NURSING EDUCATION PRACTICE ASSESSMENT
Normal Sinus Rhythm and Basic Rhythm
Identification Practice Test
Foundational ECG Interpretation
50 original multiple-choice questions
28 original ECG rhythm strips • Detailed rationales for every question
ECG principles, heart-rate calculation, sinus rhythms, and common dysrhythmias
Name: ______________________________ Date: ________________ Score: ________ / 50
Educational disclaimer
This is an original educational practice resource. It is not an official Relias examination and does not reproduce
proprietary or confidential examination questions.
, Normal Sinus Rhythm and Basic Rhythm Identification Practice Test
Instructions
This practice test contains 50 original multiple-choice questions on basic ECG principles, normal sinus
rhythm, heart-rate calculation, sinus variations, and common dysrhythmias. Each question has four
choices (A–D) and one best answer. Unless a question states otherwise, assume an adult patient.
• Read each question carefully. When an ECG figure is shown, interpret it with a systematic
approach (regularity, rate, P waves, PR interval, QRS duration) before reviewing the choices.
• ECG figures are recorded at 25 mm/s and 10 mm/mV. Each small box is 0.04 second and each
large box is 0.20 second. Enlarged figures keep the same grid values, and lettered arrows appear
only when a question refers to them.
• The correct answer and a detailed rationale follow each question. To test yourself, cover the
lines below the answer choices until you have decided on your answer.
• Consider the patient’s symptoms, vital signs, and clinical condition together with the rhythm,
not the rhythm label alone.
Categories covered
No. Category Questions
1 Category A: Basic ECG Principles 1–5
2 Category B: Normal Sinus Rhythm 6–11
3 Category C: Calculating Heart Rate 12–18
4 Category D: Rhythm Regularity and Waveform Identification 19–24
5 Category E: Sinus Rhythm Variations 25–31
6 Category F: Basic Rhythm Identification 32–41
7 Category G: Clinical Application 42–46
8 Category H: Common Interpretation Errors 47–50
1
, Normal Sinus Rhythm and Basic Rhythm Identification Practice Test
Category A: Basic ECG Principles
Question 1. Which statement best describes what an electrocardiogram (ECG) records?
A. The force with which the ventricles contract
B. The flow of blood through the coronary arteries
C. The pressure inside each heart chamber
D. The heart’s electrical activity detected through skin electrodes, reflecting depolarization and
repolarization
Correct Answer: D. The heart’s electrical activity detected through skin electrodes, reflecting
depolarization and repolarization.
Rationale: An ECG records the electrical currents produced as cardiac cells depolarize and repolarize,
detected by electrodes on the skin. It does not measure contraction strength, blood flow, or pressures.
A patient can have an organized electrical rhythm on the monitor and still have a weak or absent
pulse, so the rhythm must always be interpreted together with the patient’s pulse, blood pressure,
and perfusion.
Question 2. Why is the SA node normally the heart’s primary pacemaker?
A. It is the only tissue in the heart that can generate an impulse
B. It is located in the ventricular septum
C. It has the fastest intrinsic firing rate (about 60–100 impulses/min), so it depolarizes before lower
pacemaker sites
D. It delays the impulse so the atria can empty into the ventricles
Correct Answer: C. It has the fastest intrinsic firing rate (about 60–100 impulses/min), so it depolarizes
before lower pacemaker sites.
Rationale: Several parts of the conduction system can generate impulses, but they fire at different
intrinsic rates: the SA node at 60–100/min, the AV junction at 40–60/min, and the ventricular tissue at
20–40/min. Because the SA node is fastest, it controls the rhythm, and lower sites act as backups
(escape rhythms) only if the SA node fails or its impulses are blocked. The SA node is in the right
atrium, and the delay of the impulse is a function of the AV node.
2
, Normal Sinus Rhythm and Basic Rhythm Identification Practice Test
Question 3. In ECG Figure 1, which lettered arrow marks the waveform that represents ventricular
depolarization?
ECG Figure 1. Lead II tracing enlarged for measurement; each small box is 0.04 second horizontally and 0.1 mV vertically.
Lettered arrows mark selected waveforms.
A. Arrow A
B. Arrow B
C. Arrow C
D. Arrow D
Correct Answer: B. Arrow B.
Rationale: Arrow B points to the peak of the R wave within the QRS complex, which represents
ventricular depolarization. Arrow A points to the P wave (atrial depolarization), Arrow C points to the
ST segment (early ventricular repolarization), and Arrow D points to the T wave (ventricular
repolarization). Ventricular depolarization normally produces the tallest waveform because the
ventricles have the greatest muscle mass.
Question 4. A rhythm strip is 30 large boxes long and was recorded at the standard paper speed of 25
mm/s. How many seconds does the strip represent?
A. 3 seconds
B. 6 seconds
C. 10 seconds
D. 30 seconds
Correct Answer: B. 6 seconds.
Rationale: At 25 mm/s, each large box represents 0.20 second, so 30 large boxes represent 30 × 0.20 =
6 seconds. Five large boxes equal 1 second. This is why a standard 6-second strip is used for the six-
second method of estimating heart rate.
