Autonomic nervous system tone measured by baroreflex sensitivity is depressed in patients with end-stage liver disease

OBJECTIVES: Chronic liver disease is often associated with impairment of au tonomic nervous system (ANS) reflexes. Baroreflex sensitivity (BRS) testing is an inexpensive, relatively noninvasive test that can be used to assess ANS tone. The aims of the present study were to determine the prevalence of ANS dysfunction in cirrhotics who are being considered for liver transplan tation and to explore the potential use of BRS as a prognostic tool in iden tifying patients awaiting transplantation who are at increased risk for dea th. METHODS: We studied nine cirrhotics who were awaiting liver transplantation and seven controls without liver disease. BRS (ms/mm Hg) was measured usin g the phenylephrine method. RESULTS: BR (mean +/- SEM) (ms/mm Hg) was significantly lower in cirrhotics compared with controls (4.2 +/- 0.9 vs 21.1 +/- 3.8 ms/mm Hg; p < 0.05). F urthermore, BRS was lower in cirrhotics with hepatic encephalopathy compare d with those without (2.6 +/- 0.9 vs 6.1 +/- 1.0 ms/mm Hg, p < 0.05) and th ere was a trend toward lower BRS values in Child-Pugh class C patients as c ompared with class B (3.8 +/- 1.3 ts 5.3 +/- 1.2 ms/mm Hg; p = 0.3). At fol low-up (9 months), one patient had died and one underwent liver transplanta tion. These two patients also had the most severely impaired vagal tone (BR S = 0 and 1.2 ms/mm Hg, respectively). CONCLUSIONS: Vagal tone, as assessed by BRS, is markedly depressed in cirrh otic patients awaiting liver transplantation. (C) 1999 by Am. Cell. of Gast roenterology.