<P> The electrical conduction system of the heart transmits signals generated usually by the sinoatrial node to cause contraction of the heart muscle . The pacemaking signal generated in the sinoatrial node travels through the right atrium to the atrioventricular node , along the Bundle of His and through bundle branches to cause contraction of the heart muscle . This signal stimulates contraction first of the right and left atrium , and then the right and left ventricles . This process allows blood to be pumped throughout the body . </P>
the heart muscle is stimulated to contract by electrical impulses which are generated where
the sinoatrial node