Coronary Artery Disease
Coronary artery disease (CAD), also referred to as coronary heart disease, is a chronic disease caused by narrowed coronary arteries that limit the blood and oxygen flows to the heart. Coronary artery disease is the most common type of heart disease and it is one of the leading causes of death in both men and women in United States and Europe.
Coronary arteries constantly supply your heart with blood, oxygen and nutrients. When the arteries become narrowed or clogged and can’t supply enough blood to your heart, the result is coronary artery disease. Blood clot formation causes the coronary arteries to narrow, reducing blood flow. When one of the coronary arteries becomes severely or totally blocked, usually by a blood clot, the result can be a heart attack, also known as myocardial infarction. The part of the heart muscle that is not receiving the oxygen-rich blood that it needs, it will begin to die and some of the heart muscle may become permanently damaged.
Causes of CAD
Coronary artery disease is caused by the narrowing or blockage of the coronary arteries caused by atherosclerosis, a condition known also as "hardening of the arteries." Atherosclerosis is a chronic inflammatory response in the walls of arteries. It is the build up of cholesterol and fatty deposits, called plaques, on the inner wall of the arteries. Atherosclerosis is gradual, often taking decades before the affected person is in danger of cardiovascular problems. As a plaque builds up, blood vessels gradually harden and narrow, and this can affect the flow of blood through the artery. Without adequate blood, the heart becomes starved of oxygen and the vital nutrients it needs to work properly. Ultimately, if one or more arteries become completely blocked, heart tissue will die, resulting in heart attack.
Healthy coronary arteries are shaped like hollow tubes with smooth and elastic walls. Unhealthy or diseased arteries are stiff or hardened and present obstructions (plaques) that can interfere with normal blood flow.
The abnormal narrowing or obstruction in a blood vessel is called stenosis. The narrowing of the artery, because of the presence of plaques, restricts blood flow. Over time the plaque may calcify, reducing artery’s ability to expand and contract and narrows the artery, reducing the amount of blood that can flow through it. As a consequence, tissues supplied by the affected artery don’t receive enough blood and heart does not receive enough oxygen to work properly.
If one of these plaque deposit ruptures a blood clot can rapidly form and completely block the vessel. If the vessel is a coronary artery, it can lead to a heart attack.
CAD Risk Factors
Although the exact cause of hardening of the arteries in not known, atherosclerosis is usually caused by high cholesterol. High blood pressure, diabetes and smoking can also contribute to coronary artery disease. Physical inactivity and obesity are other factors that can lead to coronary artery disease.
Patients suffering from coronary artery disease can experience regular episodes where the heart is not receiving enough oxygen-rich flow (Cardiac ischemia). Symptoms of coronary artery disease can range from mild to severe. The most common symptom of coronary artery disease is angina pectoris, also referred to as chest pain. Other symptoms include sense of heaviness, fatigue, shortness of breath, unexplained sweating, uneven or rapid heartbeats, weakness, dizziness, or loss of consciousness. If the patient feels no symptoms, this is called silent ischemia.
Unfortunately, some people have coronary artery disease or even heart attacks without ever experiencing any of these symptoms. This can be especially true for people with diabetes.