Diastolic Function Evaluation In Hypertension With Left Ventricular Remodelling Using Tissue Doppler Imaging

Objective To investigate the effects of cardiac remodelling on left ventricular(LV) diastolic function, as evaluated by speckle tracking imaging, tissue Doppler and blood-pool indices, with respect to loading as expressed by wall stress. Cardiac remodelling is the major pathophysiological result of increased blood pressure and manifests as changes in the size, shape, and function of the heart.Methods Ninety patients with primary hypertension, including thirty cases of normal remodelling pattern, thirty cases of concentric remodelling pattern and thirty cases of concentric hypertrophy pattern were enrolled, and thirty healthy volunteers were in control group. Peak basal rotation, peak apical rotation at basal and apical short-axis views were measured with speckle tracking imaging, and peak left ventricular torsion was calculated. Mitral annular early diastolic(Ea) velocities were recorded. Filling pressures(E/Ea), relative wall thickness, LV mass index, DT, isovolumic relaxation time(IVRT), E/A ratio, and longitudinal wall stress(LWS) were also measured. Diastolic dysfunction(DD) was diagnosed based on published criteria.Results Peak left ventricular torsion was decreased in concentric remodeling group compared with normal remodelling group,and it was decreased in concentric hypertrophy group compared with concentric remodeling group.(P<0.05). Wall stress loading was higher in the normal remodelling group and lower in the concentric remodelling and concentric hypertrophy groups, despite the more deteriorated diastolic function in the latter groups. Diastolic dysfunction appeared early, even in the normal remodelling group, which had a 36.6% incidence of diastolic dysfunction compared to a 13% age-related incidence in the control group(P<0.05). When the control group was used to define the reference values for septal Ea with the cut-off set as 2SD below the mean, the normal remodelling, concentric remodeling, and concentric hypertrophy groups had abnormal diastolic function at 16.6, 26.6, and 56.6% incidence rates, respectively. Septal(Ea) was correlated with LVMI, RWT, Age, BMI, SBP, PP, and MAP, all at P<0.05. The correlations of blood-pool indices(DT, IVRT, and E/A) with the above parameters were less than that of tissue Doppler imaging(Septal and mean Ea). In a multivariate model, LVMI, SBP, and age were found to be independent predictors of diastolic dysfunction.Conclusion Diastolic dysfunction appears early in hypertensive disease, before the onset of abnormal remodelling or LV hypertrophy. With progression of the remodelling process and the advance of LVH, diastolic function progressively deteriorates. Tissue Doppler indices are better correlated with clinical and echocardiographic parameters of LV remodelling compared to blood-pool indices. Systolic torsion is significantly increased in patients with normal remodelling pattern, and declined in patients with concentric hypertrophy pattern. Systolic torsion is gradually declined with the decrease of left ventricular diastolic function. Speckle tracking imaging may provide a new index for evaluation of the left ventricular remodelling of hypertension patients with diastolic function.