Genese der Atemeffizienzstörung unter Belastung bei Patienen mit chronischer Herzinsuffizienz: Rolle der pulmonalen Perfusion und einer veränderten kardiorespiratorischen Reflexaktivierung

呼吸效率降低(以通气量与二氧化碳排出量之间的线性回归线斜率[VE/VCO2-斜率]衡量)是慢性心力衰竭的一个关键特征。在这些患者的预后评估中，它与患者的症状状态、月食甚至峰值耗氧量密切相关。肺泡死腔通风是心力衰竭患者VE/VCO2斜率增加的主要原因，肺泡死腔通风是肺血流分布不均匀的结果。目前尚不清楚这是反映了原发性肺血管病变，还是仅仅反映了运动时未能充分增加心输出量。过度换气另一个导致VE/VCO2斜率增加的因素被认为是运动中异常的换气刺激，即肌肉-麦角反射的激活。到目前为止，它与心输出量的关系还没有得到研究。因此，我们旨在研究心输出量的急、慢性变化对慢性心力衰竭患者肺泡死腔通气量、麦角反射激活和运动性过度通气量的影响。

Reduced ventilatory efficiency (as measured as the slope of the linear regression line relating ventilation to carbon dioxide output [VE/VCO2-slope]) is a key feature of chronic heart failure. It is closely associated with patients¿ symptom state and eclipses even peak oxygen consumption in the prognostic assessment of these patients. Alveolar dead space ventilation, which results from an uneven pulmonary blood flow distribution, is the major contributor to the increased VE/VCO2-slope in heart failure. It is unclear whether it reflects a primary pulmonary vascular pathology or simply the failure to adequately increase cardiac output during exercise. Hyperventilation another contributor to an increased VE/VCO2-slope is thought to arise from abnormal ventilatory stimuli, namely muscle-ergoreflex activation, during exercise. Its relation to cardiac output has not been investigated so far. We, therefore, aim to investigate the effects of acute and chronic changes in cardiac output on alveolar dead space ventilation, ergoreflex activation and exercise induced hyperventilation in patients with chronic heart failure.