The Cardiovascular system is divided into two main parts: the heart, and the blood vessels. The heart is located under the ribcage, between left and right lungs. The heart is a four- chambered organ: Left atrium, right atrium, that are received blood from the venous system, and left ventricle, right ventricle, that provide the vital organs with the needed amount of blood and nutrients trough the arteries .The human heart has its own intrinsic conduction system, in order to beat regularly for one's entire life. This intrinsic conduction system, starts with sinoatrial node, which is located in the right atrium and results in atrium depolarization and contraction. Followed by the internodal pathway, the AV node, AV bundle, the bundle of His