Cardiac Bypass Surgery

What Is Cardiac Bypass Surgery?

Cardiac bypass surgery is an operation to restore the flow of blood through the arteries that supply blood to the heart, when a blockage or partial blockage occurs in these arteries.

The arteries that supply the heart muscle with oxygen and nutrients are known as the coronary arteries. The word “coronary” means a crown, and is the name given to these arteries that circle the heart like a crown. The narrowing of the arteries of the heart is known as coronary artery disease, which is the most common form of heart disease.

The operation, also known as a coronary artery bypass graft (CABG), involves rerouting the blood flow around the obstructed part of the artery. This is done by using a portion of a blood vessel taken from another part of the body, usually the leg or chest, and surgically attaching it across a severely narrowed or blocked coronary artery, thus “bypassing” the blockage. These “new” blood vessels carry blood around the obstruction, so that the blood supply to and from the heart is restored.

Coronary artery disease develops when one or more of the coronary arteries that supply the blood to the heart become narrower than they used to be, due to the buildup of cholesterol and other substances in the wall of the artery. This affects the blood flow to the heart muscle. Without an adequate blood supply, heart muscle tissue can be damaged.

Deposits of cholesterol and other fat-like substances can build up in the inner lining of these blood vessels and become coated with scar tissue, forming a cholesterol-rich bump in the blood vessel wall known as plaque. Plaque buildup narrows and hardens the blood vessel, a process called atherosclerosis, or hardening of the arteries.

Eventually these plaque deposits can build up to significantly reduce or block blood flow to the heart. A person may experience chest pain or discomfort from inadequate blood flow to the heart, especially during exercise when the heart needs more oxygen. This is known as angina.

For further information about angina, go to Angina.

When Is Bypass Surgery Offered?

There are two main coronary arteries supplying blood to the heart, the left coronary artery and the right coronary artery. The left main coronary artery, which splits into two further branches known as the left anterior descending artery and the left circumflex artery, supplies most of the heart with blood; thus if it is diseased, can cause major problems. The right coronary artery supplies blood to the right side of the heart and the lower part of the left side of the heart.

Most people with angina have blockages in one or more of these arteries and/or their branches. A cardiologist (heart specialist) will perform various tests to determine the location and extent of the blockage.

Bypass surgery is usually performed when a person has two or three blood vessels with blockages, or when the major vessel has a severe blockage. Therefore, bypass surgery may be advised in the following situations:

• When there is severe narrowing of the left main coronary artery (because this major artery branches into several others, putting too much of the heart at risk if the angioplasty were to fail)
• If there is severe narrowing of any three arteries in a person who also has a weakly pumping heart
• If there is severe narrowing of the left anterior descending artery and at least one other coronary artery, plus either diabetes or a weakly pumping heart
• Following failed coronary angioplasty, a procedure performed to widen a narrowed coronary artery by inserting a balloon-tipped tube into the artery and inflating the balloon.

  For further information about angioplasty, go to Angioplasty.

What Is Coronary Artery Disease?

Coronary artery disease – also known as coronary heart disease (CHD) or ischemic heart disease (IHD) – affects most people as they age. The coronary arteries become constricted or blocked by atheromas – bulging masses or “plaques” that form within the walls lining the arteries.

“Atheroma” is the Italian word for porridge, because it resembles porridge when viewed under a microscope. It contains a mix of cholesterol-filled cells, inflammatory cells, and fibrous scar tissue.

Atherosclerosis is the term used to describe the gradual build-up and hardening of atheromas within the arterial walls. It is commonly referred to as “hardening of the arteries.”

It can occur in any artery of the body and depending on the artery affected, specific symptoms can be expected. When the coronary arteries are affected then angina or a heart attack may occur, if the carotid arteries in the neck (they supply blood to the brain) are affected then a stroke may occur.

In almost all cases, the underlying cause of angina is the critical narrowing of one or more of the coronary arteries that supply blood to the heart.

The more atheromas that line the coronary arteries, the narrower the pathway for blood. Atherosclerosis often restricts as much as 70% of the blood that flows through the coronary arteries. Although the heart muscle receives enough blood for routine activities like walking or sitting, myocardial ischemia (insufficient blood in the heart muscle) results when the narrow arteries do not allow enough blood to reach the heart during periods of physical or emotional stress. This lack of blood will trigger an episode of angina.

