Correlation of myocardial Doppler velocity response to exercise with independent evidence of myocardial ischemia by dual-isotope single-photon emission computed tomography

Myocardial Doppler velocity (MDV) imaging may provide an objective correlat e of ischemia, thereby reducing the expertise needed for interpreting stres s echocardiography and improving its reproducibility. This study sought to independently validate the results of exercise MDV imaging with single-phot on emission computed tomography (SPECT) perfusion imaging in 116 patients ( age 60 +/- 12 years, 28 women) referred for exercise SPECT for diagnostic o r prognostic assessment of coronary artery disease. Two-dimensional echocar diography was performed with simultaneous color MDV data acquisition before and after exercise treadmill testing. MDV data were processed oh-line to d isplay myocardial velocity profiles in each segment at rest and peak exerci se. SPECT was analyzed using a 16-segment model and segments were classifie d as normal or showing resting or stress defects. Resting defects within se gments showing normal function were attributed to attenuation. Color MDV da ta were compared with SPECT results, and a multivariate analysis (including exercise and SPECT results) was performed to identify the determinants of the exercise MDV response. Patients exercised maximally (peak Kite-pressure product 27.6 +/- 6.1 x 10(3)), and SPECT was abnormal in 33 patients. Of t he 1,333 left ventricular segments evaluable by SPECT and MDV, 1,217 segmen ts were classified as normal, 43 showed a stress defect, and 73 a rest defe ct. Segmental comparison of thallium findings and MDV showed that segments with a rest defect had a lower velocity at rest and stress than normal segm ents (p <0.001). Segments with a stress defect had a marked reduction in pe ak exercise velocity and less increment in velocity than normal segments. H eart rate, functional capacity, and presence of abnormally perfused segment s were independent predictors of myocardial velocity at peak exercise. Thus , color MDV correlates with independent evidence of ischemia, although it i s also influenced by exercise capacity and left ventricular function. This technique may permit a feasible approach to quantitation of exercise echoca rdiography. (C)2000 by Excerpta Medica, Inc.