COMPREHENSIVE DYSRHYTHMIA RECOGNITION &
CLINICAL DECISION-MAKING
RELIAS Dysrhythmia
Basic B Exam
35 Verified Questions and Answers covering cardiac rhythm
interpretation, ACLS pharmacological interventions, electrical
therapy indications, and emergency response protocols for the
2026/2027 examination cycle.
EXAM YEAR
TOTAL QUES TIONS
35 Multiple Choice
FOCUS AR EAS
Cardiac Rhythm Interpretation, ACLS Algorithms, Clinical Decision-Making
C A R D I A C N U R S I N G & A D VA N C E D T E L E M E T R Y E D U C AT I O N
, RELIAS Dysrhythmia Basic B Exam | 2026/2027 | Cardiac Rhythm Interpretation
Section 1: Sinus Rhythms and Variations (Q1 - Q8)
Q1: A 62-year-old patient is admitted for chest pain evaluation. The cardiac monitor displays a rhythm
with a regular R-R interval, a rate of 72 bpm using the 6-second method (6 QRS complexes in 5
seconds), upright P waves before each QRS that are uniform in morphology, a PR interval of 0.16
seconds, and a narrow QRS duration of 0.08 seconds. What is the correct interpretation of this
rhythm?
A. Sinus Bradycardia with first-degree AV block
B. Normal Sinus Rhythm
C. Sinus Arrhythmia with normal conduction [CORRECT]
D. Junctional Rhythm with retrograde P waves
Correct Answer: C
Rationale: Using the 6-second method, 6 QRS complexes in 5 seconds yields a rate of 72 bpm (6 x 12 = 72), which falls
within the normal sinus rhythm range of 60-100 bpm. The R-R intervals are regular, confirming rhythmic regularity.
Each P wave is upright, uniform in morphology, and precedes every QRS complex, indicating a sinus origin. The PR
interval of 0.16 seconds is within the normal range of 0.12-0.20 seconds, confirming intact AV conduction. The QRS
duration of 0.08 seconds is narrow (less than 0.12 seconds), indicating normal ventricular depolarization through the
His-Purkinje system. All five steps of the systematic interpretation confirm Normal Sinus Rhythm. Option A is incorrect
because the rate is not below 60 bpm and the PR interval is not prolonged beyond 0.20 seconds. Option C is incorrect
because the rhythm is described as regular with no variation in R-R intervals, which is required for sinus arrhythmia.
Option D is incorrect because the P waves are upright and precede the QRS, rather than being inverted or appearing after
the QRS as seen in junctional rhythms.
Q2: A 45-year-old marathon runner presents for a routine physical examination. The ECG reveals a
regular rhythm at a rate of 48 bpm (calculated using the 1500 method: 1500 divided by 31 small boxes
between R-R intervals), with upright P waves before each QRS, a PR interval of 0.14 seconds, and a
narrow QRS of 0.08 seconds. The patient is asymptomatic with a blood pressure of 118/76 mmHg.
What is the most appropriate interpretation and clinical action?
A. Sinus Bradycardia; administer atropine 0.5 mg IV to increase heart rate
B. Normal Sinus Rhythm; the rate of 48 bpm is within normal limits for an athlete [CORRECT]
C. Sinus Bradycardia; this is a pathological finding requiring immediate pacing
D. Sinus Arrest with junctional escape; prepare for transcutaneous pacing
Correct Answer: B
Rationale: Using the 1500 method, the rate calculation of 1500/31 = approximately 48 bpm confirms sinus bradycardia
(rate less than 60 bpm originating from the SA node). The P waves are upright and precede each QRS, the PR interval is
normal at 0.14 seconds, and the QRS is narrow at 0.08 seconds, all confirming sinus origin with normal conduction. In
well-conditioned athletes, sinus bradycardia is a normal physiological adaptation due to increased vagal tone and
enhanced stroke volume, not a pathological finding. The patient is hemodynamically stable with adequate blood pressure,
so no intervention is required. Option A is incorrect because atropine is indicated for symptomatic bradycardia, not for
asymptomatic physiological bradycardia in athletes. Option B is incorrect because 48 bpm is below the 60 bpm threshold
for normal sinus rhythm. Option D is incorrect because there is no evidence of sinus arrest (no missing P-QRS
complexes) or junctional escape beats (the P waves are upright and precede the QRS).