If the flow of blood is blocked completely, a heart attack, which is damage to the heart muscle, can result.

A number of things contribute to coronary artery disease, but these factors are particularly important:

• Family history
• Smoking
• Diabetes
• Hypertension (high blood pressure)
• Sedentary lifestyle
• Elevated cholesterol (a fat-like substance needed for the development of body cells that is both produced in the body and found in animal foods; if levels of cholesterol in the body are too high, it can be deposited on artery walls)
• Overweight or obesity

Someone with coronary artery disease may have one or more of these risk factors, but some people with the disease have none of the risk factors.

How Is Coronary Artery Disease Diagnosed?

The classic symptoms of heart disease include:

• Chest discomfort that gets worse with activity and improves with rest (or with nitroglycerin pills)
• Shortness of breath
• Dizziness
• Ankle swelling
• Fainting

However, many people with coronary artery disease have no symptoms. Their heart disease may be diagnosed during a routine physical examination.

If a physician suspects heart disease, one or more tests may help to find out if there is disease and how serious it is.

Tests for coronary artery disease include:

• An echocardiogram, which is a non invasive test that uses sound waves, taking pictures of how the walls of the heart move, allowing the doctor to see if they move abnormally.
• An exercise treadmill test, also known as a stress test. While you walk on a treadmill, the physician monitors the electrical signal from your heart, which is recorded as an electrocardiogram (ECG). Changes in the ECG, which can indicate whether the heart is receiving adequate blood, while you exercise, can help the doctor to make a more accurate diagnosis. An echocardiogram or specialized nuclear scanning devices may also be used.
• The stress thallium test. At the end of the regular stress test, a small amount of a safe drug is injected into your veins. This allows the physician to view the heart with a special scanning device and see which parts of the heart may not be getting enough blood.
• A coronary angiogram (or arteriogram). In this test, the doctor injects a small amount of dye into an artery, and makes a video of the heart as the dye moves through. This shows exactly where thecoronary arteries might be blocked, and how big the blockages are.

For further information about angina and the treatment of coronary artery disease, go to Angina.

For further information about lowering your cholesterol, go to Lowering Your Cholesterol.

For further information about reducing the risk of heart disease, go toHow To Reduce Your Risk For Heart Disease.

How Does Bypass Surgery Help?

After bypass surgery, the blood supply to the area of the heart that was previously restricted due to narrowing of the artery supplying that area, is restored. The blocked artery has now been bypassed.

Bypass surgery may improve quality of life and increase the life span. In some cases, it may do both. In other cases, it may only improve the quality of life.

The important thing to remember is that surgery is not a cure, but just keeps the problem under control. Once your surgeon has done the procedure, there are choices you may take to prevent the condition from recurring (coming back). How healthy you are after surgery depends in large part on the steps you take to prevent future problems.

Cardiac Bypass Surgery: Preparing For Surgery

Except in emergencies, patients and their doctors have time to prepare for bypass surgery. In addition to the various tests, you will have time to meet the surgical team and ask them questions about the procedure. If you wish, you will also be able to plan donations of your own blood, or have family members and friends donate blood for your use. If you do this, don’t forget to let the doctors who see you know about it.

Here are some questions you may wish to ask your doctor before bypass surgery:

• Why is this the best option for me?
• Are there serious problems I might have during surgery, and what are my chances of having these problems?
• Will I need more surgery in the future?

Admission To The Hospital

Blood tests, electrocardiogram (ECG) and chest x-rays will usually be done before you come into the hospital or in some cases after you are admitted. It is usual to be admitted the evening before surgery. Increasingly, however, patients check in on the morning of surgery itself.

Visit By The Anesthesiologist

The cardiovascular anesthesiologist, a specialist who manages your sedatives and pain management during surgery, will talk to you before the procedure. This physician will ask about any anesthesia (medications to make procedures more comfortable) you have had in the past, and if there were any complications.

The anesthesiologist will want to know about your general medical history, including diseases, allergies, and medications, so that he or she can find the best method of minimizing your discomfort during and after surgery.

Visit By Your Surgeon

Before the operation, your cardiac surgeon will visit. The surgeon will already know you, but will ask more questions, and explain what to expect over the next few days. If you have last-minute questions, now is the time to ask them.

