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RELIAS DYSRHYTHMIA TEST COMPREHENSIVE 2026/2027 |
Basic & Advanced Questions | Verified Answers | Complete
ECG Interpretation | Pass Guaranteed - A+ Graded
Section 1: Sinus Rhythms (Questions 1-10)
Question 1 Which of the following electrocardiographic criteria definitively identifies
normal sinus rhythm?
A. P waves inverted in leads II, III, and aVF with a regular ventricular rate of 60-100
bpm B. P waves upright in leads I, II, and aVF, regular rhythm, PR interval 0.12-0.20
seconds, and narrow QRS complexes [CORRECT] C. Irregular R-R intervals with
upright P waves in lead I and a ventricular rate between 50-120 bpm D. P waves
preceding each QRS complex with a PR interval of 0.20-0.30 seconds and a rate of
40-60 bpm
Rationale: Normal sinus rhythm originates from the sinoatrial node with P waves
upright in leads I, II, and aVF (axis 0° to +90°), a regular rhythm, normal PR interval of
0.12-0.20 seconds, and narrow QRS complexes <0.10 seconds. Option A describes an
ectopic atrial or junctional origin, Option C describes sinus arrhythmia with an
abnormal rate range, and Option D describes first-degree AV block with a junctional
rate.
Correct Answer: B
Question 2 A 68-year-old patient recovering from inferior wall myocardial infarction
has a heart rate of 48 bpm. The rhythm strip shows regular P-P and R-R intervals,
upright P waves in lead II preceding each QRS, a PR interval of 0.16 seconds, and
narrow QRS complexes. The patient is asymptomatic. Which rhythm is present?
A. Junctional escape rhythm B. Normal sinus rhythm C. Sinus bradycardia [CORRECT]
D. First-degree AV block
Rationale: The rhythm meets all criteria for sinus origin (upright P in lead II, normal
PR, narrow QRS) with a regular rate below 60 bpm, defining sinus bradycardia.
Junctional escape rhythm would typically have absent, inverted, or retrograde P
waves; normal sinus rhythm requires 60-100 bpm; and first-degree AV block requires
PR >0.20 seconds.
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Correct Answer: C
Question 3 A 32-year-old patient presents with fever, anxiety, and dehydration. The
EKG shows a regular rhythm at 118 bpm with upright P waves in lead II, normal PR
interval, and narrow QRS complexes. Which is the most appropriate interpretation?
A. Atrial tachycardia with 1:1 conduction B. Sinus tachycardia [CORRECT] C.
Supraventricular tachycardia (SVT) D. Accelerated junctional rhythm
Rationale: Sinus tachycardia is characterized by a sinus-origin rhythm (upright P in
lead II) with a rate >100 bpm, typically with gradual onset and offset, and normal P
wave morphology and PR interval. Atrial tachycardia often has abnormal P wave
morphology; SVT usually has a rate >150 bpm with absent or buried P waves; and
accelerated junctional rhythm has a rate of 60-100 bpm with retrograde or absent P
waves.
Correct Answer: B
Question 4 A rhythm strip from a 25-year-old healthy adult shows a ventricular rate
varying between 58 and 82 bpm. The R-R intervals gradually lengthen and shorten in
a cyclical pattern corresponding with respiration. P waves are upright in lead II,
normal in morphology, and precede each QRS complex with a constant PR interval of
0.14 seconds. QRS duration is 0.08 seconds. Which rhythm is present?
A. Sinus arrhythmia [CORRECT] B. Wandering atrial pacemaker C. Sinus tachycardia
with frequent PACs D. Atrial fibrillation with controlled ventricular response
Rationale: Sinus arrhythmia demonstrates phasic variation in the R-R interval
(typically increasing with inspiration and decreasing with expiration) with normal
sinus P wave morphology and a constant PR interval, indicating the impulse still
originates from the SA node. Wandering atrial pacemaker would show changing P
wave morphologies; frequent PACs would show premature, differently shaped P
waves; and atrial fibrillation would show an irregularly irregular rhythm without
distinct P waves.
