陈-施呼吸(Cheyne-Stokes Respiration,CSR)是一种异常呼吸方式,在心衰患者中的发病率约占50%。尽管CSR的发现迄今已有一百多年的历史,但其发生机制至今仍不十分清楚。一些临床研究表明,外周化学感受器反射敏感性增加可能在心衰时的呼吸调控中起重要的作用。心衰时压力感受器敏感性的降低也被许多研究所证实。由于临床研究的局限性,CSR的发生是否与外周化学感受器反射敏感性增加有关尚不能确定。目的:旨在探讨选择性颈动脉体去除(selective carotid body denervation,CBD)是否能够抑制CSR的发生以及增加压力感受
Background -Heart failure is characterized by increased ventilation during exercise, which is positively related to increased peripheral and central chemoreceptor sensitivity. Heart transplantation does not normalize ...
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Background -Heart failure is characterized by increased ventilation during exercise, which is positively related to increased peripheral and central chemoreceptor sensitivity. Heart transplantation does not normalize the ventilatory response to exercise, and its effects on the chemoreflex control of ventilation remain unknown. We tested the hypothesis that chemoreceptor sensitivity is increased in heart transplant recipients(HTRs)and linked to exercise hyperpnea. Methods and Results -We determined the ventilatory, muscle sympathetic nerve activity(MSNA), and circulatory responses to isocapnic hypoxia and hyperoxic hypercapnia 7±1 years after transplantation in 19 HTRs with a normal left ventricular ejection fraction of 60±2%. Results were compared with those of 11 closely matched referent subjects. Sixteen patients and 10 referent subjects also underwent cycle ergometer exercise tests. HTRs compared with referent subjects presented higher MSNA(52±4 versus 34±3 bursts/min; P< 0.01) and heart rates(83±3 versus 68±3 bpm; P< 0.01) during room air breathing. The ventilatory response to hypoxia was higher in HTRs than in referent subjects(P< 0.01, ANOVA). The increase in MSNA also was more marked during hypoxia in the HTRs than in the referent group(P< 0.05, ANOVA). Responses to hyperoxic hypercapnia did not differ between the HTRs and the referent group. The ventilatory response to exercise, characterized by the regression slope relating minute ventilation to CO2 output, was steeper in HTRs than in referent subjects(38±2 versus 29±1 L/mm Hg; P< 0.01). Exercise ventilation in HTRs was related to the ventilatory response to isocapnic hypoxia(r=0.57; n=16; P< 0.05) and to the ventilatory response to hyperoxic hypercapnia(r=0.50; n=16; P< 0.05). Conclusions -Peripheral chemoreceptor sensitivity is increased in HTRs and is related to exercise hyperpnea after heart transplantation.
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