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.
The most common form of heart disease is coronary artery disease, which can lead to heart attack, according to the CDC. Heart attack occurs when the heart muscleâs blood supply is cut off by a blood clot in one or more pulmonary veins or arteries.