What Is Cardiac Catheterization?

Cardiac Catheterization is a procedure that involves the insertion of a catheter into the body. The catheter is inserted into a vein or artery and directed toward the heart.

[Other terms used to describe cardiac catheterization include: coronary angiography, angiogram, and cardiac (or heart) cath.]

The Heart as a Pump

The heart is a muscular, hollow organ that constantly pumps blood throughout the body. It is made up of strong muscle tissue, called heart muscle.

The heart has four compartments, or chambers. There are two chambers on the “left side” and two chambers on the “right side.” The upper chamber on each side, called an atrium, receives and collects blood. The lower chamber on each side, called a ventricle, pumps blood.

The left ventricle is the heart’s main pumping chamber. It pumps blood to all parts of the body, except the lungs. The right ventricle pumps blood only to the lungs.

There are four valves, which control the flow of blood within the heart. They function like one-way doors, allowing blood to move in only one direction and preventing it from backing up into the chamber from which it came.

The oxygen-poor (“used”) blood that returns from the body collects in the right side of the heart. It is then pumped into the lungs, where it picks up fresh oxygen. The oxygen-rich blood coming from the lungs flows into the left side of the heart. It is then pumped into arteries.

The four heart chambers work together to contract and pump blood. As it circulates, blood delivers oxygen and nutrients throughout the body.

The Coronary Arteries

The coronary arteries are the vessels that carry oxygen-rich blood to the heart muscle.

As blood leaves the left ventricle, it is forced into the body’s main artery, the aorta. At the very beginning of the aorta, near the top of the heart, emerge the two coronary arteries. They are referred to as the “left” and “right” coronary arteries.

The first segment of the left coronary artery is called the left main artery. It is about as wide as a drinking straw, and less than an inch long

The left main artery then branches into two slightly narrower arteries: the left anterior descending, which travels down the front side of the heart; and the left circumflex, which circles around the left side and then to the back of the heart.

The right coronary artery comes from the aorta, circles around the right side, and then to the back of the heart.

The two left coronary arteries (left anterior descending and left circumflex) supply blood to the front, left side, and back of the heart. The right coronary artery supplies blood to the bottom, right side, and back of the heart.

Coronary Heart Disease

The inside walls of arteries are normally smooth and flexible, allowing blood to flow through them easily. Over the years, the inside of an artery’s wall may become plugged with fatty deposits.

As these fatty deposits, known as plaques, continue to build up, they narrow the arteries and can reduce the flow of blood. These plaques may sufficiently reduce the flow of blood in the coronary arteries to cause angina (pain or discomfort in the chest, arm, or neck) or a heart attack.

During catheterization, x-ray dye is injected into the coronary arteries and pictures are taken. In patients with coronary disease, the pictures are taken. In patients with coronary disease, the pictures show the actual blockages and their severity.

Defective Heart Valves

Valve disease is present when one or more of the heart valves do not work properly. A heart valve may be “narrowed” or “leaky.”

Most valves defects are mild and have little effect on the pumping function of the heart. Some defects, however tend to go worse with time and may cause weakening of the heart.

In some cases, catheterization may be needed to confirm the diagnosis and to accurately measure the severity of a valve’s narrowing or leakage.

Before Your Catheterization

• Get specific instructions about the food you can have. Generally, you will be asked not to eat or drink anything for 6 to 8 hours before the procedure. [You may have sips of water to swallow your medications.]
• Make arrangements for someone to drive you home after the procedure - you probably won’t be permitted to drive. Family members and friends can wait in an assigned area.
• Pack a small bag in case your doctor decides to keep you overnight in the hospital. You may want to include a robe, slippers, pajamas or nightgown, and toiletries.
• Bring a list of all the medications you are currently taking. It is important for the doctor to know the exact names and dosages of any medications that you take.
• Be sure to mention to the doctor or nurse if you have had an allergic reaction to x-ray dye (contrast), Iodine or seafood, or if you have a history of bleeding problems.
• For your comfort, empty your bladder as completely as possible before the procedure starts. [A bedpan or urinal will be available during the procedure].

During Catheterization

Cardiac catheterization is preformed in a specially equipped x-ray room, called a cardiac catheterization laboratory, or simply “cathlab.”

You will be transported to the cath lab on a movable bed, and then transferred to an x-ray table. The table has a large camera above it and television screen close by. The equipment in the cath lab also includes heart monitors and various instruments and devices.

The cathlab team generally includes a cardiologist, an assistant, a nurse, and one or two technicians.

After being positioned on the x-ray table, you’ll be connected to a variety of monitors, and covered with sterile sheets. The staff will be wearing sterile gowns, gloves, and masks.

During the Procedure

The area where the catheter will be inserted, usually the groin, is cleansed thoroughly. A local anesthetic is injected into the skin with a tiny needle, to numb the area. This may cause a stinging sensation.

