Investigation On Left Ventricular Myocardial Diatolic Strain Rate In Hypertension Using 2-dimensional Strain Echocardiography

Background and Objectives:In the natural history of hypertensive heart disease, LV diastolic dysfunction comes ahead of systolic dysfunction. Differences exist between diastolic and systolic heart failure in term of the predominant pathophysiological mechanism, the therapeutic method and prognosis. It is important to detect diastolic dysfunction of hypertensive patients for the early diagnosis and clinical intervention of the cardiac dysfunction. The study aimed to explore the association between LV remodeling and myocardial diastolic multi-dimensional stain and global LV function, and investigate the parameters change of myocardial multi-dimensional diastolic strain rate with 2-dimensional strain echocardiography (2DSE) in primary hypertension (HT).Methods:The study included 88 HT patients (57 males, 31 females, mean age 57.27±10.22 years), excluding valvular heart disease, diabetes mellitus and cardiomyopathy patients. 30 healthy volunteers matched the age and gender were as controls (14 male, 16 female, mean age 55.03±6.62 years). HT patients were classified into 2 groups on the basic of left ventricular mass index, including non-Left ventricular hypertrophy (NLVH group, 52 cases) and left ventricular hypertrophy (LVH group, 36 cases).The selected patients underwent echocardiography procedure, the following parameters were measured: 1. left-side heart structure indexes including LV diameter, wall thickness and left atrial size; 2. LV conventional systolic and diastolic indexes including LV ejection fraction (LVEF) , short-axis fractional shortening(FS), transmitral diastolic inflow velocities(E, A) , mitral annuluar systolic, early and late diastolic velocities(Sa, Ea, Aa) ; 3. 2DSE indexes including systolic, early and late diastolic longitudinal strain rate (SrL) in 4-chamber view and early diastolic and late circumferential strain rate (SrC) and radial strain rate (SrR) in LV short-axis view. Results:1. In the whole HT group, left ventricular remodeling parameters were higher than control group. There was no significant difference in LVEF between two groups [(64.05±4.93)% vs (63.52±6.05)%, p> 0.05] . There was a small decrease in left ventricular longitudinal systolic velocity (Sa) (p> 0.05). The diastolic Ea decreased and E/Ea increased (p <0.01).2. 2DSE measurements showed that LV global systolic longitudinal strain rate (SrLs), early diastolic longitudinal strain rate (SrLE) and circumferential strain rate (SrCE) were decreased (p <0.05) in HT group, and there was an association between SrLE and LVMI and total wall thickness(r, -0.47 to -0.52, p <0.01). The association between SrLs and SrLE was found ( r=0.38, p <0.01).3. LV global early diastolic strain rate (SrLE, SrCE, SrRE) decreased in the LVH group (p <0.05), which was not different in NLVH group (p> 0.05). The analysis of left ventricular diastolic different segments strain rate showed that the basal segment and middle segment of early diastolic longitudinal strain rate (SrLMV,SrLPM) decreased (p <0.05) in NLVH group .Conclusions:1. 2-dimensional strain echocardiography detected the decrease in left ventricular systolic and early diastolic strain rate in hypertensive patients with normal LVEF.2. As for the left ventricular early diastolic strain rate, the longitudinal strain rate was decreased in the early stage of the left ventricular remodeling of hypertension, and the longitudinal, circumferential and radial strain rate were all decreased in hypertrophy stage.