CLINICAL-SIGNIFICANCE OF ABRUPT VASODEPRESSION DURING DOBUTAMINE STRESS ECHOCARDIOGRAPHY

Dobutamine stress together with 2-dimensional echocardiography for identification of ischemia-induced wall motion abnormalities is emerging as an accurate method of detecting coronary artery disease.1 In a different clinical setting, exogenous catecholamine infusion during upright tilt testing has been used to elicit symptomatic hypotension and bradycardia in patients with recurrent syncope of unknown origin.2 This followed the observation that increases in heart rate and arterial pressure,3 and elevated circulating catecholamine levels4 frequently precede vasovagal reactions implicating transient heightened sympathoadrenal activity before vasodepression. Hypotension during exercise is recognized as a marker for severe coronary disease and poor prognosis, which is seen in patients with a dilated, poorly functioning left ventricle due to extensive new regional asynergy on post-treadmill exercise echocardiography.5 We describe instances of paradoxical hypotension-bradycardia in patients undergoing dobutamine stress echocardiography for suspected coronary disease, comment on its clinical significance and recommend precautions to maximize test safety. © 1992.