Clark A L, Poole-Wilson P A, Coats A J
Department of Cardiac Medicine, National Heart and Lung Institute, London, England.
J Am Coll Cardiol. 1992 Nov 15;20(6):1326-32. doi: 10.1016/0735-1097(92)90244-h.
The aim of this study was to analyze the relation between ventilation and carbon dioxide production and the control of ventilation in patients with chronic heart failure.
Patients with chronic heart failure exhibit an increased ventilatory response to exercise. Ventilation is closely linked to carbon dioxide production, producing a high correlation between the two variables. This relation is nonlinear at high levels of exercise.
The ventilation/carbon dioxide production ratio during exercise was examined in 29 patients with chronic heart failure and 9 normal volunteers.
In the patients with heart failure, there were three patterns: in the least severely affected patients, the pattern was similar to that of the normal subjects, with an initial decrease in the ventilation/carbon dioxide production ratio to a plateau maintained during exercise; in more severely affected patients, there was an increase in the ratio at the end of exercise, and in the most severely affected patients, the ratio increased from the outset of exercise. The ventilation/carbon dioxide relation is not adequately described by a straight line relation.
The ventilation/carbon dioxide ratio is not fixed, and the changes that occur in this ratio reflect either a noncarbon dioxide-driven ventilatory stimulus or an increase in ventilation-perfusion mismatch due to increased dead space ventilation. The different patterns of this ratio may provide clues to the pathophysiologic mechanisms of the excessive ventilation and breathlessness seen during exercise in chronic heart failure.
本研究旨在分析慢性心力衰竭患者通气与二氧化碳产生之间的关系以及通气控制情况。
慢性心力衰竭患者对运动的通气反应增强。通气与二氧化碳产生密切相关，这两个变量之间存在高度相关性。在高强度运动时，这种关系呈非线性。
对29例慢性心力衰竭患者和9名正常志愿者在运动期间的通气/二氧化碳产生比值进行了检测。
心力衰竭患者存在三种模式：在病情最轻的患者中，模式与正常受试者相似，通气/二氧化碳产生比值最初下降，在运动期间维持在一个平台期；在病情较重的患者中，运动结束时该比值升高；在病情最重的患者中，该比值从运动开始就升高。通气/二氧化碳关系不能用直线关系充分描述。
通气/二氧化碳比值并非固定不变，该比值发生的变化反映了非二氧化碳驱动的通气刺激或由于无效腔通气增加导致的通气-灌注不匹配增加。该比值的不同模式可能为慢性心力衰竭患者运动期间过度通气和呼吸困难的病理生理机制提供线索。
