Pathophysiology
         
Nodal (junctional) escape beat      

When the rate of depolarization of the sinoatrial node falls below the rate of the atrioventricular node, a depolarization from somewhere in the AV node will occur; either as a single escape beat, or as a series of escape beats (escape rhythm). P-wave morphology depends on the site of the ectopic focus, will be inverted; and may appear before, during, or after the QRS complex. If the P-wave occurs before the QRS complex, the PR interval will be less than 0.12 seconds. The QRS complex will usually be normal in duration and morphology.

Rhythm Strip
Nodal (junctional) escape beat Rhythm Strip

NPCs/JPCs and Nodal/Juctional Escape Beats

12 Lead EKG
Nodal (junctional) escape beat 12 Lead EKG