Angina and heart attacks are both severe forms of chest pain associated with the heart muscle being deprived of oxygen. This is usually caused by atherosclerosis blocking the coronary arteries wgich supply the heart with blood. When the blockage first happens, the pain felt is referred to as angina pectoris. The longer the vessel remains blocked is the less oxygen the muscle has left and it eventually begins to die. After one hour, the condition is usually called a heart attack, since even after restoring the blood supply to the area, some tissue already would have died and start to form scar tissue. Angina is a warning sign that you might have a heart attack if you do not do something about your arteries, but after the attack, the heart is able to go back to normal. Angina also is a warning sign for strokes and other vascular problems that can affect different systems of the body.