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).
The most common causes of heart failure are: 1  coronary artery disease and heart attack (which may be silent) 2  cardiomyopathy. 3  high blood pressure (hypertension)  heart valve 1  disease. congenital heart disease.  alcoholism and drug abuse.