Pre-Op

You will be asked to take a shower using a special soap. If you have been admitted the night before surgery, you may be given a mild sedative to help you sleep. If this doesn’t work, speak to the nurse. A good night’s sleep before surgery is important.

How Is Cardiac Bypass Surgery Performed?

Just before the surgery, you will be given a mild sedative. If you are a man, your chest will be shaved. If blood vessels are to be taken from your legs, they will be shaved too. You will then be moved to the operating room.

The operating room can be intimidating and feel cold at first, but the sedative should help you to feel calmer. If you are extremely uncomfortable, talk to the anesthesiologist. The anesthesiologist will start an intravenous line (IV) and give you more sedation. Small patches will be put on your chest for monitoring your heart, and the anesthesiologist will ask you to breathe into a mask. At this point the anesthesia starts, and you will be asleep for the procedure.

After you are asleep, the anesthesiologist will insert more IVs including special IVs to monitor the pressures in your heart. You will be washed with antiseptics and draped with sterile plastic covers and towels. The surgical team will then:

• Make an incision down the center of the breastbone
• Connect the heart to a heart-lung machine that will take over its work during surgery
• Remove a blood vessel or blood vessels from elsewhere in the body, either an artery from the chest (the internal mammary artery from the front of the chest), from the arm (the radial artery), or veins from the leg that will be used in the bypass
• Attach the new blood vessels to the coronary arteries to bypass the blockages in the arteries

The usual time for surgery is between 3 and 5 hours, depending on the number of bypasses and the complexity of the surgery.

Recovering From Cardiac Bypass Surgery

The Intensive Care Unit (ICU) will be the first stop after surgery. You will wake up a few hours after the operation, but may feel tired or groggy for a day or two.

Early in your recovery, a ventilator (respirator) will help you to breathe and will make sure your blood gets the right amount of oxygen. Your arms may be in soft restraints to prevent you from pulling out any tubes or IV lines in your sleep.

Tubes

There will be a tube in the throat called an endotracheal tube, or an ET tube. It is left in until you are able to breathe on your own, usually the night after surgery or first thing the following day. You will hear a respirator in the background, as it helps breathing.

There will be other tubes in place after surgery, including tubes into your chest and your bladder, as well as your veins and heart. Most of them will be removed during the first day.

Intravenous tubes will still be in place, and medications are given through these. The medications will be given at very controlled rates by pumps.

During Postoperative Recovery

By the end of the day after surgery, most patients are taken off the respirator, and most of the tubes are removed. You will probably be able to sit on the edge of the bed and even walk a few steps. If your condition is stable, you will be moved to the ECG monitored area.

In the monitored area a system will constantly track and measure your heart function. One-third of all patients having heart surgery will have irregularity in the heartbeat, which usually requires treatment with drugs for about six weeks. Don’t be unduly concerned if you feel a fast or irregular heartbeat, but let the medical team know if you feel anything strange. Thanks to the monitors, your nurses may be aware of irregularities before you are, and will take care of it.

The Incentive Spirometer

An incentive spirometer is a device that causes the lungs to fill with as much air as possible. This reduces the risk of pneumonia, and will help breathing in general. Using the spirometer may trigger a cough. It may hurt a little, but your incision will not come apart. The nurse will show you how to use a pillow to help with coughing.

Walking After Surgery

Walking is one of the most important steps to recovery. The medical staff will help you get started. Try to stay out of bed as much as possible, because the more you walk, the sooner you will recover. If a vein was taken from your leg, it may hurt, and you may have back pain, especially if the internal thoracic or mammary artery was used for bypass. If you have pain, talk to the medical staff. But keep walking!

The Final Days Of Hospital Stay

After two days in the monitored section, if you are eating well and able to go to the bathroom, you will be transferred to the non-monitored area. Just before transfer, someone will remove the temporary pacing wires from your chest that were placed during surgery.

The stay in the non-monitored section of the hospital will help you to gain more strength and improve your appetite. Most patients stay between two and four days. Don’t be surprised or alarmed if you tire easily. It is a normal part of the recovery.

Education

Throughout the hospital stay, nurses and others will give you information to support recovery. Group sessions with other patients and families are common, and can provide an opportunity to talk over the experience with others.

