Coronary artery vasospasm during dobutamine stress echocardiography.

Compared with the frequent occurrence of S-T segment depression, the development of S-T segment elevation during dobutamine stress echocardiography is a relatively rare finding, especially in the setting of nonobstructive coronary artery disease. We present two patients who developed chest discomfort with S-T segment elevation during dobutamine stress testing. Both patients had unremarkable baseline echocardiograms and no history suggestive of coronary vasospasm. Subsequent coronary angiography revealed nonobstructive disease. It is speculated that the likely presence of endothelial dysfunction coupled with mild coronary atherosclerosis caused an imbalance between the coronary vasodilatory and vasoconstrictive forces. The inhibition of the vasodilatory effects of beta-adrenergic receptor stimulation and flow-mediated dilation of dobutamine was overcome by the vasoconstrictive effects of dobutamine-stimulated alpha-1 receptor activation; thus, contributing to the development of coronary vasospasm. This condition is important to recognize and appreciate as the initial treatment for this condition favors the use of nitrates over beta-blockade.