ABSTRACT
Most patients on hemodialysis (HD) have left ventricular (LV) remodeling as a result of pressure and volume overload, which may lead to hypertrophy (LVH) and dilation, resulting in heart failure (HF). LV torsion by the inner and outer oblique myocardial bands may contribute in part to the ejection fraction (EF). LV dilation is associated with reduction of torsion. We assessed the hypothesis that LV dilation and decreased torsion at the sub-epicardium assessed by 3-dimensional speckle tracking echocardiography (3D-STE) may cause reduced LVEF in patients on HD. LV volume, strain, and torsion at the sub-endocardium and sub-epicardium were examined using 3D-STE in 76 patients on HD (age 64 ± 2 years) and 22 controls (age 71 ± 9 years). The HD patients were divided into 2 subgroups according to LV size (17 HD with LV end diastolic volume ≥ 70 and 59 HD with volume ＜ 70 mL/m2). Torsion (°/cm) is defined as the difference in the rotation angle between base and apex divided by the length of the LV long axis. LVEF, strain, and torsion at both layers in all HD patients (n = 76) were comparable to those in the controls (torsion at the sub-endocardium: 2.2 ± 0.7 vs 2.4 ± 1.1°/cm) despite increased LV mass and volume. In HD with dilation, LV volume increased and LVEF reduced compared to HD without dilation (LVEF: 63 ± 7, 64 ± 6, 57 ± 9％), with decreased longitudinal strain and torsion at both layers (torsion at sub-epicardium: 1.4 ± 0.7, 1.6 ± 1.0, 1.1 ± 0.6°/cm). There was no significant difference in circumferential strain at the sub-epicardium among the 3 groups. There was some correlation between torsion and EF (r = 0.34, p ＜ 0.01) and end diastolic volume (r = －0.36, p ＜ 0.01). LVEF and torsion at the sub-endocardium and sub-epicardium were reduced in HD with LV dilation, suggesting that volume control is important in HD to prevent HF with reduced EF because of reduced LVEF by LV dilation and oblique myocardial fiber damage at the sub-epicardium.