If you experience discomfort in the chest, like a feeling of tightness or severe pain, which may or may not radiate to either of the arms, with or without a choking sensation in the throat or any unusual feeling of distress in the chest, you should immediately call for an ambulance to get your pain evaluated in a nearby hospital. This is important if you are prone to coronary heart disease because of strong family history, high blood pressure, diabetes, high cholesterol or a habit of smoking. If the pain is diagnosed as acute myocardial infarction (heart attack) or unstable angina, then angiography followed by angioplasty or bypass surgery is necessary. One 325 mg tablet of Aspirin (to be avoided if there is known allergy to aspirin) dissolved in water should be taken immediately. Four to eight pills of 75 mg of Clopidogrel may be taken with a glass of water and a Sorbitrate can be taken under the tongue if there is delay in getting emergent medical help.