Background: Progressive reduction in contractility leads to graduated decrease in left ventricular ejection fraction (LVEF). This echocardiographic study used vector velocity imaging (VVI) to characterize the time course of myocardial dysfunction with respect of longitudinal and radial components, by displacement vectors calculation.

Methods: 44 patients (28 to 79% LVEF) were investigated with an Acuson Sequoia system. LV volume, LVEF, Tissue Doppler Imaging (TDI) velocities were evaluated as well as global longitudinal and transversal velocities and strain by VVI. Patients were divided in 3 groups: g1: LVEF > 60% (n = 12), g2: 40% < LVEF < 60% (n = 18), g3: LVEF < 40% (n = 14).

Results: Significant decrease in VVI velocities and strain were observed from g1 to g3 (p < 0.01). These variations were much more pronounced for longitudinal than radial components (mean variations 66-82% versus 31-51% respectively). High levels of correlations were obtained between VVI velocities or strain vs LVEF or TDI velocities (r ranging from 0.60 to 0.84). By plotting longitudinal against radial components, a logarithmic correlation was found (Figure) illustrating a preserved radial component compared to an early decrease in the longitudinal contraction.

Conclusions: VVI allows the identification of radial and longitudinal components of myocardial contraction which are dissociated in the time course of heart failure. Radial contraction is better preserved than longitudinal contraction, which is impaired earlier.