Instruction will cover exercise, diet and general activities after surgery. Remember, heart surgery does not cure coronary artery disease. It only manages the problem. Your lifestyle choices after the operation may determine your quality of life and perhaps its length.

Going Home

Most people are discharged five to seven days after surgery. You will be given prescriptions to take home, plus information on other pills you will need, such as aspirin to help prevent blood clots, iron tablets, and vitamins. There may be additional medications depending on your other medical problems. If you are not completely clear on your medications or follow-up plan, review it with the medical team.

Unless you have diabetes and need to control your glucose levels, you can eat your usual moderate diet for the first few weeks. About four weeks after surgery, beginning to adjusting your diet can help to control weight and cholesterol levels, which may help prevent future heart problems.

It is common to gain some weight after surgery. This is because fluid collects in the tissues. Your feet may be swollen, especially on the side where the veins were taken for the bypasses. Several days later when the fluid has been released from your body, you may find that you have lost a considerable amount of weight.

Care Of The Incisions

Your surgeon will give you instructions about keeping the incisions clean, and watching for problems. Call if there are any signs of infection such as:

• Redness
• An increase in pain
• Fluid coming from the wound
• Fever

Cardiac Bypass Surgery: What Are The Risks And Complications?

Any medical procedure has possible risks and complications. The most common risks in bypass surgery include:

• Too much bleeding, requiring more surgery
• Infection of the wound
• Stroke, the sudden death of brain cells due to lack of oxygen caused by a blockage
• Blood clots
• Organ failure (liver, kidney, lung)
• Heart attacks occur in 5% to 10% of patents, and are the main cause of death.

While survival rates for cardiac bypass surgery are good, if the above complications are severe, they can cause mortality (death). This may occur in about 3% of bypass operations.

Complications increase with:

• Increased age
• Poor heart muscle function
• Blockage of the main coronary artery
• Diabetes
• Chronic lung disease
• Chronic kidney failure
• Being a woman, as they develop the disease about 10 years later than men because they are protected by hormones prior to menopause. Women are generally smaller than men, with smaller coronary arteries, which may also make the procedure more difficult.

Life After Bypass Surgery

You will have a checkup with the cardiologist about 7 to 10 days after you go home. During this visit, the cardiologist will discuss your recovery, make recommendations for improving your lifestyle, and fine-tune your medications if necessary.

By the sixth week after surgery, most people resume almost all of their regular activities. You can drive, travel, return to your normal sex life, go to movies, eat out, and even return to work. However, your healing will progress most smoothly if you don’t let yourself get exhausted, and if you remember to rest when you are tired. You will notice that as your activity increases, your strength will increase too. Six weeks after discharge, you should be able to walk two to three miles in one hour.

Cardiac Rehabilitation

Your cardiologist will discuss beginning an exercise program. This will be one of the most important things that will keep your cardiovascular system healthy.

Many people choose rehabilitation classes to help them recover. These programs teach the importance of exercise, how to get started, and how to know your limits. Some programs may also help you make changes in diet, quit smoking, or control stress. Through these programs, you will meet other people who have gone through the same procedure, and will have the chance to exchange stories and tips for recovery.

Daily Exercise Program

Usually, cardiac rehabilitation classes are held three times a week. On at least two other days, exercising for approximately one hour will aid your recovery. Walking is the best exercise for improving the overall health of your heart. It may reduce the chances of future heart problems and will probably prolong your life. A walking program should be tailored to your abilities, and reach a pace of about three miles an hour within a few weeks.

Keeping Your Arteries Clear

Before bypass surgery, there are significant blockages in the coronary arteries. If preventive measures are not taken, the processes that caused those original blockages can occur in the new bypass vessels after surgery. So, it is important to reduce the risk factors for coronary artery disease that can be controlled. These include: smoking, high blood pressure, diabetes, high cholesterol, and a sedentary lifestyle.

Smoking

Smoking causes major damage to your cardiovascular system. The risk of renewed heart disease is even greater than the risk of lung cancer. Patients who continue to smoke after bypass surgery are likely to have their new arteries blocked sooner than those who do not smoke. That’s why it’s essential for patients who smoke to quit after their surgery. If you intend to smoke after surgery, it defeats the purpose of the original surgery.

