Telemetry ECG/EKG Interpretation Practice Exam verified with correct
answers and rationales 2026/2027 version
1. Which ECG component represents atrial depolarization?
A. P wave
B. QRS complex
C. T wave
D. U wave
Correct Answer: A
Rationale: The P wave represents atrial depolarization, indicating electrical activation of the
atria before atrial contraction.
2. Which ECG interval represents conduction from the atria through the AV
node?
A. PR interval
B. QT interval
C. RR interval
D. ST segment
Correct Answer: A
Rationale: The PR interval measures the time from the beginning of atrial depolarization to the
beginning of ventricular depolarization.
3. What is the normal duration of the PR interval?
A. 0.12–0.20 seconds
B. 0.04–0.08 seconds
C. 0.30–0.40 seconds
D. 0.50–0.60 seconds
Correct Answer: A
Rationale: A normal PR interval is 0.12–0.20 seconds (3–5 small boxes on ECG paper).
,4. A normal QRS complex duration is:
A. Less than 0.12 seconds
B. Greater than 0.20 seconds
C. Exactly 0.30 seconds
D. Greater than 0.50 seconds
Correct Answer: A
Rationale: A narrow QRS (<0.12 seconds) indicates normal ventricular conduction.
5. Which rhythm originates from the sinoatrial (SA) node?
A. Normal sinus rhythm
B. Ventricular tachycardia
C. Junctional rhythm
D. Idioventricular rhythm
Correct Answer: A
Rationale: Normal sinus rhythm originates in the SA node and is the heart's normal pacemaker
rhythm.
6. What is the normal adult heart rate in sinus rhythm?
A. 60–100 beats/minute
B. 40–60 beats/minute
C. 100–150 beats/minute
D. 20–40 beats/minute
Correct Answer: A
Rationale: A normal resting heart rate ranges from 60–100 bpm.
7. Sinus bradycardia is defined as:
A. Heart rate below 60 bpm with a normal sinus rhythm
B. Heart rate above 100 bpm
C. No P waves
D. Wide QRS complexes
,Correct Answer: A
Rationale: Sinus bradycardia originates from the SA node but occurs at a slower-than-normal
rate.
8. Which rhythm is characterized by a heart rate greater than 100 bpm with
normal P waves before each QRS?
A. Sinus tachycardia
B. Atrial fibrillation
C. Ventricular fibrillation
D. Junctional rhythm
Correct Answer: A
Rationale: Sinus tachycardia has a regular rhythm with normal P waves and a rate exceeding
100 bpm.
9. Which rhythm has no identifiable P waves and an irregularly irregular
rhythm?
A. Atrial fibrillation
B. Atrial flutter
C. Sinus rhythm
D. First-degree AV block
Correct Answer: A
Rationale: Atrial fibrillation is characterized by chaotic atrial activity and an irregular
ventricular response.
10. Which rhythm shows "sawtooth" flutter waves?
A. Atrial flutter
B. Ventricular tachycardia
C. Sinus bradycardia
D. Asystole
Correct Answer: A
, Rationale: Atrial flutter produces characteristic flutter (F) waves, often described as a sawtooth
pattern.
11. Which ECG finding indicates first-degree AV block?
A. PR interval greater than 0.20 seconds
B. Dropped QRS complexes
C. Absent P waves
D. Wide QRS complexes only
Correct Answer: A
Rationale: First-degree AV block involves delayed conduction through the AV node, resulting in
a prolonged PR interval.
12. Which rhythm is most commonly associated with a pulse rate of 40–60 bpm
and absent or inverted P waves?
A. Junctional rhythm
B. Ventricular fibrillation
C. Sinus tachycardia
D. Atrial flutter
Correct Answer: A
Rationale: Junctional rhythms originate near the AV junction and often have absent or inverted
P waves.
13. Which rhythm is considered life-threatening and requires immediate CPR if
pulseless?
