Evaluation Of Left Ventricular Systolic Function And Synchronism In Patients With Right Ventricular Septal And Left Bundle Branch Pacing By Layered Strain Technique

Objective:To research left ventricular systolic function,synchronization and global myocardial work in patients with right ventricular septal pacing and left bundle branch pacing by two-dimensional speckle tracking multi-layered strain technique.To evaluate whether left bundle branch pacing(LBBP)is more than right ventricular septal pacing(RVSP)in line with the requirements of physiological pacing.Methods:Forty-two patients with Ⅱ degrees Ⅱ type or Ⅲ degrees atrioventricular block(AVB)were selected as pacing group,and was divided into two groups according to different pacemaker mode:twenty patients with RVSP,twenty-two patients with LBBP.at the same time,20 patients with normal ECG were selected as control group.M-mode echocardiography of pacing group preoperative and the two-dimensional dynamic ultrasound images of pacing group 1 week after operation and control group were obtained and analyzed.Then the following date was available by two-dimensional speckle tracking multi-layered strain technique:left ventricular myocardial multi-layered longitudinal systolic peak strain,multi-layered circumferential systolic peak strain;global longitudinal systolic peak strain and peak strain dispersion;global circumferential systolic peak strain and the peak time standard deviation of cyclic strain;global radial systolic peak strain and the peak time standard deviation of radial strain;left ventricular twist peak time to aortic valve closure period;left ventricular apex rotation to left ventricular basal rotation peak time period;left ventricular global myocardial work parameters.Left ventricular ejection fraction was available by simpson.The differences among the three groups were analyzed and the high difference indexes were screened by statistically modeling.Results:Compare with the control group.the longitudinal systolic strain,circumferential systolic strain and radial systolic strain were declined in RVSP group(P<0.05).left ventricular synchrony parameters in RVSP group were prolonged(P<0.05),global wasted work increased and global work efficient decreased in RVSP group(P<0.05).left ventricular function decreased in RVSP group(P<0.05).The longitudinal systolic strain,circumferential systolic strain and radial systolic strain in LBBP group were also smaller than those in the control group,but global longitudinal systolic strain in LBBP group were higher than RVSP group(P<0.05).peak strain dispersion and the peak time standard deviation of radial strain in LBBP group were not significantly prolonged compared with the control group(P>0.05).peak strain dispersion and left ventricular apex rotation to left ventricular basal rotation peak time period was less than RVSP group(P<0.05).global wasted work in LBBP group was much than that in the control group and less than in RVSP groupC(P<0.05),global wasted efficient in LBBP group was less than that in the control group and higher than in RVSP group(P<0.05).left ventricular ejection fraction in LBBP group had no significant change compared with the control group(P>0.05).QRS,subendocardial myocardial longitudinal systolic peak strain,global longitudinal systolic peak strain,middle myocardial longitudinal systolic peak strain,left ventricular apex rotation to left ventricular basal rotation peak time period were the indexes with significant difference among LBBP and RVSP group and all index characteristics showed better in LBBP than RVSP group.Conclusions:Two-dimensional speckle tracking multi-layered strain technique can be used to evaluate the effects of pacemaker implantation on left ventricular systolic function,synchronicity and global myocardial work.The left ventricular myocardial longitudinal and radial systole in patients with LBBP synchronously,and LBBP had less influence on the left ventricle global systolic function and myocardial work than RVSP,which is a new physiological pacing operation.