Takaya Yoichi, Taniguchi Manabu, Sugawara Motoaki, Nobusada Saori, Kusano Kengo, Akagi Teiji, Ito Hiroshi
Department of Cardiovascular Medicine, Okayama UniversityGraduate School of Medicine, 2-5-1 Shikata-cho, Kita-ku,Okayama 700-8558, Japan.
Heart Vessels. 2013 Mar;28(2):179-87. doi: 10.1007/s00380-011-0224-3.
Impaired exercise capacity has been found in patients with diastolic dysfunction with preserved systolic function. Although conventional transthoracic echocardiography (TTE) provides useful clinical information about systolic and diastolic cardiac function, its capability to evaluate exercise capacity has been controversial. The inertia force of late systolic aortic flow is known to have a tight relationship with left ventricular (LV) performance during the period from near end-systole to isovolumic relaxation. The inertia force and the time constant of LV pressure decay during isovolumic relaxation can be estimated noninvasively using the second peak (W(2)) of wave intensity (WI), which is measured with an echo-Doppler system. We sought to determine whether W(2) is associated with exercise capacity in patients with chronic heart failure with normal ejection fraction (HFNEF) and to compare its ability to predict exercise capacity with parameters obtained by conventional TTE including tissue Doppler imaging. Sixteen consecutive patients with chronic HFNEF were enrolled in this study. Wave intensity was obtained with a color Doppler system for measurement of blood velocity combined with an echo-tracking system for detecting changes in vessel diameter. Concerning conventional TTE, we measured LV ejection fraction (EF), peak velocities of early (E) and late (A) mitral inflow using pulse-wave Doppler, and early (Ea) and late (Aa) diastolic velocities using tissue Doppler imaging. Left ventricular EF, E/A ratio, Ea, and E/Ea ratio did not correlate with exercise capacity, whereas W(2) significantly correlated with peak VO(2) (r = 0.54, p = 0.03), VE/VCO(2) slope (r = -0.53, p = 0.03), and ΔVO(2)/ΔWR (r = 0.56, p = 0.02). W(2) was associated with exercise capacity in patients with chronic HFNEF. In conclusion, W(2) is considered to be clinically more useful than conventional TTE indices for evaluating exercise capacity in patients with chronic HFNEF.
在收缩功能保留的舒张功能障碍患者中发现运动能力受损。尽管传统经胸超声心动图（TTE）可提供有关心脏收缩和舒张功能的有用临床信息，但其评估运动能力的能力一直存在争议。已知收缩末期主动脉血流的惯性力与从收缩末期接近到等容舒张期的左心室（LV）性能密切相关。等容舒张期LV压力衰减的惯性力和时间常数可以使用波强度（WI）的第二个峰值（W(2)）进行无创估计，该峰值通过回声多普勒系统测量。我们试图确定W(2)是否与射血分数正常的慢性心力衰竭（HFNEF）患者的运动能力相关，并将其预测运动能力的能力与通过传统TTE获得的参数（包括组织多普勒成像）进行比较。本研究纳入了16例连续的慢性HFNEF患者。使用彩色多普勒系统结合用于检测血管直径变化的回声跟踪系统获得波强度。关于传统TTE，我们测量了LV射血分数（EF）、使用脉冲波多普勒测量的二尖瓣早期（E）和晚期（A）流入峰值速度，以及使用组织多普勒成像测量的早期（Ea）和晚期（Aa）舒张速度。左心室EF、E/A比值、Ea和E/Ea比值与运动能力无关，而W(2)与峰值VO(2)（r = 0.54，p = 0.03）、VE/VCO(2)斜率（r = -0.53，p = 0.03）和ΔVO(2)/ΔWR（r = 0.56，p = 0.02）显著相关。W(2)与慢性HFNEF患者的运动能力相关。总之，对于评估慢性HFNEF患者的运动能力，W(2)在临床上被认为比传统TTE指标更有用。
