1
Relias Dysrhythmia Basic A Test Complete
Questions and Correct Answers with
Explanations Actual Exam 2026/2027 Complete
Exam-Style Questions with Detailed Rationales |
100% Verified | Pass Guaranteed – A+ Graded
Part I: EKG Fundamentals & Normal Sinus Rhythm (Questions
1-13)
Q1: You're teaching a new nursing student how to identify the
components of a normal cardiac cycle on an EKG tracing.
Starting from the beginning of one cycle, what is the correct
sequence of waveform components they should see?
A. QRS complex → P wave → T wave → PR interval
B. P wave → PR interval → QRS complex → T wave
[CORRECT]
C. T wave → P wave → QRS complex → PR interval
D. PR interval → P wave → T wave → QRS complex
Correct Answer: B
Rationale: The best answer is B because the normal cardiac
electrical cycle begins with atrial depolarization (P wave),
,2
followed by the conduction delay through the AV node (PR
interval), then ventricular depolarization (QRS complex), and
finally ventricular repolarization (T wave). This is the
fundamental sequence every clinician needs to memorize before
moving on to rhythm interpretation.
Q2: On a standard EKG tracing running at 25 mm/second, each
small square on the grid paper represents how much time, and
each large square (made up of 5 small squares) represents how
much time?
A. Small square = 0.04 seconds; Large square = 0.20 seconds
[CORRECT]
B. Small square = 0.10 seconds; Large square = 0.50 seconds
C. Small square = 0.01 seconds; Large square = 0.05 seconds
D. Small square = 0.20 seconds; Large square = 1.00 second
Correct Answer: A
Rationale: This choice is correct because at the standard paper
speed of 25 mm/sec, each 1mm small box equals 0.04 seconds
and each 5mm large box equals 0.20 seconds. These numbers
are absolutely essential for measuring intervals like PR, QRS,
and QT—without them, you can't determine if something is
normal or abnormal.
,3
Q3: The PR interval measures the time from the beginning of
the P wave to the beginning of the QRS complex. What is the
accepted normal range for the PR interval in adults?
A. 0.04 to 0.10 seconds (1 to 2.5 small squares)
B. 0.12 to 0.20 seconds (3 to 5 small squares) [CORRECT]
C. 0.20 to 0.36 seconds (5 to 9 small squares)
D. 0.08 to 0.16 seconds (2 to 4 small squares)
Correct Answer: B
Rationale: The best answer is B. A normal PR interval falls
between 0.12 and 0.20 seconds, which translates to 3 to 5 small
squares on standard EKG paper. Anything shorter than 0.12
seconds suggests pre-excitation (like WPW), and anything
longer than 0.20 seconds indicates some degree of AV block—
so this range is a critical reference point you'll use constantly.
Q4: You're looking at an EKG rhythm strip and need to
calculate the heart rate using the "1500 method" (counting small
squares between R waves). If there are exactly 21 small squares
between consecutive R waves, what is the approximate heart
rate?
A. Approximately 60 beats per minute
, 4
B. Approximately 71 beats per minute [CORRECT]
C. Approximately 85 beats per minute
D. Approximately 100 beats per minute
Correct Answer: B
Rationale: This choice is correct because the 1500 method
works by dividing 1500 by the number of small squares between
R waves. So 1500 ÷ 21 ≈ 71 bpm. It's one of the most accurate
rate calculation methods for regular rhythms, and it's worth
committing to memory alongside the 300 method (using large
squares) and the 6-second strip method.
Q5: Which structure in the cardiac conduction system serves as
the primary pacemaker of the heart under normal conditions, and
what is its intrinsic firing rate?
