Quantitative evaluation of left ventricular systolic function in patients with volumetric overload by speckle tracking echocardiography / 中华超声影像学杂志

ABSTRACT

Objective To assess global systolic function of left ventricle (LV) using speckle tracking echocardiography in patients who are left volumetric overload and to establish the correlativity between strain and left ventricle end-diastolic volume index (LVEDVI). Methods Seventy-seven patients who were left volumetric overload and 30 normal volunteers were enrolled in this study. Respective 3 high frame rate (＞ 100 frames/s) 2D images were recorded from the left ventricular short axis views the levels of mitral valve annulus, papillary muscle and apex. Three global peak systolic radical strain and strain rate were measured using 2D strain imagirg. LVEDV was obtained by two-plane Simpson method and LVEDVI was obtained by normalized LVEDV with surface body area. Patients were divided into 6 groups transitionalgroup,group A (LVEDVI90- 120 ml/m2),group B (LVEDVI 121 - 150 ml/m2 ),group C (LVEDVI151 -180 ml/m2),group D (LVEDVI 181 - 210 ml/m2),and group E (LVEDVI＞210 ml/m2). Patients were divided into two groups by left ventricular ejection fraction (LVEF) group Ⅰ (LVEF≥ 50 % ), group Ⅱ (LVEF＜50％). Results①Compared with normal control group,GRS,GRSr in transitional group showed no change at three short axis levels (P ＞0.05). The above parameters in group A, B and C were significantly higher than those in normal control group( P ＜0. 01 ). In transitional group,group A,B and C,GRS, GRSr of three short axis gradually increased with LVEDVI augmentation. Compared with group A, B,C,D and normal control group,the above parameters of 3 short aixs in group E were decreased( P ＜0. 01 ),which gradually decreased in group C, D, E with LVEDVI augmentation. ②GRS,GRSr of 3 short axis views in group Ⅰ were more significantly high than those in group Ⅱ and normal control group. The parameters above were significantly low in group Ⅱ ( P ＜0.01). ③In group A,B,C,GRS of papillary muscle and apex levels were correlated positively to LVEDVI ( rpapillary muscle = 0.55,0.64,0.76 and rspex = 0. 74, 0. 79,0.71,P ＜0.05) ; In group D, there was no correlativity between GRS of papillary muscle and LVEDVI( r =- 0.35, P ＞ 0.05) while negative correlativity was established in apex level( r = - 0.73, P ＜ 0. 05). In group E,the negative correlativity was found between GRS of papillary muscle and LVEDVI( r = -0. 70,P ＜0.05) while no correlativity was established in apex level( r = - 0.39, P ＞0. 05). GRS of mitral valve annulus was correlated positively to LVEDVI in group A, B( r = 0.79, 0.77, P ＜ 0.05) and had no correlativity in group C,D. The negative correlativity between them was found in group E( r = - 0. 54, P ＜0.05). At LVEDVI 180- 190 ml/m2 ,GRS of papillary muscle and apex level reach the peak point about 93% and 62% ;GRS of mitral valve annulus level reach the peak about 63% at LVEDVI 150 - 160 ml/m2.Conclusions Radial strain,strain rate change periodically with LV volume overload. Wall motion of left ventricle can be evaluated accurately by speckle tracking echocardiography, which provide useful modality for evaluation cardiac systolic function.