Right Ventricle Dilatation Results in Deterioration of Right Ventricle Longitudinal Systolic Velocity and Acceleration

Backgrounds: Right ventricle (RV) under volume overload presents RV dilatation. Longitudinal systolic deformation of RV is known to reflect global preload recruitable stroke work of RV. However, impact of RV dilatation on RV longitudinal systolic deformation is poorly understood. Objective: We hypothesized that RV dilatation results in decline of RV longitudinal systolic velocity and acceleration.Methods: 32 patients without cardiac disease and 38 patients with RV dilatation underwent ECG gated 64-row multislice computed tomography. Length (LI) from RV apex to tricuspid valve indexed to body surface area was measured in each timephase of systolic phase. LIes was defined as LI at endsystolic timephase. Systolic velocity (V) was defined as difference of LI at 2 successive timephase divided by systolic time (T) calculated from heart rate. Systolic acceleration (A) was defined as difference of two successive V divided by T. Peak V and peak A were defined as Vmax and Amax. Each indices were correlated with RV endsystolic volume index (RVESVI). Results: LIes correlated with RVESVI (r=0.73, p<0.001). Vmax had inverse correlation with RVESVI (r=-0.39, p<0.003). Vmax and Amax correlated inversely with LIes (r=-0.68, p<0.001 and r=-0.32, p=0.011). Conclusions: We found RV dilatation correlating with elongation of LIes. Correlation of Vmax and Amax with LIes insisted elongation of RV longitudinal axis resulting in deterioration of RV longitudinal systolic velocity and acceleration.