Effect of hemodialysis on left ventricular mechanical dyssynchrony in end-stage renal disease patients by tissue synchronization imaging

Background: Abnormal myocardial loading can contribute to left ventricular (LV) mechanical dyssynchrony in patients with end-stage renal disease (ESRD) and may be a factor contributing to the high incidence of cardiac deaths in these patients. The study aims to evaluate the possible presence of LV dyssynchrony in ESRD patients, and acute effect of hemodialysis (HD) on LV synchronicity using tissue synchronization imaging (TSI). Methods: Twenty patients with ESRD (11 males and 9 females) with mean age 63.1±4.41 were underwent echocardiographic examination before and immediately after a single HD session. Echocardiography was done using two dimensional strain imaging; global longitudinal systolic strain was measured in the apical views. LV mechanical dyssynchrony was assessed using TSI analysis enabling the retrieval of regional intraventricular systolic delay data. LV mechanical dyssynchrony was defined as a maximum regional difference in time to peak systolic velocity >105 ms and/or all segments standard deviation (SD) "dyssynchrony index" > 32.6 ms. Results: All patients had dyssynchronous LV segments before HD. A single HD session induced decrease in the global LV systolic strain from -19.65±3.03 to -16.29±2.75 (P < 0.001), it also reduced the all segments maximum difference from 123.65±33.94 to 102.60±20.84 (P < 0.001), and the all segments SD was also reduced from 52.2±12.31 to 40.15±8.51 (P < 0.001). Furthermore, the systolic dyssynchrony parameters were positively related to the LVEDD. Conclusion: LV dyssynchrony is frequently present in patients with ESRD. The severity of LV dyssynchrony decreases after a single session of HD suggesting the deleterious effect of volume overload and may be the accumulating toxins on LV myocardium in such patients.