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 heart disease. Coronary heart disease (CHD) is the leading cause of heart attacks. CHD is a condition in which the coronary arteries (the major blood vessels that supply the heart with blood) get clogged up with deposits of cholesterol. These deposits are called plaques.
Coronary artery disease causes most heart attacks and is the most common form of heart disease. The types of heart disease include: Atherosclerosis is a buildup of cholesterol, calcium and blood clotting material on the walls of the arteries. The material that builds up is called plaque.