A. AV node; 40–60 impulses per minute
B. SA node (sinoatrial node); 60–100 impulses per minute
[CORRECT]
C. Bundle of His; 40–60 impulses per minute
D. Purkinje fibers; 20–40 impulses per minute
Correct Answer: B
Relias Dysrhythmia Basic A Test Complete
Questions and Correct Answers with
Explanations Actual Exam 2026/2027 Complete
Exam-Style Questions with Detailed Rationales |
100% Verified | Pass Guaranteed – A+ Graded
Part I: EKG Fundamentals & Normal Sinus Rhythm (Questions
1-13)
Q1: You're teaching a new nursing student how to identify the
components of a normal cardiac cycle on an EKG tracing.
Starting from the beginning of one cycle, what is the correct
sequence of waveform components they should see?
A. QRS complex → P wave → T wave → PR interval
B. P wave → PR interval → QRS complex → T wave
[CORRECT]
C. T wave → P wave → QRS complex → PR interval
D. PR interval → P wave → T wave → QRS complex
Correct Answer: B
Rationale: The best answer is B because the normal cardiac
electrical cycle begins with atrial depolarization (P wave),
,2
followed by the conduction delay through the AV node (PR
interval), then ventricular depolarization (QRS complex), and
finally ventricular repolarization (T wave). This is the
fundamental sequence every clinician needs to memorize before
moving on to rhythm interpretation.
Q2: On a standard EKG tracing running at 25 mm/second, each
small square on the grid paper represents how much time, and
each large square (made up of 5 small squares) represents how
much time?
A. Small square = 0.04 seconds; Large square = 0.20 seconds
[CORRECT]
B. Small square = 0.10 seconds; Large square = 0.50 seconds
C. Small square = 0.01 seconds; Large square = 0.05 seconds
D. Small square = 0.20 seconds; Large square = 1.00 second
Correct Answer: A
Rationale: This choice is correct because at the standard paper
speed of 25 mm/sec, each 1mm small box equals 0.04 seconds
and each 5mm large box equals 0.20 seconds. These numbers
are absolutely essential for measuring intervals like PR, QRS,
and QT—without them, you can't determine if something is
normal or abnormal.
,3
Q3: The PR interval measures the time from the beginning of
the P wave to the beginning of the QRS complex. What is the
accepted normal range for the PR interval in adults?
A. 0.04 to 0.10 seconds (1 to 2.5 small squares)
B. 0.12 to 0.20 seconds (3 to 5 small squares) [CORRECT]
C. 0.20 to 0.36 seconds (5 to 9 small squares)
D. 0.08 to 0.16 seconds (2 to 4 small squares)
Correct Answer: B
Rationale: The best answer is B. A normal PR interval falls
between 0.12 and 0.20 seconds, which translates to 3 to 5 small
squares on standard EKG paper. Anything shorter than 0.12
seconds suggests pre-excitation (like WPW), and anything
longer than 0.20 seconds indicates some degree of AV block—
so this range is a critical reference point you'll use constantly.
Q4: You're looking at an EKG rhythm strip and need to
calculate the heart rate using the "1500 method" (counting small
squares between R waves). If there are exactly 21 small squares
between consecutive R waves, what is the approximate heart
rate?
A. Approximately 60 beats per minute
, 4
B. Approximately 71 beats per minute [CORRECT]
C. Approximately 85 beats per minute
D. Approximately 100 beats per minute
Correct Answer: B
Rationale: This choice is correct because the 1500 method
works by dividing 1500 by the number of small squares between
R waves. So 1500 ÷ 21 ≈ 71 bpm. It's one of the most accurate
rate calculation methods for regular rhythms, and it's worth
committing to memory alongside the 300 method (using large
squares) and the 6-second strip method.
Q5: Which structure in the cardiac conduction system serves as
the primary pacemaker of the heart under normal conditions, and
what is its intrinsic firing rate?
A. AV node; 40–60 impulses per minute
B. SA node (sinoatrial node); 60–100 impulses per minute
[CORRECT]
C. Bundle of His; 40–60 impulses per minute
D. Purkinje fibers; 20–40 impulses per minute
Correct Answer: B
