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.
Coronary artery disease. The most common underlying cause of heart attack is atherosclerosis, a condition in which a fatty substance called plaque builds up on the inside walls of blood vessels. When this occurs in the coronary arteries, it's known as coronary artery disease (CAD).
Understand Heart Attack Heart attacks are caused by heart disease, which is the number one cause of death among both men and women in the United States. According to the American Heart Association, every year in the United States roughly 785,000 people will have their first heart attack.