Sinus exit block (sinoatrial block) results from blocked sinus impulses - impulses not getting through to depolarize the atria. While the sinus is firing on schedule, the tissue around the SA node is not carrying the impulse. The seriousness of this dysrhythmia is related to the frequency and duration of the blocks. Note that each pause is equal to a multiple of previous P-P intervals. Can cause bradycardia