The Value Of High-dose Dobutamine Stress Test Combined With Two-dimensional Strain Imaging In Early Diagnosis Of Coronary Artery Disease

Objective To investigate the value of high-dose dobutamine stress echocardiography combined with two-dimensional strain imaging in early diagnosis of coronary artery disease.Methods High-dose dobutamine stress echocardiography was performed in 28 patients with suspected coronary artery disease and all wall motion movement was observed respectively in baseline and at all stress levels; the peak systolic longitudinal strain in subendomyocardial segments of left ventricular were measured to compare the sensitivity and specificity of high-dose dobutamine stress echocardiography visual method and high-dose dobutamine stress echocardiography combined with two-dimensional strain imaging in diagnosis of myocardial ischemia; the peak systolic longitudinal strain average were calculated in all groups and were compared inside and between different groups. Receiver operating characteristic analysis was used to evaluate the peak systolic longitudinal strain predicting the sensitivity and the specificity of myocardial ischemia.Results With 40μg·-Kg-1·min-1 of dobutamine dose, wall motion abnormalities occurred in 6 patients(20 segments) of coronary artery disease group; after calculating the peak systolic longitudinal strain, myocardial ischemia was found in 15 patients (148 segments); the majority of coronary artery disease ischemic segments of peak systolic longitudinal strain were significantly reduced(P<0.05) compared with the non-ischemic segments and control group. High-dose dobutamine stress echocardiography visual method and high-dose dobutamine stress echocardiography combined with two-dimensional strain imaging in diagnostic sensitivity of myocardial ischemia were respectively 35.3 % and 88.2 % (P< 0.01), the specificity were respectively 100 % and 100 % (P>0.05), and the accuracy were respectively 60.7 % and 92.8 % (P< 0.01). When the cutoff absolute value of the peak systolic longitudinal strain was less than 14.97, the sensitivity and specificity in diagnosing of myocardial ischemia were respectively 83.3 % and 91.7 % .Conclusions High-dose dobutamine stress echocardiography combined with two-dimensional strain imaging can increase the sensitivity of myocardial ischemia detection. During high-dose dobutamine stress echocardiography, measuring the peak systolic longitudinal strain by two-dimensional strain imaging could quantitatively evaluate the subendomyocardial systolic function and detect concealed myocardial ischemia by analyzing longitudinal strain. As a new non-invasive method, high-dose dobutamine stress echocardiography combined with two-dimensional strain imaging could be used in early diagnosis of coronary artery disease. Objective To assess the left ventricular diastolic function in early myocardial ischemia by strain rate imaging combined with high-dose dobutamine stress echocardiography.Methods High-dose dobutamine stress echocardiography was performed in 28 patients with suspected coronary artery disease. Early diastolic peak strain rate (SRe) and late diastolic peak strain rate (SRa) were measured. According to the results of coronary angiography myocardial segments were divided in control group and coronary artery disease group.The SRe and SRa average were calculated in all groups and were compared inside and between different groups.Results The maximum SRe in coronary artery disease ischemic group was obtained with dose of 20μg/(kg.min) and SRe decreased significantly with dose of 30 and 40μg/(kg.min), compared with the control group. When the cutoff value of SRe was less than 1.70s-1, the sensitivity and specificity of diastolic function of myocardial ischemia were respectively 88.9 % and 83.3 % .Conclusions SRe is a sensitive and specific indicator in reflecting the reduction of diastolic function in regional myocardial ischemia.