Evaluation Of Viable Myocardium By Combined Low Dose Dobutamine Echocardiography (LDDE) With Doppler Tissue Imaging (DTI) Test

To evaluate the myocardial viability by combined low dose dobutamine echocardiography (LDDE) with Doppler tissue imaging (DTI) test , and to study the consistence between combined LDDEwith DTI test and nitroglycerin (NTG) infusion tomography in evaluation of viable myocardium. Methods: The 30 patients with CAD (confirmed by coronary angiography ) were measured by echocardiography and SPECT. Regional wall motion was measured by DTI at rest, during dobutamine infusion (5,10ug'kg-1min-1). The left ventricular wall motion at rest and intravenous infusion of NTG (0.5~1.0mg) was assessed in 30 cases of CAD. Results: Viability of myocardium detected by combined LDDEwith DTI test was more frequent in hypokinetic segments than that in akinetic segments. Myocardial viability in the infarct zone by combined LDDE with DTI test was documented in 89 patients (group A) and absent in 77 patients (group B). There was difference between at rest and during dobutamine infusion in group A(P<0.05), while no difference in group B(P>0.05). There was no difference between group A and group B at rest in DTI echocardiography (P>0.05). Myocardial viability in the infarct zone by NTG infusion tomography was documented is 97 patients and absent in 88 patients. Regard the results of NTG infusion tomography as thestandard, the sensitivity and specificity of diagnosis of viable myocardium by combined LDDE with DTI test were 83% and 86%, respectively.ConcIusions: Combined LDDE with DTI test can directly and quantitatively show abnormalities of LV wall movement. It is a relatively reliable and ideal method for identifyfing viable myocardium.