Script submitted by Drummerpiper
The heart is a remarkable o***n. It is a muscle that relaxes and contracts, pumping blood carrying oxygen and nutrients throughout the body. The steady rhythm of these contractions is controlled by electrical impulses that travel through the heart, first through the upper chambers, called the atria; and then through the lower chambers, called the ventricles. In order to reach the ventricles, electrical impulses must pass here, at the atrioventricular node. Atrial fibrillation occurs when a storm of electrical impulses spread through the atria in a chaotic and disorganized pattern, causing the atria to begin rapidly contracting. as a result, the ventricles may also begin contracting faster. When the heart is in atrial fibrillation, the body can’t receive the blood and oxygen it needs.