Assessment of regional long-axis function during dobutamine echocardiography

Echocardiographic analysis of regional left ventricular function is based u pon the assessment of radial motion. Long-axis motion is an important contr ibutor to overall function. but has been difficult to evaluate clinically u ntil the recent development of tissue Doppler techniques. We sought to comp are the standard visual assessment of radial motion with quantitative tissu e Doppler measurement of peak systolic velocity. timing and strain rate (SR I) in 104 patients with known or suspected coronary artery disease undergoi ng dobutamine stress echocardiography (DbE). A standard DbE protocol was us ed with colour tissue Doppler images acquired in digital cine-loop format. peak systolic velocity (PSV), time to peak velocity (TPV) and SRI were asse ssed off-line by an independent operator. Wall motion was assessed by an ex perienced reader. Mean PSV, TPV and SRI values were compared with wall moti on and the presence of coronary artery disease by angiography. A further an alysis included assessing the extent of jeopardized myocardium by comparing average values of PSV, TPV and SRI against the previously validated angiog raphic score. Segments identified as having normal and abnormal radial wall motion showed significant differences in mean PSV (7.9 +/- 3.8 and 5.9 +/- 3.3 cm/s respectively; P < 0.001), TPV (84 <plus/minus> 40 and 95 +/- 48 m s respectively; P = 0.005) and SRI (- 1.45 +/- 0.5 and - 1.1 +/- 0.9 s(-1) respectively; P < 0.001). The presence of a stenosed subtending coronary ar tery was also associated with significant differences from normally perfuse d segments for mean PSV (8.1 <plus/minus> 3.4 compared with 5.7 +/- 3.7 cm/ s; P < 0.001), TPV (78 <plus/minus> 50 compared with 92 +/- 45 ms; P < 0.00 1) and SRI (- 1.35 <plus/minus> 0.5 compared with - 1.20 +/- 0.4 s(-1); P = 0.05). PSV, TPV and SRI also varied significantly according to the extent of jeopardized myocardium within a vascular territory. These results sugges t that peak systolic velocity, timing of contraction and SRI reflect the un derlying physiological characteristics of the regional myocardium during Db E, and may potentially allow objective analysis of wall motion.