Miyamoto Y, Hiura T, Tamura T, Nakamura T, Higuchi J, Mikami T
J Appl Physiol Respir Environ Exerc Physiol. 1982 May;52(5):1198-208. doi: 10.1152/jappl.1982.52.5.1198.
Stroke volume, heart rate, cardiac output, tidal volume, respiratory frequency, minute ventilation, end-tidal tensions of O2 and CO2, O2 uptake, CO2 output, and respiratory exchange ratio were measured simultaneously in healthy male volunteers before, during, and after upright bicycle exercise from 0 to 360 and 720 kpm/min. The circulatory variables were determined continuously once per 20 cardiac cycles and the respiratory variables breath by breath using separate computer-based systems in which an impedance pneumograph and an impedance cardiograph were incorporated. Stroke volume, heart rate, and cardiac output started to increase without measurable delay at the onset of exercise. Stroke volume increased by 20% from resting control value in response to the mildest exercise and essentially leveled off with a further increase in work load. Time constant for cardiac output increased with the increasing work load. Time constant for minute ventilation was much longer than that for cardiac output and independent of work intensity. A good synchronization between the ventilation and cardiac output responses at an initial period of transitions from rest to exercise and from exercise to rest seems to support the concept of cardiodynamic hyperpnea.
在健康男性志愿者进行从0至360和720千帕米/分钟的直立自行车运动前、运动期间和运动后,同时测量每搏输出量、心率、心输出量、潮气量、呼吸频率、分钟通气量、呼气末O₂和CO₂张力、O₂摄取量、CO₂排出量以及呼吸交换率。循环变量每20个心动周期连续测定一次,呼吸变量逐次呼吸测定,使用装有阻抗呼吸描记器和阻抗心动描记器的独立计算机系统。每搏输出量、心率和心输出量在运动开始时立即开始增加,无明显延迟。最轻微运动时,每搏输出量比静息对照值增加20%,随着工作负荷进一步增加,每搏输出量基本趋于平稳。心输出量的时间常数随工作负荷增加而增加。分钟通气量的时间常数比心输出量的时间常数长得多,且与工作强度无关。从静息到运动以及从运动到静息的过渡初期,通气和心输出量反应之间的良好同步似乎支持心动力性呼吸增强的概念。