WKRG.com - Coronary Artery Disease

Coronary Artery Disease

Coronary artery disease, or CAD, is the leading cause of death in America: every year over 500,000 Americans die of heart attacks or other complications of CAD. Approximately 13 million Americans live with coronary artery disease. 42 percent of initial heart attacks are fatal.

CORONARY ARTERY DISEASE 

Atherosclerosis is the deposition of cholesterol-containing plaque in the arteries of the body. It is more commonly described as "hardening of the arteries." Atherosclerosis is a systemic disease. Atherosclerosis can involve any of the arteries of the body: arteries of heart, brain, kidneys, intestines, or legs. The result is a progressive decrease in blood supply to the affected organ or muscle. We do not know the cause of atherosclerosis. We do know several risk factors associated with the disease. The most important of these are genetic pre-disposition, tobacco use, hypertension, diabetes and hypercholesterolemia.

When atherosclerosis involves the arteries of heart (coronary artery disease), there may be insufficient blood supply (ischemia) to the heart muscle. Initially, there may be sufficient blood supply for the heart when the body is at rest. However, with exercise, there may not be enough oxygen supply and ischemia results. Typically, this results in angina. Typical angina occurs with exercise, stress, or after eating. The pain is usually described as a pressure sensation in the chest extending down the left arm or up into the jaw. Normally, the pain is relieved with rest or with nitroglycerin. As disease in the heart arteries progresses, pain may occur with minimal exertion or even at rest. Eventually, there may be a total occlusion of the artery involved (often by a clot) resulting in a myocardial infarction (heart attack). The heart attack causes irreversible loss of function of a portion of the heart muscle because of prolonged oxygen starvation.

OPEN HEART SURGERY

Anytime we utilize the heart-lung machine, we refer to the surgery as open heart surgery. The most common procedure is coronary artery bypass grafting and the second most common is replacement of one of the heart valves. We also use the heart-lung machine to repair aneurysms of the heart, congenital defects, and certain aneurysms of the aorta in the chest.

At the time of surgery, lines are placed in the heart to carry the blue venous blood to the heart-lung machine where it receives oxygen and the now red oxygen-rich blood is returned to the aorta to supply oxygen to the head, kidneys and other organs of the body. The patient is given a blood thinner, heparin, which prevents the blood from clotting in the heart-lung machine.

After the patient is on the bypass machine, we can stop the heart with a solution high in potassium. This makes it easier to work on the arteries of the heart, open the heart and repair the valves, or fix congenital defects.

Once the bypass, valve replacement, or other intervention is finished, we allow the heart to start beating again. With the heart working on its own, we wean the patient from the bypass machine. The lines are removed from the heart and the patient is given another medication to reverse the effects of the blood thinner.

In the Intensive Care Unit, you will notice a number of tubes and wires. Temporary pacemaker wires are placed in the muscle of the heart and brought out through the skin. They are removed at the patient's bedside with minimal discomfort. Chest tubes are placed in the chest to drain any residual fluid. The chest is closed with stainless steel wire, which is permanent. This provides stability to the sternum while it heals. In some patients, we are unable to wean the heart from the bypass machine without other support.

In these cases, we insert a device called the intra-aortic balloon pump. This is a line, which is passed from the groin through the artery to the leg up into the aorta in the chest.

A balloon is located at the tip, which inflates and deflates to help the heart pump. This device is not an artificial heart but is a heart-assist device.

The first 24 hours after surgery is usually the most critical time period. The patient is carefully monitored for changes in blood pressure, heart rhythm and for bleeding. Occasionally, there will be some persistent bleeding after surgery. This is usually secondary to getting the blood to clot normally. In these cases, we will return the patient to the operating room to evacuate any blood in the chest and to check for any sites where we can aid in control of bleeding. For most patients, this is a troublesome but not dangerous complication.

CORONARY ARTERY BYPASS SURGERY

When there is atherosclerosis involving the heart arteries, the heart muscle does not receive sufficient oxygen for its needs. This may result in angina or even a heart attack. For patients with blocked coronary arteries, there are three treatment options: medication, balloon or atherectomy procedure, or surgery. Unfortunately, there is not any medication to remove the plaques caused by atherosclerosis. By controlling the risk factors for heart disease, we may slow its progression, but we can't prevent it. The major role for medication is in the treatment of the symptoms of heart disease. For selected patients, the treatment of choice will be balloon angioplasty, stent placement or atherectomy. These are procedures performed by the cardiologists in the catheterization laboratory. For many patients, the best treatment is a coronary artery bypass procedure.

This operation involves an incision in your sternum (breastbone) and usually in your legs. You are placed on the heart-lung machine and while your heart is stopped, we bypass the blocked arteries. This procedure is called a bypass procedure because we do not directly attack the cholesterol-containing plaque, but rather bypass the blood around it. This is done by bringing down the internal mammary artery from behind the sternum or by using a portion of vein from your leg. The end result is blood flowing out the aorta using the bypass to flow around the blocked coronary artery providing blood to the muscle of the heart.

The majority of patients are free of angina after coronary artery bypass. There is some risk to the procedure. For even the best patients, there is still a small risk of death, heart attack or stroke. In addition, there are usual risks of surgery including bleeding or infection. With heart surgery in particular, it is important to remember that we may not always be able to predict possible complications. We will take the very best care of you, and all our decisions will be based on what is in your best interest.

Endoscopic saphenous vein harvesting

Traditionally, harvesting the great saphenous vein from the leg has required a long incision in the thigh, down into the calf. This incision is 18-24 inches in length and frequently patients complain much more about their leg pain than they do about the pain form the chest incision. In a minimally invasive technique, we use a camera to access the vein through a one-inch incision near the knee. The vein can be removed from the thigh to the ankle with a single small skin incision.

Multiple arterial bypasses for patients with no saphenous vein

In cases where patients do not have a vein in either leg due to prior surgery, we now have multiple arterial grafts that can be utilized. These include the right and left mammary arteries, the gastro-epiploic artery from around the stomach, and the radial artery from the forearm. The radial artery can be harvested endoscopically, like the saphenous vein from the leg, with only a small incision.