What Is Cardiac Catheterization and Stents/Coronary Artery Bypass?

Reviewed by: HU Medical Review Board | Last reviewed: June 2023

Cardiac catheterization is both a diagnostic and procedural technique used to help cardiologists identify how well the heart is working. It is also used to look for certain kinds of disease or damage.1-3

The diagnostic part of the procedure focuses on examining the:1-3

  • Coronary arteries (the arteries that supply blood and oxygen to the heart muscle)
  • Valves
  • Pressures in the heart

This helps doctors find out what may be causing pain or other symptoms of heart failure (HF). If there are blockages in the arteries or damage to the valves, then your doctor will discuss possible treatments with you.1-3

Cardiac catheterization

Doctors use cardiac catheterization to look for blockages in the coronary arteries and measure the pressure and blood flow in the heart.1,3 Doctors can also use this technique to:1,3

  • Evaluate the contracting ability of the heart
  • Look for damage or defects in the heart valves
  • Take blood samples to measure the oxygen level in the heart's chambers

When doctors are looking at the coronary arteries, valves, and the contracting ability of the heart, the procedure is called a left heart catheterization. This procedure is done in a medical facility, often called a cardiac cath lab. You are placed under sedation, which means you will be awake during the procedure but relaxed with some medicine.1,3

Left heart catheterization is performed by inserting a long, thin catheter into an artery in the groin or arm. The catheter is threaded through the blood vessels up into the heart. A contrast dye is injected into the catheter, then special X-rays are taken to provide a clear image of blood flow through the arteries. The use of contrast dye is called coronary angiography, which allows the doctor to better see narrowed or blocked arteries.1,3

When evaluating the pressures and cardiac output of the heart and/or taking blood samples to measure oxygen, a long, thin catheter is inserted into a vein in the groin, arm, or neck. It is passed through to the right side of the heart into a pulmonary artery. The catheter has special sensors on it to measure pressures in the different chambers of the heart and in the pulmonary artery. This is called a right heart catheterization.1,3

This procedure is also typically performed in a cardiac cath lab with mild sedation so you are awake but comfortable. A right heart catheterization is an important tool for people with heart failure to help your doctor ensure you are being treated with the best medications.

Coronary angioplasty

Coronary angioplasty is a technique used to treat blockages in coronary arteries caused by a buildup of plaque (atherosclerosis) or clots. Coronary angioplasty is also called percutaneous coronary interventions (PCI), balloon angioplasty, or coronary artery balloon dilation.1,2,4

Using a left heart catheterization as the approach to reach the heart, a deflated balloon is attached to the tip of the catheter which is threaded up to the coronary arteries. When it reaches the area where the blood flow is blocked, the balloon is inflated. This pushes aside the plaque-fatty deposits or the clot that is causing the blockage and opens up the artery.

Angioplasty helps increase blood flow, which should reduce pain and improve your ability to perform physical activity.1,2

Featured Forum

View all responses caret icon

Stent implantation

A stent is a wire mesh tube that is placed into a blocked coronary artery to widen or open it. It is permanently positioned in the artery. This reduces the likelihood of another blockage developing in the same area.1,2

There are 2 types of stents. Drug-eluting stents are coated with medicine that prevents the artery from becoming blocked again. Stents that are not coated with drugs are called bare metal stents.1,2

A left heart catheterization/angioplasty is the technique used to access the blocked artery. Along with a balloon, a compressed stent is attached to the end of a catheter. It is then inserted through an artery in your groin or arm until it reaches the blockage. The stent is then expanded by inflating the balloon to hold open the narrowed artery.1,2,4

You can have multiple stents in the same artery and in separate arteries depending on the blockages in the blood flow to the heart. A stent helps relieve chest pain and improve blood flow to the heart.1,2

When you receive a stent, you will be placed on a medicine plan called antiplatelet therapy. This therapy helps prevent the stent from getting clogged. Your plan might include aspirin plus another antiplatelet medication. The length of time you will need this therapy is based on which kind of stent was used. It is very important to take your medicines as prescribed to prevent a blood clot that could cause a heart attack.2,4

By providing your email address, you are agreeing to our privacy policy.