While admitting a client to the emergency room, the nurse observes the cardiac monitor and identifies the following rhythm: one inverted P wave for every QRS complex and a regular heart rate of 46 beats per minute

Question

The nurse interprets this rhythm as: 1. Junctional escape rhythm.
2. Normal sinus rhythm.
3. Mobitz II heart block.
4. Complete heart block.

Answer 1

Junctional escape rhythm.

Rationale: Junctional escape rhythm results from either an irritable focus in the junctional tissue that discharges before the SA node has had a chance to or because the SA node has failed to fire, thereby making junctional node the secondary pacemaker. The impulse is initiated in the AV junctional tissue and must travel in a backward (retrograde) direction to activate the atria. Therefore, the P wave is inverted or negatively deflected, due to this retrograde conduction, and may occur before, after, or buried in the QRS complex. The intrinsic rate of the AV junction is 40 to 60 beats per minute. This is not normal sinus rhythm because it is not initiated by the SA node. Both Mobitz II and complete heart block are rhythms that occur below the AV junction and have normal P waves.