Latest Test Review
(Questions & Solutions)
2025
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,1. A patient’s intrinsic sinoatrial (SA) node fires at 55 bpm. How is this
classified?
A. Normal sinus rhythm
B. Sinus bradycardia
C. Sinus tachycardia
D. Junctional escape rhythm
ANS: B
Rationale: Sinus bradycardia is defined by an SA nodal rate below 60
bpm.
2. An atrioventricular (AV) junctional focus fires at 50 bpm in the absence
of sinus activity. What rhythm is present?
A. Accelerated junctional rhythm
B. Junctional escape rhythm
C. Premature junctional contraction
D. Ventricular escape rhythm
ANS: B
Rationale: Junctional escape rhythms originate in the AV junction at 40–
60 bpm when the SA node fails.
3. During complete heart block, the ventricles depolarize at 30 bpm.
Which pacemaker site is responsible?
A. AV node
B. SA node
C. His-Purkinje system
D. Atrial ectopic focus
ANS: C
Rationale: Ventricular (idioventricular) escape rhythms <40 bpm arise
from the His-Purkinje system.
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, 4. Which rate best defines an accelerated idioventricular rhythm (AIVR)?
A. 20–40 bpm
B. 40–60 bpm
C. 60–100 bpm
D. >100 bpm
ANS: C
Rationale: AIVR originates in ventricles at rates between 40 and 100 bpm,
faster than idioventricular escape but slower than VT.
5. An atrial ectopic focus fires at 80 bpm once the SA node fails. What is
this rhythm?
A. Atrial escape rhythm
B. Atrial tachycardia
C. Atrial flutter
D. Junctional escape rhythm
ANS: A
Rationale: An atrial escape rhythm arises from an ectopic atrial focus at
60–80 bpm when the SA node pauses.
6. The SA node pauses with no subsidiary pacemaker response. Which
ECG finding is expected?
A. Sinus pause
B. Asystole
C. Ventricular fibrillation
D. Accelerated junctional rhythm
ANS: B
Rationale: Total absence of atrial and ventricular activity produces
asystole on ECG.
7. A wide-complex rhythm at 85 bpm with fusion beats appears after
reperfusion therapy. What is this?
A. Ventricular tachycardia
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