Safety and Accuracy of Regadenoson-Atropine Stress Echocardiography in CAD

Purpose: The investigators plan to test a newly FDA approved pharmacologic stress agent, Regadenoson, in conjunction with atropine in the use of stress echocardiography for the diagnosis of coronary artery disease. The selective nature of Regadenoson allows for its use in patients with contraindications to the currently used drug, Adenosine, which is non-selective. Furthermore, the proposed protocol can be completed faster and without radiation exposure than the current protocol with adenosine. Design: This is a prospective study evaluating people with no prior diagnosis of coronary disease with a prior stress test and are scheduled for cardiac catheterization. Patients who meet inclusion criteria will undergo regadenoson-atropine echocardiography protocol prior to their catheterization. The study will be interpreted by two independent readers blinded to the catheterization results. The sensitivity, specificity, positive and negative predictive values of the regadenoson-atropine study will be then be calculated using the coronary angiogram as a gold standard.