CRAT Junctional Rhythm Analysis 3

Question 1

Which feature best differentiates a junctional rhythm from a sinus rhythm with first-degree AV block?

Accepted Answer

P wave morphology and axis — junctional P waves are inverted in inferior leads while sinus P waves are upright

Answer

QRS duration

Answer

PR interval length alone

Answer

Heart rate

Question 2

In a junctional escape rhythm, the QRS complex is typically narrow because of which reason?

Accepted Answer

The impulse reaches the ventricles via the normal His-Purkinje conduction system

Answer

The impulse bypasses the AV node entirely

Answer

Ventricular muscle activates simultaneously from multiple foci

Answer

The impulse originates in the ventricles

Question 3

A patient post-cardiac surgery develops a regular narrow-complex tachycardia at 110 bpm with inverted P waves in lead II occurring just after each QRS. Which rhythm is most likely?

Accepted Answer

Junctional tachycardia

Answer

Sinus tachycardia

Answer

Atrial flutter with 2:1 block

Answer

AVNRT

Question 4

What is the significance of a junctional escape rhythm appearing at a rate slower than 40 bpm?

Accepted Answer

It may indicate junctional suppression, possibly due to enhanced vagal tone, medication effect, or junctional disease

Answer

It is normal and expected

Answer

It indicates the rhythm is actually ventricular in origin

Answer

It confirms atropine has been given

Question 5

Digitalis toxicity is classically associated with which junctional arrhythmia pattern?

Accepted Answer

Accelerated junctional rhythm with AV dissociation

Answer

First-degree AV block without junctional escape

Answer

Atrial fibrillation with rapid ventricular response

Answer

Sinus tachycardia

Question 6

A rhythm shows no visible P waves, a narrow QRS complex, and a rate of 52 bpm. Which rhythm is this most consistent with?

Accepted Answer

Junctional escape rhythm

Answer

Sinus bradycardia

Answer

Atrial fibrillation

Answer

Accelerated idioventricular rhythm