Relias Dysrhythmia Basic A
Complete Test Review
(Questions & Solutions)
2025
1
,1. A 72-year-old post–myocardial infarction patient’s SA node fails and
the atrioventricular (AV) junction fires at 52 bpm. How is this rhythm
classified?
A. Sinus bradycardia
B. Junctional escape rhythm
C. Accelerated junctional rhythm
D. Atrial escape rhythm
ANS: B
Rationale: Junctional escape rhythms originate in the AV junction at 40–
60 bpm when the SA node fails.
2. In complete heart block, the ventricles depolarize at 30 bpm. Which
pacemaker site is responsible?
A. AV node
B. His-Purkinje system
C. Purkinje fibers
D. SA node
ANS: C
Rationale: Ventricular escape rhythms under 40 bpm arise from
Purkinje fibers.
3. A reperfused acute MI patient develops a wide-complex rhythm at 75
bpm with occasional fusion beats. Which rhythm is most likely?
A. Ventricular tachycardia
B. Accelerated idioventricular rhythm (AIVR)
C. Junctional tachycardia
D. SVT with aberrancy
2
, ANS: B
Rationale: AIVR occurs after reperfusion and features a ventricular rate
of 40–100 bpm with fusion beats.
4. An ectopic atrial focus fires at 120 bpm independently of the SA node.
Which rhythm is this?
A. Atrial tachycardia
B. Multifocal atrial tachycardia
C. Atrial flutter
D. Atrial escape rhythm
ANS: A
Rationale: Atrial tachycardia arises from a single ectopic atrial focus
with rates typically 100–250 bpm.
5. A junctional pacemaker fires at 70 bpm with inverted P waves
preceding each QRS. How is this classified?
A. Junctional escape rhythm
B. Accelerated junctional rhythm
C. Junctional tachycardia
D. Junctional bradycardia
ANS: B
Rationale: Accelerated junctional rhythm has rates of 60–100 bpm with
retrograde atrial activation (inverted P waves).
6. The SA node rate slows to 40 bpm without an escape rhythm
emerging. What is the expected ECG finding?
A. Sinus bradycardia
B. Junctional escape rhythm
C. Sinus pause progressing to asystole
D. Idioventricular rhythm
3
Complete Test Review
(Questions & Solutions)
2025
1
,1. A 72-year-old post–myocardial infarction patient’s SA node fails and
the atrioventricular (AV) junction fires at 52 bpm. How is this rhythm
classified?
A. Sinus bradycardia
B. Junctional escape rhythm
C. Accelerated junctional rhythm
D. Atrial escape rhythm
ANS: B
Rationale: Junctional escape rhythms originate in the AV junction at 40–
60 bpm when the SA node fails.
2. In complete heart block, the ventricles depolarize at 30 bpm. Which
pacemaker site is responsible?
A. AV node
B. His-Purkinje system
C. Purkinje fibers
D. SA node
ANS: C
Rationale: Ventricular escape rhythms under 40 bpm arise from
Purkinje fibers.
3. A reperfused acute MI patient develops a wide-complex rhythm at 75
bpm with occasional fusion beats. Which rhythm is most likely?
A. Ventricular tachycardia
B. Accelerated idioventricular rhythm (AIVR)
C. Junctional tachycardia
D. SVT with aberrancy
2
, ANS: B
Rationale: AIVR occurs after reperfusion and features a ventricular rate
of 40–100 bpm with fusion beats.
4. An ectopic atrial focus fires at 120 bpm independently of the SA node.
Which rhythm is this?
A. Atrial tachycardia
B. Multifocal atrial tachycardia
C. Atrial flutter
D. Atrial escape rhythm
ANS: A
Rationale: Atrial tachycardia arises from a single ectopic atrial focus
with rates typically 100–250 bpm.
5. A junctional pacemaker fires at 70 bpm with inverted P waves
preceding each QRS. How is this classified?
A. Junctional escape rhythm
B. Accelerated junctional rhythm
C. Junctional tachycardia
D. Junctional bradycardia
ANS: B
Rationale: Accelerated junctional rhythm has rates of 60–100 bpm with
retrograde atrial activation (inverted P waves).
6. The SA node rate slows to 40 bpm without an escape rhythm
emerging. What is the expected ECG finding?
A. Sinus bradycardia
B. Junctional escape rhythm
C. Sinus pause progressing to asystole
D. Idioventricular rhythm
3
