Relias Dysrhythmia Basic B Exam 2026/2027:
Actual Questions with Verified Answers –
Complete Study Guide for Medical & Nursing
Students – Graded A+
SECTION 1: NORMAL SINUS RHYTHM & VARIANTS (Questions 1-4)
Q1: A cardiac monitor displays a regular rhythm at 72 bpm with upright P waves before
every QRS, PR interval of 0.16 seconds, and QRS duration of 0.08 seconds. What is this
rhythm?
A. Sinus bradycardia
B. Normal sinus rhythm
C. Sinus tachycardia
D. First-degree AV block
Correct Answer: B
Rationale: Normal sinus rhythm is characterized by a regular rhythm with rate 60-100
bpm, upright P waves preceding each QRS complex in lead II, PR interval 0.12-0.20
seconds, and QRS duration <0.12 seconds. This strip meets all criteria. Sinus
bradycardia (A) would have rate <60 bpm. Sinus tachycardia (C) would have rate >100
bpm. First-degree AV block (D) requires PR interval >0.20 seconds.
(Topic: Normal Sinus Rhythm | Difficulty: Easy)
,Memory Aid: "RATE 60-100 + UPRIGHT P + NORMAL PR + NARROW QRS = NSR"
Q2: A 24-year-old athlete presents for a pre-participation physical. The ECG shows a
regular rhythm at 52 bpm with normal P waves, PR interval of 0.14 seconds, and narrow
QRS complexes. The patient is asymptomatic. What is the correct interpretation?
A. Normal sinus rhythm
B. Sinus bradycardia requiring immediate atropine
C. Sinus bradycardia, likely physiologic
D. First-degree AV block
Correct Answer: C
Rationale: This is sinus bradycardia (rate <60 bpm) with normal conduction intervals. In
a young, asymptomatic athlete, this is likely physiologic due to increased vagal tone and
cardiovascular conditioning. No treatment is indicated for asymptomatic sinus
bradycardia. Option A is incorrect because the rate is below 60 bpm. Option B is
incorrect because asymptomatic bradycardia does not require atropine. Option D is
incorrect because the PR interval is normal.
(Topic: Sinus Bradycardia | Difficulty: Easy)
Memory Aid: "Athlete's Heart = Slow but Strong"
Q3: A telemetry strip shows a rhythm that varies with respiration—increasing during
inspiration and decreasing during expiration. The rate ranges from 68-88 bpm. P waves
are normal and present before each QRS. PR interval is constant at 0.18 seconds. What
is this rhythm?
, A. Sinus arrhythmia
B. Atrial fibrillation
C. Sinus tachycardia with PACs
D. Wandering atrial pacemaker
Correct Answer: A
Rationale: Sinus arrhythmia is characterized by a phasic variation in heart rate with
respiration (inspiration increases rate, expiration decreases rate), with normal P waves,
constant PR interval, and normal QRS complexes. This is a benign finding, especially in
young healthy individuals. Atrial fibrillation (B) would show no P waves and irregularly
irregular rhythm. Wandering atrial pacemaker (D) would show at least 3 different P wave
morphologies.
(Topic: Sinus Arrhythmia | Difficulty: Easy)
Memory Aid: "Breathe In = Speed Up, Breathe Out = Slow Down"
Q4: A post-operative patient in the PACU has a heart rate of 128 bpm. The rhythm is
regular with normal P waves preceding each QRS, PR interval 0.15 seconds, and narrow
QRS complexes. The patient is febrile with a temperature of 38.8°C and reports pain at
the surgical site. What is the most appropriate initial management?
A. Immediate synchronized cardioversion
B. Administer IV adenosine
C. Treat the underlying causes (fever and pain)
D. Initiate transcutaneous pacing
Actual Questions with Verified Answers –
Complete Study Guide for Medical & Nursing
Students – Graded A+
SECTION 1: NORMAL SINUS RHYTHM & VARIANTS (Questions 1-4)
Q1: A cardiac monitor displays a regular rhythm at 72 bpm with upright P waves before
every QRS, PR interval of 0.16 seconds, and QRS duration of 0.08 seconds. What is this
rhythm?
A. Sinus bradycardia
B. Normal sinus rhythm
C. Sinus tachycardia
D. First-degree AV block
Correct Answer: B
Rationale: Normal sinus rhythm is characterized by a regular rhythm with rate 60-100
bpm, upright P waves preceding each QRS complex in lead II, PR interval 0.12-0.20
seconds, and QRS duration <0.12 seconds. This strip meets all criteria. Sinus
bradycardia (A) would have rate <60 bpm. Sinus tachycardia (C) would have rate >100
bpm. First-degree AV block (D) requires PR interval >0.20 seconds.
(Topic: Normal Sinus Rhythm | Difficulty: Easy)
,Memory Aid: "RATE 60-100 + UPRIGHT P + NORMAL PR + NARROW QRS = NSR"
Q2: A 24-year-old athlete presents for a pre-participation physical. The ECG shows a
regular rhythm at 52 bpm with normal P waves, PR interval of 0.14 seconds, and narrow
QRS complexes. The patient is asymptomatic. What is the correct interpretation?
A. Normal sinus rhythm
B. Sinus bradycardia requiring immediate atropine
C. Sinus bradycardia, likely physiologic
D. First-degree AV block
Correct Answer: C
Rationale: This is sinus bradycardia (rate <60 bpm) with normal conduction intervals. In
a young, asymptomatic athlete, this is likely physiologic due to increased vagal tone and
cardiovascular conditioning. No treatment is indicated for asymptomatic sinus
bradycardia. Option A is incorrect because the rate is below 60 bpm. Option B is
incorrect because asymptomatic bradycardia does not require atropine. Option D is
incorrect because the PR interval is normal.
(Topic: Sinus Bradycardia | Difficulty: Easy)
Memory Aid: "Athlete's Heart = Slow but Strong"
Q3: A telemetry strip shows a rhythm that varies with respiration—increasing during
inspiration and decreasing during expiration. The rate ranges from 68-88 bpm. P waves
are normal and present before each QRS. PR interval is constant at 0.18 seconds. What
is this rhythm?
, A. Sinus arrhythmia
B. Atrial fibrillation
C. Sinus tachycardia with PACs
D. Wandering atrial pacemaker
Correct Answer: A
Rationale: Sinus arrhythmia is characterized by a phasic variation in heart rate with
respiration (inspiration increases rate, expiration decreases rate), with normal P waves,
constant PR interval, and normal QRS complexes. This is a benign finding, especially in
young healthy individuals. Atrial fibrillation (B) would show no P waves and irregularly
irregular rhythm. Wandering atrial pacemaker (D) would show at least 3 different P wave
morphologies.
(Topic: Sinus Arrhythmia | Difficulty: Easy)
Memory Aid: "Breathe In = Speed Up, Breathe Out = Slow Down"
Q4: A post-operative patient in the PACU has a heart rate of 128 bpm. The rhythm is
regular with normal P waves preceding each QRS, PR interval 0.15 seconds, and narrow
QRS complexes. The patient is febrile with a temperature of 38.8°C and reports pain at
the surgical site. What is the most appropriate initial management?
A. Immediate synchronized cardioversion
B. Administer IV adenosine
C. Treat the underlying causes (fever and pain)
D. Initiate transcutaneous pacing