Page 1
, RELIAS Dysrhythmia Basic B Exam | 2026/2027 | Cardiac Rhythm Interpretation
Q3: A 58-year-old patient with pneumonia and a fever of 102.4 degrees Fahrenheit is on telemetry. The
rhythm strip shows a regular narrow-complex tachycardia at a rate of 118 bpm (approximately 13
QRS complexes in a 6-second strip). Each QRS is preceded by an upright, uniform P wave. The PR
interval measures 0.14 seconds and the QRS duration is 0.07 seconds. The patient reports feeling
palpitations but is hemodynamically stable with a blood pressure of 128/82 mmHg. Which rhythm is
demonstrated and what is the primary intervention?
A. Sinus Tachycardia; treat the underlying cause (fever and infection) [CORRECT]
B. Supraventricular Tachycardia; administer adenosine 6 mg rapid IV push
C. Atrial Flutter with 2:1 conduction; administer diltiazem for rate control
D. Sinus Tachycardia; administer metoprolol 5 mg IV to reduce heart rate
Correct Answer: A
Rationale: Using the 6-second method, 13 QRS complexes yield a rate of approximately 118 bpm (13 x 10 = 130, or
more precisely 13 complexes in 6 seconds = approximately 130 bpm), which is consistent with sinus tachycardia (rate
greater than 100 bpm with sinus origin). The key differentiating feature is the presence of one upright, uniform P wave
preceding each QRS complex, confirming sinus origin. The PR interval of 0.14 seconds is normal and fixed, ruling out
atrial flutter with variable block. The QRS is narrow at 0.07 seconds, indicating normal ventricular conduction. Sinus
tachycardia is a compensatory response to physiological demands such as fever, infection, hypovolemia, or pain. The
primary intervention is to treat the underlying cause rather than the rhythm itself. Option B is incorrect because adenosine
is indicated for regular narrow-complex tachycardias of non-sinus origin (such as AVNRT), not for sinus tachycardia
where identifiable P waves are present. Option C is incorrect because atrial flutter would show sawtooth flutter waves
rather than discrete upright P waves, and 2:1 conduction at this rate would show a ventricular rate of approximately 150
bpm (flutter rate of 300/2). Option D is incorrect because administering beta-blockers without addressing the underlying
infection could compromise the patient's compensatory tachycardic response.
Q4: A 24-year-old healthy nursing student has a routine ECG performed during a clinical skills lab.
The rhythm demonstrates a rate that varies between 56 bpm and 82 bpm over the 10-second recording.
The R-R intervals shorten during inspiration and lengthen during expiration. Each QRS is preceded
by an upright P wave with consistent morphology. The PR interval is 0.16 seconds and the QRS is 0.08
seconds. What is the correct interpretation?
A. Second-Degree Type I AV Block (Wenckebach) due to the variable R-R intervals
B. Sinus Arrhythmia, a normal variant commonly seen in young healthy adults [CORRECT]
C. Atrial Fibrillation with slow ventricular response due to irregular R-R intervals
D. Wandering Atrial Pacemaker due to varying P wave morphologies
Correct Answer: B
Rationale: The hallmark finding of sinus arrhythmia is the variation in R-R intervals that correlates with the respiratory
cycle: the rate increases during inspiration (shorter R-R intervals) and decreases during expiration (longer R-R intervals).
The rate range of 56-82 bpm is entirely normal. Crucially, each QRS is preceded by an upright P wave with consistent
morphology, which confirms sinus origin and rules out wandering atrial pacemaker (which would show at least three
different P wave morphologies). The PR interval remains constant at 0.16 seconds, which rules out Second-Degree Type
I AV Block (Wenckebach), where the PR interval progressively prolongs until a QRS is dropped. The presence of
identifiable P waves before each QRS rules out atrial fibrillation, which is characterized by the absence of discrete P
waves and a totally irregular R-R pattern. Sinus arrhythmia is a benign, normal variant that is especially common in
young, healthy individuals and is mediated by vagal tone fluctuations during the respiratory cycle. Option A is incorrect
because there are no dropped beats or progressively prolonging PR intervals. Option C is incorrect because atrial
fibrillation has no discernible P waves and a chaotically irregular rhythm, not a cyclical pattern tied to breathing. Option
D is incorrect because all P waves have the same morphology, whereas wandering atrial pacemaker requires at least three
different P wave configurations.
