CRAT - Certified Rhythm Analysis Technician Junctional Rhythm Analysis Questions and Answers 1

Question 1

A rhythm analysis technician is reviewing a 6-second strip that shows a regular rhythm with a heart rate of 50 bpm. P waves are not discernible, and the QRS complexes are narrow, measuring 0.08 seconds. Which rhythm should the technician identify?

Accepted Answer

Junctional Rhythm

Answer

This rhythm is identified as a Junctional Rhythm (or Junctional Escape Rhythm) because the heart rate is between 40-60 bpm, which is the intrinsic rate of the AV junction. The absence of P waves and the presence of a narrow QRS complex are classic indicators that the impulse is originating from the AV junction and traveling down the normal ventricular conduction pathway.

Question 2

Which of the following ECG findings is the most definitive characteristic of a rhythm originating from the AV junction?

Accepted Answer

An inverted or absent P wave with a short PR interval if visible

Answer

Rhythms originating in the AV junction cause retrograde (backward) depolarization of the atria. This results in P waves that are inverted in leads II, III, and aVF, or are absent because they are buried within the QRS complex. If a P wave precedes the QRS, the PR interval is short (<0.12 seconds) because the impulse has less distance to travel to the ventricles.

Question 3

A CRAT observes a regular rhythm on a patient's monitor with a rate of 75 bpm. The QRS complexes are 0.06 seconds wide. There are inverted P waves in lead II just before each QRS complex, with a PR interval of 0.10 seconds. What is the correct interpretation of this rhythm?

Accepted Answer

Accelerated Junctional Rhythm

Answer

This rhythm is an Accelerated Junctional Rhythm. The rate of 61-100 bpm is faster than the intrinsic rate of the AV junction but slower than tachycardia. The presence of inverted P waves with a short PR interval confirms the junctional origin. Junctional Escape Rhythm is slower (40-60 bpm), and Junctional Tachycardia is faster (>100 bpm).

Question 4

What is the intrinsic pacemaker rate of the atrioventricular (AV) junction?

Accepted Answer

40-60 bpm

Answer

The AV junction, which includes the AV node and the bundle of His, has an intrinsic pacemaker rate of 40-60 beats per minute. It serves as a secondary pacemaker, taking over if the primary pacemaker, the SA node (60-100 bpm), fails.

Question 5

A patient's ECG shows a regular, narrow-complex rhythm at a rate of 120 bpm. No P waves are visible before, during, or after the QRS complexes. This rhythm is best described as:

Accepted Answer

Junctional Tachycardia

Answer

This rhythm is Junctional Tachycardia. The rate is greater than 100 bpm, the QRS is narrow, and there are no visible P waves, which are characteristic findings. The AV junction has overridden the SA node due to enhanced automaticity, firing at a rate above 100 bpm.

CRAT - Certified Rhythm Analysis Technician Practice Test

CRAT - Certified Rhythm Analysis Technician Practice Test

CRAT - Certified Rhythm Analysis Technician Junctional Rhythm Analysis Questions and Answers 1