Relias Dysrhythmia Basic A Test | Correctly Answered and Graded A+ Latest 2026/2027 2026/2027
OBJECTIVE ASSESSMENT - EXAM
Relias Dysrhythmia Basic A Test | Correctly Answered
and Graded A+ Latest 2026/2027 2026/2027
EDITION
75 100% 2026/2027
QUESTIONS VERIFIED ANSWERS EDITION
TOPICS COVERED
Cardiac Anatomy & Physiology Atrial & Ventricular Dysrhythmias
ECG Interpretation & Rhythm Analysis Conduction Blocks & Pacing
Normal Sinus Rhythm & Variations
COVER PAGE - 1
, SECTION 1 | Cardiac Anatomy & Physiology | Q1-Q15 | 2026/2027
Relias Dysrhythmia Basic A Test | Correctly Answered and Graded A+ Latest 2026/2027 2026/2027
Q1 Question 1 of 75
A 55-year-old patient is admitted with chest pain, and the nurse is reviewing the conduction system of
the heart. The electrical impulse normally originates in which structure?
A. The sinoatrial node located in the upper right atrium
B. The atrioventricular node located in the lower right atrium
C. The bundle of His located in the interventricular septum
D. The Purkinje fibers located in the ventricular myocardium
Correct Answer: A
Rationale:
The sinoatrial (SA) node in the upper right atrium is the heart's primary pacemaker, normally firing at 60 to 100 beats per
minute. The AV node delays the impulse, the bundle of His conducts it to the ventricles, and Purkinje fibers distribute it
through the ventricular muscle.
Q2 Question 2 of 75
A nurse is teaching a patient about the cardiac cycle. The P wave on an ECG tracing represents which
electrical event?
A. Ventricular depolarization preceding contraction
B. Atrial depolarization preceding atrial contraction
C. Ventricular repolarization following contraction
D. The delay of the impulse at the AV node
Correct Answer: B
Rationale:
The P wave represents atrial depolarization, which triggers atrial contraction. Ventricular depolarization produces the
QRS complex, ventricular repolarization produces the T wave, and the PR segment reflects the AV nodal delay.
Relias Dysrhythmia Basic A Test | Correctly Answered and Graded A+ Latest 2026/2027 2026/2027 - 2026/2027 | Passing Score: 80% | Page 2 of 42
, Q3 Question 3 of 75
A patient in the ICU has a heart rate of 45 beats per minute with a regular rhythm. The nurse
understands that when the SA node fails to fire, which structure typically takes over as the pacemaker?
A. The Purkinje fibers at a rate of 20 to 40 beats per minute
B. The bundle of His at a rate of 70 to 80 beats per minute
C. The AV node at a rate of 40 to 60 beats per minute
D. The coronary sinus at a rate of 50 to 70 beats per minute
Correct Answer: C
Rationale:
When the SA node fails, the AV junction (AV node) typically takes over as the pacemaker at an intrinsic rate of 40 to 60
beats per minute, producing a junctional escape rhythm. Purkinje fibers pace at 20 to 40 beats per minute and would
only activate if higher pacemakers fail.
Q4 Question 4 of 75
A nursing student is studying the autonomic nervous system's effect on heart rate. Stimulation of the
parasympathetic nervous system (vagus nerve) produces which effect on the SA node?
A. Decreased heart rate and decreased conduction velocity
B. Increased heart rate and increased conduction velocity
C. Increased heart rate with no effect on conduction
D. No change in heart rate or conduction velocity
Correct Answer: A
Rationale:
Parasympathetic stimulation via the vagus nerve releases acetylcholine, which slows the SA node firing rate and
decreases AV node conduction velocity, lowering heart rate. Sympathetic stimulation has the opposite effect, increasing
heart rate and conduction.
Relias Dysrhythmia Basic A Test | Correctly Answered and Graded A+ Latest 2026/2027 2026/2027 - 2026/2027 | Passing Score: 80% | Page 3 of 42
, Q5 Question 5 of 75
A patient with coronary artery disease asks why heart muscle needs a continuous oxygen supply. The
nurse explains that cardiac muscle cells differ from skeletal muscle cells because they are:
A. Voluntary, non-striated, and use anaerobic metabolism
B. Involuntary, striated, and rely almost exclusively on aerobic metabolism
C. Involuntary, non-striated, and have multiple nuclei per cell
D. Voluntary, striated, and can tolerate long periods without oxygen
Correct Answer: B
Rationale:
Cardiac muscle cells are involuntary, striated, and depend heavily on aerobic metabolism, making them highly sensitive
to oxygen deprivation. Unlike skeletal muscle, they cannot tolerate significant anaerobic periods without damage, and
they are striated rather than smooth.
Q6 Question 6 of 75
A nurse is explaining the cardiac conduction pathway to a patient's family. After the impulse leaves the
AV node, what is the correct sequence of conduction?
A. Purkinje fibers, bundle branches, bundle of His
B. Right and left bundle branches, Purkinje fibers, bundle of His
C. Bundle of His, right and left bundle branches, Purkinje fibers
D. Bundle of His, Purkinje fibers, bundle branches
Correct Answer: C
Rationale:
After leaving the AV node, the impulse travels through the bundle of His, then divides into the right and left bundle
branches, and finally spreads through the Purkinje fibers to stimulate ventricular contraction. Reversing or scrambling
this sequence disrupts normal ventricular depolarization.
