Left heart catheterization describes the placement of a tube into the heart. It is most commonly done to examine the arteries that supply the heart. It may also used to examine the structure and function of the left side of the heart.

Who is a candidate for the procedure?

Most people undergo this procedure because a blockage in the heart arteries, known as coronary artery disease, is suspected. These blockages may increase the risk of, or cause, heart attacks.

Sometimes the procedure is done to:

How is the procedure performed?

The most common method of left heart catheterization is described below.

An intravenous or IV line is put in a vein in the person's arm and a sedative is usually given. The person is asked to lie on a flat table in the procedure room.

Skin on one side of the groin is cleaned. An incision is made in the thigh area near the groin. This incision cuts into a major artery. A tube, or catheter, is inserted into the artery. The tube is then advanced into the artery and up toward the heart. A special X-ray machine can follow the tube as it moves forward. The tube eventually reaches the heart.

Once the tube is in the right place, dye is squirted through it. This dye shows up well on the X-rays giving clear pictures of the arteries of the heart and the heart itself.

Any blockage or defects in the heart or arteries can be seen, too. If certain blockages or heart valve problems are seen, the doctor may try to correct them with tiny instruments that can be inserted through the tube.

For example, a balloon can be inserted through the tube into a blocked artery. The balloon can be inflated to open the blockage. This is known as angioplasty. A rigid tube, or stent, may be placed into the artery to keep it from becoming blocked again. Sometimes a blood clot is seen and a "clot-busting" medication is given to dissolve the clot.

After the pictures are taken and any corrections done, the tube is removed from the body. Pressure is applied over the incision to prevent bleeding.