Cardiac Diagnosis, Imaging and Medical Tests include physical exam, personal and family medical history, blood tests and a chest X-ray, tests to diagnose heart disease can include Electrocardiogram (ECG), Holter monitoring, Echocardiogram, cardiac catheterization, cardiac computerized tomography (CT) scan; cardiac magnetic resonance imaging (MRI). Nuclear cardiology studies use noninvasive techniques to assess myocardial blood flow, evaluate the pumping function of the heart as well as visualize the size and location of a heart attack. Among the techniques of nuclear cardiology, myocardial perfusion imaging is the most widely used. During a nuclear cardiology test, a very small amount of radioactive tracer (radionuclide) is injected into a vein and is taken up by the heart. A very sensitive gamma camera then takes still pictures and movies of the heart with rest, exercise, or medication-induced stress testing.