Newton Julia L, Allen John, Kerr Simon, Jones David E J
Cardiovascular Investigation Unit, School of Clinical Medical Sciences, University of Newcastle, Newcastle upon Tyne, UK.
Liver Int. 2006 Mar;26(2):197-202. doi: 10.1111/j.1478-3231.2005.01214.x.
Standardized mortality ratio for primary biliary cirrhosis (PBC) is 2.87. Even after accounting for liver and cancer-related deaths there is an unexplained excess mortality associated with PBC. We have assessed heart rate variability (HRV) and baroreflex sensitivity (BRS) risk factors associated with cardiovascular mortality, in 57 PBC patients and age- and sex-matched normal controls.
HRV and BRS were measured non-invasively in subjects and controls. Beat to beat RR interval and 'Portapres' blood pressure data were processed using power spectral analysis. Power was calculated in very low frequency (VLF), low-frequency (LF) and high-frequency (HF) bands according to international guidelines. BRS (alpha) was computed using cross-spectrum analysis. Patients also underwent fatigue severity assessment using a measure validated for use in PBC.
PBC patients had significantly lower total HRV compared with controls (P=0.02), with the reduction occurring predominantly in the LF domain (P=0.03). BRS was also significantly reduced compared with controls (P=0.02). There were no significant differences in HRV or BRS between cirrhotic and non-cirrhotic patients. Within the PBC patient group HRV was significantly lower in fatigued than in non-fatigued patients (P<0.05).
Abnormalities of HRV and BRS in PBC are not specific to advanced disease but are associated with fatigue severity. Abnormalities could be associated with increased risk of sudden cardiac death, potentially contributing to the excess mortality seen in PBC.
原发性胆汁性肝硬化（PBC）的标准化死亡率为2.87。即使在考虑了肝脏和癌症相关死亡因素之后，PBC仍存在无法解释的额外死亡率。我们评估了57例PBC患者以及年龄和性别匹配的正常对照者中与心血管死亡率相关的心率变异性（HRV）和压力反射敏感性（BRS）危险因素。
对受试者和对照者进行HRV和BRS的无创测量。使用功率谱分析处理逐搏RR间期和“ Portapres”血压数据。根据国际指南，计算极低频（VLF）、低频（LF）和高频（HF）频段的功率。使用互谱分析计算BRS（α）。患者还使用经过验证可用于PBC的方法进行了疲劳严重程度评估。
与对照组相比，PBC患者的总HRV显著降低（P = 0.02），主要在LF域降低（P = 0.03）。与对照组相比，BRS也显著降低（P = 0.02）。肝硬化和非肝硬化患者之间的HRV或BRS没有显著差异。在PBC患者组中，疲劳患者的HRV显著低于非疲劳患者（P <0.05）。
PBC患者的HRV和BRS异常并非晚期疾病所特有，而是与疲劳严重程度相关。这些异常可能与心源性猝死风险增加有关，可能是导致PBC患者额外死亡率的原因。
