Coronary Artery Disease (CAD)

Coronary Artery Disease (CAD)

There are several coronary arteries which deliver oxygen and nutrients to the heart’s own tissue. These coronary arteries can become blocked by a buildup of cholesterol fats, often referred to as “plaque”. Plaque deposits can make the arteries stiff and irregular. This is called atherosclerosis, or “hardening of the arteries”. There can be a single blockage or multiple blockages, and they can vary in severity and location.

Any narrowing, or blockage, of the coronary arteries reduces the blood supply to the heart tissue, therefore reducing the amount of oxygen and nutrients delivered. This inhibits the normal function of the heart muscle.

Symptoms of Coronary Artery Disease

A person with one or more blocked arteries may feel pain and periodic discomfort in the chest, radiating to the neck and/or arms (usually on the left side). Symptoms can be triggered by physical exertion, eating, changes in temperature, extreme emotion or may be present even at rest. The symptoms may last 3 to 5 minutes until the cause is relieved; otherwise symptoms may last longer. If this continues, it can starve the heart muscle cells of oxygen and eventually lead to a heart attack.

What are the risk factors that contribute to CAD?

Several factors are known to contribute to the build up of plaque in the coronary arteries. It is often the combination of several of these risk factors, rather than a single factor that contributes to the development of CAD. Some of the risk factors such as gender, age, and heredity can only be noted–they cannot be changed. Other factors, however, can be controlled. Once coronary artery disease is established and becomes symptomatic most people will have a stress test and then an angiogram. In patients with blockages in two or three arteries, the cardiologist will usually recommend coronary bypass surgery.

High blood pressure
Smoking
High cholesterol levels
Lack of proper exercise
Body weight
Diabetes
Stress
Poor Diet

What to expect in coronary surgery

Coronary artery bypass grafting (CABG) requires a team of experts. A cardiothoracic surgeon will do the surgery with support from an anesthesiologist, perfusionist (heart-lung bypass machine specialist), other surgeons, and nurses.

There are several types of CABG. They range from traditional surgery to newer, less-invasive methods.

Traditional Coronary Artery Bypass Grafting

This type of surgery usually lasts 3–6 hours, depending on the number of arteries being bypassed. Many steps take place during traditional CABG.

You’ll be under general anesthesia for the surgery. The term “anesthesia” refers to a loss of feeling and awareness. General anesthesia temporarily puts you to sleep.

During the surgery, the anaesthetist will check your heartbeat, blood pressure, oxygen levels, and breathing. A breathing tube will be placed in your lungs through your throat. The tube will connect to a ventilator (a machine that supports breathing).

The surgeon will make an incision (cut) down the centre of your chest. He or she will cut your chest bone and open your rib cage to reach your heart.

You’ll receive medicines to stop your heart. This allows the surgeon to operate on your heart while it’s not beating. You’ll also receive medicines to protect your heart function during the time that it’s not beating.

A heart-lung bypass machine will keep oxygen-rich blood moving throughout your body during the surgery.

The surgeon will take an artery or vein from your body—for example, from your chest or leg—to use as the bypass graft. For surgeries with several bypasses, both artery and vein grafts are commonly used.

  • Artery grafts. These grafts are much less likely than vein grafts to become blocked over time. The left internal mammary artery most often is used for an artery graft. This artery is located inside the chest, close to the heart. Arteries from the arm or other places in the body also are used. At Perth Cardiothoracic surgery we use Right internal mammary arteries and radial arteries (from the arm). These arteries are able to be removed safely without ill effects.
  • Vein grafts. Although veins are commonly used as grafts, they’re more likely than artery grafts to become blocked over time. The saphenous vein—a long vein running along the inner side of the leg—typically is used.

When the surgeon finishes the grafting, he or she will restore blood flow to your heart. Usually, the heart starts beating again on its own. Sometimes mild electric shocks are used to restart the heart.

You’ll be disconnected from the heart-lung bypass machine. Then, tubes will be inserted into your chest to drain fluid.