Cardiac rhythm interpretation for nurses
150 practice questions with answer rationales
COURSE Cardiac rhythm interpretation
QUESTIONS 150
PREPARED August 2026
,Cardiac rhythm interpretation
Exam Overview
This academic exam resource gives Nursing School a focused 150-question practice set for Cardiac
rhythm interpretation. The material is written to support careful review, practical reasoning, and
steady preparation without promotional claims or repeated title wording. Questions use clear
professional language, credible answer choices, and concise rationales that help students understand
why one option is best. The document provides high-quality academic material for independent
revision, classroom reinforcement, and identifying knowledge gaps before assessments. Students
should pair it with course notes, textbooks, instructor guidance, and current academic standards for
the strongest preparation. Each item supports careful review, confident practice, and steady.
Question 1: Which ECG feature best identifies normal sinus rhythm?
A. Irregularly irregular R-R intervals with no discernible P waves
B. No P waves and an absent QRS complex
C. Wide QRS complexes with sawtooth flutter waves
D. A P wave before every QRS with a consistent PR interval
Answer: D
Rationale: Normal sinus rhythm has a regular rate, one P wave before each QRS, and a consistent PR
interval.
Question 2: Which ECG finding is expected in a normal sinus rhythm at the bedside
monitor?
A. Atrial rate slower than ventricular rate with inverted P waves
B. Sawtooth flutter waves with variable AV conduction
C. Wide, bizarre QRS complexes with no preceding P waves
D. Each P wave is followed by a QRS complex at a regular rate
Answer: D
Rationale: Normal sinus rhythm starts in the sinus node, so atrial depolarization should be regular
and each impulse should conduct through the AV node to a QRS complex. Wide complexes without P
waves suggest ventricular origin, not sinus rhythm.
Question 3: Which rhythm is classically described as having an 'irregularly irregular'
ventricular response?
A. Normal sinus rhythm
B. Sinus bradycardia
C. Third-degree heart block
D. Atrial fibrillation
Answer: D
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,Cardiac rhythm interpretation
Rationale: Atrial fibrillation typically produces an irregularly irregular rhythm without organized
atrial activity.
Question 4: On a standard ECG strip, what does the PR interval represent?
A. Ventricular depolarization only
B. Ventricular repolarization
C. Time from one R wave to the next R wave
D. Atrial depolarization to the start of ventricular depolarization
Answer: D
Rationale: The PR interval measures conduction from atrial depolarization through the AV node to
the start of ventricular depolarization.
Question 5: On an ECG strip, what does the P wave represent?
A. AV nodal delay
B. Ventricular depolarization
C. Atrial repolarization
D. Atrial depolarization
Answer: D
Rationale: The P wave reflects electrical activation of the atria before they contract. Ventricular
depolarization is shown by the QRS complex, which is a common point of confusion.
Question 6: A premature ventricular contraction (PVC) is most likely identified by which
pattern?
A. Continuous sawtooth baseline between QRS complexes
B. Regular narrow QRS complexes with upright P waves
C. Slow rhythm with prolonged PR interval
D. Early wide QRS complex without a preceding P wave
Answer: D
Rationale: PVCs are early ventricular beats that usually appear as wide QRS complexes not preceded
by a P wave.
Question 7: Which rhythm is most associated with a classic sawtooth atrial pattern on
ECG?
A. Ventricular fibrillation
B. Sinus bradycardia
C. Junctional rhythm
D. Atrial flutter
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, Cardiac rhythm interpretation
Answer: D
Rationale: Atrial flutter produces organized rapid atrial activity that often appears as sawtooth flutter
waves. Ventricular fibrillation is chaotic, and junctional rhythms do not create the same atrial
waveform.
Question 8: What does the PR interval measure on a standard ECG?
A. Time from ventricular repolarization to the next atrial depolarization
B. Time from one R wave to the next R wave
C. Duration of ventricular depolarization only
D. Time from onset of atrial depolarization to onset of ventricular depolarization
Answer: D
Rationale: The PR interval captures conduction from the start of atrial depolarization through the AV
node and into the beginning of ventricular depolarization. The RR interval measures rate, not AV
conduction time.
Question 9: Which rhythm is characterized by delayed AV conduction with a prolonged
PR interval but every P wave still conducts?
A. Second-degree AV block type II
B. Ventricular tachycardia
C. Atrial fibrillation
D. First-degree AV block
Answer: D
Rationale: First-degree AV block has a prolonged PR interval with 1:1 conduction.
Question 10: Which ECG finding is expected in sinus tachycardia?
A. Dropped QRS complexes after every P wave
B. Absent QRS complexes
C. Wide, chaotic waves with no organized pattern
D. Heart rate above 100/min with normal P waves
Answer: D
Rationale: Sinus tachycardia is a fast rhythm that still originates from the sinus node, so P waves
remain normal.
Question 11: A telemetry strip shows a regular rhythm with normal P waves before every
QRS and a rate of 48/min. Which rhythm is most consistent with this finding?
