Coronary Artery Disease
The heart is a functioning muscle and needs oxygen and fuel in order to do its work. It is
the job of the
coronary arteries to supply the necessary oxygen and nutrients to the muscle. There are three major coronary arteries. When these arteries become narrowed or blocked, blood flow to the muscle is diminished, resulting in angina, a feeling of tightness or pressure in the chest often associated with shortness of breath. At first, angina may only be evident during periods of exercise or emotional stress, resolving when the activity ceases. Later, it may occur even at rest. If the blood flow to an area of the heart completely stops, heart muscle cells die, resulting in a myocardial infarction, or heart attack. The infarcted area heals by forming a scar and is no longer a functioning part of heart muscle.
There are many risk factors for coronary artery disease. Smoking and elevated cholesterol levels are major factors, and obesity, hypertension, and diabetes mellitus have proven to have adverse effects. A family history of coronary artery disease is also a major risk factor.
The treatment of coronary artery disease is initially directed toward lifestyle changes, such as cessation of smoking, moderate exercise, and low-cholesterol diet. If medical therapy is required, beta blocking or calcium channel blocking agents are utilized along with nitrates and aspirin. If angina worsens despite medical therapy, a procedure to revascularize the coronary arteries may be necessary. This may be accomplished by percutaneous transluminal coronary angioplasty, which opens clogged arteries by dilating them with tiny balloon catheters, or by coronary artery bypass surgery, where a section of blood vessel or a prosthesis is implanted to bypass a blockage. An acute myocardial infarction may be treated early in its evolution by drugs that dissolve blood clots and in some cases by emergency angioplasty.