Application of tissue Doppler to interpretation of Dobutamine echocardiography and comparison with quantitative coronary angiography

The main limitation of dobutamine echocardiography (DE) is its subjective i nterpretation. We sought to reduce the need for expert interpretation by de veloping a quantitative approach to DE using myocardial Doppler velocity (M DV) in 242 patients undergoing DE. In 128 patients with a normal dobutamine echocardiogram, the normal range was designed to give a specificity of 80% . The accuracy of this range was investigated in 114 consecutive patients w ho underwent coronary angiography within 2 months of DE. A standard dobutam ine echocardiographic protocol was used, with MDV gathered from color tissu e Doppler at rest and peak stress; Wall motion at these stages was scored b y experienced observers using a 16-segment model and MDV was measured off-l ine. Sensitivity and specificity of wall motion scoring and MDV were obtain ed by comparison with angiographic evidence of disease, defined as stenosis >50% of the coronary artery diameter. The normal range in tethered segment s (septum, anteroseptum, and inferior) was greater than or equal to7 cm/s i n the basal segments and greater than or equal to5 cm/s in the midsegments. In the free wall (anterior, lateral, and posterior), the cutoff was greate r than or equal to6 cm/s in the base and greater than or equal to4 cm/s in the midventricle. Of 114 patients undergoing angiography, 84 (75%) had sign ificant stenoses, and the sensitivity of wall motion scoring and MDV were 8 8% and 83%, respectively, with specificities of 81% and 72% (p = NS). The a ccuracy was similar overall (86% vs 80%), as well as in each vascular terri tory. These data suggest that a fully quantitative interpretation of DE usi ng site-specific normal ranges of tissue Doppler, which account for regiona l variations of base-apex function, is feasible and equivalent in accuracy to expert wall motion scoring. (C) 2001 by Excerpta Medica, Inc.