A. Sinus tachycardia
B. Atrial fibrillation
C. Second-degree AV block type II
Page 3 of 42
150 practice questions with answer rationales
COURSE Cardiac rhythm interpretation
QUESTIONS 150
PREPARED August 2026
,Cardiac rhythm interpretation
Exam Overview
This academic exam resource gives Nursing School a focused 150-question practice set for Cardiac
rhythm interpretation. The material is written to support careful review, practical reasoning, and
steady preparation without promotional claims or repeated title wording. Questions use clear
professional language, credible answer choices, and concise rationales that help students understand
why one option is best. The document provides high-quality academic material for independent
revision, classroom reinforcement, and identifying knowledge gaps before assessments. Students
should pair it with course notes, textbooks, instructor guidance, and current academic standards for
the strongest preparation. Each item supports careful review, confident practice, and steady.
Question 1: Which ECG feature best identifies normal sinus rhythm?
A. Irregularly irregular R-R intervals with no discernible P waves
B. No P waves and an absent QRS complex
C. Wide QRS complexes with sawtooth flutter waves
D. A P wave before every QRS with a consistent PR interval
Answer: D
Rationale: Normal sinus rhythm has a regular rate, one P wave before each QRS, and a consistent PR
interval.
Question 2: Which ECG finding is expected in a normal sinus rhythm at the bedside
monitor?
A. Atrial rate slower than ventricular rate with inverted P waves
B. Sawtooth flutter waves with variable AV conduction
C. Wide, bizarre QRS complexes with no preceding P waves
D. Each P wave is followed by a QRS complex at a regular rate
Answer: D
Rationale: Normal sinus rhythm starts in the sinus node, so atrial depolarization should be regular
and each impulse should conduct through the AV node to a QRS complex. Wide complexes without P
waves suggest ventricular origin, not sinus rhythm.
Question 3: Which rhythm is classically described as having an 'irregularly irregular'
ventricular response?
A. Normal sinus rhythm
B. Sinus bradycardia
C. Third-degree heart block
D. Atrial fibrillation
Answer: D
Page 1 of 42
,Cardiac rhythm interpretation
Rationale: Atrial fibrillation typically produces an irregularly irregular rhythm without organized
atrial activity.
Question 4: On a standard ECG strip, what does the PR interval represent?
A. Ventricular depolarization only
B. Ventricular repolarization
C. Time from one R wave to the next R wave
D. Atrial depolarization to the start of ventricular depolarization
Answer: D
Rationale: The PR interval measures conduction from atrial depolarization through the AV node to
the start of ventricular depolarization.
Question 5: On an ECG strip, what does the P wave represent?
A. AV nodal delay
B. Ventricular depolarization
C. Atrial repolarization
D. Atrial depolarization
Answer: D
Rationale: The P wave reflects electrical activation of the atria before they contract. Ventricular
depolarization is shown by the QRS complex, which is a common point of confusion.
Question 6: A premature ventricular contraction (PVC) is most likely identified by which
pattern?
A. Continuous sawtooth baseline between QRS complexes
B. Regular narrow QRS complexes with upright P waves
C. Slow rhythm with prolonged PR interval
D. Early wide QRS complex without a preceding P wave
Answer: D
Rationale: PVCs are early ventricular beats that usually appear as wide QRS complexes not preceded
by a P wave.
Question 7: Which rhythm is most associated with a classic sawtooth atrial pattern on
ECG?
A. Ventricular fibrillation
B. Sinus bradycardia
C. Junctional rhythm
D. Atrial flutter
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, Cardiac rhythm interpretation
Answer: D
Rationale: Atrial flutter produces organized rapid atrial activity that often appears as sawtooth flutter
waves. Ventricular fibrillation is chaotic, and junctional rhythms do not create the same atrial
waveform.
Question 8: What does the PR interval measure on a standard ECG?
A. Time from ventricular repolarization to the next atrial depolarization
B. Time from one R wave to the next R wave
C. Duration of ventricular depolarization only
D. Time from onset of atrial depolarization to onset of ventricular depolarization
Answer: D
Rationale: The PR interval captures conduction from the start of atrial depolarization through the AV
node and into the beginning of ventricular depolarization. The RR interval measures rate, not AV
conduction time.
Question 9: Which rhythm is characterized by delayed AV conduction with a prolonged
PR interval but every P wave still conducts?
A. Second-degree AV block type II
B. Ventricular tachycardia
C. Atrial fibrillation
D. First-degree AV block
Answer: D
Rationale: First-degree AV block has a prolonged PR interval with 1:1 conduction.
Question 10: Which ECG finding is expected in sinus tachycardia?
A. Dropped QRS complexes after every P wave
B. Absent QRS complexes
C. Wide, chaotic waves with no organized pattern
D. Heart rate above 100/min with normal P waves
Answer: D
Rationale: Sinus tachycardia is a fast rhythm that still originates from the sinus node, so P waves
remain normal.
Question 11: A telemetry strip shows a regular rhythm with normal P waves before every
QRS and a rate of 48/min. Which rhythm is most consistent with this finding?
A. Sinus tachycardia
B. Atrial fibrillation
C. Second-degree AV block type II
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