Usefulness Of Speckle Tracking Imaging For Assessment Of Myocardial Regional Sistolic Function In Patients With Coronary Artery Disease

Objective:To assess the myocardial regional function in patients with coronary artery disease (CAD) by two-dimensional speckle tracking imaging (STI).Methods Ninety-four subjects who underwent echocardiography and coronary angiography (CAG) were evaluated. They were grouped according to the CAG findings as follows:Control group with normal coronary artery(n= 40,male=18); Mild group with left anterior descending(LAD) stenosis 50%-74% (n=23,male=15); Severe group with LAD stenosis 75%-99%(n=31,male=18). We prospectively imaged all of the subjects within 48 hours of CAG. High frame rate of two-dimensional images were recorded from the parasternal short axis view at the mitral valve level, papillary muscle level, apical level and the apical four-chamber view, long-axis view and two-chamber view of the left ventricle respectively. The peak systolic longitudinal strain(SL), circumferential strain(Sc), radial strain(SR) of LAD segments were measured using Q-Lab 6.0 software.Results:1) The age, gender, height, weight, BMI and heart rate among all the subjects showed no significantly different in three groups (P>0.05);the morbidities of hypertension and diabetes melitus were significantly different in three groups (P<0.01).2) The tracking results:two-dimensional strain was obtained in 579 of 658(88.0%) segments with LAD regional walls in SL; 586 of 658(89.1%) segments was obtained in Sc; 552 of 658(83.9%) segments in SR.3) There were no segmental wall motion abnormal in all subjects, the LVEF was normal in all of the subjects and no significantly different among the three groups(P>0.05).4) The results of SL:the apical inferoseptal, mid and apical anteroseptal, mid and apical anterior segments in sever group were significantly decreased compared with that of control group (P<0.01); the apical anterior segments in mild group were significantly decreased compared with that of control group(P< 0.05).5) The results of SC:apical inferoseptal, mid and apical anteroseptal, mid and apical anterior segments in sever group were significantly decreased compared with that of control group (P<0.05); mid and apical anteroseptal segments in mild group were significantly decreased compared with that of control group(P<0.05).6) The results of SR:all of the LAD segments in sever group were significantly decreased compared with that of control group (P<0.01); all of the LAD segments except apical anterior in mild group were significantly decreased compared with that of control group(P<0.01); mid anteroseptal and all anterior segments in sever group were decreased compared with that of mild group(P< 0.05).Conclusion:1) The regional systolic function had been decreased while the global function was normal in patients of coronary artery disease.2) The regional systolic function had been decreased while no segmental wall motion abnormal.3) Regional wall motion of left ventricule in patients with myocardial infarction can be evaluated accurately with speckle tracking imaging. It is more usefull to calculate the apical inferoseptal, mid and apical anteroseptal, mid and apical and anterior segments for estimating the LAD stenosis. SR has more clinical value in detection patients with coronary artery disease.4) STI can be used as a new technique and a reliable parameter for evaluating regional myocardial function noninvasively and quantitatively.