Relias Dysrhythmia Basic A Test (pdf) | 2026/2027 | Dysrhythmia
Q&A | Cardiac Rhythm
1. A patient's ECG shows a regular rhythm with a heart rate of 68 bpm,
normal P waves preceding each QRS complex, a PR interval of 0.16 seconds,
and a QRS duration of 0.08 seconds. What is the correct interpretation?
A) Sinus bradycardia
B) Normal sinus rhythm
C) Sinus tachycardia
D) Sinus arrhythmia
Correct Answer: Normal sinus rhythm
Rationale: Normal sinus rhythm (NSR) is defined by a rate of 60-100 bpm, a
regular rhythm, a P wave before each QRS, a normal PR interval (0.12-0.20
sec), and a normal QRS duration (<0.12 sec). All criteria are met in this
description. Sinus bradycardia would have a rate <60 bpm, and sinus
tachycardia would have a rate >100 bpm.
2. An ECG tracing reveals a regular rhythm with a heart rate of 110 bpm.
There are upright P waves before each QRS, and the PR and QRS intervals
are within normal limits. What is this rhythm?
A) Normal sinus rhythm
B) Sinus bradycardia
C) Sinus tachycardia
D) Atrial fibrillation
Correct Answer: Sinus tachycardia
Rationale: Sinus tachycardia is a sinus rhythm with a rate exceeding 100
bpm (typically 100-150 bpm). The presence of normal P waves and normal
,intervals confirms the sinus origin. Normal sinus rhythm is 60-100 bpm, and
sinus bradycardia is <60 bpm.
3. An ECG shows a regular rhythm with a heart rate of 45 bpm. P waves are
present and upright before each QRS complex, with a normal PR interval and
QRS duration. This rhythm is best described as:
A) Normal sinus rhythm
B) Sinus bradycardia
C) First-degree AV block
D) Junctional rhythm
Correct Answer: Sinus bradycardia
Rationale: Sinus bradycardia is characterized by a regular sinus rhythm with
a rate below 60 bpm. The presence of normal P waves and normal intervals
differentiates it from junctional rhythms, which lack normal P waves, and AV
blocks, which have prolonged PR intervals.
4. A patient's cardiac monitor displays an irregular rhythm with no
discernible P waves and a chaotic, fibrillatory baseline. The ventricular
response is variable. What is the rhythm?
A) Atrial flutter
B) Atrial fibrillation
C) Ventricular fibrillation
D) Multifocal atrial tachycardia
Correct Answer: Atrial fibrillation
Rationale: Atrial fibrillation is characterized by an irregularly irregular rhythm,
the absence of discernible P waves, and a chaotic baseline due to fibrillatory
,waves. The ventricular rate is variable. Atrial flutter has a saw-tooth pattern
of flutter waves, and ventricular fibrillation has no identifiable QRS
complexes.
5. An ECG shows a regular rhythm with a ventricular rate of 72 bpm. Instead
of distinct P waves, there are saw-tooth flutter waves present at a rate of
approximately 300 bpm. What is the rhythm?
A) Atrial fibrillation
B) Atrial flutter
C) Supraventricular tachycardia
D) Wandering atrial pacemaker
Correct Answer: Atrial flutter
Rationale: Atrial flutter is typically a regular rhythm with a characteristic saw-
tooth pattern of flutter waves, usually at a rate of 250-350 bpm. The
ventricular rate is variable and is a fraction of the atrial rate (e.g., 2:1, 4:1
block). Atrial fibrillation lacks organized flutter waves.
6. A patient's ECG reveals a regular, narrow-complex tachycardia with a
heart rate of 180 bpm. P waves are not clearly visible, and the rhythm is
regular. What is the most likely rhythm?
A) Sinus tachycardia
B) Atrial fibrillation
C) Supraventricular tachycardia
D) Ventricular tachycardia
Correct Answer: Supraventricular tachycardia
, Rationale: Supraventricular tachycardia (SVT) is a regular, narrow-complex
tachycardia originating above the ventricles, with a rate typically between
150-350 bpm. P waves are often hidden in the QRS or T waves. Sinus
tachycardia has visible P waves. Ventricular tachycardia has wide QRS
complexes.
7. An ECG displays a regular rhythm with a heart rate of 52 bpm. There are
no visible P waves, but the QRS complexes are narrow (0.08 sec). What is the
rhythm?
A) Sinus bradycardia
B) Junctional rhythm
C) Idioventricular rhythm
D) First-degree AV block
Correct Answer: Junctional rhythm
Rationale: A junctional rhythm originates from the AV junction and typically
has a rate of 40-60 bpm. P waves are absent or inverted and may appear
before, during, or after the QRS complex, with narrow QRS complexes.
Idioventricular rhythm would have wide QRS complexes and a rate of 20-40
bpm.
8. An ECG shows a regular rhythm with a heart rate of 72 bpm. Inverted P
waves precede each narrow QRS complex with a PR interval of 0.10 seconds.
What is this rhythm?
