Value Of Ultrasonic Integrated Backscatter In Coronary Heart Disease: Comparison With Single Photon Emission Computed Tomography

To observe the change of myocardium ultrasonic integrated backscatter parameters in coronary heart disease , and clarify whether the abnormalities in integrated backscatter correlated with myocardial perfusion defects of the relative myocardial segments by single photon emission computed tomography (SPECT), and discuss the application worth of ultrasonic integrated backscatter in coronary heart disease. Methods The myocardium of 107 inpatients with coronary angiography(CAG) and SPECT examination was carved up according to 16-segments standard, which of 472 segments was taken as subjects. 191 segments of anteroseptal myocardium, 83 segments of inferior myocarium and 198 segments of posterior myocardium, according to the result of CAG and SPECT, were each grouped for four teams. Anteroseptal myocardium teams were: Anteroseptal 1 (normal team): 51 segments, left anterior descending branch(LAD) was normal. Relative myocardial perfusion defects(MPD) was negative. Anteroseptal 2 (ischemic team): 36, LAD stenosis 50%, MPD positive. Anteroseptal 3: 42, LAD stenosis 50%, MPD negative. Anteroseptal 4 (infarct team): 65, LAD stenosis > 95%, MPD positive. Inferior myocardial teams were: inferior 1 (normal team): 18 segments, right coronary artery(RCA) was normal, relative MPD was negative. Inferior 2: 22, RCA stenosis was less severe than 50%, MPD negative. Inferior 3 (ischemic team): 17, RCA stenosis 50%, MPD positive. Inferior 4 (infarct team): 26, RCA steosis 95%, MPD positive. Posterior myocardial teams were: Posterior 1 (normal team): 60 segments, right coronary artery(RCA) and left circumflex artery(LCX) was normal, relative MPD was negative. Posterior 2: 44, RCA and LCX stenosis was less severe than 50%,MPD negative. Posterior 3 (ischemic team): 39, RCA stenosis > 50%, LCX < 50%, MPD positive. Posterior 4 (infarct team): 55, RCA steosis > 95%, LCX < 50%, MPD positive. The interval of SPECT and ultrasonic integrated backsatter examination was 1-3 day. ultrasonic integrated backsatter examination was applied HP SONOS 5500 type instrument, and stayed the parasternal short-axis, the long-axis views of left ventricle. Each myocardial segment was measured three parameters of CVIB, IBS% and N-delay, which each parameter was measured for three times. Results 1. Calibrated myocardial integrated backscatter (IBS%) was higher, the magnitude of cyclic variation in integrated backscatter (CVIB) was lower and the delayed time of cyclic variation of integrated backscatter(N-Delay) was longer in the ischemia and infarct myocardium, compared with the myocardium of normal subjects. 2. Compared with normal myocardium, when CAG stenosis was more than 50 percent, in SPECT positive team and negative team myocardial integrated backscatter parameters all have difference in statistics. But compared SPECT positive team with SPECT negative team, integrated backscatter parameters has not difference in statistics. 3. Compared with normal myocardial parameters, CAG stenosis less than 50 percent, myocardial parmeters of SPECT positive team has not difference hi statistics. 4. Anteroseptal infarct myocardial CVIB has a negative correlation with relative MPD(the short axis r=-0.708, p < 0.01; the long axis r=-0.675, p < 0.01 ) , but its IBS% has no; inferior and posterior infarct myocardial CVIB, IBS% have no correltion ( p > 0.05 ) . 5. In CAG stenosis more than 50%, SPECT positive team, anteroseptal myocardial CVIB, IBS% have no correlation with relative MPD. Conclusions When coronary artery stenosis is more than 50%, ischemic and infarct myocardial integrated backscatter parameters have changed compared with normal myocardium. In anterior myocardial infarction, integrated backscatter hasa good relation with SPECT, may provide a new noninvasive tool for assessment of myocardial ischemia and viability.