Evaluation Of Left Ventricular Rotation And Twist In Uremia Patients By Two-dimensional Speckle Tracking Echocardiography

Objective:This study was performed to evaluate the rotation and twist of the left ventriclein uremia patients by measurement of angle using two-dimensional speckle trackingechocardiography, for the sake of providing a new detection means for clinicalcomprehensive assessment of uremia patients.Methods:Forty six uremia patients and fifty healthy volunteers were enrolled. Check leftlateral postition,connected to a three-lead ECG.S5-1ultrasound probe in the standardleft ventricular long axis measurement. Interventricular septum thickness and leftventricular post wall thickness at end-diastole,were acquired from left ventricularlong-axis view. End-diastolic volume, end-systolic volume and ejection fraction ofleft ventricle were calculated with double plane simpson method. The measurementof end-diastolic blood flow peak velocity and early-diastolic blood flow peak velocityat mitral orifice were three numerical averages with pulse Doppler imaging fromapical four-chamber view. High frame rate two-dimensional images of threeconsecutive cardiac cycles were recorded from the short-axis views at the levels ofmitral annulus and apex of the LV respectively.2D images were transferred to Qlabwork station to analyze global myocardial longitudinal strain、circumferential strainand radial strain,global and segmental rotation at the levels of mitral annulus andapex，and LV peak systolic global twist. The correlation between the parameter aboveand LV peak systolic global twist was analyzed as well.Results:1. When compared with healthy subjects, interventricular septum thickness andleft ventricular post wall thickness at end-diastole,end-diastolic volume, end-systolicvolume of left ventricle and end-diastolic blood flow peak velocity were significantly higher in the uremia patients （P<0.05）, while E/A and left ventricular ejectionfraction were significantly lower in uremia patients（P<0.05）。2. When compared with healthy subjects, all segmental LV rotation of the apicalplane was significantly reduced (P<0.05), while only the posterior and inferior of thebasal plane was significantly decreased (P<0.05).3. The maximal global counterclockwise apical rotation was significantlydecreased (P<0.05), and the maximal global clockwise basal rotation was alsoreduced although the differences were not significant (P>0.05). The peak systolic LVtwist was significantly decreased in uremia patients (P<0.05).4. Systolic peak twist was significantly correlated with LVEF, LV end-diastolicvolume, LV end-systolic volume and apical rotation velocity in uremia patient（r=-0.560，P<0.05；r=-0.750，P<0.05；r=0.822，P<0.05；r=0.599，P<0.05）.5. The maximal global counterclockwise apical rotation was significantlycorrelated with apical myocardial circumferential strain（r=0.740，P<0.05）, but showno correlation with apical longitudinal strain and radial strain (P>0.05). The maximalglobal clockwise basal rotation was significantly correlated with basal myocardialcircumferential strain and radial strain（r=0.504，P<0.05；r=0.332，P<0.05）, but showno correlation with basal longitudinal strain(P>0.05).6. Systolic peak twist was significantly correlated with global myocardialcircumferential strain and radial strain（r=0.877，P<0.05；r=0.699，P<0.05）, butsystolic peak twist show no correlation with global longitudinal strain(P>0.05).Conclusions:1. The function of left ventricular twist in uremia patients had been impaird.2. Two-dimensional Speckle Tracking Echocardiography is a new method toassess the regional and global systolic function via the measurement of peak twist andglobal and segmental rotation of left ventricle.3. The peak twist and all segmental and global LV rotation of the apical planewas significantly reduced. And systolic peak twist was significantly correlated withparameters such as left ventricular ejection fraction in uremia patient.