A) Normal sinus rhythm
B) Junctional rhythm
C) Accelerated junctional rhythm
D) First-degree AV block
Correct Answer: Accelerated junctional rhythm
Q&A | Cardiac Rhythm
1. A patient's ECG shows a regular rhythm with a heart rate of 68 bpm,
normal P waves preceding each QRS complex, a PR interval of 0.16 seconds,
and a QRS duration of 0.08 seconds. What is the correct interpretation?
A) Sinus bradycardia
B) Normal sinus rhythm
C) Sinus tachycardia
D) Sinus arrhythmia
Correct Answer: Normal sinus rhythm
Rationale: Normal sinus rhythm (NSR) is defined by a rate of 60-100 bpm, a
regular rhythm, a P wave before each QRS, a normal PR interval (0.12-0.20
sec), and a normal QRS duration (<0.12 sec). All criteria are met in this
description. Sinus bradycardia would have a rate <60 bpm, and sinus
tachycardia would have a rate >100 bpm.
2. An ECG tracing reveals a regular rhythm with a heart rate of 110 bpm.
There are upright P waves before each QRS, and the PR and QRS intervals
are within normal limits. What is this rhythm?
A) Normal sinus rhythm
B) Sinus bradycardia
C) Sinus tachycardia
D) Atrial fibrillation
Correct Answer: Sinus tachycardia
Rationale: Sinus tachycardia is a sinus rhythm with a rate exceeding 100
bpm (typically 100-150 bpm). The presence of normal P waves and normal
,intervals confirms the sinus origin. Normal sinus rhythm is 60-100 bpm, and
sinus bradycardia is <60 bpm.
3. An ECG shows a regular rhythm with a heart rate of 45 bpm. P waves are
present and upright before each QRS complex, with a normal PR interval and
QRS duration. This rhythm is best described as:
A) Normal sinus rhythm
B) Sinus bradycardia
C) First-degree AV block
D) Junctional rhythm
Correct Answer: Sinus bradycardia
Rationale: Sinus bradycardia is characterized by a regular sinus rhythm with
a rate below 60 bpm. The presence of normal P waves and normal intervals
differentiates it from junctional rhythms, which lack normal P waves, and AV
blocks, which have prolonged PR intervals.
4. A patient's cardiac monitor displays an irregular rhythm with no
discernible P waves and a chaotic, fibrillatory baseline. The ventricular
response is variable. What is the rhythm?
A) Atrial flutter
B) Atrial fibrillation
C) Ventricular fibrillation
D) Multifocal atrial tachycardia
Correct Answer: Atrial fibrillation
Rationale: Atrial fibrillation is characterized by an irregularly irregular rhythm,
the absence of discernible P waves, and a chaotic baseline due to fibrillatory
,waves. The ventricular rate is variable. Atrial flutter has a saw-tooth pattern
of flutter waves, and ventricular fibrillation has no identifiable QRS
complexes.
5. An ECG shows a regular rhythm with a ventricular rate of 72 bpm. Instead
of distinct P waves, there are saw-tooth flutter waves present at a rate of
approximately 300 bpm. What is the rhythm?
A) Atrial fibrillation
B) Atrial flutter
C) Supraventricular tachycardia
D) Wandering atrial pacemaker
Correct Answer: Atrial flutter
Rationale: Atrial flutter is typically a regular rhythm with a characteristic saw-
tooth pattern of flutter waves, usually at a rate of 250-350 bpm. The
ventricular rate is variable and is a fraction of the atrial rate (e.g., 2:1, 4:1
block). Atrial fibrillation lacks organized flutter waves.
6. A patient's ECG reveals a regular, narrow-complex tachycardia with a
heart rate of 180 bpm. P waves are not clearly visible, and the rhythm is
regular. What is the most likely rhythm?
A) Sinus tachycardia
B) Atrial fibrillation
C) Supraventricular tachycardia
D) Ventricular tachycardia
Correct Answer: Supraventricular tachycardia
, Rationale: Supraventricular tachycardia (SVT) is a regular, narrow-complex
tachycardia originating above the ventricles, with a rate typically between
150-350 bpm. P waves are often hidden in the QRS or T waves. Sinus
tachycardia has visible P waves. Ventricular tachycardia has wide QRS
complexes.
7. An ECG displays a regular rhythm with a heart rate of 52 bpm. There are
no visible P waves, but the QRS complexes are narrow (0.08 sec). What is the
rhythm?
A) Sinus bradycardia
B) Junctional rhythm
C) Idioventricular rhythm
D) First-degree AV block
Correct Answer: Junctional rhythm
Rationale: A junctional rhythm originates from the AV junction and typically
has a rate of 40-60 bpm. P waves are absent or inverted and may appear
before, during, or after the QRS complex, with narrow QRS complexes.
Idioventricular rhythm would have wide QRS complexes and a rate of 20-40
bpm.
8. An ECG shows a regular rhythm with a heart rate of 72 bpm. Inverted P
waves precede each narrow QRS complex with a PR interval of 0.10 seconds.
What is this rhythm?
A) Normal sinus rhythm
B) Junctional rhythm
C) Accelerated junctional rhythm
D) First-degree AV block
Correct Answer: Accelerated junctional rhythm
