Doppler echocardiography in stress testing.

Doppler ultrasound may have a role in the stress testing laboratory for the identification of patients with coronary disease through the assessment of dynamic ventricular systolic function. Quantitative systolic ejection phase indexes of maximal acceleration, peak velocity, and volume of blood ejected from the left ventricle can be obtained in the exercising patient. Trials comparing stress Doppler ultrasound with ST-segment changes, gated blood pool radionuclide or echocardiographic studies of ejection fraction or wall motion abnormality, and thallium scintigraphic perfusion defects have returned comparable or better sensitivity and specificity referencing coronary angiography. Graded treadmill exercise, stationary bicycle exercise, and pharmacological stress (dipyridamole) have been used. The normal Doppler stress response is a near linear increase in peak ejection velocity with increasing cardiac work, as reflected in heart rate. Patients with coronary artery disease show blunted augmentation of Doppler ejection dynamics between rest and peak stress, and the degree of blunting appears to be proportional to the anatomic extent of coronary disease and the magnitude of ventricular perfusion and performance impairment. Stress Doppler ultrasound achieves diagnostic power for coronary disease with ultrasonic technology, inexpensive equipment, without ionizing radiation, and few personnel.