Reduced test time by early identification of patients requiring atropine during dobutamine stress echocardiography

In a randomized, controlled clinical trial, we evaluated the ability of an algorithm to identify, before peak stress, patients who will ultimately require atropine during dobutamine stress echocardiography. The effects of early atropine administration on test duration, atropine dose, dobutamine dose, and heart rate response also were studied. Compared with conventional atropine administration at peak dobutamine infusion, early atropine administration reduced test duration 8% (1.1 minutes, p = 0.02) and total dobutamine use 11% (0.41 mg/kg, p = 0.02) but required 90% more atropine (0.36 mg, p < 0.001). Conventional atropine administration resulted in a late, rapid rise in both heart rate and rate-pressure product. However, the heart rate and rate-pressure product curves for patients receiving early atropine paralleled those seen in patients not requiring atropine during dobutamine stress echocardiography. In conclusion, early atropine administration provides a more balanced stress and reduces test duration, thus decreasing total exposure to dobutamine and potentially increasing test efficiency.