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.
Common causes of heart failure include the following: 1  Damage from a prior heart attack â Also called a myocardial infarction, a heart attack occurs when an artery that supplies blood to the heart is blocked so that no oxygen reaches the heart muscle. When this happens, part of the heart dies.. The medical term for the area of dead muscle is called the infarct..