart Failure Patients

Jian Cui, PhD; Armin Arbab-Zadeh, MD; Anand Prasad, MD; Sylvain Durand, PhD; Benjamin D. Levine, MD; Craig G. Crandall, PhD

From the Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas, Dallas, Tex (J.C., A.A.-Z., A.P., S.D., B.D.L., C.G.C.); and the Department of Internal Medicine, Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, Tex (A.A.-Z., A.P., B.D.L., C.G.C.).

Correspondence to Craig G. Crandall, PhD/Benjamin D. Levine, MD, Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas, 7232 Greenville Ave, Dallas, TX 75231. E-mail CraigCrandall{at}texashealth.org

Received February 3, 2005; revision received July 8, 2005; accepted July 22, 2005.

Background— Clinical observations suggest that tolerance to heat stress may be impaired in patients with cardiovascular diseases, particularly those associated with impaired ventricular function and congestive heart failure (CHF). However, thermoregulatory function during a controlled heat stress challenge in patients with CHF has not been studied.

Methods and Results— To test the hypothesis that thermoregulatory responses are attenuated in such patients, we assessed cutaneous vasodilation and sweat rate in patients with stable class II–III CHF and in matched healthy subjects during passive whole-body heating. Whole-body heating induced a similar increase in internal temperature (0.85°C) in both groups. The sweating responses in patients with CHF were not significantly different from that in control subjects. In contrast, the elevation in forearm cutaneous vascular conductance in patients with CHF was reduced by nearly 50% relative to the control subjects (3.8±0.8 versus 6.9±1.0 mL/100 mL tissue per minute per 100 mm Hg, P=0.04). Moreover, maximal cutaneous vasodilator capacity to direct local heating in patients with CHF was also significantly lower than in control subjects, suggesting that vascular remodeling may be limiting cutaneous vasodilation during hyperthermia.

Conclusions— These observations suggest that patients with CHF exhibit attenuated cutaneous vasodilator responses to both whole-body and local heating, whereas sweating responses are preserved. Attenuated cutaneous vasodilation may be a potential mechanism for heat intolerance in patients with CHF.

Key Words: blood flow • heart failure • hemodynamics • cardiovascular diseases • nervous system, autonomic

This article has been cited by other articles:

				M Stafoggia, F Forastiere, D Agostini, N Caranci, F de'Donato, M Demaria, P Michelozzi, R Miglio, M Rognoni, A Russo, et al. Factors affecting in-hospital heat-related mortality: a multi-city case-crossover analysis J. Epidemiol. Community Health, March 1, 2008; 62(3): 209 - 215. [Abstract] [Full Text] [PDF]