Atropine Augmentation of Treadmill Exercise Stress Echocardiography

Abstract

Performance of exercise stress testing depends on adequate workload and is limited by patients' inability to reach target heart rate due to noncardiac illness or medications such as beta-blockers. This study aimed to assess the utility of atropine administration to augment the chronotropic response of patients undergoing treadmill exercise stress echocardiography. In a retrospective study, we assessed the utility of atropine administration to augment the chronotropic response in 1,396 patients undergoing treadmill exercise stress echocardiography between January 2004 and January 2009, compared with a historical control group with no atropine augmentation. Atropine was well tolerated. The proportion of abnormal studies differed significantly between patients who underwent exercise with and without atropine augmentation (15% vs. 10%; P < 0.0001). Compared with the historical control group, the proportion of patients who achieved ≥85% of their target heart rates increased from 67% to 78% (P < 0.0001). While atropine augmentation is safe and feasible, further studies are required to determine whether it is an equivalent surrogate to achieving target heart rate through exercise alone.