Dobutamine Stress Tissue Doppler for Detection of Myocardial Viability

Objective: Investigate the rule of Dobutamine stress Tissue Doppler in viability assessment.Methods: 25 patients with coronary stenosis 50%, EF 45%, and SWMAs were included. Pulsed wave-Tissue Doppler were applied to basal and mid myocardial segments with measuring of S, E and A velocities at rest, low dose dobutamine (LDD: 10mic/Kg/min), and peak stress.Results: After exclusions of apical segments, 200 segments were analyzed, 100 were normal, 79 hypokinetic and 21 akinetic by visual interpretation at rest. At LDD: 62 (78%) of hypokinetic segments showed improvement in contractility, the others were considered non viable. At peak stress: Hibernating segments developed biphasic response, continuous improvement or worsened while non viable segments showed no change.Using Pulsed TD: At rest, akinetic segments had significantly lower S and E velocities than hypokinetic ones (p 0.05). At LDD and peak stress, S was higher and E was higher in hibernating than non viable segments (p 0.05). No difference in A in all segments at different stages of stress.Cutoff Values for Viability: An increase of S by 2.9cm/s and E by 1.5cm/sec during LDDSE (sensitivity 90%, 96% and specificity 87%, 97% respectively).Conclusion: LDD-Pulsed TDI is a reliable tool for detection of viability.