Chest pain from a heart attack usually lasts longer and is more severe than pain from simple angina. It's often accompanied by clammy skin, sweating, nausea, dizziness, shortness of breath, weakness and palpitations. Mild pain can occur before a major artery is completely blocked, so people often experience mild discomfort two or three days before the crushing pain of a heart attack. If you have chest pain or pressure that is brought on by exertion or exercise and diminishes with rest, call your doctor. If your symptoms don't subside with rest, go straight to the emergency room.
Every minute counts with a heart attack.
The quicker you seek treatment, the less damage will be done to your heart and the better your chances of a good recovery. New medical advances may actually be able to stop the heart attack if you are treated immediately.