Two-dimensional speckle tracking to image ventricular-arterial coupling in uremia

Abstract

Objective: To study ventricular-arterial coupling(VAC) in uremic patients by application of two-dimensional speckle tracing imaging (2DSTI).

Methods: One hundred uremic patients were divided into two groups based on left ventricular ejection fraction (LVEF): group 1 with LVEF ≥ 5%, and group 2 with LVEF < 55%. Forty healthy subjects were recruited as a control group. Conventional echocardiography was performed; VAC components and myocardial performance index were calculated. Longitudinal strain (LS) of 17 segments was measured using 2DSTI. Mean base (LS_BA ), papillary muscle (LS_PM ), and apex values (LS_AP ) were calculated.

Results: Compared to subjects in the control group and group 1, subjects in group 2 exhibited decreased LV end-diastolic volume (EDV), end-systolic volume (ESV), LV mass index (LVMI), and VAC (P < 0.05). EF, fractional shortening (FS), end-systolic elastance (Ees) were significantly higher in group 2 (P < 0.05). SL_BA , SL_PM , and SL_AP differed significantly among the groups (all P < 0.05). SL_BA , SL_PM , and SL_AP correlated positively with Ees, EF, and FS (all P < 0.05) but negatively with arterial elastance (Ea), VAC, systemic vascular resistance index (SVRI), and rate-pressure product (RPP) (all P < 0.05). Multiple regression analysis revealed that relative wall thickness (RWT), LVMI, LS_AP , and stroke works (SW) were independent predictors of VAC (b' = -0.443, 0.537, -0.470, and -0.491, all P < 0.05).

Conclusions: In patients with uremia, LV myocardial LS gradually decreased as LV systolic dysfunction decreased. VAC correlated negatively with left ventricular LS, and LS_AP was an independent predictor for VAC.

Keywords: arterial elastance; end-systolic elastance; left ventricular function; speckle tracking imaging; uremia; ventricular-arterial coupling.