Correct Answer: A
Question 5 A rhythm strip shows a sudden pause where an expected P-QRS-T
complex is absent. The pause duration is measured at exactly 2.8 seconds. The
underlying sinus rate is 70 bpm (P-P interval approximately 0.86 seconds). The pause
, 3
interval is NOT a multiple of the underlying P-P interval. Which mechanism best
explains this finding?
A. Sinoatrial exit block, Type I B. Sinus arrest [CORRECT] C. Sinoatrial exit block, Type
II D. Second-degree AV block, Type II
Rationale: In sinus arrest, the SA node fails to generate an impulse, resulting in a
pause that is NOT a multiple of the underlying P-P interval. In sinoatrial exit block
(Type I or II), the SA node fires but the impulse fails to depolarize the atria, producing
a pause that IS a multiple of the basic P-P interval. Second-degree AV block would
show P waves that are not conducted, not an absence of P waves entirely.
Correct Answer: B
Question 6 Which statement accurately describes the electrocardiographic finding in
sinus arrest?
A. The pause duration equals exactly twice the preceding P-P interval B. P waves are
present during the pause but fail to conduct to the ventricles C. There is a complete
absence of P waves, QRS complexes, and T waves during the pause, and the pause is
not a multiple of the basic cycle length [CORRECT] D. The rhythm is regularly
irregular with changing P wave morphologies
Rationale: Sinus arrest is characterized by a failure of the SA node to generate an
impulse, resulting in a pause with no atrial or ventricular activity (no P, QRS, or T
waves) and the pause duration is not a multiple of the underlying P-P interval.
Option A describes sinoatrial exit block; Option B describes AV block; and Option D
describes wandering atrial pacemaker.
Correct Answer: C
Question 7 A rhythm strip from a monitored patient shows an underlying regular
sinus rhythm at 75 bpm. Suddenly, there is a pause with no P wave, QRS complex, or
T wave. The pause measures exactly 1.6 seconds, which is precisely twice the
underlying P-P interval of 0.80 seconds. After the pause, the sinus rhythm resumes at
the same rate with identical P wave morphology. Which diagnosis is correct?
A. Sinus arrest B. Sinoatrial exit block [CORRECT] C. Second-degree AV block, Type I
D. High-grade AV block
RELIAS DYSRHYTHMIA TEST COMPREHENSIVE 2026/2027 |
Basic & Advanced Questions | Verified Answers | Complete
ECG Interpretation | Pass Guaranteed - A+ Graded
Section 1: Sinus Rhythms (Questions 1-10)
Question 1 Which of the following electrocardiographic criteria definitively identifies
normal sinus rhythm?
A. P waves inverted in leads II, III, and aVF with a regular ventricular rate of 60-100
bpm B. P waves upright in leads I, II, and aVF, regular rhythm, PR interval 0.12-0.20
seconds, and narrow QRS complexes [CORRECT] C. Irregular R-R intervals with
upright P waves in lead I and a ventricular rate between 50-120 bpm D. P waves
preceding each QRS complex with a PR interval of 0.20-0.30 seconds and a rate of
40-60 bpm
Rationale: Normal sinus rhythm originates from the sinoatrial node with P waves
upright in leads I, II, and aVF (axis 0° to +90°), a regular rhythm, normal PR interval of
0.12-0.20 seconds, and narrow QRS complexes <0.10 seconds. Option A describes an
ectopic atrial or junctional origin, Option C describes sinus arrhythmia with an
abnormal rate range, and Option D describes first-degree AV block with a junctional
rate.
Correct Answer: B
Question 2 A 68-year-old patient recovering from inferior wall myocardial infarction
has a heart rate of 48 bpm. The rhythm strip shows regular P-P and R-R intervals,
upright P waves in lead II preceding each QRS, a PR interval of 0.16 seconds, and
narrow QRS complexes. The patient is asymptomatic. Which rhythm is present?
A. Junctional escape rhythm B. Normal sinus rhythm C. Sinus bradycardia [CORRECT]
D. First-degree AV block
Rationale: The rhythm meets all criteria for sinus origin (upright P in lead II, normal
PR, narrow QRS) with a regular rate below 60 bpm, defining sinus bradycardia.
Junctional escape rhythm would typically have absent, inverted, or retrograde P
waves; normal sinus rhythm requires 60-100 bpm; and first-degree AV block requires
PR >0.20 seconds.
