Like the other organs of the body, the hardworking heart requires oxygen and nutrients to function. This need is met by the coronary arteries, two small vessels on the outer surface of the heart muscle. The right coronary artery supplies the undersurface of the heart. The left artery runs for about an inch at the top of the heart before dividing into two main branches called the "left anterior descending," traveling to the front of the heart, and "circumflex" supplying the back of the heart. These three arteries (right, left anterior descending and circumflex) and their branches send smaller tributaries into the substance of the hart muscle to supply it with the oxygen and nutrients needed to contract and pump normally.

The coronary arteries are more susceptible than most other arteries to athererosclerosis (also known as arteriosclerosis), a buildup of cholesterol with the walls of the vessels. When severe, this buildup may obstruct the artery. Under resting conditions, the blood flowing through the diseased coronary artery may be sufficient to supply a specific area of heart muscle, but under more demanding conditions, such as exercise, when the heart is working harder and requires oxygen and nutrients, the obstruction may not allow sufficient blood through to meet the needs of the heart area it supplies. An imbalance of oxygen supply and demand (called "ischemia") is created. When this occurs, the afflicted individual often experiences symptoms of chest discomfort called "angina pectoris."

A diseased coronary artery can also become unstable, resulting in ulceration or total disruption of a cholesterol deposit. This often leads to major problems. An ulcerated or disrupted coronary artery is susceptible to blood clots forming on its exposed surface. When this occurs, the vessel can become completely occluded. As a result, the portion of heart muscle supplied by that artery becomes starved for vital oxygen and nutrients. If the occlusion persists for more than an hour, the affected muscle begins to die. This is usually accompanied by severe, persistent crushing pain over the center of the chest, the prime symptom of a heart attack.

When this symptom strikes, it is urgent to get to the nearest hospital emergency room-- immediately! Cardiologists can now thread a balloon catheter from the groin into the blocked area and open it up, salvaging precious heart muscle, which can substantially improve long-term prognosis. Remember: your heart is a remarkably resilient organ. It can suffer significant damage before impairment in function occurs. The outlook for patients with coronary atherosclerosis depends on the extent of heart muscle damage from a heart attack and on the extent of blockage in the coronary arteries. Reducing the initial damage, as well as taking the vital steps to reduce your risk factors for a second attack (i.e. lowering your cholesterol, normalizing blood pressure, supervised exercise, diet and weight reduction, reducing stress, etc.) are the keys to living a long and healthy life after suffering a heart attack.