Kamath Sandeep A, Drazner Mark H, Tasissa Gudaye, Rogers Joseph G, Stevenson Lynne Warner, Yancy Clyde W
University of Texas Southwestern Medical Center, Dallas, TX 75390-9047, USA.
Am Heart J. 2009 Aug;158(2):217-23. doi: 10.1016/j.ahj.2009.06.002.
Impedance cardiography (ICG) is a noninvasive modality that uses changes in impedance across the thorax to assess hemodynamic parameters, including cardiac output (CO). The utility of ICG in patients hospitalized with heart failure is uncertain.
The BioImpedance CardioGraphy in Advanced Heart Failure study was a prospective substudy of the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness. A total of 170 subjects underwent blinded ICG measurements using BioZ (CardioDynamics, San Diego, CA); of these, 82 underwent right heart catheterization. We compared ICG with invasively measured hemodynamics by simple correlation and compared overall ICG hemodynamic profiles ("wet" [thoracic fluid content > or =47/kOhm in men and > or =37/kOhm in women] and "cold" [cardiac index < or =2.2 L min(-1)m(-2)) versus those determined by invasive measurements (wet [pulmonary capillary wedge pressure > or =22 mm Hg] and cold [cardiac index < or =2.2 L min(-1)m(-2)). We also determined whether ICG measurements were associated with subsequent death or hospitalization within 6 months.
There was modest correlation between ICG and invasively measured CO (r = 0.4 to 0.6 on serial measurement). Thoracic fluid content measured by ICG was not a reliable measure of pulmonary capillary wedge pressure. There was poor agreement between ICG and invasively measured hemodynamic profiles (kappa < or =0.1). No ICG variable alone or in combination was associated with outcome.
In hospitalized patients with advanced heart failure, ICG provides some information about CO but not left-sided filling pressures. Impedance cardiography did not have prognostic utility in this patient population.
阻抗心动图（ICG）是一种非侵入性检查方法，利用胸部阻抗变化来评估包括心输出量（CO）在内的血流动力学参数。ICG在心力衰竭住院患者中的应用价值尚不确定。
晚期心力衰竭生物阻抗心动图研究是充血性心力衰竭和肺动脉导管插入术有效性评估研究的一项前瞻性子研究。共有170名受试者使用BioZ（加利福尼亚州圣地亚哥市CardioDynamics公司）进行了盲法ICG测量；其中82人接受了右心导管插入术。我们通过简单相关性比较了ICG与有创测量的血流动力学，并比较了ICG总体血流动力学特征（“湿”[男性胸液含量≥47/kΩ，女性≥37/kΩ]和“冷”[心脏指数≤2.2 L·min⁻¹·m⁻²]）与有创测量确定的特征（“湿”[肺毛细血管楔压≥22 mmHg]和“冷”[心脏指数≤2.2 L·min⁻¹·m⁻²]）。我们还确定了ICG测量是否与随后6个月内的死亡或住院相关。
ICG与有创测量的CO之间存在中等程度的相关性（系列测量时r = 0.4至0.6）。ICG测量的胸液含量不是肺毛细血管楔压的可靠指标。ICG与有创测量的血流动力学特征之间一致性较差（kappa≤0.1）。没有单独或联合的ICG变量与预后相关。
在晚期心力衰竭住院患者中，ICG可提供一些关于CO的信息，但不能提供左侧充盈压信息。阻抗心动图在该患者群体中没有预后价值。
