Assessment Of regional diastolic dysfunction in coronary artery disease by tissue doppler during dobutamine stress echocardiography

The present study aimed to evaluate the role of tissue Doppler imaging in diagnosis of diastolic dysfunction during Dobutamine stress echocardiography and to compare it with coronary angiography. Sixty patients were included in this study, 40 of them were with ischemic heart disease according to the result of coronary angiography and 20 of them were coronary arteries free also according to the coronary angiography. All patients were subjected to thorough clinical examination, resting ECG, conventional transthoracic echocardiography and Dobutamine stress echocardiography. Dose of Dobutamine was 5 micro g/kg/min in each stage [3 min for each stage] up to 50 micro g/kg/min or target heart rates achieved, detection of wall motion abnormality or dangerous arrhythmias occur [Mc Neil et al., 1992] [1]. Tissues Doppler echocardiography was used at baseline, low dose and peak stress. Tissue Doppler echocardiography wave form at mitral annulus in 4 left ventricular sectors [lateral, septal, anterior and inferior] were used to measure early filling wave [Em cm/sec], late filling wave [Am cm/s] and deceleration time [DTm ms]. Coronary angiography was performed to each patient and control.1- Higher association of ischemic heart disease and male sex, diabetes, hypercholesterolemia and positive family history for ischemia.2- Low accuracy of mitral E/A ratio for diagnosis of coronary artery disease, as there was non-significant difference between both groups.3- The presence of heterogeneity of regional contraction and relaxation in control group.4- Reduced Em wave in ischemic area when comparing it with the corresponding wall in healthy subject.5- Biphasic response of Em wave in ischemic region during Dobutamine stress test i.e. increase with low dose and decreased with high dose.6-Progressive increment of Am wave in each work step of Dobutamine infusion in both healthy and ischemic patients.7- Shorter DTm in ischemic group when it compared with that of control group.8- Progressive decrement of DTm during Dobutainine stress from low to peak in ischemic patients.9- Low accuracy of wall motion score index in diagnosis of coronary artery disease when compared it with tissue Doppler accuracy.10- Higher agreement between tissue Doppler and results of coronary angiography, which is the golden standard for diagnosis of ischemic heart disease. The presents study demonstrate the usefulness and advantage of combining these techniques in diagnosis of ischemic heart disease. The biphasic response of Em velocity is characteristic and diagnostic of ischemic heart disease