EKG Technician Certification Practice Test | 100
Comprehensive Practice Questions with Verified
Answers & Detailed Rationales (2026 Edition)
1. What does the “P wave” on an ECG represent?
A. Ventricular depolarization
B. Atrial depolarization
C. Ventricular repolarization
D. Atrial repolarization
Correct Answer: B. Atrial depolarization
Rationale: The P wave reflects the electrical impulse traveling through the atria, causing
atrial contraction.
2. Which ECG paper speed is standard in most healthcare settings?
A. 10 mm/sec B. 15 mm/sec C. 25 mm/sec D. 50 mm/sec
Correct Answer: C. 25 mm/sec
Rationale: Standard ECG recordings are obtained at a paper speed of 25 mm/second.
3. Which lead is placed on the right arm?
A. RA B. LA C. RL D. LL
Correct Answer: A. RA
Rationale: RA stands for Right Arm and is one of the four limb electrodes.
4. Before applying electrodes, the technician should first:
A. Apply lotion B. Clean and dry the skin C. Shave after recording D. Place electrodes over
clothing
Correct Answer: B. Clean and dry the skin
Rationale: Proper skin preparation improves electrode adhesion and reduces artifact.
5. Which rhythm originates in the sinoatrial (SA) node?
A. Atrial flutter B. Sinus rhythm C. Ventricular tachycardia D. Atrial fibrillation
,Correct Answer: B. Sinus rhythm
Rationale: The SA node is the heart’s natural pacemaker and initiates normal sinus rhythm.
6. The normal adult heart rate ranges from:
A. 30–50 bpm B. 40–60 bpm C. 60–100 bpm D. 100–140 bpm
Correct Answer: C. 60–100 bpm
Rationale: A resting heart rate between 60 and 100 bpm is considered normal in adults.
7. Which ECG component represents ventricular depolarization?
A. P wave B. T wave C. QRS complex D. U wave
Correct Answer: C. QRS complex
Rationale: The QRS complex reflects electrical activation of the ventricles.
8. A patient has excessive movement during an ECG. This most likely causes:
A. Bradycardia B. Artifact C. Myocardial infarction D. Heart block
Correct Answer: B. Artifact
Rationale: Patient movement introduces electrical interference, creating artifacts.
9. The chest lead V1 is placed:
A. Fourth intercostal space, right sternal border B. Fourth intercostal space, left sternal
border C. Fifth intercostal space, midclavicular line D. Midaxillary line
Correct Answer: A. Fourth intercostal space, right sternal border
Rationale: Correct placement of V1 is essential for accurate ECG interpretation.
10. Which chamber pumps oxygenated blood to the body?
A. Right atrium B. Right ventricle C. Left atrium D. Left ventricle
Correct Answer: D. Left ventricle
Rationale: The left ventricle pumps oxygen-rich blood into the systemic circulation.
11. The PR interval represents:
A. Ventricular contraction only B. Time from atrial depolarization to ventricular
depolarization C. Ventricular repolarization D. Cardiac output
Correct Answer: B
, Rationale: The PR interval measures conduction from the atria through the AV node to the
ventricles.
12. A heart rate below 60 bpm is called:
A. Tachycardia B. Bradycardia C. Fibrillation D. Flutter
Correct Answer: B
Rationale: Bradycardia is defined as a heart rate less than 60 bpm.
13. Which electrolyte imbalance commonly produces peaked T waves?
A. Hypokalemia B. Hyperkalemia C. Hyponatremia D. Hypocalcemia
Correct Answer: B
Rationale: Elevated potassium levels characteristically produce tall, peaked T waves.
14. Which electrode serves as the electrical ground?
A. RA B. LA C. RL D. LL
Correct Answer: C
Rationale: The right leg electrode functions as the ground electrode.
15. The T wave represents:
A. Atrial contraction B. Ventricular depolarization C. Ventricular repolarization D. AV
conduction
Correct Answer: C
Rationale: The T wave reflects ventricular recovery (repolarization).
16. The ECG technician should verify patient identity using:
A. Room number only B. Patient’s first name only C. At least two patient identifiers D. Bed
assignment
Correct Answer: C
Rationale: Two identifiers reduce the risk of patient identification errors.
