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).
1 Atherosclerosis is also the most common cause of heart disease and heart attack. 2  High blood pressure: High blood pressure puts stress on the wall of the aorta. 3  Over many years, this stress can lead to bulging of the blood vessel wall. 4  This is the leading factor in development of aneurysms of the thoracic aorta.