Diagnostic accuracy of a new shorter dobutamine infusion protocol in stress echocardiography

Currently, a transthoracic echocardiographic examination is routinely included in the assessment of the majority of patients with cardiac disease. Other examinations are also demanded every day from the echocardiography laboratory. Of these, stress echocardiography is particularly time consuming. Shortening the time of infusion of a drug would increase the feasibility and the cost effectiveness of stress echocardiography,1 provided of course that the diagnostic accuracy achieved using the classic drug infusion protocol is maintained. An “accelerated” dipyridamole infusion protocol has been already used2 and validated in a large study.1 The standard protocol of dobutamine includes an initial dose of 10 μg/kg/min with increments of 10 μg/kg/min every three minutes up to 40 μg/kg/min which is maintained over six minutes and makes this procedure particularly long. Keeping these considerations in perspective, we have tested the diagnostic accuracy of an “accelerated” dobutamine stress echocardiographic procedure in patients with suspected coronary artery disease. We prospectively enrolled 94 consecutive patients (mean (SD) age 61 (46) years; 67 male) who complained of chest pain, had no known history of coronary artery disease, and who underwent coronary angiography. Forty eight patients were receiving β blockers. Informed consent was obtained from all patients. Dobutamine was administered intravenously at an initial dose of 20 μg/kg/min that was maintained over three minutes. Then, 40 μg/kg/min was infused over three minutes. At this point, 1 mg of atropine was given if the test was still negative and the patient had not reached 85% of the maximum predicted heart rate. …