Service of Cardiology, Internal Medicine Clinic, University Clinical Centre of Kosova, Prishtina, Kosovo.
Int J Cardiol. 2011 Feb 3;146(3):385-9. doi: 10.1016/j.ijcard.2009.07.018. Epub 2009 Aug 20.
Six minute walking test (6-MWT) may serve as a reproducible test for assessing exercise capacity in heart failure (HF) patients and can be clinically predicted. We aimed in this study to ascertain if global markers of ventricular asynchrony can predict 6MWT distance in a group of patients with HF and left ventricular (LV) ejection fraction (EF) <45%.
This study included 77 consecutive patients (60 ± 12 years) with stable HF. LV end-diastolic and end-systolic dimensions, shortening fraction (SF), EF, myocardial velocities, t-IVT, and Tei index were measured, as well as 6-MWT distance. Patients with limited exercise performance (≤ 300 m) had lower SF (p = 0.02) and EF (p = 0.017), longer t-IVT (p = 0.001), higher Tei index (p = 0.002) and higher E/E' ratio (p < 0.001) compared with good performance patients. In multivariate analysis, only E/E' ratio [0.800 (0.665-0.961), p = 0.017], and t-IVT [0.769 (0.619-0.955), p = 0.018] independently predicted poor exercise performance.
In heart failure patients, the higher the filling pressures and the more asynchronous the left ventricle, the poorer is the patient's exercise capacity. These findings highlight specific LV functional disturbances that should be targeted for better optimization of medical and/or electrical therapy.
六分钟步行试验（6-MWT）可作为评估心力衰竭（HF）患者运动能力的一种可重复的测试方法，并且可以进行临床预测。本研究旨在确定心室不同步的整体标志物是否可以预测一组左心室射血分数（EF）<45%的 HF 患者的 6MWT 距离。
这项研究纳入了 77 例连续稳定的 HF 患者（60±12 岁）。测量了 LV 舒张末期和收缩末期内径、缩短分数（SF）、EF、心肌速度、t-IVT 和 Tei 指数以及 6MWT 距离。运动能力受限（≤300m）的患者 SF（p=0.02）和 EF（p=0.017）较低，t-IVT（p=0.001）较长，Tei 指数（p=0.002）和 E/E'比值（p<0.001）较高。多变量分析表明，只有 E/E'比值[0.800（0.665-0.961），p=0.017]和 t-IVT[0.769（0.619-0.955），p=0.018]独立预测运动能力差。
在心力衰竭患者中，充盈压越高，左心室不同步越严重，患者的运动能力越差。这些发现突出了特定的 LV 功能障碍，应针对这些障碍进行治疗，以更好地优化药物和/或电疗。
