Cardiac catheterization (angiography): This test, which requires minor sedation, is a method of viewing and assessing the health of your heart. Through a small incision in your leg or arm, your doctor inserts a catheter (a long, thin, flexible tube) into the blood vessel and passes the tube into your heart and surrounding blood vessels. A dye is injected into the tube to allow your doctor to see your heart’s pumping action and any valve leaks, blockages, or narrowing of your coronary arteries.