ECHELON QUIZ 2025-2026 |
Questions and Answers |
Complete Solutions | Echelon
Exam Prep | A+ Graded | Pass
Guaranteed
[DOMAIN 1: LEAD PLACEMENT & WAVEFORM COMPONENTS - 25 Questions]
1. Which lead is helpful in monitoring atrial rhythms and hemiblocks?
A) Lead II
B) Lead III
C) Lead I ✔✔ [CORRECT]
D) MCL1
Rationale: Lead I is the most useful for monitoring atrial rhythms and hemiblocks because it
provides a clear view of atrial activity and is perpendicular to the electrical axis, making it ideal
for detecting left or right hemiblocks.
2. Which lead is helpful in assessing bundle branch defects and confirming pacemaker wire
placement?
A) Lead II
B) Lead III
C) MCL1 ✔✔ [CORRECT]
D) aVF
Rationale: MCL1 (Modified Chest Lead 1) is the standard lead for assessing bundle branch
blocks and confirming pacemaker wire placement because it mimics V1 and provides excellent
visualization of ventricular conduction patterns.
3. Which lead is the most useful for routine monitoring and monitoring the sinus node?
A) Lead I
B) Lead II ✔✔ [CORRECT]
C) Lead III
D) aVL
Rationale: Lead II is the gold standard for routine EKG monitoring because the electrical axis of
the heart flows toward the positive electrode of Lead II, producing the tallest, most visible P
waves—essential for identifying sinus node activity.
, . Along with Lead II, which lead is most helpful in monitoring changes in the inferior wall of the
4
heart?
A) Lead I
B) aVL
C) Lead III ✔✔ [CORRECT]
D) V1
Rationale: Lead III, together with Lead II and aVF, forms the inferior leads (II, III, aVF). These
leads view the inferior wall of the heart and are crucial for detecting inferior wall myocardial
infarction.
5. What are the best areas to place electrodes?
A) Over bony prominences
B) Over major muscle groups
C) On soft tissue ✔✔ [CORRECT]
D) Over surgical incisions
Rationale: Electrodes should be placed on soft tissue (fleshy areas) to ensure good skin contact
and reduce motion artifact. Bony prominences and muscle groups can produce electrical
interference.
6. The EKG produces an upright pattern on the paper in response to electrical activity in the
heart flowing towards what?
A) Negative electrode
B) Ground electrode
C) Positive electrode ✔✔ [CORRECT]
D) Reference electrode
Rationale: By convention, EKG machines record positive deflections when electrical current
flows toward the positive electrode and negative deflections when current flows away from it.
7. What is the normal measurement of a QRS complex?
A) 0.06-0.12 seconds
B) 0.04-0.10 seconds ✔✔ [CORRECT]
C) 0.12-0.20 seconds
D) 0.20-0.40 seconds
Rationale: Normal QRS duration is 0.04-0.10 seconds (1-2.5 small boxes). This represents
normal ventricular depolarization through the His-Purkinje system. Values >0.12 seconds
indicate bundle branch block or ventricular origin.
8. What are EKG artifacts?
A) Normal variations in cardiac rhythm
B) False cardiac waveforms ✔✔ [CORRECT]
C) Pathological Q waves
D) ST-segment elevations
Rationale: Artifacts are false waveforms caused by patient movement, loose electrodes,
electrical interference, or muscle tremors. They can mimic arrhythmias and must be
distinguished from true cardiac electrical activity.
9. What is the first step in preparing a patient for an EKG?
A) Attaching the electrodes
B) Reassuring the patient and maintaining privacy ✔✔ [CORRECT]
, ) Shaving excessive hair
C
D) Cleaning the skin with alcohol
Rationale: Patient preparation begins with explanation, reassurance, and privacy. This reduces
anxiety (which can affect heart rate) and ensures cooperation. Technical preparation follows
psychological preparation.
10. Electrode location sites should be rotated or changed when?
A) Q12h
B) Q24h ✔✔ [CORRECT]
C) Q48h
D) Only when they fall off
Rationale: Electrodes should be rotated every 24 hours (Q24h) or when the patient is sweaty or
has had a bath. This prevents skin irritation and maintains optimal electrical contact.
11. What part of the EKG reflects the refractory period?
A) The P wave
B) The ST segment
C) The QRS to the peak of the T wave ✔✔ [CORRECT]
D) The PR interval
Rationale: The absolute refractory period extends from the beginning of the QRS complex to
approximately the peak of the T wave. During this time, the ventricles cannot respond to
additional stimuli, preventing tetanic contraction.
12. 5 large EKG strip boxes totals how much time?
A) 0.5 seconds
B) 1 second ✔✔ [CORRECT]
C) 1.5 seconds
D) 2 seconds
Rationale: Each large box (5mm) = 0.20 seconds. Therefore, 5 large boxes = 5 × 0.20 = 1.0
second. This is the basis for the "6-second method" of calculating heart rate (30 large boxes = 6
seconds).
13. The PRI is considered abnormal or prolonged if it is:
A) >0.12 seconds
B) >0.16 seconds
C) >0.20 seconds ✔✔ [CORRECT]
D) >0.24 seconds
Rationale: Normal PR interval is 0.12-0.20 seconds (3-5 small boxes). A PR interval >0.20
seconds indicates first-degree AV block, representing delayed conduction through the AV node.
14. What is the most common cause for an alarm sounding on a cardiac monitor?
A) True arrhythmia
B) A loose lead wire ✔✔ [CORRECT]
C) Patient deterioration
D) Battery failure
Rationale: Loose lead wires are the most common cause of monitor alarms. This creates artifact
that the monitor may interpret as asystole or ventricular fibrillation. Always check equipment
before assuming patient pathology.
