Autonomic and cardiac dysfunction is frequent in cirrhosis, and includes increased sympathetic nervous activity, impaired heart rate variability (HRV) and baroreflex sensitivity (BRS). Quantified 123I-metaiodobenzylguanidine (mIBG) scintigraphy reflects cardiac noradrenaline uptake and in patients with cardiac failure it predicts outcome. In this study we aimed to investigate cardiac sympathetic function in cirrhosis by mIBG scintigraphy in relation to cardiovascular function. Ten patients with cirrhosis and 10 matched healthy controls participated in the study. Heart/mediastinum (H/M) ratios of mIBG uptake were calculated 15 and 230 minutes after intravenous injection of mIBG. Furthermore, washout rate (WOR) of mIBG was calculated. The patients underwent a liver vein catherization with determination of splanchnic and systemic haemodynamics and measurement of HRV and BRS. mIBG-scintigraphy revealed significantly increased WOR in patients with cirrhosis compared to controls (p<0.005), whereas H/M-uptakes were equal in the groups. Forty percent of the patients had reduced uptake of mIBG in the infero-lateral segment of the left ventricle. WOR correlated significantly with central circulation time, an estimate of central hypovolaemia (r=-0.64, P<0.05) and frequency-corrected QTF interval (r=0.71, p=0.01). Patients with cirrhosis had significantly decreased HRV and BRS correlating with indicators of abnormal cathecholamine up-take by mIBG although the catecholamine level was normal in the patients. In conclusion, in alcoholic cirrhosis, mIBG-scintigraphy reveals autonomic dysfunction and impaired myocardial distribution of sympathetic nervous activity. It is associated to indicators of central hypovolaemia, QT-interval, decreased HRV and BRS. Measurement of myocardial catecholamine-uptake by mIBG may add important information on autonomic and cardiac dysfunction in cirrhosis.
|American Journal of Physiology: Gastrointestinal and Liver Physiology
|Udgivet - 2012