Laffi G, Lagi A, Cipriani M, Barletta G, Bernardi L, Fattorini L, Melani L, Riccardi D, Bandinelli G, Mannelli M, La Villa G, Gentilini P
Dipartimento di Medicina Interna, Ospedale Santa Maria Nuova, Florence, Italy.
Hepatology. 1996 Nov;24(5):1063-7. doi: 10.1053/jhep.1996.v24.pm0008903376.
The autonomic regulation of cardiovascular function was evaluated in 15 cirrhotic patients with ascites and in 13 healthy subjects by the autoregressive power spectral analysis (PSA) of the intervals between adjacent R waves of the electrocardiogram (RR) interval and arterial pressure variability. Total power, low frequency (LF; index of the sympathetic activity of the heart and circulation), and high frequency (HF; index of vagal tone to the heart) components of the RR interval, systolic, and diastolic arterial pressure were evaluated in the supine position and during passive tilting, together with plasma norepinephrine levels. In the supine position, no significant differences in the PSA data were observed between the control subjects and cirrhotic patients, who had higher plasma norepinephrine levels. In healthy subjects, tilting was associated with an increase in the LF of the RR interval and arterial pressure and a decrease in the HF of the RR interval. In contrast, patients with cirrhosis showed a decrease of both LF and HF. Consequently, the LF/HF ratio significantly increased in healthy subjects, whereas it was unchanged in cirrhotic patients. The LF component of the diastolic pressure also decreased during tilting in cirrhotic patients. Plasma norepinephrine increased after tilting in both groups. These results indicate that the autonomic response to passive tilting is impaired in cirrhotic patients with ascites at both the cardiac and vascular levels, as a result of an altered sympatho-vagal balance, with reduced sympathetic predominance. These alterations occurred despite an appropriate response to the tilting of plasma norepinephrine, pointing to a receptorial or postreceptorial site of the autonomic impairment.
通过对心电图相邻R波间期（RR间期）和动脉压变异性进行自回归功率谱分析（PSA），评估了15例肝硬化腹水患者和13名健康受试者的心血管功能自主调节情况。在仰卧位和被动倾斜过程中，评估RR间期、收缩压和舒张压的总功率、低频（LF；心脏和循环交感神经活动指标）和高频（HF；心脏迷走神经张力指标）成分，同时检测血浆去甲肾上腺素水平。在仰卧位时，对照组受试者和血浆去甲肾上腺素水平较高的肝硬化患者之间的PSA数据未观察到显著差异。在健康受试者中，倾斜与RR间期和动脉压的LF增加以及RR间期的HF降低有关。相比之下，肝硬化患者的LF和HF均降低。因此，健康受试者的LF/HF比值显著增加，而肝硬化患者则无变化。肝硬化患者在倾斜过程中舒张压的LF成分也降低。两组在倾斜后血浆去甲肾上腺素均升高。这些结果表明，由于交感-迷走平衡改变，交感优势减弱，肝硬化腹水患者在心脏和血管水平对被动倾斜的自主反应受损。尽管对血浆去甲肾上腺素的倾斜有适当反应，但这些改变仍然发生，这表明自主神经损伤位于感受器或感受器后部位。