3
Normal Sinus Rhythm and Basic Rhythm
Identification Practice Test
Foundational ECG Interpretation
50 original multiple-choice questions
28 original ECG rhythm strips • Detailed rationales for every question
ECG principles, heart-rate calculation, sinus rhythms, and common dysrhythmias
Name: ______________________________ Date: ________________ Score: ________ / 50
Educational disclaimer
This is an original educational practice resource. It is not an official Relias examination and does not reproduce
proprietary or confidential examination questions.
, Normal Sinus Rhythm and Basic Rhythm Identification Practice Test
Instructions
This practice test contains 50 original multiple-choice questions on basic ECG principles, normal sinus
rhythm, heart-rate calculation, sinus variations, and common dysrhythmias. Each question has four
choices (A–D) and one best answer. Unless a question states otherwise, assume an adult patient.
• Read each question carefully. When an ECG figure is shown, interpret it with a systematic
approach (regularity, rate, P waves, PR interval, QRS duration) before reviewing the choices.
• ECG figures are recorded at 25 mm/s and 10 mm/mV. Each small box is 0.04 second and each
large box is 0.20 second. Enlarged figures keep the same grid values, and lettered arrows appear
only when a question refers to them.
• The correct answer and a detailed rationale follow each question. To test yourself, cover the
lines below the answer choices until you have decided on your answer.
• Consider the patient’s symptoms, vital signs, and clinical condition together with the rhythm,
not the rhythm label alone.
Categories covered
No. Category Questions
1 Category A: Basic ECG Principles 1–5
2 Category B: Normal Sinus Rhythm 6–11
3 Category C: Calculating Heart Rate 12–18
4 Category D: Rhythm Regularity and Waveform Identification 19–24
5 Category E: Sinus Rhythm Variations 25–31
6 Category F: Basic Rhythm Identification 32–41
7 Category G: Clinical Application 42–46
8 Category H: Common Interpretation Errors 47–50
1
, Normal Sinus Rhythm and Basic Rhythm Identification Practice Test
Category A: Basic ECG Principles
Question 1. Which statement best describes what an electrocardiogram (ECG) records?
A. The force with which the ventricles contract
B. The flow of blood through the coronary arteries
C. The pressure inside each heart chamber
D. The heart’s electrical activity detected through skin electrodes, reflecting depolarization and
repolarization
Correct Answer: D. The heart’s electrical activity detected through skin electrodes, reflecting
depolarization and repolarization.
Rationale: An ECG records the electrical currents produced as cardiac cells depolarize and repolarize,
detected by electrodes on the skin. It does not measure contraction strength, blood flow, or pressures.
A patient can have an organized electrical rhythm on the monitor and still have a weak or absent
pulse, so the rhythm must always be interpreted together with the patient’s pulse, blood pressure,
and perfusion.
Question 2. Why is the SA node normally the heart’s primary pacemaker?
A. It is the only tissue in the heart that can generate an impulse
B. It is located in the ventricular septum
C. It has the fastest intrinsic firing rate (about 60–100 impulses/min), so it depolarizes before lower
pacemaker sites
D. It delays the impulse so the atria can empty into the ventricles
Correct Answer: C. It has the fastest intrinsic firing rate (about 60–100 impulses/min), so it depolarizes
before lower pacemaker sites.
Rationale: Several parts of the conduction system can generate impulses, but they fire at different
intrinsic rates: the SA node at 60–100/min, the AV junction at 40–60/min, and the ventricular tissue at
20–40/min. Because the SA node is fastest, it controls the rhythm, and lower sites act as backups
(escape rhythms) only if the SA node fails or its impulses are blocked. The SA node is in the right
atrium, and the delay of the impulse is a function of the AV node.
2
, Normal Sinus Rhythm and Basic Rhythm Identification Practice Test
Question 3. In ECG Figure 1, which lettered arrow marks the waveform that represents ventricular
depolarization?
ECG Figure 1. Lead II tracing enlarged for measurement; each small box is 0.04 second horizontally and 0.1 mV vertically.
Lettered arrows mark selected waveforms.
A. Arrow A
B. Arrow B
C. Arrow C
D. Arrow D
Correct Answer: B. Arrow B.
Rationale: Arrow B points to the peak of the R wave within the QRS complex, which represents
ventricular depolarization. Arrow A points to the P wave (atrial depolarization), Arrow C points to the
ST segment (early ventricular repolarization), and Arrow D points to the T wave (ventricular
repolarization). Ventricular depolarization normally produces the tallest waveform because the
ventricles have the greatest muscle mass.
Question 4. A rhythm strip is 30 large boxes long and was recorded at the standard paper speed of 25
mm/s. How many seconds does the strip represent?
A. 3 seconds
B. 6 seconds
C. 10 seconds
D. 30 seconds
Correct Answer: B. 6 seconds.
Rationale: At 25 mm/s, each large box represents 0.20 second, so 30 large boxes represent 30 × 0.20 =
6 seconds. Five large boxes equal 1 second. This is why a standard 6-second strip is used for the six-
second method of estimating heart rate.
3
