Evaluation Of Left Ventricular Longitudinal Shrinkage Function In Patients With Mitral Regurgitation Using Two-dimensional Speckle Tracking Imaging

Objective:To evaluate left ventricular(LV) longitudinal shrinkage function in patients with mitral regurgitation(MR) by two-dimensional speckle tacking imaging(2D-STI).Methods:Thirty healthy controls(Group A) and 60 patients with MR(32 patientswith moderate MR(Group B) and 28 with severe MR(Group C)) were enrolled in this study.Select GE Vivid color Doppler imaging instrument, M5 S probe, frequency 2~4 MHz,frame40 to frame 80, measure the LAD、LVIDd、LVIDs in the parasternal long axis view of the left ventricle using M5 S probe. Measure the LVEF using the simpson method. The following parameters were measured : peak velocity of early rapid filling(E),peak Velocity of atrial filling(A) and the ratio of E to A(E/A).2D echocardiography images were obtained from LV apical 4-chamber(4C),long axis(LAX), and 2-chamber(2C) views.analysis Images of three section using two dimensional strain function imaging software.The instrument provided 18-bit three segments SLs of apical section,as well as the average strain(GLS-LAX,GLS-A4 C,GLS-A2C) and left ventricular myocardial longitudinal systolic average peak strain(GLS-Avg)of each section.Finally The software provided bull’s-eye plot of the subject automatically.Results:The global peak systolic strain of LV apical long axis(LAX),4-chamber(4C),2-chamber(2C)views and the average systolic globalpeak longitudinal strain(GLS-Avg) were significant differences between the healthy control group and the MR group(t=6.7、7.2、6.3、7.4,all P<0.01).The global peak systolic strain of LV apical long axis(LAX),4-chamber(4C),2-chamber(2C)views and the average systolic globalpeak longitudinal strain(GLS-Avg) were significant differences among the three groups( F =31.4、29.9、24.4、33.1,all P < 0.01) as following Group C with Group A and Group B,Group B and Group A(q=11.1、5.6、5.9;10.7、3.9、7.1;9.9、4.2、5.9;11.3、4.8、6.8;all P <0.01). Systolic peak longitudinal strain(LS)of six ventricular walls were significant differences among the three groups(F value of Ventricular septal, lateral wall, anterior wall, inferior wall, anterior septum, posterior wall were 71.4 、31.6、15.1、20.6、16.9、31.4 respectively,all P < 0.01) as following Group C except for the anterior wall of five wall LS with Group A and Group B,Group B and Group A except for the anterior wall of five walls(q value of ventricular septal, lateral wall, inferior wall,anterior septum, posterior wall LS were 16.5、6.0、11.1;11.0、4.3、7.0;9.0、3.3、5.9;8.3、4.2、4.2;11.2、5.3、6.2;all p<0.05). The global peak systolic strain of Basal segment、middle segment and apical segment were significant differences among the three groups(F=33.0、23.5 、 18.8,all P < 0.01) as following Group C with Group A and Group B,Group B and Group A(q=11.4、9.7、8.7;4.7、3.9、3.6;7.0、6.1、5.2,all P <0.05).Conclusion:By 2D speckle tracking technology measured the left ventricle in patients with mitral regurgitation each strain index becomes lower than the healthy control group,so the reduced longitudinal strain could detect LV dysfunction in patients with MR in early stage by2D-STI.