HAVE A HEART: The heart pumps 5.6 liters of blood through the entire body in roughly 20 seconds; each day your blood travels some 12,000 miles, and your heart beats about 100,000 times. This delivers oxygen and other essential nutrients to the body's cells and organs. A heart attack occurs when the blood supply to the heart muscle is cut off, either because part of the heart is damaged (such as the valves to the chambers), or because plaque has built up inside the arteries, narrowing them and severely restricting blood flow. Symptoms of a heart attack include a squeezing discomfort in the center of the chest, pain or tingling in the left arm, shortness of breath, and sometimes a cold sweat, nausea, or dizziness.
ABOUT HEART DISEASE: Most heart diseases arise from hardening of the arteries, especially the buildup of fatty material along the inner lining of the arteries. Coronary arteries supply blood to the heart. When a blockage occurs, this flow is decreased. Heart medications target these blockages in several different ways. Nitrates dilate the veins, decreasing the oxygen requirements of the heart. They also dilate the coronary arteries to increase blood flow to the heart. Beta-blockers decrease the heart rate and the force of the heart's contractions. Aspirin prevents platelets in the blood from clotting and clumping on blood vessel walls.