Use of atropine to maintain higher heart rate after exercise during treadmill stress echocardiography

The sensitivity of treadmill stress echocardiography (SE), which is extensively used as a noninvasive test to detect myocardial ischemia, is contingent on the rapid acquisition of 2-dimensional echocardiographic (2D) images immediately after exercise, before a substantial decrease in heart rate (HR). This test is technically challenging and needs proficient sonographers to obtain the images rapidly. This study was designed to determine whether administration of atropine at peak exercise would maintain a higher HR longer after exercise, thereby facilitating acquisition of images. Two comparable groups of patients were randomized to receive either 0.5 mg atropine intravenously (i.v.) (n = 20), or no medication (n = 19) at peak exercise. HR was significantly higher in the atropine group compared with the control group (P <.05) at 60, 90, and 120 seconds after exercise. There were no serious complications in either group. Atropine can be safely used to maintain a higher HR after exercise during SE, thus reducing the technical challenge of obtaining postexercise 2D images while HR remains elevated.