Secondhand smoke may also increase your risk, so this is a good time for all members of your household to quit. For information on finding support to quit smoking, see “Additional Sources of Information”.

High Blood Pressure

Many patients have hypertension (high blood pressure) before surgery. It is essential to monitor your pressure carefully after surgery. Poor control of blood pressure after surgery can worsen blockages in your arteries and speed up changes in your bypass grafts.

Your doctors will help you work out a plan for controlling blood pressure with diet, and perhaps medication. Keep track of the blood pressure numbers yourself, so you know how well you are doing.

For further information about high blood pressure, go to High Blood Pressure.

Diabetes

Diabetes increases the risk for coronary artery disease. Control of blood sugar after heart surgery is just as important as before surgery, to keep the bypass grafts open. Continue to work closely with your diabetes team to keep your diabetes in check.

Elevated Cholesterol

Poor control of cholesterol after surgery increases the risk that your new bypass grafts will be blocked. If changes in diet and lifestyle are not successful in reducing the level of cholesterol, then medications may be necessary in addition to the changes in diet recommended by your doctors. Remember that all medications have side effects, so altering your diet is an ideal strategy to improve your lifelong health.

For further information about lowering your cholesterol, go to How To Lower Your Cholesterol Level.

Sedentary Lifestyle

Moderate amounts of physical activity, including daily walks, swimming, or biking for fun can make big differences in how you feel and how your heart works. To become more physically active:

• Start slow. Begin by walking or being active just 15-30 minutes each day, and work up slowly from there.
• Find ways to do more physical activities. From washing the car, to gardening, to taking the stairs rather than the elevator, all movement counts as physical activity.
• Find activities you enjoy doing. Physical activity seems easier when it’s fun.
• Be active with a friend. Walking, biking, or other activities are great ways to spend time with people.

Stress

Learning about and controlling stress can help your recovery and make it easier to tackle other lifestyle changes. There are many ways that people reduce daily stress: Some have quiet hobbies, some meditate, and some are physically active. Do whatever works for you, or sign up for a stress-control class. Remember, everyone is exposed to stress. But how you handle it can either support or undermine your long-term health.

For further information about reducing stress, go to Stress And How To Manage It.

Diet

Improving eating habits can help reduce risk for heart disease. Here are some tips to reduce the saturated fat and cholesterol in your diet:

• Try lean meats like skinless chicken or turkey, and fish instead of higher fat meats like bacon, sausages, and marbled steaks.
• Try main dishes featuring whole-wheat pasta, rice, beans, and/or vegetables.
• Use lower-fat cooking methods, like boiling, broiling, baking, roasting, poaching, steaming, sauteing, stir-frying, or microwaving.
• Trim off the fat you can see before cooking meat or poultry.
• Substitute leaner foods for egg yolks and organ meats.
• Choose fat-free or 1% milk, and nonfat or low-fat yogurt and cheeses.
• Eat five or more servings of fruits or vegetables each day.
• Choose whole-grain cereals and breads.

Major dietary change is a challenge for anyone. But, by making gradual changes, you may find that you actually enjoy a healthy diet more. A registered dietitian can help you to make the transition to healthy eating.

Are There Other Treatments For Heart Disease?

In addition to bypass surgery, there are two other types of treatment for coronary artery disease:

• Medication
• Angioplasty

Medication

Medication is useful for patients with disease in the earlier stages with just one or two arteries that are partially blocked. It is also useful if for some reason your coronary artery disease cannot be treated in other ways.

These medications are designed to:

• Slow your heart down to decrease its work
• Lower your blood pressure so that the heart does not have to work as hard
• Partially “relax” the arteries of the heart so that they can carry more blood
• Lower the chance that a clot will develop in your arteries

Coronary Angioplasty

Coronary Angioplasty is a medical procedure that widens narrowed arteries in the heart without the need for open heart surgery.

In an angioplasty:

• A specially trained doctor inserts a long, narrow tube (called a catheter) through a small cut in the thigh or the arm.
• The doctor threads the catheter through blood vessels leading to the heart until it reaches the narrowed part of the artery.
• The doctor positions a tiny balloon that is attached to the tip of the catheter right at site of the narrowing, and then inflates it with air. The pressure of the balloon flattens the plaque in several spots and allows the artery to open wider.
• Often, a tiny wire tube called a stent is left inside the artery to hold it open.

