Center. of Functional Imaging and Research, Department of Clinical Physiology and Nuclear Medicine, Hvidovre Hospital, Kettegaard Alle 30, DK-2650 Hvidovre, Copenhagen, Denmark.
Am J Physiol Gastrointest Liver Physiol. 2012 Dec 1;303(11):G1228-35. doi: 10.1152/ajpgi.00303.2012. Epub 2012 Sep 27.
Autonomic and cardiac dysfunction is frequent in cirrhosis and includes increased sympathetic nervous activity, impaired heart rate variability (HRV), and baroreflex sensitivity (BRS). Quantified (123)I-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 neuronal function in cirrhosis by mIBG scintigraphy in relation to cardiovascular function. Ten patients with alcoholic cirrhosis and 10 age- and sex-matched healthy controls participated in the study. Heart/mediastinum (H/M) ratios of mIBG uptake were calculated 15 and 230 min after intravenous injection of mIBG. Furthermore, washout rate (WOR) of mIBG was calculated. The patients underwent a liver vein catheterization with determination of splanchnic and systemic hemodynamics and measurement of HRV and BRS. mIBG-scintigraphy revealed significantly increased WOR in patients with cirrhosis compared with 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 hypovolemia (r = -0.64, P < 0.05) and frequency-corrected QT(F) interval (r = 0.71, P = 0.01). Patients with cirrhosis had significantly decreased HRV and BRS correlating with indicators of abnormal cathecholamine uptake 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 hypovolemia, QT interval, and decreased HRV and BRS. Measurement of myocardial catecholamine uptake by mIBG may add important information on autonomic and cardiac dysfunction in cirrhosis.
自主和心脏功能障碍在肝硬化中很常见，包括交感神经活动增加、心率变异性（HRV）受损和压力反射敏感性（BRS）受损。量化的（123）I-间碘苄胍（mIBG）闪烁显像反映了心脏去甲肾上腺素摄取，并且在心力衰竭患者中预测预后。在这项研究中，我们旨在通过 mIBG 闪烁显像研究肝硬化患者的心脏交感神经功能与心血管功能的关系。10 例酒精性肝硬化患者和 10 例年龄和性别匹配的健康对照者参加了这项研究。静脉注射 mIBG 后 15 和 230 分钟计算 mIBG 摄取的心脏/纵隔（H/M）比值。此外，还计算了 mIBG 的洗脱率（WOR）。患者接受肝静脉导管插入术，以确定内脏和全身血液动力学，并测量 HRV 和 BRS。与对照组相比，肝硬化患者的 mIBG 闪烁显像显示 WOR 明显增加（P < 0.005），而两组的 H/M 摄取量相等。40%的患者左心室下外侧节段的 mIBG 摄取减少。WOR 与中央循环时间显著相关，中央低血容量的估计值（r = -0.64，P < 0.05）和频率校正 QT（F）间隔（r = 0.71，P = 0.01）。尽管患者的儿茶酚胺水平正常，但肝硬化患者的 HRV 和 BRS 显著降低，与 mIBG 异常儿茶酚胺摄取的指标相关。总之，在酒精性肝硬化中，mIBG 闪烁显像显示自主神经功能障碍和心肌交感神经活动分布受损。它与中央低血容量、QT 间隔以及 HRV 和 BRS 降低的指标相关。通过 mIBG 测量心肌儿茶酚胺摄取可能会增加肝硬化自主和心脏功能障碍的重要信息。
