 Currently, Regadenoson is approved by the US Food and Drug Administration as a coronary vasodilator, for myocardial perfusion imaging in patients with suspected myocardial coronary artery disease. Single-photon emission computed tomography SPECT imaging performed with 99mTc-sestamibi radiotracer is used to measure coronary blood flow both at rest and stress conditions with Regadenoson. While the adverse event profile is similar to adenosine, the most common side effects of Regadenoson are flushing, chest pain, dyspnea and headaches. 