Liver Fibrosis: What's the Beginning of Autonomic Deficit?

Histologic diagnoses were made using standard criteria and two independent observers scored all samples using the Scheuer staging system (3). We distinguished between patients affected by moderate e brosis (scores 2 and 3) and those affected by severe e brosis, corresponding to cirrhosis (score 4). Cardiac index was determined using pulsed-wave Doppler echocardiography (Hewlett-Packard Sonos 2000, Andover, Mass., USA). Peripheral vascular resistance (PVR) was calculated as the mean arterialpressure/cardiacoutput £80.Heartratevariabilitywas evaluated in the frequency domain using appropriate software (Rozinn Electronics H4W 3.6F, Glendale, N.Y., USA). A series of consecutive 5-min intervals was calculated from the Holter ECG as a function of beat numbers. Power spectral analysis of the intervals between adjacent R waves of the electrocardiogram (RR) was performed using the fast Fourier transform mathematical function (5). Low frequency (LF; 0.04‐0.15 Hz) and high frequency (HF; 0.15‐0.40 Hz) spectral powers and the ratio of LF to HF (LF/HF) were calculated and expressed in normalized units (nU). The recordings were obtained with 5 min in the supine position and 5 min in passive head-up tilt (70°). Statistical analysis was performed using an appropriate t test. P values lower than 0.05 were regarded as statistically signie cant. None of the patients included in this study, with either chronic viral hepatitis or with cirrhosis, showed evidence of hyperdynamic circulation. Cardiac index and peripheral vascular resistances were not signie cantly different from those of healthy subjects. Moreover, our results showed no differences between patients and controls in mean systolic and diastolic arterial pressures, either in the supine or in the tilt position. The power spectral analysis showed the occurrence of a