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.
Heart-related causes. Examples of heart-related causes of chest pain include: 1  Heart attack. 2  A heart attack is a result of a blood clot that's blocking blood flow to your heart muscle. 3  Angina. 4  Thick plaques can gradually build up on the inner walls of the arteries that carry blood to your heart.