Heart attack is a serious health problem that happens when one of the vessels that supply blood to the heart gets blocked all of a sudden usually due to clot. When such a sudden block occur, the part of the heart that normally gets blood from that vessel is damaged due to lack of oxygen and nutrients. The larger the area supplied by the blocked artery, the bigger the heart attack. When a large part of heart muscle (more than 40%) is damaged due to heart attack, it is considered massive heart attack. This is most likely to occur when such a sudden block occur in initial portion of main blood vessels that supply the heart. It may lead to fall in blood pressure, failure of heart and even sudden death in majority of patients. Even with treatment, they can cause death in as high as 40 to 50% of patients. Without treatment, they are almost always fatal. If such blocks occur at level of sub branches or too far away from origin in vessel that supply the heart, they lead to a non-massive heart attack (not considered minor heart attack because even these can serious problem if treatment is not taken promptly). Symptoms and Diagnosis are usually similar to large extent in both types.

Though heart attack is a life threatening condition, chances of survival  improved substantially  in the recent time with advancement in medical field to as low as 3% (Combining massive and non-massive heart attack).  Still massive heart attacks can take risk of death to as high as 50%.

Survival chances not only depends on size of heart attack, but also on a variety of factors that include age, blood pressure, and heart rate, presence of diabetes and kidney problem.

Chances of survival improves dramatically if occluded vessel is opened early. It can be done by giving injection called thrombolytics (dissolves the clot) or by stenting. Stenting is associated with improvement in survival over thrombolytics (also called fibrinolytics).
Every 30 minutes delay in opening the occlude vessel decreases the survival chances by 8%. Better results expected if vessel is opened within 2 hours. Only a little benefited is gained if it is opened after 24 hours after start of heart attack.

 

Survivors of massive heart attack may have a variety of health issues in future. They are at substantial risk for future heart attacks, heart failure, and sudden death. It puts huge burden on health expenditure.