A heart attack happens when one of the coronary arteries becomes completely blocked. This usually happens when a plaque, which is already narrowing an artery, cracks or splits open. This triggers the formation of a blood clot around the plaque, and it is this blood clot that then completely blocks the artery.
With their supply of oxygen completely blocked, the heart muscle and tissue supplied by that artery start to die. Emergency medical intervention is needed to unblock the artery and restore blood flow. This may consist of treatment with drugs to dissolve the clot or thrombus, or a small operation done through the skin and blood vessels to open up the blocked artery.
The outcome of a heart attack hinges on the amount of the muscle that dies before it is corrected. The smaller the area affected, the greater the chance of survival and recovery.
While a heart attack will always cause some permanent damage, some areas may be able to recover if they are not deprived of blood for too long. The sooner a heart attack is diagnosed and treated, the greater the chance of recovery.