A small incision is made in the skin, and a needle is used to puncture the blood vessel (vein or artery) into which the catheter will be inserted.

After the catheter has been inserted into the blood vessel, it is slowly advanced toward the heart. The doctor and staff can follow its progress on the television screen.

Measuring the pressures inside the heart allows doctors to assess the heart’s pumping function and estimate the severity of valve defects. The pressure waves are displayed on monitor screens and can be recorded on special tracing paper.

During a coronary angiogram, specially shaped catheters are inserted, one after the other. They are directed toward the openings of the coronary arteries. Dye is injected through the catheter into each coronary artery, and an x-ray camera takes pictures. These pictures help detect areas of narrowing (“blockages”) and assess their severity.

During a left ventriculogram, a special catheter is directed into the left ventricle (the hearts main pumping chamber). Dye is injected under pressure into the ventricle. A series of pictures is obtained, giving a detailed view of the left ventricle during its pumping action.

Tilting the camera allows multiple shots to be taken at multiple angles. This allows a more detailed study of the coronary arteries and heart chambers.

What You Can Expect

You will be awake during the procedure, and you may be asked to take a deep breath and hold it. You may also be asked to cough forcefully several times. Cardiac catheterization generally is not painful, although you may feel some discomfort during the insertion of the catheter(s) in the groin. You will not feel the catheters moving through the blood vessels and into the heart.

During the injection of dye into the ventricle, you may feel a warm sensation, or “hot flash,” over your body, lasting for 10 to 20 seconds.

A complete catheterization study usually takes from one to two hours. If at any time during the study you feel pain or discomfort, let the staff know.

Most of the complications associated with catheterization are minor and of no long-term consequence. These include nausea and vomiting, allergic skin rash (hives), and heartbeat irregularity.

Some patients may develop bleeding at the insertion site. Blood collects under the skin, resulting in a local swelling and/ or a “bruise.”

Rarely, catheterization may be associated with more serious complications. These include damage to blood vessels, formation of blood clots, infection, abnormal heart rhythms, a heart attack, or a stroke. Deaths are very rare.

Potential Benefits

Catheterization provides important information about the heart’s pumping function and the condition of the coronary arteries and heart valves.

This kind of information often cannot be obtained by any other means. It allows an accurate diagnosis and enables your doctor to begin treatment before irreversible damage to the heart occurs.

After Your Catheterization

After the procedure is completed and the catheters are removed, the doctor (or nurse) will apply firm pressure over the groin for about 10 to 20 minutes. This is done to prevent bleeding.

You’ll be transported to the recovery area or to your room. The nurse will apply a pressure dressing over the insertion site. Sometimes a weight (usually a small sandbag) is applied at the site.

You’ll need to lie flat in bed for 4 to 6 hours, to allow a small seal to form over the puncture in the artery. During that time, do not bend or lift the leg where the catheters were inserted. To relieve stiffness, you may move your foot or wiggle your toes.

The nurse will check your pulse and blood pressure frequently, and will also keep checking the site where the catheters were inserted. If you fell sudden pain at the site, or if you notice a warm, sticky sensation of fluid, notify the nurse immediately.

You will be able to eat shortly after the procedure is over. You’ll be encouraged to drink plenty of liquids, to flush the x-ray dye out of the body.

At Home, After the Procedure

• Have a family member or friend drive you home from the hospital.
• Limit your activity during the first 24 hours after returning home. You may move about, but do not strain or lift heavy objects.
• Leave the dressing on your groin (or arm) until the day after the procedure. The nurse will tell you how to take it off and when it’s okay to take a shower.
• A bruise or small lumps under the skin at the insertion site are common. They generally disappear within 3 to 4 weeks.
• Call your doctor if the insertion site begins to bleed, the bruising or swelling increases, or the leg (or arm) in which the catheters were inserted feels cold or numb.
• Call your doctor or nurse if the insertion site becomes painful or warm to the touch, or if you develop a fever over 100 degrees F.
• Ask your doctor when you can return to your normal activities, and whether there are any specific restrictions.
• Be sure to check with your doctor or nurse about medications - which ones to continue, and which ones to stop.

Coronary Angioplasty

Coronary angioplasty is non-surgical technique used to open narrowed arteries. A special catheter with a balloon at its tip is passed into the narrowed artery. The balloon is inflated, compressing the fatty deposits against the artery’s walls. This allows better flow of blood to the heart muscle.

Changes in Your Lifestyle

No matter which treatment your doctor recommends, it is important that you make some changes in your lifestyle. This will help eliminate certain factors (such as high blood cholesterol and smoking) that can lead to the continuing build-up of fatty deposits in your arteries.

• Enjoy a diet low in fat and cholesterol.
• Lose extra weight, and keep it off.
• Exercise regularly (consult your doctor before starting an exercise program).
• Keep your blood pressure under control.
• Reduce excess tension and stress.
• If you smoke—quit!