Wang Jianwen, Khoury Dirar S, Thohan Vinay, Torre-Amione Guillermo, Nagueh Sherif F
Department of Cardiology and Methodist DeBakey Heart Center, The Methodist Hospital, Houston, Tex 77030, USA.
Circulation. 2007 Mar 20;115(11):1376-83. doi: 10.1161/CIRCULATIONAHA.106.662882. Epub 2007 Mar 5.
Diastolic strain rate (SR) measurements that comprise all left ventricular (LV) segments are advantageous over myocardial velocity for assessment of diastolic function. Mitral early diastolic velocity (E)/SR ratio during the isovolumetric relaxation (IVR) period can be used to estimate LV filling pressures.
Simultaneous echocardiographic imaging and LV pressure measurements (7F catheters) were performed in 7 adult dogs. Loading conditions were altered by saline infusion and caval occlusion, and lusitropic state was changed by dobutamine and esmolol infusion. A curve depicting global SR was derived from each of the 3 apical views, and SR was measured during IVR (SR(IVR)) and early LV filling (SR(E)). SR(IVR) had a strong correlation with time constant of LV pressure decay during the IVR period (tau) (r=-0.83, P<0.001), whereas SR(E) was significantly related to LV end-diastolic pressure (r=0.52, P=0.005) in the experimental stages where tau was <40 ms. In 50 patients with simultaneous right heart catheterization and echocardiographic imaging, mitral E/SR(IVR) ratio had the best correlation with mean wedge pressure (r=0.79, P<0.001), as well as in 24 prospective patients (r=0.84, P=0.001). E/SR(IVR) was most useful in patients with ratio of E to mitral annulus early diastolic velocity (E/Ea ratio) 8 to 15 and was more accurate than E/Ea in patients with normal ejection fraction and regional dysfunction (both P<0.01).
Global SR(IVR) by 2-dimensional speckle tracking is strongly dependent on LV relaxation. E/SR(IVR) can predict LV filling pressures with reasonable accuracy, particularly in patients with normal ejection fraction and in those with regional dysfunction.
包含所有左心室节段的舒张期应变率（SR）测量在评估舒张功能方面比心肌速度更具优势。等容舒张期（IVR）二尖瓣舒张早期速度（E）/SR比值可用于估计左心室充盈压。
对7只成年犬进行同步超声心动图成像和左心室压力测量（7F导管）。通过输注生理盐水和腔静脉闭塞改变负荷条件，通过输注多巴酚丁胺和艾司洛尔改变舒张功能状态。从3个心尖视图中的每一个得出描绘整体SR的曲线，并在IVR期间（SR(IVR)）和左心室早期充盈期间（SR(E)）测量SR。在IVR期间，SR(IVR)与左心室压力衰减的时间常数（tau）密切相关（r = -0.83，P < 0.001），而在tau < 40 ms的实验阶段，SR(E)与左心室舒张末期压力显著相关（r = 0.52，P = 0.005）。在50例同时进行右心导管检查和超声心动图成像的患者中，二尖瓣E/SR(IVR)比值与平均楔压的相关性最佳（r = 0.79，P < 0.001），在24例前瞻性患者中也是如此（r = 0.84，P = 0.001）。E/SR(IVR)在E与二尖瓣环舒张早期速度比值（E/Ea比值）为8至15的患者中最有用，并且在射血分数正常和存在节段性功能障碍的患者中比E/Ea更准确（两者P < 0.01）。
二维斑点追踪得到的整体SR(IVR)强烈依赖于左心室舒张。E/SR(IVR)能够以合理的准确性预测左心室充盈压，尤其是在射血分数正常的患者和存在节段性功能障碍的患者中。
