Sino-atrial exit block

This is part of: Sinus node rhythms and arrhythmias

Sino-atrial exit block

During sino-atrial exit block, the depolarizations that occur in the sinus node cannot leave the node towards the atria. They are blocked. On the ECG this is expressed as a pause. SA exit block can be destinguished from Sinus Pause because the pause in SA exit block is a multiple of the P-P interval that preceded the pause.