Page 2
CLINICAL DECISION-MAKING
RELIAS Dysrhythmia
Basic B Exam
35 Verified Questions and Answers covering cardiac rhythm
interpretation, ACLS pharmacological interventions, electrical
therapy indications, and emergency response protocols for the
2026/2027 examination cycle.
EXAM YEAR
TOTAL QUES TIONS
35 Multiple Choice
FOCUS AR EAS
Cardiac Rhythm Interpretation, ACLS Algorithms, Clinical Decision-Making
C A R D I A C N U R S I N G & A D VA N C E D T E L E M E T R Y E D U C AT I O N
, RELIAS Dysrhythmia Basic B Exam | 2026/2027 | Cardiac Rhythm Interpretation
Section 1: Sinus Rhythms and Variations (Q1 - Q8)
Q1: A 62-year-old patient is admitted for chest pain evaluation. The cardiac monitor displays a rhythm
with a regular R-R interval, a rate of 72 bpm using the 6-second method (6 QRS complexes in 5
seconds), upright P waves before each QRS that are uniform in morphology, a PR interval of 0.16
seconds, and a narrow QRS duration of 0.08 seconds. What is the correct interpretation of this
rhythm?
A. Sinus Bradycardia with first-degree AV block
B. Normal Sinus Rhythm
C. Sinus Arrhythmia with normal conduction [CORRECT]
D. Junctional Rhythm with retrograde P waves
Correct Answer: C
Rationale: Using the 6-second method, 6 QRS complexes in 5 seconds yields a rate of 72 bpm (6 x 12 = 72), which falls
within the normal sinus rhythm range of 60-100 bpm. The R-R intervals are regular, confirming rhythmic regularity.
Each P wave is upright, uniform in morphology, and precedes every QRS complex, indicating a sinus origin. The PR
interval of 0.16 seconds is within the normal range of 0.12-0.20 seconds, confirming intact AV conduction. The QRS
duration of 0.08 seconds is narrow (less than 0.12 seconds), indicating normal ventricular depolarization through the
His-Purkinje system. All five steps of the systematic interpretation confirm Normal Sinus Rhythm. Option A is incorrect
because the rate is not below 60 bpm and the PR interval is not prolonged beyond 0.20 seconds. Option C is incorrect
because the rhythm is described as regular with no variation in R-R intervals, which is required for sinus arrhythmia.
Option D is incorrect because the P waves are upright and precede the QRS, rather than being inverted or appearing after
the QRS as seen in junctional rhythms.
Q2: A 45-year-old marathon runner presents for a routine physical examination. The ECG reveals a
regular rhythm at a rate of 48 bpm (calculated using the 1500 method: 1500 divided by 31 small boxes
between R-R intervals), with upright P waves before each QRS, a PR interval of 0.14 seconds, and a
narrow QRS of 0.08 seconds. The patient is asymptomatic with a blood pressure of 118/76 mmHg.
What is the most appropriate interpretation and clinical action?
A. Sinus Bradycardia; administer atropine 0.5 mg IV to increase heart rate
B. Normal Sinus Rhythm; the rate of 48 bpm is within normal limits for an athlete [CORRECT]
C. Sinus Bradycardia; this is a pathological finding requiring immediate pacing
D. Sinus Arrest with junctional escape; prepare for transcutaneous pacing
Correct Answer: B
Rationale: Using the 1500 method, the rate calculation of 1500/31 = approximately 48 bpm confirms sinus bradycardia
(rate less than 60 bpm originating from the SA node). The P waves are upright and precede each QRS, the PR interval is
normal at 0.14 seconds, and the QRS is narrow at 0.08 seconds, all confirming sinus origin with normal conduction. In
well-conditioned athletes, sinus bradycardia is a normal physiological adaptation due to increased vagal tone and
enhanced stroke volume, not a pathological finding. The patient is hemodynamically stable with adequate blood pressure,
so no intervention is required. Option A is incorrect because atropine is indicated for symptomatic bradycardia, not for
asymptomatic physiological bradycardia in athletes. Option B is incorrect because 48 bpm is below the 60 bpm threshold
for normal sinus rhythm. Option D is incorrect because there is no evidence of sinus arrest (no missing P-QRS
complexes) or junctional escape beats (the P waves are upright and precede the QRS).
