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 cause of a heart attack (myocardial infarction) is a blood clot that lodges in an artery and blocks blood flow to the heart muscle.This often causes a painful pressure, cramping or squeezing sensation in the chest. The discomfort can refer from your chest into your back.he most common cause of a heart attack (myocardial infarction) is a blood clot that lodges in an artery and blocks blood flow to the heart muscle.