Early impairment of left ventricular function in patients with systemic hypertension: New insights with 2-dimensional speckle tracking echocardiography

摘要

Background: Two-dimensional strain imaging allows rapid and accurate analysis of regional left ventricular (LV) principal strains in the longitudinal, radial, and circumferential directions. The aim of this study was to assess the ability of subtle differences in LV principal strains to characterize features of subclinical LV dysfunction in patients with systemic hypertension and apparently preserved LV systolic function. Methods: 2-dimensional echocardiographic (2DE) images of the LV were acquired in apical 4-chamber and parasternal short-axis at the basal, mid, and apical levels in 59 subjects, including 25 healthy controls (33 +/- 4 yrs, 14 male) and 34 patients with systemic hypertension (36 +/- 3 yrs, 24 male). Longitudinal (LS), circumferential (CS) and radial strains (RS) were quantified in an 18-segment model using a novel speckle tracking system (2D Cardiac Performance Analysis, TomTec Imaging System, Munich, Germany). Results: In comparison with normal controls, peak LS was markedly attenuated in the subendocardial and subepicardial regions in patients with systemic hypertension. However, circumferential strain was reduced only in subepicardial region; radial strain was not significantly different in the two groups. The subendocardial-to-subepicardial gradient of circumferential deformation correlated with the radial strains in both controls and hypertensive patients (R = 0.87, p < 0.001). Conclusions: Despite reduced longitudinal shortening, LV wall thickening in patients with systemic hypertension remains unaltered due to relatively preserved circumferential shortening. Characterizing the disparities in LV principal strains reveals the presence of subclinical LV dysfunction and provides unique insights into functional adaptations that maintain global LV ejection fraction in patients with systemic hypertension.