Atherosclerosis
The coronary arteries can become clogged, or even completely blocked, by atherosclerosis (hardening of the arteries). Atherosclerosis is the main cause of heart disease, which is in turn the leading cause for coronary artery bypass graft (CABG) surgery.

Atherosclerosis occurs when cholesterol, a waxy, fat-like substance, inflammatory cells, and other substances in the blood start to stick to the inner lining of the arteries. If cholesterol levels remain high, this buildup continues over a period of years and develops into hard deposits known as plaque. The ever-growing plaque reduces the diameter of the arteries. This makes it harder for the blood to get through, forces the heart to work harder, and increases the amount of pressure inside the artery (raises blood pressure). In response to inflammation and increased pressure, the arteries start to produce more support cells to form in the blood vessel wall. The arterial walls both weaken and stiffen, resulting in atherosclerosis.

As the coronary arteries become increasingly narrow, blood flow to the heart decreases and the heart muscle doesn't receive the blood supply it requires. It becomes starved of oxygen in a condition called ischemia. The result can be shortness of breath, fatigue, and angina (chest pain).

Atherosclerosis is the main cause of coronary heart disease (CHD), also known as coronary artery disease (CAD). CHD is the leading cause of death in the US. It includes angina, heart attacks, sudden cardiac death syndrome, arrhythmias (abnormal heart rhythms), and heart failure due to a weakened heart. All these conditions are caused by clogged cardiac arteries.

Symptoms of Atherosclerosis
Because atherosclerosis develops slowly, there may be no symptoms until an artery is so clogged that it can't deliver adequate blood and oxygen to the organs or tissues. If atherosclerosis diminishes blood flow to the

• coronary arteries, symptoms can include chest pain (angina), shortness of breath, and fatigue.
• brain, stroke-like symptoms may occur, such as sudden numbness or weakness in the arms and legs, difficulty speaking, or drooping facial muscles.
• arms and legs, walking may become painful.

Risk Factors for Atherosclerosis
The more risk factors a person has, the greater the chance that he or she will develop atherosclerosis. Fortunately, most of the risk factors for atherosclerosis are controllable:

• High blood cholesterol, particularly high LDL cholesterol
• High blood pressure
• Overweight or obesity
• Smoking or using tobacco in any form
• Diabetes
• Lack of exercise
• Unmanaged response to stress

Risk factors that can't be controlled include:

• Genetics (family history of early heart disease)
• Aging

More on this topic

What is Coronary Bypass Surgery? (VIDEO)
Restoring Flow
Stiff & Narrow
The Consequences of Clots
Testing & Diagnosis
Bypass Background
The Way to Your Heart
New Connections
Recovery from Bypass
Lifestyle for a Healthy Heart

Related Health Centers:

Aneurysm and Stent, Angioplasty, Arrhythmia, Cardiovascular Continuum, Cholesterol and Atherosclerosis, Coronary Bypass Surgery, Heart Attack and Angina, Hypertension, Stroke, Thrombosis and Embolism, Women and Cardiovascular Health