Determination of Mitral Flow Velocity by Pulsed Doppler Echocardiography During Exercise: Comparison with ECG Exercise testing

Exercise-induced myocardial ischemia results in both diastolic and systolic lcft ventricular (LV) dysfunction. To determine the utility of Doppler assessment of LV diastolic function during exercise, 12 normal subjects and 4 7 patients (one-vessel disease (VD), n=l4; 2 VD, n=l6; 3 VD, n=l7) underwent exercise pulsed Doppler echocardiography, including measurement of mitral flow velocity by pulsed Doppler and simultaneous electrocardiography (ECG) exercise testing. The mean initral flow velocity was measured as the integrated area under the LV diastolic inflow Doppler spectral display. The change in mean mitral flow velocity from resting to immediate postexercise was compared among 2 patient groups. The percent. increase in mean mitral flow velocity was 101 % (± 19) for controls and 38 % (±13) for patients with coronary artery disease (p<0.005). An increase in mean mitral now velocity with exercise of >50 % occurred in 11 of 12. nonischemic control patients. On the other hand , an increase ln mean velocity of < 50 % occurred in 42 of 47 patients with coronary artery disease (lVD 11/ 16, 79 %; 2 VD 14/16, 88 %, 3VD 17/16, 94 %). An increase in mean mitral flow veIocity of <50 % showed a sensitivity of 89 % and specificity of 92 % in detecting patients with coronary artery disease. On the contrary, ECG exercise testing showed a sensitivily of 81 % and specificity of 75 % in this study group. Thus, the results of this study indicate that Doppler assessment of percent change in the mean velocity of mitral flow during exercise is a useful indicator of exercise - induced myocardial ischemia.