RELIAS DYSRHYTHMIA BASIC A TEST – 2026/2027
Complete Questions and Correct Answers with Explanations
SECTION 1: RHYTHM IDENTIFICATION & FEATURES (Questions 1-25)
Q1: Analyze this 6-second rhythm strip:
● Rate: 75 bpm (ventricular), 75 bpm (atrial)
● Rhythm: Regular R-R and P-P intervals
● P waves: Upright, present before each QRS, uniform morphology
● PR interval: 0.16 seconds, constant
● QRS duration: 0.08 seconds, narrow
Identify this rhythm.
A. Sinus Tachycardia
B. Normal Sinus Rhythm [CORRECT]
C. First Degree AV Block
D. Sinus Arrhythmia
Correct Answer: B
Rationale: This strip demonstrates Normal Sinus Rhythm (NSR). The rate of 75 bpm
falls within the normal 60-100 bpm range. The rhythm is regular with consistent R-R
intervals. There is a uniform P wave before each QRS complex with normal upright
morphology, indicating sinoatrial (SA) node origin. The PR interval is 0.16 seconds
(normal 0.12-0.20 sec) and constant. The QRS is narrow (<0.12 sec), indicating normal
ventricular conduction. Why others are wrong: (A) Sinus Tachycardia requires rate >100
,bpm; (C) First Degree AV Block requires PR interval >0.20 seconds; (D) Sinus Arrhythmia
shows irregular R-R intervals varying with respiration.
Q2: Analyze this 6-second rhythm strip:
● Rate: 52 bpm (ventricular), 52 bpm (atrial)
● Rhythm: Regular R-R and P-P intervals
● P waves: Present, upright, one before each QRS
● PR interval: 0.18 seconds, constant
● QRS duration: 0.09 seconds, narrow
Identify this rhythm.
A. Sinus Bradycardia [CORRECT]
B. Junctional Escape Rhythm
C. Second Degree AV Block, Type II
D. Idioventricular Rhythm
Correct Answer: A
Rationale: This is Sinus Bradycardia. The rate of 52 bpm is below 60 bpm, meeting
bradycardia criteria. The rhythm maintains all features of normal sinus origin: regular
R-R intervals, upright P waves preceding each QRS with consistent morphology, normal
PR interval (0.18 sec), and narrow QRS complexes. The slowing originates at the SA
node, not from an escape mechanism. Why others are wrong: (B) Junctional rhythm
would show absent, inverted, or retrograde P waves (after QRS), not upright P waves
before each QRS; (C) Second Degree Type II would show non-conducted P waves with
constant PR interval in conducted beats; (D) Idioventricular rhythm would have wide
QRS complexes (>0.12 sec), no consistent P wave relationship, and rate typically 20-40
bpm.
,Q3: Analyze this 6-second rhythm strip:
● Rate: 118 bpm (ventricular), 118 bpm (atrial)
● Rhythm: Regular R-R and P-P intervals
● P waves: Present, upright, one before each QRS
● PR interval: 0.14 seconds, constant
● QRS duration: 0.08 seconds, narrow
Identify this rhythm.
A. Supraventricular Tachycardia (SVT)
B. Atrial Flutter with 2:1 block
C. Sinus Tachycardia [CORRECT]
D. Atrial Fibrillation with rapid ventricular response
Correct Answer: C
Rationale: This strip shows Sinus Tachycardia. The rate of 118 bpm exceeds 100 bpm.
The rhythm is regular with visible, upright P waves preceding each QRS complex,
indicating the SA node remains the pacemaker despite the accelerated rate. The PR
interval is normal and constant (0.14 sec), and QRS complexes are narrow. This
represents appropriate physiological response or pathological SA node acceleration.
Why others are wrong: (A) SVT typically shows rate 150-250 bpm with often absent or
abnormal P waves; (B) Atrial Flutter would show characteristic sawtooth flutter waves,
not discrete upright P waves; (D) Atrial Fibrillation would show irregularly irregular
rhythm with absent P waves and fibrillatory baseline.
Q4: Analyze this 6-second rhythm strip:
● Rate: 68 bpm (ventricular), 68 bpm (atrial)
, ● Rhythm: Irregular R-R intervals (variation >0.12 sec), P-P intervals vary with
respiration
● P waves: Present, upright, one before each QRS, morphology normal
● PR interval: 0.15-0.17 seconds (slight variation), within normal
● QRS duration: 0.08 seconds, narrow
Identify this rhythm.
A. Sinus Arrhythmia with PVCs
B. Sinus Arrhythmia [CORRECT]
C. First Degree AV Block
D. Second Degree AV Block, Type I
Correct Answer: B
Rationale: This is Sinus Arrhythmia, a normal variant where the heart rate increases with
inspiration and decreases with expiration. The rhythm is irregular with cyclical variation
in R-R intervals corresponding to respiratory phases. All other features remain normal:
upright P waves before each QRS, normal PR interval (with slight physiologic variation),
narrow QRS complexes, and normal rate. This is common in young, healthy individuals
and athletes. Why others are wrong: (A) No PVCs present—all QRS complexes are
narrow and preceded by P waves; (C) First Degree AV Block requires fixed PR interval
>0.20 seconds; (D) Second Degree Type I would show progressive PR prolongation with
grouped beating and dropped beats.
