NREMT Advanced EMT Practice Test #3

Answer - B - The primary pacemaker of the heart is the sinoatrial node that has an intrinsic discharge rate of 60 to 100 beats per minute. The intraatrial pathways only distribute the discharge wave for uniform atrial contraction. The AV node is the secondary pacemaker with a discharge rate of 40 to 60 beats per minute. The bundle of His transmits the impulse from the AV nod to the bundle branches.