Medizinische Klinik und Poliklinik I, Universitätsklinikum, Oberdürrbacher Strasse 6, 97080 Würzburg, Germany.
Europace. 2010 May;12(5):731-40. doi: 10.1093/europace/eup413. Epub 2010 Jan 6.
Heart failure patients are often equipped with implanted devices and are frequently hospitalized due to volume overload. Reliable prediction of imminent fluid congestion has the potential to provide early detection of cardiac decompensation and therefore might be capable of enhancing therapy management. We investigated whether implant-based impedance (Z) measurement is closely correlated with directly assessed extravascular lung water and might thus be useful for patient monitoring.
In sheep, pulmonary fluid congestion was induced. Continuous haemodynamic monitoring was performed and extravascular lung water index (EVLWI) assessed. An implanted device with a right ventricular lead measured Z using different electrode configurations. All animals developed gradual pulmonary fluid accumulation leading to inclining lung oedema: EVLWI did increase from 9.5 +/- 1 to 21.1 +/- 5.1 mL/kg (+127%). A concomitant decrease of Z by up to 23%, depending on the electrode configuration, was observed and regression analysis between Z and EVLWI yielded a significant inverse correlation.
Changes of Z show a strong inverse correlation with changes of directly measured EVLWI. This allows the application of Z as a measure of intrathoracic fluid status and has the potential to optimize patient care, especially in the context of evolving telemedicine concepts.
心力衰竭患者通常配备有植入式设备，并且由于容量超负荷而经常住院。可靠地预测即将发生的液体蓄积有可能提供心脏失代偿的早期检测，因此可能能够增强治疗管理。我们研究了基于植入物的阻抗（Z）测量是否与直接评估的血管外肺水密切相关，因此可能对患者监测有用。
在绵羊中诱导肺液充血。进行连续血流动力学监测并评估血管外肺水指数（EVLWI）。带有右心室导联的植入式设备使用不同的电极配置测量 Z。所有动物均逐渐发生肺液积聚，导致肺水肿加重：EVLWI 从 9.5±1 增加到 21.1±5.1 mL/kg（增加 127%）。观察到 Z 相应地降低了 23%，这取决于电极配置，并且 Z 与 EVLWI 之间的回归分析显示出显著的负相关。
Z 的变化与直接测量的 EVLWI 的变化呈强烈的负相关。这允许将 Z 用作胸腔内液体状态的测量指标，并有可能优化患者护理，特别是在不断发展的远程医疗概念的背景下。
