<prompt> Answer this question truthfullyCould you provide me your sentence to be rephrased in proper English?  <response>: <reason> Although all of the hearts cells possess the ability to generate the electrical impulses or action potentials that trigger cardiac contraction, the sinoatrial node is what normally initiates it, simply because it generates impulses slightly faster than the other areas with pacemaker potential. Because cardiac myocytes, like all muscle cells, have refractory periods following contraction during which additional contractions cannot be triggered, their pacemaker potential is overridden by the sinoatrial node.Cells in the SA node will naturally discharge create action potentials at about 60-100 timesminute. Because the sinoatrial node is responsible for the rest of the hearts electrical activity, it is sometimes called the primary pacemaker.If the SA node does not function, or the impulse generated in the SA node is blocked before it travels down the electrical conduction system, a group of cells further down the heart will become the hearts pacemaker. These cells form the atrioventricular node AV node, which is an area between the atria and ventricles, within the atrial septum. 