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.
A heart attack (myocardial infarction) is most often due to a blood clot that blocks blood flow into the heart muscle. Most commonly, this causes a pressure, cramping or squeezing pain in your chest, but the pain can also spread to your neck. heart attack (myocardial infarction) is most often due to a blood clot that blocks blood flow into the heart muscle. Most commonly, this causes a pressure, cramping or squeezing pain in your chest, but the pain can also spread to your neck.