Background: Abnormal myocardial loading can contribute to left ventricular (LV) mechanical dyssynchrony in patients with end-stage renal disease (ESRD). The aims of this study were to characterize and quantify LV function and mechanical dyssynchrony in patients with ESRD, and to elucidate the impact of haemodialytic (HD) therapy on these parameters by speckle-tracking strain imaging.
Methods: Twenty-three patients with ESRD (63 ± 11 years) before (pre-dialysis group) and after HD therapy (post-dialysis group) and 28 normal subjects (control group; 60 ± 10 years) were examined by echocardiography. Global and segmental LV peak systolic strain (PSS) were analysed, and LV mechanical dyssynchrony was assessed by calculating the standard deviation of the segmental time-to-PSS over longitudinal, circumferential or radial regions, respectively.
Results: Global PSS and LV ejection fraction in the pre-dialysis group were similar to those in the control group, and were not altered by HD therapy. LV mechanical dyssynchronies in the longitudinal and radial directions, but not in the circumferential direction, were significantly greater in the pre-dialysis group than those in the control group [longitudinal direction: 63 ± 15 (P < 0.05 vs. the control group) vs. 49 ± 15 ms, circumferential direction: 44 ± 24 vs. 41 ± 23 ms, and radial direction: 47 ± 29 (P < 0.05 vs. the control group) vs. 16 ± 18 ms]. HD therapy dramatically improved only the radial LV dyssynchrony in the post-dialysis group (23 ± 24 ms, P < 0.05 vs. the pre-dialysis group).
Conclusions: The presence of ESRD was associated with longitudinal and radial LV dyssynchronies. In addition, HD therapy dramatically improved radial LV dyssynchrony, which strongly indicates that only radial LV dyssynchrony is preload dependent among the three LV systolic directions.