A. Ventricular fibrillation
B. Sinus rhythm
C. First-degree AV block
D. Atrial flutter
Correct Answer: A
Rationale: Ventricular fibrillation is a chaotic rhythm with no effective cardiac output and
requires immediate defibrillation and CPR.
answers and rationales 2026/2027 version
1. Which ECG component represents atrial depolarization?
A. P wave
B. QRS complex
C. T wave
D. U wave
Correct Answer: A
Rationale: The P wave represents atrial depolarization, indicating electrical activation of the
atria before atrial contraction.
2. Which ECG interval represents conduction from the atria through the AV
node?
A. PR interval
B. QT interval
C. RR interval
D. ST segment
Correct Answer: A
Rationale: The PR interval measures the time from the beginning of atrial depolarization to the
beginning of ventricular depolarization.
3. What is the normal duration of the PR interval?
A. 0.12–0.20 seconds
B. 0.04–0.08 seconds
C. 0.30–0.40 seconds
D. 0.50–0.60 seconds
Correct Answer: A
Rationale: A normal PR interval is 0.12–0.20 seconds (3–5 small boxes on ECG paper).
,4. A normal QRS complex duration is:
A. Less than 0.12 seconds
B. Greater than 0.20 seconds
C. Exactly 0.30 seconds
D. Greater than 0.50 seconds
Correct Answer: A
Rationale: A narrow QRS (<0.12 seconds) indicates normal ventricular conduction.
5. Which rhythm originates from the sinoatrial (SA) node?
A. Normal sinus rhythm
B. Ventricular tachycardia
C. Junctional rhythm
D. Idioventricular rhythm
Correct Answer: A
Rationale: Normal sinus rhythm originates in the SA node and is the heart's normal pacemaker
rhythm.
6. What is the normal adult heart rate in sinus rhythm?
A. 60–100 beats/minute
B. 40–60 beats/minute
C. 100–150 beats/minute
D. 20–40 beats/minute
Correct Answer: A
Rationale: A normal resting heart rate ranges from 60–100 bpm.
7. Sinus bradycardia is defined as:
A. Heart rate below 60 bpm with a normal sinus rhythm
B. Heart rate above 100 bpm
C. No P waves
D. Wide QRS complexes
,Correct Answer: A
Rationale: Sinus bradycardia originates from the SA node but occurs at a slower-than-normal
rate.
8. Which rhythm is characterized by a heart rate greater than 100 bpm with
normal P waves before each QRS?
A. Sinus tachycardia
B. Atrial fibrillation
C. Ventricular fibrillation
D. Junctional rhythm
Correct Answer: A
Rationale: Sinus tachycardia has a regular rhythm with normal P waves and a rate exceeding
100 bpm.
9. Which rhythm has no identifiable P waves and an irregularly irregular
rhythm?
A. Atrial fibrillation
B. Atrial flutter
C. Sinus rhythm
D. First-degree AV block
Correct Answer: A
Rationale: Atrial fibrillation is characterized by chaotic atrial activity and an irregular
ventricular response.
10. Which rhythm shows "sawtooth" flutter waves?
A. Atrial flutter
B. Ventricular tachycardia
C. Sinus bradycardia
D. Asystole
Correct Answer: A
, Rationale: Atrial flutter produces characteristic flutter (F) waves, often described as a sawtooth
pattern.
11. Which ECG finding indicates first-degree AV block?
A. PR interval greater than 0.20 seconds
B. Dropped QRS complexes
C. Absent P waves
D. Wide QRS complexes only
Correct Answer: A
Rationale: First-degree AV block involves delayed conduction through the AV node, resulting in
a prolonged PR interval.
12. Which rhythm is most commonly associated with a pulse rate of 40–60 bpm
and absent or inverted P waves?
A. Junctional rhythm
B. Ventricular fibrillation
C. Sinus tachycardia
D. Atrial flutter
Correct Answer: A
Rationale: Junctional rhythms originate near the AV junction and often have absent or inverted
P waves.
13. Which rhythm is considered life-threatening and requires immediate CPR if
pulseless?
A. Ventricular fibrillation
B. Sinus rhythm
C. First-degree AV block
D. Atrial flutter
Correct Answer: A
Rationale: Ventricular fibrillation is a chaotic rhythm with no effective cardiac output and
requires immediate defibrillation and CPR.
