Pre-Algebra on Khan Academy: No way, this isn't your run of the mill arithmetic. This is Pre-algebra. You're about to play with the professionals. Think of pre-algebra as a runway.
Heart attack - Causes. Heart attacks are caused by the blood supply to the heart being suddenly interrupted. Without this supply, heart muscles may be damaged and begin to die. Without treatment, the heart muscles will experience irreversible damage.
A heart attack (myocardial infarction) is most often due to a blood clot that blocks blood flow into the heart muscle. Most commonly, this causes a pressure, cramping or squeezing pain in your chest, but the pain can also spread to your neck. heart attack (myocardial infarction) is most often due to a blood clot that blocks blood flow into the heart muscle. Most commonly, this causes a pressure, cramping or squeezing pain in your chest, but the pain can also spread to your neck.