Possible risks of angioplasty include:

• Worsened angina
• Emergency bypass surgery
• Heart attack
• Damage to the artery
• Re-blockage of the artery
• Death

Not everyone can benefit from this procedure; it’s best for patients with only one or two blockages in their arteries.

For further information about angioplasty, go to Angioplasty.

Frequently Asked Questions: Cardiac Bypass Surgery

Here are some frequently asked questions related to cardiac bypass surgery.

Q: Are there any new developments in coronary bypass surgery?

A: Recent advances in stabilizing the heart as it beats allows surgeons to do coronary bypass surgery without the use of cardiopulmonary bypass. This is known as beating heart surgery. There are several stabilizers available that immobilize the heart at the point of the graft. This allows the surgeon to do the grafting on immobilized tissue while the rest of the heart beats. Advantages of beating heart surgery include the decrease in the inflammatory response, decreased bleeding, and improved organ function. Disadvantages include the difficulty in accessing areas of the heart that continue to beat.

Q: Why is aspirin helpful in preventing blockages?

A: Aspirin is usually used to relieve a headache or a fever. But because it thins the blood, aspirin also can prevent blood clots from forming. These are the same kind of blood clots that can block the coronary arteries and cause a heart attack.Acetaminophen (for example, Tylenol^TM) and ibuprofen (for example, Advil^TM) are not the same as aspirin and should not be used in place of aspirin.Most people diagnosed with heart disease will be told to take aspirin every day. Your doctor will tell you how much to take. Coated or buffered aspirin may reduce major side effects, which include too much bleeding. Aspirin should not be used if you are allergic to it or if you have had an ulcer or any other bleeding problem.

Q: What is normal blood pressure?

A: Normal blood pressure is stated as 120/80. In the measurement, the top number (systolic pressure) represents the pressure in the arteries as the heart contracts. The bottom number (diastolic pressure) is the minimum pressure in the artery as the heart relaxes after contraction.Generally, a blood pressure measurement of 140/90 Hg that has been confirmed on multiple occasions is considered high. Experts tend to consider high blood pressure a continuum rather than a set number. For example, people with kidney disease or diabetes would be considered to have high blood pressure at a lower measurement.

Q: Are there any alternative therapies available?

A: Several dietary supplements show promise in preventing heart disease. The omega-3 fatty acids found in fish and fish oil have been shown in studies to be preventive. Coenzyme Q10 is a powerful antioxidant which has been thought to be important in the protection against cardiovascular disease. Several alternative practices including yoga and meditation are excellent stress management tools. Studies using these therapies in combination with a very low-fat diet and physical activity have showed great promise in treating heart disease.

Putting It All Together: Cardiac Bypass Surgery

Here is a summary of the important facts and information related to cardiac bypass surgery.

• Cardiac bypass surgery, also know as cardiac artery bypass graft (CABG) is an operation to restore blood flow to the arteries around the heart, performed when a person’s coronary arteries become blocked.
• Coronary artery disease is the condition which may lead to cardiac bypass surgery. It is a condition where the arteries around the heart become clogged or blocked by plaque.
• Risk factors for developing coronary artery disease include family history, smoking, diabetes, hypertension (high blood pressure), a sedentary lifestyle, elevated cholesterol, and being overweight.
• Tests for coronary artery disease include an exercise treadmill test, also known as a stress test, the stress thallium test, and acoronary angiogram (or arteriogram).
• An anesthesiologist will use a number of medications to put you to sleep during the operation, and to help you remain comfortable immediately after the operation.
• The procedure will be done by making an incision down the center of the breastbone, connecting the heart to a heart-lung machine that will take over its work during surgery, removing the blood vessels from the leg (or the chest) that will be used in the bypass, and attaching the new blood vessels to the coronary arteries.
• The usual time for surgery is between 3 and 5 hours, depending on the number of bypasses and the complexity of the surgery.
• Complications of the procedure include too much bleeding which may require more surgery, infection of the wound, stroke, blood clots, organ failure, and heart attacks.
• Remember is that surgery is not a cure, but just addresses the symptoms of heart disease. Once your surgeon has done the procedure, there are choices you may take to prevent the condition from recurring. How healthy you are after surgery depends in large part on the steps you take to prevent future problems.

