Application Value In The Diagnosis Of Coronary Heart Disease By Real-time Three-dimensional Speckle Tracking Echocardiography Technology

Background:The morbidity of coronary atherosclerotic heart disease (coronary heart disease, CHD) is increasing and becoming increasingly younger in China. Whether CHD can be diagnosed early, accurately or not has become an overarching concern for the medical profession. At present, there are so many methods for diagnosis of coronary heart disease, such as ECG, radionuclide examination, serum enzyme level, multi-row spiral CT angiography, coronary angiography, echocardiography. Coronary angiography has been recognized as the gold standard in the diagnosis of coronary artery stenosis. Because of expensive, invasive, radiant, high technology to operate and the operation risk, coronary angiography can not be a widespread application.The development of echocardiography is only dozens of years, but it has become an important diagnostic tool for heart disease, because of its noninvasive, inexpensive, repeated and simple operation. The important value of echocardiography in the diagnosis of coronary heart disease is to observe wall motion of ventricular to determine myocardial ischemia or myocardial infarction, and then to evaluate global cardiac systolic function. Clinically, we often use visual method and semi quantitative analysis method to determine the ventricular wall motion. Because of simple to operate and relatively low requirement for equipment, the two kinds of methods have been widely applied clinically. But conventional echocardiogram in detecting coronary artery disease still has many defects. On the one hand, the operator’s subjective factors will influence the results most, on the other hand, it difficult to discriminate akinetic segments that are pulled from normal myocardium, moreover, coronary artery stenosis is mild or coronary artery stenosis is heavy, but it has established a good collateral circulation, and some patients have evidences of myocardial infarction clinically, the wall motion of myocardial segment would still remain normal, which makes it difficult to observe the abnormal wall motion.Two-dimensional speckle tracking is automatically tracking the position of region of interest in myocardial tissue which has different pixels based on each of two-dimensional ultrasound image, and then calculated the distance between two adjacent spots with the time coursing, which we call it strain (or strain rate), reflected the myocardial deformation, so that we can qualitative and quantitative analyze of myocardial mechanical characteristics in the cardiac cycle. The technology is not susceptible to interference by being pulled from the surrounding myocardium and the global wall motion, and realizing the evaluation of myocardial motion no angle dependence. In recent years the scholars used them to evaluate the myocardial ischemia or myocardial infarction, and to discriminate myocardial viability. However, the premise of this technique is the mode of motion in two-dimensional slices, the results based on the same plane of the myocardial tissue. While the heart itself is a three-dimensional structure, the exercise of myocardial tissue is a complex three-dimensional form, so the actual motion mode of 2D-speckle tracking technology can not reflect the real wall motion. The appearance of the real-time three-dimensional speckle tracking echocardiography technology (RT3D-STI), overcame the two-dimensional speckle tracking technology is only confined to reflect the movement of myocardium on the same plane, can reflect the actual mode of myocardial motion based on the three-dimensional space. This study used RT3D-STI to quantitative analysis the left ventricular segmental and global systolic function, in order to evaluate its application value in the diagnosis of CHD.Objective:To quantitative analyze segmental and global left ventricular systolic function, and evaluate its value of application in patients with coronary heart disease(CHD) with real-time 3D speckle tracking echocardiography (RT3D-STI).Material and methods:80 cases of resident patients with a history of chest tightness or angina pectoris, confirmed CHD by coronary angiography were selected in the Department of cardiology, and 20 cases of outpatients as the normal control group. According with CGA results, near the middle of each main coronary artery stenosis different division:the 0 groups no stenosis,the control group;the 1 group 0-50% stenosis; the 2 groups 50-75% stenosis; the 3 group stenosis>75%.The 3D full volume images of left ventricular were collected,and then 17 segments of "bovine eye chart" of the left ventricular end-systolic were captured with the application of LVQ workstation software, so as to quantitative analyze global and each segmental longitudinal strains (LS), circumferential strains (CS), radial strains (RS), area strains (AS). According to the left ventricular segments were supplied by a relatively fixed coronary artery, the average value of each segmental strains of the perfusion of coronary branch was calculated, namely the territorial strain.Result:1.Coronary angiography:17 cases of single branch lesions,28 cases of double branch lesions,35 cases of three vessel lesions in coronary heart disease group. Grouped according to the different degrees of coronary artery stenosis; the 0 groups: 20 branches of left anterior descending(LAD), and 20 branches of left circumflex coronary artery(LCX), and 20 branches of right coronary artery(RCA);the 1 group:8 branches of LAD,29 branches of LCX, and 25 branches of RCA; the 2 groups 12 branches of LAD,31 branches of LCX, and 12 branches of RCA; the 3 group:30 branches of LAD, and 20 branches of LCX,43 branches of RCA.2.The global strains:The "bovine map" color distribution is uniform and neat, regularity of strain curve of longitudinal strains (LS), circumferential strains (CS), radial strains (RS), area strains (AS) in the control group; and the "bovine map" color distribution is uneven, the segment is dim, strain curve is disorder in the CHD group. There were statistical significant difference in the global longitudinal strains, global radial strains, global area strains, circumferential strains compared with the control group and CHD group (P<0.05).3.Segmental longitudinal strains:There were no statistical significant difference between the 1 grade group and the 0 grade group (P>0.05); There were statistical significant difference in the absolute value