CRAT Junctional Rhythm Analysis 2

Question 1

A junctional escape rhythm typically fires at which rate?

Accepted Answer

40-60 bpm

Answer

The AV junction has an intrinsic automaticity rate of 40-60 bpm, which emerges when the SA node fails to fire or its rate falls below this threshold.

Question 2

In a junctional rhythm, P waves appear inverted in the inferior leads (II, III, aVF) because of which mechanism?

Accepted Answer

Retrograde atrial activation from the AV junction travels superiorly, opposite to normal sinus direction

Answer

Junctional impulses activate the atria in a retrograde (bottom-up) direction, causing the electrical wavefront to travel toward the base of the heart — opposite to normal sinus direction — producing inverted P waves in inferior leads.

Question 3

An accelerated junctional rhythm differs from a junctional escape rhythm primarily in which way?

Accepted Answer

Accelerated junctional rhythm has a rate of 60-100 bpm, faster than normal junctional escape

Answer

Accelerated junctional rhythm occurs when the junctional pacemaker fires faster than its intrinsic 40-60 bpm escape rate, at 60-100 bpm, usurping the sinus node.

Question 4

If a junctional rhythm shows P waves occurring immediately AFTER each QRS complex (short RP interval), what does this timing indicate?

Accepted Answer

Retrograde atrial activation occurs after ventricular depolarization because the atria are activated slower than the ventricles

Answer

When the AV junction activates both ventricles (antegrade via His-Purkinje) and atria (retrograde), the timing of P waves relative to QRS depends on which pathway conducts faster; slow retrograde conduction produces P waves after QRS.

Question 5

Junctional tachycardia is defined by a junctional rhythm exceeding which rate threshold?

Accepted Answer

100 bpm

Answer

Any junctional rhythm exceeding 100 bpm is classified as junctional tachycardia, distinct from the accelerated (60-100 bpm) and escape (40-60 bpm) categories.

CRAT - Certified Rhythm Analysis Technician Practice Test

CRAT - Certified Rhythm Analysis Technician Practice Test

CRAT Junctional Rhythm Analysis 2