Severe hypotension induced by combination of dobutamine and dipyridamole

Pharmacologic testing with dobutamine or dipyridamole in conjunction with echocardiography has become an accepted method for diagnosis of coronary artery disease (CAD). The sensitivity of dobutamine echo ranges from 68 to 86%, and of dipyridamole from 53 to 69% for diagnosis of CAD. Our purpose was to investigate whether the addition of dipyridamole to dobutamine, which may improve the test sensitivity, is safe. Ten patients with low probability of CAD underwent dobutamine echo; 5 were control patients and 5 patients had low dose dipyridamole added at the maximal dose of dobutamine. Four of the latter patients had severe hypotension, while no hypotension was observed in control patients. Our findings suggest that this combination of dobutamine and dipyridamole can be hazardous and should not be used in patients with suspected CAD.