To evaluate the left ventricular systolic function of uremic patients after peritoneal dialysis measured by two-dimensional speckle tracking imaging.

Thirty uremic patients with their left ventricular ejection fraction (LVEF)>50% who had not been underwent dialysis were enrolled in this study. Thirty healthy volunteers were involved as controls. For both groups, the basic data and routine cardiac ultrasound parameters were measured, and the images were collected to be analyzed by QLab software. The left ventricular 16-segment time-strain curves were obtained, and the peak strain of the systolic phase of each segment was measured. The data of 2 groups were analyzed by two independent samples t-test. After 6 months of peritoneal dialysis, the uremic patients were checked again. By using paired t-test, we analyzed the difference in left ventricular systolic dysfunction of uremic patients before and after peritoneal dialysis.

(1) Comparison between uremia group (nondialysis patients) and control group: systolic arterial pressure, diastolic arterial pressure and pulse pressure of uremic patients increased (t=-4.445, -4.531 and -2.203, P<0.05); left atrial anterior and posterior diameter (LAAPD), left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), left ventricular end diastolic volume (LVEDV), left ventricular end systolic volume (LVESV) and left ventricular mass index (LVMI) of uremic patients were larger. Interventricular septum thickness (IVST), left ventricular posterior wall thickness (LVPWT) and relative wall thickness (RWT) were thicker (t=-6.461, -5.168, -4.660, -3.578, -2.872, -6.819, -6.251, -7.108 and -2.659, P<0.05); the longitudinal, radial and circumferential directions peak systolic strain of 16 segment myocardial of uremic patients decreased (the longitudinal strain: t=-7.063, -5.391, -3.351, -5.323, -5.586, -7.842, -5.265, -5.587, -5.037, -3.051, -4.584, -3.936, -4.168, -9.783, -9.175 and -3.805; the radial strain: t=3.659, 3.58, 5.368, 2.649, 2.928, 4.344, 2.754, 5.031, 5.025, 2.277, 2.691, 2.731, 3.187, 4.179, 5.292 and 4.429; the circumferential strain: t=-5.158, -3.959, -2.164, -3.592, -2.324, -5.672, -4.946, -7.184, -7.748, -5.014, -2.439, -6.299, -8.072, -8.410, -7.884 and -8.854, P<0.05). (2) Comparison between uremic patients before and after dialysis: the systolic arterial pressure of uremic patients decreased after dialysis (t=2.833, P<0.05); LAAPD and LVMI of uremic patients decreased after dialysis (t=4.805, 2.631, P<0.05); BAS, BA, BIL, BI, BIS, MAS, MAL, MIL, APA and APL longitudinal systolic peak strain and the BAL, MAL, MIS, APS, APL and API radial systolic peak strain of uremic patients increased after dialysis (t=5.199, 4.127, 3.781, 3.380, 4.114, 3.116, 2.840, 3.243, 4.003 and 5.605, P<0.05; t=-3.343, -3.687, -2.488, -2.921, -3.826 and -3.339, all P<0.05). There were no statistical differences in circumferential peak systolic strain (P>0.05).

In uremic patients, the structure of the left ventricle changed, the function of myocardial contraction decreased, and the function of myocardial contraction improved after peritoneal dialysis. 2D-STI was able to quantitatively and objectively evaluate the function of the left ventricular myocardial constriction before and after dialysis.