Walsh J T, Andrews R, Batin P D, Cowley A J
Department of Cardiovascular Medicine, University Hospital, Nottingham, England.
Eur J Appl Physiol Occup Physiol. 1995;72(1-2):76-80. doi: 10.1007/BF00964118.
Many patients with angina note that their symptoms deteriorate in cold weather, although the precise physiological mechanism that explains this remains unclear. Exposure of the face to cool winds may be a contributory factor. The cardiovascular and hormonal response to a localised stream of room (22 degrees C) and cold (4 degrees C) air during submaximal treadmill exercise was therefore studied in nine normal subjects. Cardiac output and respiratory gases were measured with a mass spectrometer, using the indirect Fick principle. Blood samples were taken for plasma noradrenaline. A localised stream of air at 5 m.s-1 produced significant cardiovascular effects at rest, some of which persisted during exercise. In response to cold air, stroke volume, cardiac output, blood pressure and oxygen uptake increased (all P < 0.05). There was a trend towards a reduction in heart rate at rest and increase in plasma noradrenaline. Room air caused a reduction in blood pressure (P = 0.01) but stroke volumes and oxygen uptake were unchanged. The results of this study demonstrate significant cardiovascular effects of a cooled air facial stimulus at rest and during exercise. They may, in part, explain the effects of cold winds on patients with angina.
许多心绞痛患者指出，他们的症状在寒冷天气会恶化，尽管对此作出解释的确切生理机制尚不清楚。面部暴露于冷风可能是一个促成因素。因此，在9名正常受试者中研究了在次极量跑步机运动期间，面部暴露于室内（22摄氏度）和寒冷（4摄氏度）局部气流时的心血管和激素反应。使用间接菲克原理，通过质谱仪测量心输出量和呼吸气体。采集血样检测血浆去甲肾上腺素。5米/秒的局部气流在静息时产生了显著的心血管效应，其中一些效应在运动期间持续存在。对冷空气的反应是，每搏输出量、心输出量、血压和摄氧量增加（均P<0.05）。静息时心率有降低趋势，血浆去甲肾上腺素增加。室内空气导致血压降低（P=0.01），但每搏输出量和摄氧量未改变。这项研究的结果表明，在静息和运动期间，冷空气面部刺激具有显著的心血管效应。它们可能部分解释了冷风对心绞痛患者的影响。
