A “sinus pause” ensues afterward and would be shorter than two of the preceding RR intervals. Here is an example: Second-degree SA exit block type II occurs when there are consistent RR and PP ...

Severe sinus bradycardia Sinus pauses/sinus arrest Sinoatrial nodal exit block Chronotropic incompetence (failure of heart rate to increase during exercise) Clinical symptoms depend on the mechanism.

sinoatrial block, and alternating episodes of tachycardia and bradycardia. [1] A large proportion of SND patients also have atrial fibrillation (AF) and prolonged sinus pauses after AF termination ...