Cardiac catheterization is an x-ray test that uses radiographic contrast (dye) to visualize the coronary arteries and pinpoint the presence and severity of blockages and, more importantly, to determine the best treatment available. If the test reveals a blockage you will be offered one of the following treatment modalities: medication only, angioplasty, stent, atherectomy, or bypass surgery. The test can be done on an outpatient basis. The patient is mildly sedated but awake during the procedure. A local anesthetic is used to numb the area (usually the right groin). Soft plastic tubes (catheters) are inserted into the artery then advanced under x-ray guidance. The dye is injected into the heart chambers and coronary arteries – pictures are taken from different angles. This is the best test available to find and visualize the blockages.