Prediction of viability by pulsed-wave Doppler tissue sampling of asynergic myocardium during low-dose dobutamine challenge

Dobutamine stress echocardiography is widely used to predict reversible lef t ventricular dysfunction, but evaluation with this method is subjective. P ulsed-wave tissue Doppler imaging is a new technique that allows to obtain quantitative data on wall motion velocities of different myocardial segment s through sample-volume placement. Therefore, this tool in combination with DSE may be suitable for identifying viability in asynergic myocardium. To evaluate this, in 40 patients (mean age 57+/-9) with resting dyssynergy (ak inesis in 52, hypokinesis in 30) baseline wall motion scores and tissue Dop pler variables were collected before and after 5 min infusion of 10 mu g/kg per min dobutamine. Forty-six of 82 segments were classified as viable (a reduction in segmental score of at least one grade) according to follow-up echocardiography that was performed 4 weeks after revascularization. While myocardial S velocity percent increase in viable segments was 45+/-10, the increase was 25+/-12 in necrotic segments (n=36) during 10 mu g dobutamine infusion (P=0.0001). Assuming 35% as a cut-off for viability the increase i n S velocities by DSE yielded an 89% sensitivity and 86% specificity for pr edicting post-revascularization functional recovery. In conclusion, pulsed- wave tissue Doppler imaging of asynergic myocardium during dobutamine stres s echocardiography can identify the viability quantitatively. (C) 2000 Else vier Science Ireland Ltd. All nights reserved.