17. Which condition is characterized by an irregularly irregular rhythm?
A. Sinus rhythm B. Atrial fibrillation C. First-degree AV block D. Sinus bradycardia
Correct Answer: B
Comprehensive Practice Questions with Verified
Answers & Detailed Rationales (2026 Edition)
1. What does the “P wave” on an ECG represent?
A. Ventricular depolarization
B. Atrial depolarization
C. Ventricular repolarization
D. Atrial repolarization
Correct Answer: B. Atrial depolarization
Rationale: The P wave reflects the electrical impulse traveling through the atria, causing
atrial contraction.
2. Which ECG paper speed is standard in most healthcare settings?
A. 10 mm/sec B. 15 mm/sec C. 25 mm/sec D. 50 mm/sec
Correct Answer: C. 25 mm/sec
Rationale: Standard ECG recordings are obtained at a paper speed of 25 mm/second.
3. Which lead is placed on the right arm?
A. RA B. LA C. RL D. LL
Correct Answer: A. RA
Rationale: RA stands for Right Arm and is one of the four limb electrodes.
4. Before applying electrodes, the technician should first:
A. Apply lotion B. Clean and dry the skin C. Shave after recording D. Place electrodes over
clothing
Correct Answer: B. Clean and dry the skin
Rationale: Proper skin preparation improves electrode adhesion and reduces artifact.
5. Which rhythm originates in the sinoatrial (SA) node?
A. Atrial flutter B. Sinus rhythm C. Ventricular tachycardia D. Atrial fibrillation
,Correct Answer: B. Sinus rhythm
Rationale: The SA node is the heart’s natural pacemaker and initiates normal sinus rhythm.
6. The normal adult heart rate ranges from:
A. 30–50 bpm B. 40–60 bpm C. 60–100 bpm D. 100–140 bpm
Correct Answer: C. 60–100 bpm
Rationale: A resting heart rate between 60 and 100 bpm is considered normal in adults.
7. Which ECG component represents ventricular depolarization?
A. P wave B. T wave C. QRS complex D. U wave
Correct Answer: C. QRS complex
Rationale: The QRS complex reflects electrical activation of the ventricles.
8. A patient has excessive movement during an ECG. This most likely causes:
A. Bradycardia B. Artifact C. Myocardial infarction D. Heart block
Correct Answer: B. Artifact
Rationale: Patient movement introduces electrical interference, creating artifacts.
9. The chest lead V1 is placed:
A. Fourth intercostal space, right sternal border B. Fourth intercostal space, left sternal
border C. Fifth intercostal space, midclavicular line D. Midaxillary line
Correct Answer: A. Fourth intercostal space, right sternal border
Rationale: Correct placement of V1 is essential for accurate ECG interpretation.
10. Which chamber pumps oxygenated blood to the body?
A. Right atrium B. Right ventricle C. Left atrium D. Left ventricle
Correct Answer: D. Left ventricle
Rationale: The left ventricle pumps oxygen-rich blood into the systemic circulation.
11. The PR interval represents:
A. Ventricular contraction only B. Time from atrial depolarization to ventricular
depolarization C. Ventricular repolarization D. Cardiac output
Correct Answer: B
, Rationale: The PR interval measures conduction from the atria through the AV node to the
ventricles.
12. A heart rate below 60 bpm is called:
A. Tachycardia B. Bradycardia C. Fibrillation D. Flutter
Correct Answer: B
Rationale: Bradycardia is defined as a heart rate less than 60 bpm.
13. Which electrolyte imbalance commonly produces peaked T waves?
A. Hypokalemia B. Hyperkalemia C. Hyponatremia D. Hypocalcemia
Correct Answer: B
Rationale: Elevated potassium levels characteristically produce tall, peaked T waves.
14. Which electrode serves as the electrical ground?
A. RA B. LA C. RL D. LL
Correct Answer: C
Rationale: The right leg electrode functions as the ground electrode.
15. The T wave represents:
A. Atrial contraction B. Ventricular depolarization C. Ventricular repolarization D. AV
conduction
Correct Answer: C
Rationale: The T wave reflects ventricular recovery (repolarization).
16. The ECG technician should verify patient identity using:
A. Room number only B. Patient’s first name only C. At least two patient identifiers D. Bed
assignment
Correct Answer: C
Rationale: Two identifiers reduce the risk of patient identification errors.
17. Which condition is characterized by an irregularly irregular rhythm?
A. Sinus rhythm B. Atrial fibrillation C. First-degree AV block D. Sinus bradycardia
Correct Answer: B