Q5: Analyze this 6-second rhythm strip:
● Rate: 110 bpm (ventricular), unable to determine atrial rate
● Rhythm: Irregularly irregular R-R intervals (no pattern)
● P waves: Absent; baseline shows fine, chaotic, low-amplitude fibrillatory waves (f
waves)
Complete Questions and Correct Answers with Explanations
SECTION 1: RHYTHM IDENTIFICATION & FEATURES (Questions 1-25)
Q1: Analyze this 6-second rhythm strip:
● Rate: 75 bpm (ventricular), 75 bpm (atrial)
● Rhythm: Regular R-R and P-P intervals
● P waves: Upright, present before each QRS, uniform morphology
● PR interval: 0.16 seconds, constant
● QRS duration: 0.08 seconds, narrow
Identify this rhythm.
A. Sinus Tachycardia
B. Normal Sinus Rhythm [CORRECT]
C. First Degree AV Block
D. Sinus Arrhythmia
Correct Answer: B
Rationale: This strip demonstrates Normal Sinus Rhythm (NSR). The rate of 75 bpm
falls within the normal 60-100 bpm range. The rhythm is regular with consistent R-R
intervals. There is a uniform P wave before each QRS complex with normal upright
morphology, indicating sinoatrial (SA) node origin. The PR interval is 0.16 seconds
(normal 0.12-0.20 sec) and constant. The QRS is narrow (<0.12 sec), indicating normal
ventricular conduction. Why others are wrong: (A) Sinus Tachycardia requires rate >100
,bpm; (C) First Degree AV Block requires PR interval >0.20 seconds; (D) Sinus Arrhythmia
shows irregular R-R intervals varying with respiration.
Q2: Analyze this 6-second rhythm strip:
● Rate: 52 bpm (ventricular), 52 bpm (atrial)
● Rhythm: Regular R-R and P-P intervals
● P waves: Present, upright, one before each QRS
● PR interval: 0.18 seconds, constant
● QRS duration: 0.09 seconds, narrow
Identify this rhythm.
A. Sinus Bradycardia [CORRECT]
B. Junctional Escape Rhythm
C. Second Degree AV Block, Type II
D. Idioventricular Rhythm
Correct Answer: A
Rationale: This is Sinus Bradycardia. The rate of 52 bpm is below 60 bpm, meeting
bradycardia criteria. The rhythm maintains all features of normal sinus origin: regular
R-R intervals, upright P waves preceding each QRS with consistent morphology, normal
PR interval (0.18 sec), and narrow QRS complexes. The slowing originates at the SA
node, not from an escape mechanism. Why others are wrong: (B) Junctional rhythm
would show absent, inverted, or retrograde P waves (after QRS), not upright P waves
before each QRS; (C) Second Degree Type II would show non-conducted P waves with
constant PR interval in conducted beats; (D) Idioventricular rhythm would have wide
QRS complexes (>0.12 sec), no consistent P wave relationship, and rate typically 20-40
bpm.
,Q3: Analyze this 6-second rhythm strip:
● Rate: 118 bpm (ventricular), 118 bpm (atrial)
● Rhythm: Regular R-R and P-P intervals
● P waves: Present, upright, one before each QRS
● PR interval: 0.14 seconds, constant
● QRS duration: 0.08 seconds, narrow
Identify this rhythm.
A. Supraventricular Tachycardia (SVT)
B. Atrial Flutter with 2:1 block
C. Sinus Tachycardia [CORRECT]
D. Atrial Fibrillation with rapid ventricular response
Correct Answer: C
Rationale: This strip shows Sinus Tachycardia. The rate of 118 bpm exceeds 100 bpm.
The rhythm is regular with visible, upright P waves preceding each QRS complex,
indicating the SA node remains the pacemaker despite the accelerated rate. The PR
interval is normal and constant (0.14 sec), and QRS complexes are narrow. This
represents appropriate physiological response or pathological SA node acceleration.
Why others are wrong: (A) SVT typically shows rate 150-250 bpm with often absent or
abnormal P waves; (B) Atrial Flutter would show characteristic sawtooth flutter waves,
not discrete upright P waves; (D) Atrial Fibrillation would show irregularly irregular
rhythm with absent P waves and fibrillatory baseline.
Q4: Analyze this 6-second rhythm strip:
● Rate: 68 bpm (ventricular), 68 bpm (atrial)
, ● Rhythm: Irregular R-R intervals (variation >0.12 sec), P-P intervals vary with
respiration
● P waves: Present, upright, one before each QRS, morphology normal
● PR interval: 0.15-0.17 seconds (slight variation), within normal
● QRS duration: 0.08 seconds, narrow
Identify this rhythm.
A. Sinus Arrhythmia with PVCs
B. Sinus Arrhythmia [CORRECT]
C. First Degree AV Block
D. Second Degree AV Block, Type I
Correct Answer: B
Rationale: This is Sinus Arrhythmia, a normal variant where the heart rate increases with
inspiration and decreases with expiration. The rhythm is irregular with cyclical variation
in R-R intervals corresponding to respiratory phases. All other features remain normal:
upright P waves before each QRS, normal PR interval (with slight physiologic variation),
narrow QRS complexes, and normal rate. This is common in young, healthy individuals
and athletes. Why others are wrong: (A) No PVCs present—all QRS complexes are
narrow and preceded by P waves; (C) First Degree AV Block requires fixed PR interval
>0.20 seconds; (D) Second Degree Type I would show progressive PR prolongation with
grouped beating and dropped beats.
Q5: Analyze this 6-second rhythm strip:
● Rate: 110 bpm (ventricular), unable to determine atrial rate
● Rhythm: Irregularly irregular R-R intervals (no pattern)
● P waves: Absent; baseline shows fine, chaotic, low-amplitude fibrillatory waves (f
waves)
