The Study Of Cardiac Mechanics In Mild Hypertension With Two-dimensional Strain Imaging

Objective:Left ventricular function in patients with mild hypertension were studied to evaluate their clinical value using two-dimensional peckle tracking strain imaging.Methods:Standard 2D Doppler echocardiography, tissue Doppler imaging,and 2D speckle strain imaging were performed in 51 hypertensive subjects and 32 control subjects of similar age.The apical 2-chamber views,4-chamber views and long-axis of left ventricular views were collected in the two-dimensional gray-scale state. Peak systolic, and diastolic annular velocities were obtained by tissue Doppler imaging,whereas longitudinal myocardial systolic velocity and circumferential, longitudinal,and radial strains were obtained by speckle tracking.Midwall fractional shortening and peak basal longitudinal strain were used as indices of regional function.Results:①Systolic function:Mild hypertension group and the healthy control group,the basal segment longitudinal strain rates were(18 ± 3)%,(21 ± 3)%,the difference was statistically significant(p <0.01);Longitudinal myocardial velocities were(3.9 ± 1.0) cm / s,(4.4 ± 1.1) cm / s,(P <0.05);②Diastolic function:Mild hypertension group and the healthy control group,peak systolic mitral annular velocity,respectively(9 ± 3) cm / s,(10± 2) cm / s,(P <0.05);early diastolic mitral annular velocity peak(11 ± 3) cm / s,(15 ± 2) cm / s,(p <0.05); the ratio of the former to the peak early diastolic mitral flow velocity respectively(1.2 ± 0.2),(1.4 ± 0.4),(P <0.05).All the difference was statistically significant. ③Midwall fractional shortening and relative wall thickness were negatively related(r=-0.743,P <0.001); Circumferential strain and relative wall thickness were not related;Basal segments of the longitudinal strain rate and the left ventricular mass negatively related(r =-0.35, P <0.05);The left ventricular mass and overall longitudinal strain(r =-0.34, P <0.05) and circumferential strain(r =-0.8, P <0.001) negatively related.Conclusion:Hypertensive heart disease with normal ejection fraction is associated with reduced myocardial velocities, reduced regional function and reduced diastolic function but normal global strains.Our data suggest that velocity abnormalities occur early in hypertension and may be an appropriate target for preventive strategies because they occur before abnormalities in global strains.Two-dimensional strain imaging can accurately evaluate the early changes of the left ventricular myocardium function in patients with hypertension. Identifying subclinical left ventricular systolic dysfunction among hypertensive subjects might be helpful in identifying patients at higher risk for heart failure.Also,identifying patients at high risk for heart failure might permit targeted preventive strategie.