Glossary: Cardiac Bypass Surgery

Here are definitions of medical terms related to cardiac bypass surgery.

Angina: Temporary chest pain or feeling of pressure that occurs because the heart is not getting enough oxygen due to the diminished blood flow.

Angioplasty: A procedure in which a physician threads a catheter through blood vessels leading to the heart and uses a balloon or other device attached to the tip of the catheter to widen coronary arteries that have been narrowed by coronary artery disease.

Artery: A blood vessel that carries blood to from the heart.

Atherosclerosis: A form of coronary heart disease in which the inner layers of the artery walls become thick and irregular due to deposits of fat, cholesterol, and other substances.

Balloon angioplasty: A procedure in which a balloon-tipped catheter is used to widen a narrowed coronary artery.

Cardiovascular system: The entire system that circulates blood throughout the body, including the heart, veins, arteries, and blood. Its main function is to transport oxygen and nutrients to all areas of the body.

Cardiac bypass surgery: This surgery involves taking blood vessels from other parts of the body and surgically attaching them above and below a severely narrowed or blocked coronary artery, to improve blood supply to the heart muscle.

Catheter: A thin tube that is threaded through the blood vessels.

Cholesterol: A fat-like material that is eaten as part of meat and other animal products, and is also made by the human body. Cholesterol has several beneficial uses in the body, but it can also be harmful when it builds up in the walls of arteries and causes them to narrow.

Chronic kidney failure: A long-term condition where the kidney does not function properly, which will impact blood pressure, hydration and the quality of the blood.

Chronic lung disease: A long-term condition that reduces the air capacity of the lungs.

Coronary angiography: An x-ray procedure in which a catheter is threaded through the blood vessels leading to the heart and special x-ray dye is injected. It enables the cardiologist to see whether the arteries in the heart are narrowed or blocked by plaque build-up or a blood clot and how severe the problem is.

Coronary arteries: The arteries that provide blood to the heart muscle. The most important of the arteries supplying blood to the heart are the left main, left circumflex, left anterior descending, and right coronary arteries.

Coronary artery disease: The narrowing of the coronary arteries caused by deposits of cholesterol, fat, and other substances that form plaque.

Diabetes: A long-term condition where glucose (sugar) metabolism is impaired. Glucose in the blood is not adequately absorbed into the cells, so too much sugar remains in the blood.

ECG: An electrocardiogram, a measurement of heart function. Also called an EKG.

Heart attack: Also called a myocardial infarction. This occurs when the heart muscle is damaged by not receiving enough blood.

Intravenous: Into a vein.

Plaque: The deposits of fat, cholesterol, and other substances inside blood vessels that cause the walls of the arteries to become narrowed.

Pneumonia: An infection in the lungs.

Recur: Happens again, comes back.

Revascularization: A broad term that describes surgical and catheter procedures that are used to restore blood flow to the heart.

Stress test: Also known as an exercise treadmill test. While you walk on a treadmill the physician monitors the electrical signal from your heart, which is recorded as an electrocardiogram (ECG). Changes in the ECG while you exercise can help the doctor to make a more accurate diagnosis.

Stress thallium test: At the end of the regular stress test, a small amount of a safe drug is injected into your veins. This allows the physician to view the heart with a special scanning device and see which parts of the heart may not be getting enough blood.

Stent: A small, metal device inserted by a catheter into a narrowed artery wall and then left in place, to help keep the artery open.

Additional Sources Of Information: Cardiac Bypass Surgery

Here are some reliable sources that can provide more information on cardiac bypass surgery.

American College of Cardiology 
Phone: 301-897-5400
Phone: 800-253-4636
http://www.acc.org

American Heart Association 
Phone: 800-227-2345
Phone: 214-373-6300
http://www.americanheart.org

National Heart, Lung, and Blood Institute (NHLBI) Information Center 
Phone: 800-575-WELL
Phone: 301-251-1222
http://www.nhlbi.nih.gov

National Centers for Chronic Disease Prevention and Health Promotion Tobacco Prevention Resources 
http://www.cdc.gov/tobacco/how2quit.htm