OS 37-08 ASSOCIATION OF CENTRAL HEMODYNAMICS AND NEUROHORMONAL FACTORS TO MECHANICAL ADAPTATION OF LEFT VENTRICLE IN HYPERTENSION: A STUDY WITH TWO DIMENSIONAL LAYER SPECIFIC SPECKLE TRACKING STRAIN IMAGING.

OBJECTIVE: The aim of this study was to comprehensively assess mechanical adaptation of LV in subclinical patients with hypertension(HTN) using a layer specific speckle-tracking echocardiography.

DESIGN AND METHOD: Conventional transthoracic echocardiography (TTE) with 2D-layer specific speckle-tracking echocardiography was performed on 218 HTN patients with preserved LV ejection fraction (EF > 50%). Endocardial, epicardial, and transmural global longitudinal strain (GLS), global circumferential strains (GCS), and peak LV torsion were measured. Time dependent measures, time to peak standard deviation (TTP_SD) of longitudinal strain and time to peak (TTP) LV torsion, were measured. Plasma aldosterone and renin were obtained at the time of TTE. Central hemodynamics including central aortic pressures, pulse pressure (PP), augmentation index, PP amplification, and pulse wave velocity (PWV) were measured.

RESULTS: LVendo GLS was well correlated with CPP (r = -0.179, p = 0.03), PWV (r = 0.165, p = 0.04), and PP amplification(r = 0.201, p = 0.01). TTP LV torsion showed good correlations with PWV(r = 0.217, p < 0.01) and PP amplification (r = -0.249, p < 0.01). Peak LV torsion was well correlated with AI@75(r = 0.209, p = 0.02). Log aldosterone was well correlated with LV peak torsion (r = -0.203, p = 0.04) and LVtransumural GCS (r = 0.344, p = 0.02) Correlation between LVendo GLS and PP amplification was more significant in LVH(n = 56) group (r = 0.45, p < 0.01), while correlation between TTP LV torsion and PP amplification was more significant in those without LVH (n = 162). (r = -0.272, p < 0.01) (Figure).

CONCLUSIONS: Before the LV remodeling occurs, central hemodynamics affects LV torsion and time dependent parameters in a more prominent way. After LV adaptation from LV occurs, LV GLS, especially endocardium, is more dominantly affected by central aortic stiffness, as the endomyocardium is the most susceptible to pressure overloads. On the other hand, aldosterone, a neurohormone, affects circumferential LV function.2D-layer specific speckle-tracking echocardiography sensitively detects impaired LV functions in subclinical HTN and may further reveal pathophysiologic mechanism LV adaptations in HTN.