Seasonal Variation in Cardiovascular Functioning

Abstract

Ninety-three subjects were observed In a darkened soundproof room over 900 times at intervals off approximately. 10 weeks throughout two years. At conditions of essentially constant temperature and humidity throughout the year, blood pressures, heart rates, respiratory rates and skin resistance levels were recorded Monthly standard score means for each variable were not random but revealed seasonal patterns in which during the warm reasons, systolic blood pressures were significantly lower, pulse pressures were narrow, heart rates significantly slower, respiratory rates slightly faster, and skin resistance significantly higher, with the reverse being true in cold seasons. The results reflect chronic adaptive changes necessary to allow for either dissipation or conservation off body heat depending on the seasonal temperature; changes in peripheral vascular resistance of the body shell appear to play an important role in “acclimatization.”.