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.
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.. The remaining, healthy tissue must take over the job of pumping blood, an extra burden that may weaken the heart's pumping ability.