Effects of heat stress on thermoregulatory responses in congestive heart failure patients
Effects of heat stress on thermoregulatory responses in congestive heart failure patients
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DOI：
10.1161/circulationaha.105.540773
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发表时间：
2005-10-11
期刊：
影响因子：
37.8
通讯作者：
Crandall, CG
中科院分区：
文献类型：
--
作者：
Cui, J;Arbab-Zadeh, A;Crandall, CG
背景-临床观察表明，心血管疾病患者对热应激的耐受性可能受损，特别是那些与心室功能受损和充血性心力衰竭（CHF）相关的患者。然而，在控制热应激的挑战，在CHF患者的体温调节功能还没有studyed.Methods和结果-为了检验这一假设，体温调节反应减弱，在这样的患者，我们评估了皮肤血管舒张和出汗率在稳定的II - III类CHF患者和匹配的健康受试者在被动全身加热。两组动物的全身加热引起了相似的内部温度升高（约0.85摄氏度）。CHF患者的出汗反应与对照组无显著差异。相比之下，CHF患者前臂皮肤血管传导性的升高相对于对照受试者降低了近50%（3.8 +/- 0.8 vs 6.9 +/- 1.0 mL/ 100 mL组织/min/100 mm Hg，P = 0.04）。此外，最大的皮肤血管扩张能力，直接在CHF患者的局部加热也显着低于对照组，这表明血管重塑可能会限制皮肤血管扩张在hypertemia.Conclusions -这些观察表明，CHF患者表现出衰减的皮肤血管扩张反应，全身和局部加热，而出汗反应被保存。皮肤血管舒张减弱可能是CHF患者热耐受不良的一个潜在机制。
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 (approximate to 0.85 degrees 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.