RELIAS Dysrhythmia Basic A Test Exam 2026–2027: 100
Comprehensive Practice Questions with Verified
Answers and Detailed Rationales
1. Which ECG component represents ventricular depolarization?
A. P wave
B. QRS complex
C. T wave
D. PR interval
Answer: B
Rationale: The QRS complex represents ventricular depolarization.
2. A normal adult sinus rhythm has a heart rate of:
A. 30–50 bpm
B. 40–60 bpm
C. 60–100 bpm
D. 100–150 bpm
Answer: C
Rationale: Normal sinus rhythm ranges from 60 to 100 beats per minute.
3. The first step in rhythm interpretation is to:
A. Measure the PR interval
B. Determine the heart rate
C. Identify the P waves
D. Count the QRS complexes
Answer: B
Rationale: Determining the heart rate helps establish whether the rhythm is bradycardic,
normal, or tachycardic.
4. Sinus bradycardia is defined as a heart rate less than:
,A. 40 bpm
B. 50 bpm
C. 60 bpm
D. 70 bpm
Answer: C
Rationale: Sinus bradycardia is a sinus rhythm with a rate below 60 bpm.
5. Which rhythm originates from the sinoatrial (SA) node?
A. Ventricular tachycardia
B. Atrial fibrillation
C. Normal sinus rhythm
D. Junctional rhythm
Answer: C
Rationale: Normal sinus rhythm originates in the SA node.
6. The normal PR interval measures:
A. 0.04–0.10 seconds
B. 0.12–0.20 seconds
C. 0.22–0.30 seconds
D. Greater than 0.30 seconds
Answer: B
Rationale: A normal PR interval is 0.12–0.20 seconds.
7. Which rhythm has no identifiable P waves and an irregularly irregular rhythm?
A. Sinus tachycardia
B. Atrial flutter
C. Atrial fibrillation
D. Ventricular fibrillation
Answer: C
, Rationale: Atrial fibrillation produces absent P waves and an irregular ventricular response.
8. Which dysrhythmia is characterized by “sawtooth” flutter waves?
A. Ventricular tachycardia
B. Atrial flutter
C. Sinus arrhythmia
D. First-degree AV block
Answer: B
Rationale: Atrial flutter has characteristic flutter (F) waves.
9. A QRS duration greater than 0.12 seconds suggests:
A. Normal conduction
B. Delayed ventricular conduction
C. Sinus rhythm
D. Atrial enlargement
Answer: B
Rationale: A widened QRS indicates abnormal ventricular conduction.
10. Which rhythm requires immediate CPR and defibrillation if the patient is unresponsive?
A. Sinus tachycardia
B. Atrial flutter
C. Ventricular fibrillation
D. First-degree AV block
Answer: C
Rationale: Ventricular fibrillation is a shockable cardiac arrest rhythm.
11. Which rhythm has a regular rhythm with narrow QRS complexes and a rate of 150–250
bpm?
A. Supraventricular tachycardia
B. Ventricular fibrillation
Comprehensive Practice Questions with Verified
Answers and Detailed Rationales
1. Which ECG component represents ventricular depolarization?
A. P wave
B. QRS complex
C. T wave
D. PR interval
Answer: B
Rationale: The QRS complex represents ventricular depolarization.
2. A normal adult sinus rhythm has a heart rate of:
A. 30–50 bpm
B. 40–60 bpm
C. 60–100 bpm
D. 100–150 bpm
Answer: C
Rationale: Normal sinus rhythm ranges from 60 to 100 beats per minute.
3. The first step in rhythm interpretation is to:
A. Measure the PR interval
B. Determine the heart rate
C. Identify the P waves
D. Count the QRS complexes
Answer: B
Rationale: Determining the heart rate helps establish whether the rhythm is bradycardic,
normal, or tachycardic.
4. Sinus bradycardia is defined as a heart rate less than:
,A. 40 bpm
B. 50 bpm
C. 60 bpm
D. 70 bpm
Answer: C
Rationale: Sinus bradycardia is a sinus rhythm with a rate below 60 bpm.
5. Which rhythm originates from the sinoatrial (SA) node?
A. Ventricular tachycardia
B. Atrial fibrillation
C. Normal sinus rhythm
D. Junctional rhythm
Answer: C
Rationale: Normal sinus rhythm originates in the SA node.
6. The normal PR interval measures:
A. 0.04–0.10 seconds
B. 0.12–0.20 seconds
C. 0.22–0.30 seconds
D. Greater than 0.30 seconds
Answer: B
Rationale: A normal PR interval is 0.12–0.20 seconds.
7. Which rhythm has no identifiable P waves and an irregularly irregular rhythm?
A. Sinus tachycardia
B. Atrial flutter
C. Atrial fibrillation
D. Ventricular fibrillation
Answer: C
, Rationale: Atrial fibrillation produces absent P waves and an irregular ventricular response.
8. Which dysrhythmia is characterized by “sawtooth” flutter waves?
A. Ventricular tachycardia
B. Atrial flutter
C. Sinus arrhythmia
D. First-degree AV block
Answer: B
Rationale: Atrial flutter has characteristic flutter (F) waves.
9. A QRS duration greater than 0.12 seconds suggests:
A. Normal conduction
B. Delayed ventricular conduction
C. Sinus rhythm
D. Atrial enlargement
Answer: B
Rationale: A widened QRS indicates abnormal ventricular conduction.
10. Which rhythm requires immediate CPR and defibrillation if the patient is unresponsive?
A. Sinus tachycardia
B. Atrial flutter
C. Ventricular fibrillation
D. First-degree AV block
Answer: C
Rationale: Ventricular fibrillation is a shockable cardiac arrest rhythm.
11. Which rhythm has a regular rhythm with narrow QRS complexes and a rate of 150–250
bpm?
A. Supraventricular tachycardia
B. Ventricular fibrillation