of each segmental longitudinal strains compare the 2or3 grade group with the 0 grade group (P<0.05), and the value of them is on the low side. There were statistical significant difference in the absolute value of most of the segmental longitudinal strains compare the 2or3 grade group with the 1 grade group (P<0.05), and the value of them is on the low side. There were statistical significant difference in each of strains among posterior basal segments, lateral basal segments, lateral middle section, posterior septal basal segment, inferior basal segment, inferior middle section(P<0.05), and no significant difference in other segments (P<0.05).4. Segmental circumferential strains:There were no statistical significant difference between the 1 grade group and the 0 grade group (P>0.05); There were statistical significant difference in the absolute value of some segmental longitudinal strains compare the Oorl grade group with the 2 grade group (P<0.05), and the value of them is on the low side. There were statistical significant difference in the absolute value of most of the segmental longitudinal strains compare the Oorl grade group with the 3grade group (P<0.05), and the value of them is significantly lower. There were statistical significant difference in each of strains among posterior basal segments, lateral basal segments, lateral middle section, posterior septal basal segment, inferior basal segment, inferior middle section(P<0.05), and no significant difference in other segments (P<0.05).5. Segmental radial strains:There were no statistical significant difference in each of strains among anterior septal basal segment, middle segment of anterior wall, the apex of left ventricular, lateral basal segments, posterior septal basal segment among all groups(P>0.05), and no significant difference in other segments between the 1 grade group and 0 grade group (P>0.05). There were statistical significant difference in each of strains among anterior septal basal segment, apical ventricular septal, posterior septal basal segment, posterior middle segment, lateral apical ventricular and the value of them is on the low side compare 2 grade group with 0 grade group (P<0.05); There were statistical significant difference in each of strains among apical ventricular septal, posterior middle segment, lateral apical ventricular and the value of them is lower in 2 grade group compare with 0 grade group (P<0.05); There were statistical significant difference in each of strains among anterior septal basal segment, anterior septal apical ventricular, apical ventricular septal, posterior middle segment, lateral middle segment, lateral apical ventricular, inferior middle segment, posterior septal middle segment and the value of them is significantly lower in 2 grade group compare with 0 grade group (P<0.05); There were statistical significant difference in each of strains among anterior septal basal segment, posterior septal middle segment, inferior middle segment in 2 grade group compare with 3 grade group (P<0.05).6. Segmental area strains:There were no statistical significant difference between the 1 grade group and the 0 grade group (P>0.05); There were statistical significant difference in the absolute value of a few segmental strains compare the Oorl grade group with the 2 grade group (P<0.05), and the value of them is lower. There were statistical significant difference in the absolute value of most of segmental strains compare the Oorl grade group with the 3 grade group (P<0.05), and the value of them is much lower(except the apical ventricular compare with 3orl grade group). There were statistical significant difference in each of strains among anterior wall middle segment, anterior septal basal segment, posterior wall middle segment, posterior basal segment, lateral basal segment, posterior middle segment, posterior middle segment, posterior septal basal segment, inferior middle segment, inferior apical ventricular (P<0.05), and no significant difference in other segments (P<0.05).7. Territorial strains:① There were no statistical significant difference between territorial longitudinal strains, territorial circumferential strains, territorial radial strains and territorial area strains in 0 grade group compared with 1 grade group(P>0.05); There were statistical significant difference between territorial longitudinal strains, territorial circumferential strains, territorial radial strains and territorial area strains in 2 grade group compared with 0 grade group(P<0.05); There were statistical significant difference between territorial longitudinal strains, territorial circumferential strains, and territorial area strains in 2 grade group compared with 1 grade group(P<0.05), and no significant difference in territorial radial strains (P<0.05). There were statistical significant difference between territorial longitudinal strains, territorial circumferential strains, territorial radial strains and territorial area strains in 3 grade group compared with 0orlor2 grade group(P<0.05).②The diagnostic value of each territorial strain parameters, such as territorial longitudinal strains, territorial circumferential strains, territorial radial strains and territorial area strains were more significant to vascular stenosis>75% than to stenosis>50%. Based on ROC analysis, the area under the curve(AUC) of territorial longitudinal strain(TSL) was the biggest(0.959) compared with other indexes, and its diagnostic value was the highest. The cutoff value of predictive value of the territorial longitudinal strains was-15.35% with a sensibility of 91.6%, specificity of 85.2% in diagnosis of CHD.Conclusion:RT3D-STI can quantitative evaluate the left ventricular global systolic function in the CHD patients; because of the changes of myocardial mechanics in different directions caused by different degree of stenosis, the corresponding segment 3D strain is decrease. When the coronary artery stenosis>75% (grade 3 group), the absolute values of segmental longitudinal strains, segmental circumferential strains, segmental area strains were decreased significantly, so were the territorial longitudinal strains, territorial circumferential strains, territorial radial strains, territorial area strains. The result of ROC analysis showed all of those had the higher value in diagnosis of CHD, and the AUC of territorial longitudinal strain is biggest which has the better sensibility cognition of ischemic myocardium and the territorial area strain is the second.