Background: Dobutamine stress echocardiography (DSE) has several potential advantages over currently used non-invasive technique. It is inexpensive and provides an alternative in the patients who cannot perform leg or arm exercise. The equipment used is highly portable and thus studies can be performed in coronary care units.
Objectives: To study the role of tissue Doppler imaging during dobutamine stress echocardiography for differentiating ischemic from non-ischemic cardiomyopathy.
Patients and methods: forty six of patients were included in this study, and diagnosed as dilated cardiomyopathy by resting conventional echocardiography. The patients divided into two groups group l (18 patients) with normal coronary angiography, and group ll(28 patients) with coronary artery disease. All patients subjected for full history taking, clinical examination, resting surface electrocardiograms, echocardiography, low and peak dose DSE associated with tissue Doppler with detection of mitral annulus systolic and diastolic velocities in six sectors of LV myocardium ( anterior, inferior, anterior septum, posterior septum, posterior and lateral walls).
Results: In group I, there is no change in the mean value of systolic velocities of all six sectors at baseline was (6.5±1.6 cm/s) and at low dose was (6.9±2.3 cm/s) p value > 0.05, while in group II there is significant improvement in the mean value of systolic velocities of six sectors at low dose (11.3±3.1 cm/s) compared to that in the baseline resting stat (7.0±1.6 cm/s) followed by gradual decrease in the systolic velocity to peak dose (9.1±2.6 cm/s) (Biphasic response) p value < 0.01. The E'/A' ratio of diastolic function estimated by TDI at base line and during DSE, there is insignificant changes in both groups. The sensitivity of tissue Doppler with DSE for detection of coronary artery disease in patient with dilated cardiomyopathy was 85.7%, and specificity was 77.8%.
Conclusion: Tissue Doppler with DSE is non invasive simple method with high sensitivity and specificity for detection of coronary artery disease in patient with dilated cardiomyopathy.