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.
Heart attack - Causes. Heart attacks are caused by the blood supply to the heart being suddenly interrupted. Without this supply, heart muscles may be damaged and begin to die. Without treatment, the heart muscles will experience irreversible damage.
Heart attack (myocardial infarction (MI), is the leading cause of death among Americans. It often results from coronary artery disease, the most common form of heart disease to affect adults. See your doctor immediately if you feel pressure or a squeezing sensation in your chest, neck, jaw, shoulders, back or arms, especially if itâs accompanied by sweating, nausea, vomiting, or shortness of breath.