Relias Dysrhythmia Basic B Practice Test
2026 – ECG Rhythm Interpretation Study
Guide with Questions, Answers & Detailed
Rationales
Relias Dysrhythmia Basic B Practice Test 2026 – ECG Rhythm Interpretation
Study Guide
• This guide contains multiple-choice questions covering ECG rhythm strip
interpretation, rate calculation, conduction abnormalities, and emergency
dysrhythmia recognition, each with a clearly marked correct answer and a detailed
EXPERT RATIONALE.
• Work through the questions in order or by topic block, cover the answer choices
first to test recall, then review the EXPERT RATIONALE to reinforce the underlying
ECG principle before moving on.
Question 1: What is the normal range for a sinus rhythm heart rate in adults?
A. 40–60 bpm
B. 60–100 bpm
C. 100–150 bpm
D. 150–200 bpm
E. 30–50 bpm
Correct Answer: B. 60–100 bpm
EXPERT RATIONALE: A normal sinus rhythm originates from the SA node and
produces a regular rate between 60 and 100 beats per minute in adults. Rates
below 60 are termed bradycardia, and rates above 100 are termed tachycardia,
even if the rhythm origin remains the SA node.
Question 2: Which wave on the ECG represents atrial depolarization?
A. QRS complex
,B. T wave
C. P wave
D. U wave
E. ST segment
Correct Answer: C. P wave
EXPERT RATIONALE: The P wave reflects the spread of electrical impulse through
the atria, causing atrial contraction. It precedes the QRS complex, which represents
ventricular depolarization.
Question 3: What does the QRS complex represent?
A. Atrial repolarization
B. Ventricular depolarization
C. Ventricular repolarization
D. SA node firing
E. AV node delay
Correct Answer: B. Ventricular depolarization
EXPERT RATIONALE: The QRS complex represents the spread of the electrical
impulse through the ventricles, triggering ventricular contraction. Atrial
repolarization is hidden within this complex due to its larger amplitude.
Question 4: The PR interval represents which of the following?
A. Time for ventricular depolarization
B. Time from the start of atrial depolarization to the start of ventricular
depolarization
C. Time for ventricular repolarization
,D. Time between two consecutive P waves
E. Time for atrial repolarization only
Correct Answer: B. Time from the start of atrial depolarization to the start
of ventricular depolarization
EXPERT RATIONALE: The PR interval measures the time from the beginning of the
P wave to the beginning of the QRS complex, reflecting the impulse traveling
through the atria, AV node, and into the ventricles. Normal duration is 0.12–0.20
seconds.
Question 5: What is the normal duration of the QRS complex?
A. 0.04–0.08 seconds
B. 0.06–0.10 seconds
C. 0.08–0.12 seconds
D. 0.12–0.20 seconds
E. 0.20–0.40 seconds
Correct Answer: C. 0.08–0.12 seconds
EXPERT RATIONALE: A normal QRS duration is 0.08 to 0.12 seconds (2 to 3 small
boxes). A widened QRS (greater than 0.12 seconds) suggests a ventricular origin or
a conduction delay such as a bundle branch block.
Question 6: Using the 6-second method, if there are 8 QRS complexes in a 6-
second strip, what is the heart rate?
A. 48 bpm
B. 60 bpm
C. 80 bpm
D. 100 bpm
, E. 120 bpm
Correct Answer: C. 80 bpm
EXPERT RATIONALE: The 6-second method involves counting the number of QRS
complexes in a 6-second strip and multiplying by 10. Eight complexes multiplied by
10 equals 80 beats per minute, providing a quick estimate especially useful for
irregular rhythms.
Question 7: Which lead is most commonly used for continuous cardiac
monitoring?
A. Lead I
B. Lead II
C. Lead V1
D. aVR
E. Lead III
Correct Answer: B. Lead II
EXPERT RATIONALE: Lead II is most commonly used for continuous monitoring
because it typically provides a clear view of the P wave and QRS complex, as the
electrical axis runs roughly parallel to this lead's vector, making rhythm
identification easier.
