Cardiac catheterization is the insertion of a catheter into a chamber or vessel of the heart. Coronary catheterization is a subset of this technique, involving the catheterization of the coronary arteries. This is done for both investigational and interventional purposes.

A cardiac catheterization is a general term for a group of procedures that are performed using this method, such as coronary angiography,  as well as left ventrical angiography. Once the catheter is in place, it can be used to perform a number of procedures including angiography, angioplasty, and balloon septostomy.

Once the catheter engages the artery with the blockage, the doctor will perform one of the interventional procedures described such as  balloon angioplasty and stent.

Cardiac interventions such as the insertion of a stent prolong both the procedure itself as well as the post-catheterization time spent in allowing the wound to clot. Stents are commonly placed during interventional procedures such as angioplasty to help keep the coronary artery open. Some stents contain medicine and are designed to reduce the risk of reblockage  or restenosis. A thin plastic tube  is inserted into an artery  which usually in your groin, but sometimes in the arm. A long, narrow, hollow tube, called a catheter, is passed through the sheath and guided up the blood vessel to the arteries surrounding the heart.

A small puncture is made in a vessel in the groin, the inner bend of the elbow or neck area  then a guidewire is inserted into the incision and threaded through the vessel into the area of the heart that requires treatment, visualized by fluoroscopy or echocardiogram,  and a catheter is then threaded over the guidewire.

If X-ray fluoroscopy is used, a radiocontrast agent will be administered to the patient during the procedure. When the necessary  procedures are complete, the catheter is removed.

A small amount of contrast material is injected through the catheter and is photographed as it moves through the heart's chambers, valves, and major vessels. From the digital pictures of the contrast material, the doctors can tell whether the coronary arteries are narrowed and/or whether the heart valves are working correctly. This technique has several goals to confirm the presence of a suspected heart ailment, quantify the severity of the disease and its effect on the heart, seek out the cause of a symptom such as shortness of breath or signs of cardiac insufficiency and make a patient assessment prior to heart surgery.

A probe that is opaque to X-rays is inserted into the left or right chambers of the heart for the following reasons to measure intracardiac and intravascular blood pressures, take tissue samples for biopsy and to inject various agents for measuring blood flow in the heart and also to detect and quantify the presence of an intracardiac shunt.