Value of low dose dobutamine Doppler tissue imaging for detecting hibernating myocardium

Summary  In order to assess the value of Doppler tissue imaging (DTI) in detecting viable hibernating myocardium, 20 patients with coronary artery disease and chronic left ventricular dysfunction underwent low dose dobutamine stress e-chocardiography and low dose dobutamine stress DTI. The results showed that among the 100 asynergic segments, 35 segments showed improvement after dobutamine infusion (group H) and no changes were observed in the remaining 65 segments (group N). The left ventricular echocardiographic score index decreased from 1.60±0.35 to 1.44±0.36 (n = 20,P< 0.01). During low dose dobutamine stress DTI. there was no difference in the values of velosity of S wave (V₃) before dobutamine infusion between two groups. However, after dobutamine infusion, the values of V₃ and VR in group H were significantly higher than those in group N (V₃:10.1±3.0 cm/s vs 7. 3±2. 2cm/s,P< 0.01; VR: 60 %±41% vs 25%± 32%,P< 0. 001). 95.7% asynergic myocardial segments with VR≤0 had no viability while 86% asynergic segments with VR> 80% were viable myocardium. It is concluded that the different reactions to dobutamine stress between hibernating and necrosis myocardium could be showed by DTI and it is more clinically significant when VR≤0 and VR> 80%.