What is arteriosclerosis? How is it different from atherosclerosis?

Arteriosclerosis, often called hardening of the arteries, is a term used to describe a variety of conditions where the artery walls have thickened and lost elasticity. Atherosclerosis is one type of arteriosclerosis. Atherosclerosis is caused by fatty deposits accumulating on the inner lining of the arteries. Other arteriosclerosis conditions occur from calcification of the artery walls, or wall thickening as a result of high blood pressure.

What is coronary artery disease (CAD)? How is it different from coronary heart disease (CHD)?
Coronary artery disease (CAD) refers to conditions that cause narrowing of the coronary arteries resulting in a reduction of blood flow to the heart. CAD is only one type of atherosclerosis. It is caused by accumulation of fat, cholesterol, and other substances known as plaque. Plaque deposits can block the coronary arteries or rupture causing blood clots to form resulting in a heart attack, stroke, and other serious problems.

Coronary heart disease is the most common heart condition in the United States. Coronary heart disease (CHD) is caused by atherosclerotic narrowing of the coronary arteries often resulting in chest pain (angina), shortness of breath, or heart attack.

The terms coronary heart disease, coronary artery disease and arteriosclerotic heart disease are frequently used interchangeably. The most commonly used of the three terms is coronary heart disease (CHD).

The coronary arteries are the blood vessels that supply the heart muscle tissue with blood. The heart is a muscle that pumps blood throughout the circulatory system. Each heartbeat is a contraction of that muscle. There are three major coronary arteries: the right coronary artery (supplying the right and back sides of the heart), the left anterior descending artery (supplying the front and middle walls of the heart), and the left circumflex artery (supplying the left lateral and the back walls of the heart).

Coronary heart disease results from the development of plaque, which is composed of fats, cells, and protein-like substances deposited along the walls of the arteries. These plaques can begin to develop early in life, even in childhood, and most people show some evidence of coronary disease by middle age. Plaques, which can rupture under stress, cause the circulating blood to clot and rapidly block off a vessel. If the vessel completely blocks and remains blocked, then a person experiences a heart attack, or myocardial infarction. If the vessel only partly blocks with clot and plaque, then a person can experience angina, or chest pain.

Back to Top

To learn more about coronary heart disease, click on the links below:

• Coronary Heart Disease: Risk factors
• Coronary Heart Disease: Symptoms
• Coronary Heart Disease: Treatments

Coronary Heart Disease: Risk Factors
There are many risk factors for coronary artery disease and coronary heart disease. Some are more controllable than others and may even be reversible. Others are not reversible and we cannot change them. Risk factors are further classified as major and contributing risk factors. Major risk factors have been proven through research to cause a significant increase in risk to heart and cardiovascular disease. Contributing risk factors are known to be associated with increased risk, but their significance are not always fully known.

Major nonreversible risk factors

• Age: The risk of heart disease increases with age, especially after age 65.
• Gender: Males have a greater life-long risk for heart disease than females and men have heart attacks earlier in life. However, after menopause a woman's risk for heart disease increases sharply.
• Hereditary: Family history of coronary heart disease, especially before age 50, increases risk. Higher rates of heart disease and high blood pressure exist among African American as compared to Caucasians.

Major reversible or modifiable risk factors

• Smoking significantly raises the risk of death from CHD for smokers to 2-3 times that of nonsmokers. Exposure to other people's smoke increases the risk of heart disease for nonsmokers.
• High blood cholesterol or hypercholesterolemia is a major risk factor for coronary heart disease (CHD). High levels of low-density lipoprotein, or LDL, often referred to as "bad" cholesterol, can form plaque, making the arteries to the heart narrowed and less flexible. A blocked artery can result in heart attack or stroke. HDL cholesterol is often called "good" cholesterol because high levels of HDL are associated with a reduced risk of heart attack, while low levels associate with an increased risk of heart disease. LDL levels can be reduced with a low-fat, low-cholesterol diet and/or medications to lower cholesterol (e.g., statin drugs). Stopping smoking, doing regular exercise, and consuming moderate amounts of alcohol can all increase the good cholesterol, or HDL, levels.
• High triglycerides can also increase the risk of coronary disease. Triglycerides can be lowered by weight reduction, increase in physical activity, smoking cessation, and reduction of alcohol consumption.
• High blood pressure can be reduced with a low-fat and low-salt diet, weight loss, increased physical activity, reduced alcohol consumption, or medications.
• Diabetes, even when treated and glucose is under control, raises the risk for heart disease. Approximately 75% of those with diabetes die from some form of cardiovascular disease. Risk for heart disease can be reduced by closely controlling blood sugar levels.
• Obesity increases the workload of the heart, raises blood pressure, and negatively affects cholesterol and triglycerides and increases risk for developing diabetes. Fat concentrated around the waist (trunkal obesity) is especially associated with an increased risk for heart disease.
• Physical inactivity is a known major risk factor for heart disease. Research also shows that regular physical activity helps prevent heart and vascular diseases, and can help control blood pressure, cholesterol, diabetes, and obesity.
• Metabolic syndrome is generally identified as a risk in individuals that have three or more of the following: elevations in weight (as measured in weight circumference [trunkal obesity]), triglycerides, blood pressure, or glucose or reduced HDL (good cholesterol).

