| The sinoatrial (SA) node is the primary pacemaker of the heart and is located in the upper posterior portion of the right atrial wall. The intrinsic rate of the SA node is 60-100 beats per minute. The SA node generates an electrical signal to the AV node, which is located in the center of the heart between the atria and ventricles. The AV node slows the electrical current before passing to the ventricles; this delay allows the atria to contract fully and fill the ventricles before they are stimulated. [26] | | | | | | |
