Mechanisms of Hypotension During Dobutamine Stress Echocardiography in Patients With Coronary Artery Disease

Fifty-nine consecutive patients with angiographically documented coronary artery disease were prospectively studied during dobutamine stress echocardiography. Twelve patients (20%) developed hypotension, defined as a decrease in systolic blood pressure of ≥20mm Hg compared with baseline. The transmitral flow velocities, isovolumic relaxation time (IVRT), and flow in the left ventricular (LV) outflow tract were measured at baseline, at maximal dobutamine dose, or during a hypertensive episode; stroke volume, cardiac output, and systemic vascular resistance (SVR) were computed. Correlates of hypotensive response to dobutamine stress echocardiography included therapy with angiotensin-converting enzyme inhibitors (p=0.032), a longer IVRT at baseline (121±25 vs 103±28ms, p=0.047), a greater decrease in LV end-diastolic (−6.0±3.1 vs −2.2±2.1mm, p