,2
Correct Answer: C
Question 3 A 32-year-old patient presents with fever, anxiety, and dehydration. The
EKG shows a regular rhythm at 118 bpm with upright P waves in lead II, normal PR
interval, and narrow QRS complexes. Which is the most appropriate interpretation?
A. Atrial tachycardia with 1:1 conduction B. Sinus tachycardia [CORRECT] C.
Supraventricular tachycardia (SVT) D. Accelerated junctional rhythm
Rationale: Sinus tachycardia is characterized by a sinus-origin rhythm (upright P in
lead II) with a rate >100 bpm, typically with gradual onset and offset, and normal P
wave morphology and PR interval. Atrial tachycardia often has abnormal P wave
morphology; SVT usually has a rate >150 bpm with absent or buried P waves; and
accelerated junctional rhythm has a rate of 60-100 bpm with retrograde or absent P
waves.
Correct Answer: B
Question 4 A rhythm strip from a 25-year-old healthy adult shows a ventricular rate
varying between 58 and 82 bpm. The R-R intervals gradually lengthen and shorten in
a cyclical pattern corresponding with respiration. P waves are upright in lead II,
normal in morphology, and precede each QRS complex with a constant PR interval of
0.14 seconds. QRS duration is 0.08 seconds. Which rhythm is present?
A. Sinus arrhythmia [CORRECT] B. Wandering atrial pacemaker C. Sinus tachycardia
with frequent PACs D. Atrial fibrillation with controlled ventricular response
Rationale: Sinus arrhythmia demonstrates phasic variation in the R-R interval
(typically increasing with inspiration and decreasing with expiration) with normal
sinus P wave morphology and a constant PR interval, indicating the impulse still
originates from the SA node. Wandering atrial pacemaker would show changing P
wave morphologies; frequent PACs would show premature, differently shaped P
waves; and atrial fibrillation would show an irregularly irregular rhythm without
distinct P waves.
Correct Answer: A
Question 5 A rhythm strip shows a sudden pause where an expected P-QRS-T
complex is absent. The pause duration is measured at exactly 2.8 seconds. The
underlying sinus rate is 70 bpm (P-P interval approximately 0.86 seconds). The pause
, 3
interval is NOT a multiple of the underlying P-P interval. Which mechanism best
explains this finding?
A. Sinoatrial exit block, Type I B. Sinus arrest [CORRECT] C. Sinoatrial exit block, Type
II D. Second-degree AV block, Type II
Rationale: In sinus arrest, the SA node fails to generate an impulse, resulting in a
pause that is NOT a multiple of the underlying P-P interval. In sinoatrial exit block
(Type I or II), the SA node fires but the impulse fails to depolarize the atria, producing
a pause that IS a multiple of the basic P-P interval. Second-degree AV block would
show P waves that are not conducted, not an absence of P waves entirely.
Correct Answer: B
Question 6 Which statement accurately describes the electrocardiographic finding in
sinus arrest?
A. The pause duration equals exactly twice the preceding P-P interval B. P waves are
present during the pause but fail to conduct to the ventricles C. There is a complete
absence of P waves, QRS complexes, and T waves during the pause, and the pause is
not a multiple of the basic cycle length [CORRECT] D. The rhythm is regularly
irregular with changing P wave morphologies
Rationale: Sinus arrest is characterized by a failure of the SA node to generate an
impulse, resulting in a pause with no atrial or ventricular activity (no P, QRS, or T
waves) and the pause duration is not a multiple of the underlying P-P interval.
Option A describes sinoatrial exit block; Option B describes AV block; and Option D
describes wandering atrial pacemaker.
Correct Answer: C
Question 7 A rhythm strip from a monitored patient shows an underlying regular
sinus rhythm at 75 bpm. Suddenly, there is a pause with no P wave, QRS complex, or
T wave. The pause measures exactly 1.6 seconds, which is precisely twice the
underlying P-P interval of 0.80 seconds. After the pause, the sinus rhythm resumes at
the same rate with identical P wave morphology. Which diagnosis is correct?
A. Sinus arrest B. Sinoatrial exit block [CORRECT] C. Second-degree AV block, Type I
D. High-grade AV block
