Heart attack or Myocardial Infarction (MI) is another form of presentation. While angina is almost completely reversible, MI threatens permanent myocardial damage. This happens when there is sudden complete occlusion in the coronary arteries. Usually this occlusion occurs at pre-existing stenotic lesions. The common cause is a plaque rupture (separation of the atheromatous plaque and clot formation underneath). The myocardium supplied by the particular coronary artery is under threat of permanent damage.
The pain of MI is more severe and lasts longer. Patient may vomit and sweat. It is often described as a feeling of 'Impending death'. This condition is severe and can be fatal at times. It calls for urgent attention. Patient needs urgent hospitalisation and treatment.