Relias Dysrhythmia Basic A – 2026 – Complete Practice
Test with Verified Answers
This comprehensive practice guide contains 100+ exam-style questions covering
ECG interpretation, rhythm identification, and clinical priorities for the Relias
Dysrhythmia Basic A exam. All answers are verified and include detailed
rationales to reinforce learning.
DOMAIN 1: ECG FOUNDATIONS & MEASUREMENTS
1. The electrical impulse normally originates from which structure of the heart?
A) AV node
B) Bundle of His
C) SA node
D) Purkinje fibers
Answer: C) SA node
Rationale: The sinoatrial (SA) node, located in the upper wall of the right atrium, is the
heart's natural pacemaker. It has the highest degree of automaticity (60-100 bpm) and
overrides other potential pacemakers.
2. At what rate does the SA node normally fire in a resting adult?
A) 20-40 beats per minute
B) 40-60 beats per minute
C) 60-100 beats per minute
D) 100-150 beats per minute
Answer: C) 60-100 beats per minute
, Rationale: The SA node is the primary pacemaker with an intrinsic firing rate of 60-100
bpm. The AV junction has a backup rate of 40-60 bpm, and the Purkinje fibers have an
intrinsic rate of 20-40 bpm.
3. On standard ECG paper, what is the standard recording speed?
A) 15 mm/second
B) 25 mm/second
C) 50 mm/second
D) 100 mm/second
Answer: B) 25 mm/second
Rationale: The standard ECG paper speed is 25 mm per second. At this speed, each
small box (1 mm) represents 0.04 seconds, and each large box (5 mm) represents 0.20
seconds.
4. What does the horizontal axis on an ECG measure?
A) Voltage
B) Time
C) Amplitude
D) Resistance
Answer: B) Time
Rationale: The horizontal axis on ECG paper represents time. The vertical axis represents
voltage/amplitude.
5. What is the duration of one small box on standard ECG paper?
A) 0.04 seconds
B) 0.20 seconds
, C) 0.10 seconds
D) 0.01 seconds
Answer: A) 0.04 seconds
Rationale: At standard speed (25 mm/sec), each small box = 0.04 sec (40 ms). Each
large box (5 small boxes) = 0.20 sec.
6. How many seconds does one large box represent on ECG paper?
A) 0.04 seconds
B) 0.20 seconds
C) 0.10 seconds
D) 1.00 seconds
Answer: B) 0.20 seconds
Rationale: One large box equals five small boxes, representing 0.20 seconds.
7. What voltage does one small box on the vertical axis represent?
A) 0.1 mV
B) 0.5 mV
C) 1.0 mV
D) 0.01 mV
Answer: A) 0.1 mV
Rationale: Vertically, each small box represents 0.1 millivolts of amplitude.
8. Where is the SA node located?
A) Left atrium
, B) Right atrium
C) Left ventricle
D) Interventricular septum
Answer: B) Right atrium
Rationale: The sinoatrial node is located in the upper wall of the right atrium, near the
opening of the superior vena cava.
9. Where is the AV node located?
A) Floor of the right atrium
B) Apex of the right ventricle
C) Interventricular septum
D) Left atrium
Answer: A) Floor of the right atrium
Rationale: The atrioventricular node is located in the floor of the right atrium near the
interatrial septum.
10. What structure directly follows the AV node in the conduction pathway?
A) Bundle branches
B) Purkinje fibers
C) Bundle of His
D) Internodal pathways
Answer: C) Bundle of His
Rationale: The electrical impulse travels from the AV node to the Bundle of His, then to
the bundle branches, and finally to the Purkinje fibers.
Test with Verified Answers
This comprehensive practice guide contains 100+ exam-style questions covering
ECG interpretation, rhythm identification, and clinical priorities for the Relias
Dysrhythmia Basic A exam. All answers are verified and include detailed
rationales to reinforce learning.
DOMAIN 1: ECG FOUNDATIONS & MEASUREMENTS
1. The electrical impulse normally originates from which structure of the heart?
A) AV node
B) Bundle of His
C) SA node
D) Purkinje fibers
Answer: C) SA node
Rationale: The sinoatrial (SA) node, located in the upper wall of the right atrium, is the
heart's natural pacemaker. It has the highest degree of automaticity (60-100 bpm) and
overrides other potential pacemakers.
2. At what rate does the SA node normally fire in a resting adult?
A) 20-40 beats per minute
B) 40-60 beats per minute
C) 60-100 beats per minute
D) 100-150 beats per minute
Answer: C) 60-100 beats per minute
, Rationale: The SA node is the primary pacemaker with an intrinsic firing rate of 60-100
bpm. The AV junction has a backup rate of 40-60 bpm, and the Purkinje fibers have an
intrinsic rate of 20-40 bpm.
3. On standard ECG paper, what is the standard recording speed?
A) 15 mm/second
B) 25 mm/second
C) 50 mm/second
D) 100 mm/second
Answer: B) 25 mm/second
Rationale: The standard ECG paper speed is 25 mm per second. At this speed, each
small box (1 mm) represents 0.04 seconds, and each large box (5 mm) represents 0.20
seconds.
4. What does the horizontal axis on an ECG measure?
A) Voltage
B) Time
C) Amplitude
D) Resistance
Answer: B) Time
Rationale: The horizontal axis on ECG paper represents time. The vertical axis represents
voltage/amplitude.
5. What is the duration of one small box on standard ECG paper?
A) 0.04 seconds
B) 0.20 seconds
, C) 0.10 seconds
D) 0.01 seconds
Answer: A) 0.04 seconds
Rationale: At standard speed (25 mm/sec), each small box = 0.04 sec (40 ms). Each
large box (5 small boxes) = 0.20 sec.
6. How many seconds does one large box represent on ECG paper?
A) 0.04 seconds
B) 0.20 seconds
C) 0.10 seconds
D) 1.00 seconds
Answer: B) 0.20 seconds
Rationale: One large box equals five small boxes, representing 0.20 seconds.
7. What voltage does one small box on the vertical axis represent?
A) 0.1 mV
B) 0.5 mV
C) 1.0 mV
D) 0.01 mV
Answer: A) 0.1 mV
Rationale: Vertically, each small box represents 0.1 millivolts of amplitude.
8. Where is the SA node located?
A) Left atrium
, B) Right atrium
C) Left ventricle
D) Interventricular septum
Answer: B) Right atrium
Rationale: The sinoatrial node is located in the upper wall of the right atrium, near the
opening of the superior vena cava.
9. Where is the AV node located?
A) Floor of the right atrium
B) Apex of the right ventricle
C) Interventricular septum
D) Left atrium
Answer: A) Floor of the right atrium
Rationale: The atrioventricular node is located in the floor of the right atrium near the
interatrial septum.
10. What structure directly follows the AV node in the conduction pathway?
A) Bundle branches
B) Purkinje fibers
C) Bundle of His
D) Internodal pathways
Answer: C) Bundle of His
Rationale: The electrical impulse travels from the AV node to the Bundle of His, then to
the bundle branches, and finally to the Purkinje fibers.
