The possible P waveforms that are associated with junctional rhythms include which of the following? (Select all that apply.)
A) No P wave
B) Inverted P wave
C) Shortened PR interval
D) P wave after the QRS complex
E) Normal P wave and PR interval

Question

Quizplus · Accepted Answer

Because of the location of the AV node-in the center of the heart-impulses generated may be conducted forward,backward,or both.With the potential of forward,backward,or bidirectional impulse conduction,three different P waveforms may be associated with junctional rhythms: When the AV node impulse moves forward,P waves may be absent because the impulse enters the ventricle first.The atria receives the wave of depolarization at the same time as the ventricles; thus,because of the larger muscle mass of the ventricles,there is no P wave.When the AV node impulse is conducted backward,the impulse enters the atria first.When depolarization occurs backward,an inverted P wave is created.Once the atria have been depolarized,the impulse moves down the bundle of His and depolarizes both ventricles normally.A short PR interval (<0.12 second)is noted.When the impulse is conducted both forward and backward,P waves may be present after the QRS complex.

The Possible P Waveforms That Are Associated with Junctional Rhythms