CARDIOVASCULAR ORIGINS OF HEATSTROKE PATHO-PHYSIOLOGY - AN ANESTHETIZED RAT MODEL

  • 1 January 1982
    • journal article
    • research article
    • Vol. 53  (2) , 171-178
Abstract
Opinion is divided on issues concerning a cardiovascular origin of heatstroke pathophysiology as well as those concerning the mechanism of circulatory failure in heat. Such controversies seem to arise because of insufficient data covering the prodromal period of heatstroke. A reappraisal of the nature and sequence of early circulatory responses to heat stress was undertaken by subjecting male albino rats to an environmental temperature of 45.degree. C at 15% relative humidity until overt circulatory failure occurred. Although the initial circulatory responses were normal for mild exertion, an inapparent circulatory crisis developed, probably a result of the abolishment of compensatory splanchnic vasoconstriction. The impending threat of functional hypovolemia was, temporarily at least, obscured by cardiac compensation, and the extent of cardiovascular commitments may, therefore, have been underestimated. Cardiovascular adjustments during the heat stress may prove to be an essential feature of heatstroke pathophysiology.