15. The QT interval represents:
Questions and Answers |
Complete Solutions | Echelon
Exam Prep | A+ Graded | Pass
Guaranteed
[DOMAIN 1: LEAD PLACEMENT & WAVEFORM COMPONENTS - 25 Questions]
1. Which lead is helpful in monitoring atrial rhythms and hemiblocks?
A) Lead II
B) Lead III
C) Lead I ✔✔ [CORRECT]
D) MCL1
Rationale: Lead I is the most useful for monitoring atrial rhythms and hemiblocks because it
provides a clear view of atrial activity and is perpendicular to the electrical axis, making it ideal
for detecting left or right hemiblocks.
2. Which lead is helpful in assessing bundle branch defects and confirming pacemaker wire
placement?
A) Lead II
B) Lead III
C) MCL1 ✔✔ [CORRECT]
D) aVF
Rationale: MCL1 (Modified Chest Lead 1) is the standard lead for assessing bundle branch
blocks and confirming pacemaker wire placement because it mimics V1 and provides excellent
visualization of ventricular conduction patterns.
3. Which lead is the most useful for routine monitoring and monitoring the sinus node?
A) Lead I
B) Lead II ✔✔ [CORRECT]
C) Lead III
D) aVL
Rationale: Lead II is the gold standard for routine EKG monitoring because the electrical axis of
the heart flows toward the positive electrode of Lead II, producing the tallest, most visible P
waves—essential for identifying sinus node activity.
, . Along with Lead II, which lead is most helpful in monitoring changes in the inferior wall of the
4
heart?
A) Lead I
B) aVL
C) Lead III ✔✔ [CORRECT]
D) V1
Rationale: Lead III, together with Lead II and aVF, forms the inferior leads (II, III, aVF). These
leads view the inferior wall of the heart and are crucial for detecting inferior wall myocardial
infarction.
5. What are the best areas to place electrodes?
A) Over bony prominences
B) Over major muscle groups
C) On soft tissue ✔✔ [CORRECT]
D) Over surgical incisions
Rationale: Electrodes should be placed on soft tissue (fleshy areas) to ensure good skin contact
and reduce motion artifact. Bony prominences and muscle groups can produce electrical
interference.
6. The EKG produces an upright pattern on the paper in response to electrical activity in the
heart flowing towards what?
A) Negative electrode
B) Ground electrode
C) Positive electrode ✔✔ [CORRECT]
D) Reference electrode
Rationale: By convention, EKG machines record positive deflections when electrical current
flows toward the positive electrode and negative deflections when current flows away from it.
7. What is the normal measurement of a QRS complex?
A) 0.06-0.12 seconds
B) 0.04-0.10 seconds ✔✔ [CORRECT]
C) 0.12-0.20 seconds
D) 0.20-0.40 seconds
Rationale: Normal QRS duration is 0.04-0.10 seconds (1-2.5 small boxes). This represents
normal ventricular depolarization through the His-Purkinje system. Values >0.12 seconds
indicate bundle branch block or ventricular origin.
8. What are EKG artifacts?
A) Normal variations in cardiac rhythm
B) False cardiac waveforms ✔✔ [CORRECT]
C) Pathological Q waves
D) ST-segment elevations
Rationale: Artifacts are false waveforms caused by patient movement, loose electrodes,
electrical interference, or muscle tremors. They can mimic arrhythmias and must be
distinguished from true cardiac electrical activity.
9. What is the first step in preparing a patient for an EKG?
A) Attaching the electrodes
B) Reassuring the patient and maintaining privacy ✔✔ [CORRECT]
, ) Shaving excessive hair
C
D) Cleaning the skin with alcohol
Rationale: Patient preparation begins with explanation, reassurance, and privacy. This reduces
anxiety (which can affect heart rate) and ensures cooperation. Technical preparation follows
psychological preparation.
10. Electrode location sites should be rotated or changed when?
A) Q12h
B) Q24h ✔✔ [CORRECT]
C) Q48h
D) Only when they fall off
Rationale: Electrodes should be rotated every 24 hours (Q24h) or when the patient is sweaty or
has had a bath. This prevents skin irritation and maintains optimal electrical contact.
11. What part of the EKG reflects the refractory period?
A) The P wave
B) The ST segment
C) The QRS to the peak of the T wave ✔✔ [CORRECT]
D) The PR interval
Rationale: The absolute refractory period extends from the beginning of the QRS complex to
approximately the peak of the T wave. During this time, the ventricles cannot respond to
additional stimuli, preventing tetanic contraction.
12. 5 large EKG strip boxes totals how much time?
A) 0.5 seconds
B) 1 second ✔✔ [CORRECT]
C) 1.5 seconds
D) 2 seconds
Rationale: Each large box (5mm) = 0.20 seconds. Therefore, 5 large boxes = 5 × 0.20 = 1.0
second. This is the basis for the "6-second method" of calculating heart rate (30 large boxes = 6
seconds).
13. The PRI is considered abnormal or prolonged if it is:
A) >0.12 seconds
B) >0.16 seconds
C) >0.20 seconds ✔✔ [CORRECT]
D) >0.24 seconds
Rationale: Normal PR interval is 0.12-0.20 seconds (3-5 small boxes). A PR interval >0.20
seconds indicates first-degree AV block, representing delayed conduction through the AV node.
14. What is the most common cause for an alarm sounding on a cardiac monitor?
A) True arrhythmia
B) A loose lead wire ✔✔ [CORRECT]
C) Patient deterioration
D) Battery failure
Rationale: Loose lead wires are the most common cause of monitor alarms. This creates artifact
that the monitor may interpret as asystole or ventricular fibrillation. Always check equipment
before assuming patient pathology.
15. The QT interval represents:
