Macey Paul M, Valderama Claire, Kim Amy H, Woo Mary A, Gozal David, Keens Thomas G, Harper Rebecca K, Harper Ronald M
Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, Los Angeles, CA 90095-1763, USA.
Pediatr Res. 2004 Jun;55(6):953-9. doi: 10.1203/01.PDR.0000125262.82405.3C. Epub 2004 Mar 17.
Congenital central hypoventilation syndrome (CCHS) patients exhibit respiratory deficits to ventilatory challenges, diminished breathing drive during sleep, and reduction of respiratory-related heart rate variation, but at least partially preserved peripheral chemoreception. We hypothesized that integration of afferent activity with respiratory motor output is deficient in CCHS, rather than chemoreceptor failure, and that examination of trends in heart and breathing rates and variabilities following ventilatory challenges may clarify the deficient mechanisms. Twelve children with CCHS and 12 age- and gender-matched control cases were subjected to hyperoxic hypercapnic, poikylocapnic hypoxic, and hyperoxic challenges while supine. Heart and respiratory rates and variabilities during 60-s baseline and 120-s challenge periods were assessed. Hypoxia and hypercapnia enhanced breathing rate in control subjects; in CCHS cases, the rise differed during hypercapnia and did not occur to hypoxia. Hyperoxia showed initial transient patterns in breathing rate that differed between groups. A heart rate increase to hypoxia and late decline to hyperoxia were muted in CCHS patients. In hypercapnia, heart rate followed similar rising patterns in both groups. Overall CCHS heart rate variability was lower in baseline and challenge periods, principally due to diminished respiratory-related variation, especially during hypercapnia. No heart rate variability group differences emerged in hypoxia, and only a late increase for CCHS cases developed in hyperoxia. The findings indicate retention of aspects of chemoreceptor sensitivity in CCHS cases. The heart rate alterations to ventilatory challenges suggest specific compensatory responses of a slower nature remain intact in CCHS, whereas other rapidly changing components are deficient.
先天性中枢性低通气综合征（CCHS）患者在面对通气挑战时表现出呼吸功能缺陷、睡眠期间呼吸驱动力减弱以及呼吸相关心率变异性降低，但外周化学感受至少部分保留。我们假设，CCHS患者传入活动与呼吸运动输出的整合存在缺陷，而非化学感受器功能衰竭，并且在通气挑战后检查心率、呼吸频率及其变异性的趋势可能会阐明缺陷机制。12名患有CCHS的儿童和12名年龄及性别匹配的对照病例在仰卧位时接受了高氧高碳酸血症、变碳酸血症性低氧血症和高氧挑战。评估了60秒基线期和120秒挑战期内的心率、呼吸频率及其变异性。低氧和高碳酸血症可提高对照受试者的呼吸频率；在CCHS病例中，高碳酸血症期间呼吸频率的升高有所不同，低氧时则未出现升高。高氧时两组呼吸频率均呈现初始短暂模式。CCHS患者对低氧的心率增加及对高氧的后期下降均减弱。在高碳酸血症时，两组心率呈现相似的上升模式。总体而言，CCHS患者在基线期和挑战期的心率变异性较低，主要是由于呼吸相关变异性降低，尤其是在高碳酸血症期间。低氧时两组心率变异性无差异，高氧时CCHS病例仅出现后期增加。这些发现表明CCHS病例中化学感受器敏感性的某些方面得以保留。通气挑战引起的心率改变表明，CCHS患者中较慢性质的特定代偿反应仍然完整，而其他快速变化的成分存在缺陷。
