Pre-ejection mitral annular motion velocity responses to dobutamine infusion: a quantitative approach for assessment of myocardial viability

ABSTRACT

Dobutamine stress echocardiography [DSE] is widely used for detection of myocardial viability. The main limitation of DSE is its subjective interpretation. Assessment of mitral annular motion velocities with tissue Doppler imaging is a simple and quantitative measurement. To determine the relationship between myocardial viability and regional systolic mitral annular motion tissue Doppler velocities responses to dobutamine stress. Our study group included 42 patients with previous myocardial infarction referred for coronary angiography and revascularization. We did dobutamine stress tissue Doppler echocardiography [DSTDE] measuring velocities of pre-ejection wave [pre-Ej] and peak ejection wave [Ej] at rest and during low-dose dobutamine infusion. We did follow up echocardiography after 1 month. After exclusion of the normokinetic walls, we analyzed 196 walls. Using receiver operator characteristic ROC curves, the optimal cut-off value for viability assessment was an increase of 1.75cm/s in pre-ejection velocity during DSTDE [area under the curve 0.70, p<0.001]. On the other hand, the optimal cut-off value for viability assessment was an increase of 1.75cm/s in ejection velocity during DSTDE [area under the curve 0.613, p=0.01]. The sensitivity, specificity, and total accuracy of the DSTSE [pre-Ej] versus the gold standard for detection of myocardial viability were 66.15%, 67.94%, and 67.35%, respectively. The sensitivity, specificity, and total accuracy of the DTSE [Ej] were 56.92%, 64.12%, and 61.43%, respectively. There was a good correlation between the pre-Ej at 5 ug/kg/min dobutamine infusion and the pre-Ej after revascularization [r=0.64, p=0.01] while the correlation with the Ej was moderate [r=0.50, p=0.01]. Viable left ventricular myocardium could be identified easily and quantitatively with pre-ejection mitral annular velocity during dobutamine infusion. The pre-ejection wave during DSTDE showed greater sensitivity and specificity for the prediction of myocardial viability than the ejection wave