Cardiac Catheterization

Cardiac catheterization is a diagnostic tool used by cardiologists to perform various heart function tests, including angiography, and electrophysiology studies. It is an imaging procedure that involves inserting a catheter into a blood vessel in the leg or arm and guiding it to the heart with the aid of a special x-ray machine. Contrast dye is injected through the catheter so that x-ray movies of the valves, coronary arteries, and heart chambers can be taken. Cardiologists use cardiac catheterization to evaluate or confirm the presence of heart disease; evaluate heart muscle function; or determine the need for further treatment (percutaneous coronary intervention or bypass surgery). An immediate percutaneous coronary intervention may be performed if treatable coronary artery disease is discovered. Also, electrical impulses may be sent through the catheter to study irregular heartbeats (see electrophysiology studies).

How It Works

During cardiac catheterization, a long, narrow tube called a catheter is inserted through a plastic introducer sheath (a short, hollow tube that is inserted into a blood vessel in the leg or arm). The catheter is guided through the blood vessel to the heart with the aid of a special x-ray machine.

Contrast dye is injected through the catheter, and x-ray movies are created as the dye moves through the heart’s chambers, valves, and major vessels. This part of the procedure is called a coronary angiogram (or coronary angiography). Digital photographs of the contrast material are used to identify sites of narrowing or blockage in the coronary arteries.

Additional imaging procedures, such as intravascular ultrasound or fractional flow reserve, may be performed along with cardiac catheterization to obtain detailed images of the walls of the blood vessels. Cardiac catheterization, angiography, and arteriography can also be used to see blood vessels in other parts of the body, including the carotid arteries.


Texas Heart Institute
Cleveland Clinic