Ponikowski P, Chua T P, Piepoli M, Banasiak W, Anker S D, Szelemej R, Molenda W, Wrabec K, Capucci A, Coats A J
Cardiac Medicine Department, Imperial College National Heart and Lung Institute, London, United Kingdom.
Am J Cardiol. 1998 Aug 1;82(3):338-44. doi: 10.1016/s0002-9149(98)00303-8.
In chronic congestive heart failure (CHF) an overactivity of muscle ergoreceptors and peripheral chemoreceptors may lead to an increased ventilatory response to exercise and contribute to the autonomic imbalance. The analysis of heart rate variability (HRV), which is a reliable method of studying autonomic regulations within the cardiovascular system, showed depressed HRV indexes in CHF, but predictors of abnormal HRV pattern in CHF remain controversial. Considering a common mechanism involved in generation of both abnormal ventilation and autonomic dysfunction in CHF, we hypothesized that impaired ventilation may be better than other variables of CHF severity in determining HRV parameters. Seventy-two patients with CHF (57+/-9 years, ejection fraction: 28+/-11%) underwent cardiopulmonary exercise testing; the relation between ventilation and carbon dioxide production (VE/VCO2) was used as an index of the ventilatory response to exercise. Time and frequency-domain measurements of HRV were derived from 24-hour electrocardiographic monitoring. Patients had reduced exercise tolerance with abnormal ventilatory response (peak oxygen consumption [VO2max]: 17.8+/-5.5 ml/kg/min, VE/VCO2: 36.0+/-9.8). Correlations were found between HRV measures and etiology, New York Heart Association (NYHA) functional class, and VO2max, but the strongest relation was observed for VE/VCO2 slope (r values from -0.33 to -0.65, p <0.01). In the multiple regression analysis only VE/VCO2 was found to correlate independently with all HRV measurements. To investigate the role of peripheral chemoreceptor overactivity as the mechanism of autonomic imbalance and the increased ventilatory response to exercise, we assessed peripheral chemosensitivity in 22 patients (mean value of peripheral chemosensitivity: 0.62+/-0.34 L/min/%SaO2, significantly higher than in normal controls, mean value: 0.29+/-0.20 L/min/%SaO2 in our laboratory). The activity of the peripheral chemoreflex inversely correlated with all parameters of HRV. Increased ventilatory response to exercise correlated with depressed HRV measures in patients with CHF better than other clinical variables. An important role of the increased peripheral chemosensitivity in this relation may be relevant, being also a potential link between functional severity and sympathovagal imbalance in CHF.
在慢性充血性心力衰竭（CHF）中，肌肉运动感受器和外周化学感受器的过度活跃可能导致运动时通气反应增加，并促成自主神经失衡。心率变异性（HRV）分析是研究心血管系统内自主神经调节的可靠方法，结果显示CHF患者的HRV指标降低，但CHF中HRV异常模式的预测因素仍存在争议。考虑到CHF中异常通气和自主神经功能障碍产生的共同机制，我们假设在确定HRV参数方面，通气功能受损可能比CHF严重程度的其他变量更具优势。72例CHF患者（年龄57±9岁，射血分数：28±11%）接受了心肺运动试验；通气与二氧化碳产生量的关系（VE/VCO2）被用作运动通气反应的指标。HRV的时域和频域测量值来自24小时心电图监测。患者运动耐量降低，通气反应异常（峰值耗氧量[VO2max]：17.8±5.5 ml/kg/min，VE/VCO2：36.0±9.8）。发现HRV测量值与病因、纽约心脏协会（NYHA）功能分级和VO2max之间存在相关性，但与VE/VCO2斜率的关系最为密切（r值在-0.33至-0.65之间，p<0.01）。在多元回归分析中，仅发现VE/VCO2与所有HRV测量值独立相关。为了研究外周化学感受器过度活跃作为自主神经失衡和运动通气反应增加的机制的作用；我们评估了这22例患者的外周化学敏感性（外周化学敏感性平均值：0.62±0.34 L/min/%SaO2，显著高于正常对照组，我们实验室的平均值：0.29±0.20 L/min/%SaO2）。外周化学反射的活性与HRV的所有参数呈负相关。与其他临床变量相比，CHF患者运动通气反应增加与HRV测量值降低的相关性更好。外周化学敏感性增加在这种关系中的重要作用可能具有相关性，它也是CHF功能严重程度与交感迷走神经失衡之间的潜在联系。