Other factors that contribute to coronary heart disease risk

• Stress may contribute to overall risk for heart disease, especially if the stress results in overeating, smoking or other behaviors that would negatively affect known risk factors.
• Alcohol in excess can cause heart failure, irregular heartbeats, high triglycerides, high blood pressure, and stroke. The risk of heart disease is lower in moderate* drinkers than in non-drinkers. However, it is not recommended that non-drinkers start drinking alcohol to reduce risk.
  
  *Moderate drinkers defined as one drink daily for women and one to two drinks daily for men.

Back to Top 

Coronary Heart Disease: Symptoms
Signs and symptoms of coronary heart disease depend to some degree on what stage of the disease is present.

• Angina is the most common symptom of CHD. It is caused by reduced blood supply to the heart muscle, often from coronary artery disease (CAD), which results when the formation of plaque causes a narrowing and hardening of the arteries known as atherosclerosis. Most people think of angina as synonymous with chest pain. However, it is often not described as pain, but rather as a discomfort, an ache, a sense of chest pressure. Its location can vary, although it is most often centered under the breastbone. It can be felt in the left shoulder, left arm, back, throat, jaw, and teeth. Typical angina occurs with exertion and subsides with rest or nitroglycerin. Atypical chest pain is unrelated to exertion and is not relieved by rest or nitroglycerin. Atypical chest pain is a more common symptom among women with CHD than men with heart disease. Indeed, in those individuals presenting with typical chest pain, CHD is the primary cause.
• Heart attack or myocardial infarction can start like angina, but is more intense and lasts longer. If angina lasts more than 30 minutes, a patient should seek medical attention because he or she may be having a heart attack. Other symptoms of a heart attack can include shortness of breath, sweating, nausea, vomiting, lightheadedness, palpitations, anxiety, and a sense of impending doom. Older adults often present differently, particularly with more shortness of breath and less chest pain. Myocardial infarction (MI), or heart attack, is due to the abrupt and complete blockage of a coronary artery, which results in damage to a portion of the heart muscle. Most often this complete blockage follows the rupture of a plaque. Platelets and proteins gather at such ruptures and form a blood clot that completely halts the flow of blood through that artery, starving the heart of blood and oxygen.

Back to Top

Coronary Heart Disease: Treatments
Treatment for CHD depends on the severity and symptoms of the disease. Treatments may range from simple lifestyle changes or may also include medications, medical procedures, and sometimes surgery.

 Lifestyle changes

• smoking cessation
• weight reduction
• healthy diet low in saturated fats, trans fat and cholesterol
• low sodium intake to maintain blood pressure control
• regular exercise
• control of blood sugar, diabetes

Medications used to treat CHD may include:

• Cholesterol-lowering drugs (e.g., statins)
• Blood-thinning medications (e.g., aspirin)
• Beta-blockers to lower heart rate and blood pressure
• Nitrates (nitroglycerin) to dilate arteries, relieve chest pain, and improve blood flow to the heart
• Calcium-channel blockers to relax arteries, reduce the workload of the heart, and lower blood pressure
• ACE inhibitors or angiotensin receptor blockers to lower blood pressure and limit left ventricular remodeling

Medical procedures

• PCIs, or percutaneous coronary interventions, which include coronary angioplasty (balloon PTCA) and coronary atherectomy, are used to treat diseased arteries.
• Coronary stenting involves placing a tube, known as a stent, in the artery to keep it open.
• Coronary radiation implant, also known as coronary brachytherapy, is a new therapy that is used in cases where stent implantation has failed. This new treatment involves exposing the coronary arteries to beta or gamma radiation.

Surgical procedures

• Coronary artery bypass surgery
• Minimally invasive heart surgery

See the American Heart Association web site for more important information to assess your risk of heart attack and heart attack prevention at http://www.americanheart.org/

Back to Top

Content on Infoaging is constantly reviewed and updated by leading researchers specializing in the biology of aging and the diseases of aging. For a list of our content experts, click here.