Coronary angiography (also known as coronary arteriography) is the gold standard test to detect blockages in the coronary arteries. It is performed when a resting ECG and a stress test indicate that portions of the heart are receiving insufficient blood.
A catheter (a small tube) is inserted into an artery through a small incision in the groin or arm and is threaded through the blood vessels into the coronary arteries. A dye or contrast material is injected into the catheter to allow the arteries to be imaged on x-ray film. From these x-rays, your doctor will be able to detect the presence, location, and severity of obstructions.
Doctors often use this test to determine whether angioplasty or bypass surgery is needed (angioplasty is usually carried out at the same time as angiography). Although considered very safe, particularly when performed by a doctor highly experienced in the procedure, angiography is an invasive test and there is a small (less than 1%) risk of a heart attack, stroke, major bleeding, or death. This risk increases in older, less healthy people.