Usefulness of atropine in patients with chronotropic incompetence and poor exercise capacity during treadmill stress testing

AbstractBackgroundAtropine, an anticholinergic agent, has been shown to increase heart rate and enhance the sensitivity of dobutamine stress echocardiography in the detection of CAD in patients with chronotropic incompetence; however, the addition of atropine to exercise stress testing EST, in these types of patients has not been well studied previously.ObjectiveInvestigating the usefulness and accuracy of atropine in decreasing the number of inconclusive results of EST in patients with chronotropic incompetence and poor exercise capacity.MethodsThirty patients (16 males and 14 females with the age range of 40:73years with mean of 55±8) out of 180 patients who preformed EST were chosen as having chronotropic incompetence or poor exercise capacity by Borg scale. Atropine was administered during the exercise phase in doses of 0.5mg per minute until test conclusion or the maximum dose of 2mg was reached. All patients were subjected to stress myocardial perfusion imaging SMPI to confirm accuracy.ResultsConclusive test results were achieved in 29 patients (97%). Heart rate and blood pressure were markedly increased with statically highly significant difference (P value