Heart is a four chambered muscular organ which continuously works throughout the life. It receives the impure (deoxygenated) blood from different parts of body, and then pumps the pure (oxygenated) blood to different organs. Heart attack or Myocardial infarction refers to necrosis (death of the cells) of the heart muscle wall (myocardium) due to prolonged deprivation of blood supply and hence oxygen. It is one of the serious consequences of coronary artery (artery supplying the heart) narrowing by atheromatous plaque in which irreversible damage to heart muscle occurs which can severely affect the functioning of heart. The chamber of heart which pumps the blood to various parts of the body (i.e. the left ventricle) exerts maximally and therefore needs more oxygen and blood supply for its sustenance. No wonder, why left ventricle is commonly involved in heart attack. The severity of damage depends on the size of the coronary artery (bigger the artery bigger the area of damage), number of arteries involved and presence of collateral (alternative routes) vessels. For the damage to be irreversible as much as 8 hours are required, so timely diagnosis and prompt treatment is essential (for preserving optimal myocardial functioning i.e. for better myocardial salvage and outcome).