Relias Dysrhythmia Basic A Test | Correctly Answered and Graded A+ Latest 2026/2027 2026/2027 - 2026/2027 | Passing Score: 80% | Page 4 of 42
OBJECTIVE ASSESSMENT - EXAM
Relias Dysrhythmia Basic A Test | Correctly Answered
and Graded A+ Latest 2026/2027 2026/2027
EDITION
75 100% 2026/2027
QUESTIONS VERIFIED ANSWERS EDITION
TOPICS COVERED
Cardiac Anatomy & Physiology Atrial & Ventricular Dysrhythmias
ECG Interpretation & Rhythm Analysis Conduction Blocks & Pacing
Normal Sinus Rhythm & Variations
COVER PAGE - 1
, SECTION 1 | Cardiac Anatomy & Physiology | Q1-Q15 | 2026/2027
Relias Dysrhythmia Basic A Test | Correctly Answered and Graded A+ Latest 2026/2027 2026/2027
Q1 Question 1 of 75
A 55-year-old patient is admitted with chest pain, and the nurse is reviewing the conduction system of
the heart. The electrical impulse normally originates in which structure?
A. The sinoatrial node located in the upper right atrium
B. The atrioventricular node located in the lower right atrium
C. The bundle of His located in the interventricular septum
D. The Purkinje fibers located in the ventricular myocardium
Correct Answer: A
Rationale:
The sinoatrial (SA) node in the upper right atrium is the heart's primary pacemaker, normally firing at 60 to 100 beats per
minute. The AV node delays the impulse, the bundle of His conducts it to the ventricles, and Purkinje fibers distribute it
through the ventricular muscle.
Q2 Question 2 of 75
A nurse is teaching a patient about the cardiac cycle. The P wave on an ECG tracing represents which
electrical event?
A. Ventricular depolarization preceding contraction
B. Atrial depolarization preceding atrial contraction
C. Ventricular repolarization following contraction
D. The delay of the impulse at the AV node
Correct Answer: B
Rationale:
The P wave represents atrial depolarization, which triggers atrial contraction. Ventricular depolarization produces the
QRS complex, ventricular repolarization produces the T wave, and the PR segment reflects the AV nodal delay.
Relias Dysrhythmia Basic A Test | Correctly Answered and Graded A+ Latest 2026/2027 2026/2027 - 2026/2027 | Passing Score: 80% | Page 2 of 42
, Q3 Question 3 of 75
A patient in the ICU has a heart rate of 45 beats per minute with a regular rhythm. The nurse
understands that when the SA node fails to fire, which structure typically takes over as the pacemaker?
A. The Purkinje fibers at a rate of 20 to 40 beats per minute
B. The bundle of His at a rate of 70 to 80 beats per minute
C. The AV node at a rate of 40 to 60 beats per minute
D. The coronary sinus at a rate of 50 to 70 beats per minute
Correct Answer: C
Rationale:
When the SA node fails, the AV junction (AV node) typically takes over as the pacemaker at an intrinsic rate of 40 to 60
beats per minute, producing a junctional escape rhythm. Purkinje fibers pace at 20 to 40 beats per minute and would
only activate if higher pacemakers fail.
Q4 Question 4 of 75
A nursing student is studying the autonomic nervous system's effect on heart rate. Stimulation of the
parasympathetic nervous system (vagus nerve) produces which effect on the SA node?
A. Decreased heart rate and decreased conduction velocity
B. Increased heart rate and increased conduction velocity
C. Increased heart rate with no effect on conduction
D. No change in heart rate or conduction velocity
Correct Answer: A
Rationale:
Parasympathetic stimulation via the vagus nerve releases acetylcholine, which slows the SA node firing rate and
decreases AV node conduction velocity, lowering heart rate. Sympathetic stimulation has the opposite effect, increasing
heart rate and conduction.
Relias Dysrhythmia Basic A Test | Correctly Answered and Graded A+ Latest 2026/2027 2026/2027 - 2026/2027 | Passing Score: 80% | Page 3 of 42
, Q5 Question 5 of 75
A patient with coronary artery disease asks why heart muscle needs a continuous oxygen supply. The
nurse explains that cardiac muscle cells differ from skeletal muscle cells because they are:
A. Voluntary, non-striated, and use anaerobic metabolism
B. Involuntary, striated, and rely almost exclusively on aerobic metabolism
C. Involuntary, non-striated, and have multiple nuclei per cell
D. Voluntary, striated, and can tolerate long periods without oxygen
Correct Answer: B
Rationale:
Cardiac muscle cells are involuntary, striated, and depend heavily on aerobic metabolism, making them highly sensitive
to oxygen deprivation. Unlike skeletal muscle, they cannot tolerate significant anaerobic periods without damage, and
they are striated rather than smooth.
Q6 Question 6 of 75
A nurse is explaining the cardiac conduction pathway to a patient's family. After the impulse leaves the
AV node, what is the correct sequence of conduction?
A. Purkinje fibers, bundle branches, bundle of His
B. Right and left bundle branches, Purkinje fibers, bundle of His
C. Bundle of His, right and left bundle branches, Purkinje fibers
D. Bundle of His, Purkinje fibers, bundle branches
Correct Answer: C
Rationale:
After leaving the AV node, the impulse travels through the bundle of His, then divides into the right and left bundle
branches, and finally spreads through the Purkinje fibers to stimulate ventricular contraction. Reversing or scrambling
this sequence disrupts normal ventricular depolarization.
Relias Dysrhythmia Basic A Test | Correctly Answered and Graded A+ Latest 2026/2027 2026/2027 - 2026/2027 | Passing Score: 80% | Page 4 of 42
