In 66 patients unable to exercise referred for pharmacologic stress single-photon emission computed tomographic myocardial perfusion imaging, a moderate dose of dobutamine was combined with intravenous dipyridamole and the results were compared with standard intravenous dipyridamole stress. The combined stress protocol resulted in increased defect size and reversibility with technetium-99m sestamibi single-photon emission computed tomographic myocardial perfusion imaging.