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.
A SCD attack is not the same as a heart attack. SCD is caused by an abnormal heart rhythm due to abnormal âelectrical circuitryâ of the heart. A heart attack is caused by blockage or occlusion of the arteries supplying blood to the heart, causing a portion of the heart muscle to be damaged.