Coronary Heart Disease
What are the coronary arteries?
Coronary arteries supply blood to the heart muscle. Like all other tissues in the
body, the heart muscle needs oxygen-rich blood to function, and oxygen-depleted blood
must be carried away. The coronary arteries run along the outside of the heart and
have small branches that supply blood to the heart muscle.
What are the different coronary arteries?
The 2 main coronary arteries are the left main and right coronary arteries.
Right coronary artery (RCA). The right coronary artery supplies blood to the right ventricle, the right atrium,
and the SA (sinoatrial) and AV (atrioventricular) nodes, which regulate the heart
rhythm. The right coronary artery divides into smaller branches, including the right
posterior descending artery and the acute marginal artery.
Additional smaller branches of the coronary arteries include the obtuse marginal (OM),
septal perforator (SP), and diagonals.
Why are the coronary arteries important?
Since coronary arteries deliver blood to the heart muscle, any coronary artery disorder
or disease can reduce the flow of oxygen and nutrients to the heart, which may lead
to a heart attack and possibly death. Atherosclerosis is inflammation and a buildup
of plaque in the inner lining of an artery causing it to narrow or become blocked.
It is the most common cause of heart disease.
What is coronary artery disease?
Coronary heart disease, or coronary artery disease (CAD), is characterized by inflammation
and the buildup of and fatty deposits along the innermost layer of the coronary arteries.
The fatty deposits may develop in childhood and continue to thicken and enlarge throughout
the life span. This thickening, called atherosclerosis, narrows the arteries and can
decrease or block the flow of blood to the heart.
The American Heart Association estimates that over 16 million Americans suffer from
coronary artery disease--the number one killer of both men and women in the U.S.
What are the risk factors for coronary artery disease?
Risk factors for CAD often include:
High LDL cholesterol, high triglycerides levels, and low HDL cholesterol
High blood pressure (hypertension)
High saturated fat diet
Controlling risk factors is the key to preventing illness and death from CAD.
What are the symptoms of coronary artery disease?
The symptoms of coronary heart disease will depend on the severity of the disease.
Some people with CAD have no symptoms, some have episodes of mild chest pain or angina,
and some have more severe chest pain.
If too little oxygenated blood reaches the heart, a person will experience chest pain
called angina. When the blood supply is completely cut off, the result is a heart
attack, and the heart muscle begins to die. Some people may have a heart attack and
never recognize the symptoms. This is called a "silent" heart attack.
Symptoms of coronary artery disease include:
Heaviness, tightness, pressure, or pain in the chest behind the breastbone
Pain spreading to the arms, shoulders, jaw, neck, or back
Shortness of breath
Weakness and fatigue
How is coronary artery disease diagnosed?
In addition to a complete medical history and physical exam, tests for coronary artery
disease may include the following:
Electrocardiogram (ECG or EKG). This test records the electrical activity of the heart, shows abnormal rhythms (arrhythmias),
and detects heart muscle damage.
Stress test (also called treadmill or exercise ECG). This test is given while you walk on a treadmill to monitor the heart during exercise.
Breathing and blood pressure rates are also monitored. A stress test may be used to
detect coronary artery disease, or to determine safe levels of exercise after a heart
attack or heart surgery. This can also be done while resting using special medicines
that can synthetically place stress on the heart.
Cardiac catheterization. With this procedure, a wire is passed into the coronary arteries of the heart and
X-rays are taken after a contrast agent is injected into an artery. It's done to locate
the narrowing, blockages, and other problems.
Nuclear scanning. Radioactive material is injected into a vein and then is observed using a camera
as it is taken up by the heart muscle. This indicates the healthy and damaged areas
of the heart.
Treatment for coronary heart disease
Treatment may include:
Modification of risk factors. Risk factors that you can change include smoking, high cholesterol levels, high blood
glucose levels, lack of exercise, poor dietary habits, being overweight, and high
Medicines. Medicine that may be used to treat coronary artery disease include:
Antiplatelets. These decrease blood clotting. Aspirin, clopidogrel, ticlopidine, and prasugrel are
examples of antiplatelets.
Antihyperlipidemics. These lower lipids (fats) in the blood, particularly low density lipid (LDL) cholesterol.
Statins are a group of cholesterol-lowering medicines, and include simvastatin, atorvastatin,
and pravastatin, among others. Bile acid sequestrants--colesevelam, cholestyramine
and colestipol--and nicotinic acid (niacin) are other medicines used to reduce cholesterol
Antihypertensives. These lower blood pressure. Several different groups of medicines work in different
ways to lower blood pressure.
Coronary angioplasty. With this procedure, a balloon is used to create a bigger opening in the vessel to
increase blood flow. Although angioplasty is done in other blood vessels elsewhere
in the body, percutaneous coronary intervention (PCI) refers to angioplasty in the
coronary arteries to permit more blood flow into the heart. PCI is also called percutaneous
transluminal coronary angioplasty (PTCA). There are several types of PCI procedures,
Balloon angioplasty. A small balloon is inflated inside the blocked artery to open the blocked area.
Coronary artery stent. A tiny mesh coil is expanded inside the blocked artery to open the blocked area and
is left in place to keep the artery open.
Atherectomy. The blocked area inside the artery is cut away by a tiny device on the end of a catheter.
Laser angioplasty. A laser used to "vaporize" the blockage in the artery.
Coronary artery bypass. Most commonly referred to as simply "bypass surgery" or CABG (pronounced "cabbage"),
this surgery is often done in people who have chest pain (angina) and coronary artery
disease. During the surgery, a bypass is created by grafting a piece of a vein above
and below the blocked area of a coronary artery, enabling blood to flow around the
blockage. Veins are usually taken from the leg, but arteries from the chest or arm
may also be used to create a bypass graft. Sometimes, multiple bypasses may be needed
to fully restore blood flow to all regions of the heart.