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 > or = 20 mm 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 hypotensive 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 +/- 28 ms, p = 0.047), a greater decrease in LV end-diastolic (-6.0 +/- 3.1 vs -2.2 +/- 2.1 mm, p < 0.0001) and end-systolic (-8.3 +/- 7.0 vs -5.1 +/- 3.7 mm, p = 0.037) dimensions, and a greater decrease in stroke volume (-10 +/- 10 vs -2 +/- 11 ml, p = 0.023) compared with those with a normal response. The groups did not differ significantly with regard to baseline stroke volume, cardiac output, SVR, and LV ejection fraction or LV mass.(ABSTRACT TRUNCATED AT 250 WORDS)