Page 1
, RELIAS Dysrhythmia Basic B Exam | 2026/2027 | Cardiac Rhythm Interpretation
Q3: A 58-year-old patient with pneumonia and a fever of 102.4 degrees Fahrenheit is on telemetry. The
rhythm strip shows a regular narrow-complex tachycardia at a rate of 118 bpm (approximately 13
QRS complexes in a 6-second strip). Each QRS is preceded by an upright, uniform P wave. The PR
interval measures 0.14 seconds and the QRS duration is 0.07 seconds. The patient reports feeling
palpitations but is hemodynamically stable with a blood pressure of 128/82 mmHg. Which rhythm is
demonstrated and what is the primary intervention?
A. Sinus Tachycardia; treat the underlying cause (fever and infection) [CORRECT]
B. Supraventricular Tachycardia; administer adenosine 6 mg rapid IV push
C. Atrial Flutter with 2:1 conduction; administer diltiazem for rate control
D. Sinus Tachycardia; administer metoprolol 5 mg IV to reduce heart rate
Correct Answer: A
Rationale: Using the 6-second method, 13 QRS complexes yield a rate of approximately 118 bpm (13 x 10 = 130, or
more precisely 13 complexes in 6 seconds = approximately 130 bpm), which is consistent with sinus tachycardia (rate
greater than 100 bpm with sinus origin). The key differentiating feature is the presence of one upright, uniform P wave
preceding each QRS complex, confirming sinus origin. The PR interval of 0.14 seconds is normal and fixed, ruling out
atrial flutter with variable block. The QRS is narrow at 0.07 seconds, indicating normal ventricular conduction. Sinus
tachycardia is a compensatory response to physiological demands such as fever, infection, hypovolemia, or pain. The
primary intervention is to treat the underlying cause rather than the rhythm itself. Option B is incorrect because adenosine
is indicated for regular narrow-complex tachycardias of non-sinus origin (such as AVNRT), not for sinus tachycardia
where identifiable P waves are present. Option C is incorrect because atrial flutter would show sawtooth flutter waves
rather than discrete upright P waves, and 2:1 conduction at this rate would show a ventricular rate of approximately 150
bpm (flutter rate of 300/2). Option D is incorrect because administering beta-blockers without addressing the underlying
infection could compromise the patient's compensatory tachycardic response.
Q4: A 24-year-old healthy nursing student has a routine ECG performed during a clinical skills lab.
The rhythm demonstrates a rate that varies between 56 bpm and 82 bpm over the 10-second recording.
The R-R intervals shorten during inspiration and lengthen during expiration. Each QRS is preceded
by an upright P wave with consistent morphology. The PR interval is 0.16 seconds and the QRS is 0.08
seconds. What is the correct interpretation?
A. Second-Degree Type I AV Block (Wenckebach) due to the variable R-R intervals
B. Sinus Arrhythmia, a normal variant commonly seen in young healthy adults [CORRECT]
C. Atrial Fibrillation with slow ventricular response due to irregular R-R intervals
D. Wandering Atrial Pacemaker due to varying P wave morphologies
Correct Answer: B
Rationale: The hallmark finding of sinus arrhythmia is the variation in R-R intervals that correlates with the respiratory
cycle: the rate increases during inspiration (shorter R-R intervals) and decreases during expiration (longer R-R intervals).
The rate range of 56-82 bpm is entirely normal. Crucially, each QRS is preceded by an upright P wave with consistent
morphology, which confirms sinus origin and rules out wandering atrial pacemaker (which would show at least three
different P wave morphologies). The PR interval remains constant at 0.16 seconds, which rules out Second-Degree Type
I AV Block (Wenckebach), where the PR interval progressively prolongs until a QRS is dropped. The presence of
identifiable P waves before each QRS rules out atrial fibrillation, which is characterized by the absence of discrete P
waves and a totally irregular R-R pattern. Sinus arrhythmia is a benign, normal variant that is especially common in
young, healthy individuals and is mediated by vagal tone fluctuations during the respiratory cycle. Option A is incorrect
because there are no dropped beats or progressively prolonging PR intervals. Option C is incorrect because atrial
fibrillation has no discernible P waves and a chaotically irregular rhythm, not a cyclical pattern tied to breathing. Option
D is incorrect because all P waves have the same morphology, whereas wandering atrial pacemaker requires at least three
different P wave configurations.
Page 2
