Cardiac catheterization is used to evaluate the heart and surrounding blood vessels and can determine if coronary artery disease is present. This procedure involves inserting a catheter (a tiny hollow tube) into an artery of the arm or leg, where it is advanced into the heart. During this procedure, the blood pressure in the heart and amount of oxygen in the blood can be measured, heart valves and pumping function can be evaluated, and blood samples can be taken. During the angiography portion of this test, contrast medium or X-ray dye is injected into the coronary arteries and an X-ray camera films the dye as it travels through the heart. This allows the doctor to see if the arteries are narrowed or blocked.

 
If blockages in the coronary arteries are present, the doctor can open them up by using the catheter to perform a percutaneous coronary intervention (PCI), such as an angioplasty.