Question 8: A regular rhythm with a rate of 45 bpm, normal P waves, normal
PR interval, and normal QRS complexes is best described as:
A. Sinus tachycardia
B. Sinus bradycardia
C. Sinus arrhythmia
D. Junctional rhythm
2026 – ECG Rhythm Interpretation Study
Guide with Questions, Answers & Detailed
Rationales
Relias Dysrhythmia Basic B Practice Test 2026 – ECG Rhythm Interpretation
Study Guide
• This guide contains multiple-choice questions covering ECG rhythm strip
interpretation, rate calculation, conduction abnormalities, and emergency
dysrhythmia recognition, each with a clearly marked correct answer and a detailed
EXPERT RATIONALE.
• Work through the questions in order or by topic block, cover the answer choices
first to test recall, then review the EXPERT RATIONALE to reinforce the underlying
ECG principle before moving on.
Question 1: What is the normal range for a sinus rhythm heart rate in adults?
A. 40–60 bpm
B. 60–100 bpm
C. 100–150 bpm
D. 150–200 bpm
E. 30–50 bpm
Correct Answer: B. 60–100 bpm
EXPERT RATIONALE: A normal sinus rhythm originates from the SA node and
produces a regular rate between 60 and 100 beats per minute in adults. Rates
below 60 are termed bradycardia, and rates above 100 are termed tachycardia,
even if the rhythm origin remains the SA node.
Question 2: Which wave on the ECG represents atrial depolarization?
A. QRS complex
,B. T wave
C. P wave
D. U wave
E. ST segment
Correct Answer: C. P wave
EXPERT RATIONALE: The P wave reflects the spread of electrical impulse through
the atria, causing atrial contraction. It precedes the QRS complex, which represents
ventricular depolarization.
Question 3: What does the QRS complex represent?
A. Atrial repolarization
B. Ventricular depolarization
C. Ventricular repolarization
D. SA node firing
E. AV node delay
Correct Answer: B. Ventricular depolarization
EXPERT RATIONALE: The QRS complex represents the spread of the electrical
impulse through the ventricles, triggering ventricular contraction. Atrial
repolarization is hidden within this complex due to its larger amplitude.
Question 4: The PR interval represents which of the following?
A. Time for ventricular depolarization
B. Time from the start of atrial depolarization to the start of ventricular
depolarization
C. Time for ventricular repolarization
,D. Time between two consecutive P waves
E. Time for atrial repolarization only
Correct Answer: B. Time from the start of atrial depolarization to the start
of ventricular depolarization
EXPERT RATIONALE: The PR interval measures the time from the beginning of the
P wave to the beginning of the QRS complex, reflecting the impulse traveling
through the atria, AV node, and into the ventricles. Normal duration is 0.12–0.20
seconds.
Question 5: What is the normal duration of the QRS complex?
A. 0.04–0.08 seconds
B. 0.06–0.10 seconds
C. 0.08–0.12 seconds
D. 0.12–0.20 seconds
E. 0.20–0.40 seconds
Correct Answer: C. 0.08–0.12 seconds
EXPERT RATIONALE: A normal QRS duration is 0.08 to 0.12 seconds (2 to 3 small
boxes). A widened QRS (greater than 0.12 seconds) suggests a ventricular origin or
a conduction delay such as a bundle branch block.
Question 6: Using the 6-second method, if there are 8 QRS complexes in a 6-
second strip, what is the heart rate?
A. 48 bpm
B. 60 bpm
C. 80 bpm
D. 100 bpm
, E. 120 bpm
Correct Answer: C. 80 bpm
EXPERT RATIONALE: The 6-second method involves counting the number of QRS
complexes in a 6-second strip and multiplying by 10. Eight complexes multiplied by
10 equals 80 beats per minute, providing a quick estimate especially useful for
irregular rhythms.
Question 7: Which lead is most commonly used for continuous cardiac
monitoring?
A. Lead I
B. Lead II
C. Lead V1
D. aVR
E. Lead III
Correct Answer: B. Lead II
EXPERT RATIONALE: Lead II is most commonly used for continuous monitoring
because it typically provides a clear view of the P wave and QRS complex, as the
electrical axis runs roughly parallel to this lead's vector, making rhythm
identification easier.
Question 8: A regular rhythm with a rate of 45 bpm, normal P waves, normal
PR interval, and normal QRS complexes is best described as:
A. Sinus tachycardia
B. Sinus bradycardia
C. Sinus arrhythmia
D. Junctional rhythm
