EKG Technician Certification Exam Prep
(2026 Updated) | Real Practice Questions,
Answers & Detailed Rationales, ECG
Interpretation Study Guide & Passing
Review
• This prep guide contains 200 exam-style questions covering all core EKG
Technician Certification topics — use it by attempting each question first before
checking the correct answer and EXPERT RATIONALE.
• Each question includes 5 options (A–E), a highlighted correct answer, and a
detailed EXPERT RATIONALE to reinforce your understanding and build exam
confidence.
EKG TECHNICIAN CERTIFICATION EXAM PREP (2026)
200 Real Practice Questions | Answers & Detailed EXPERT RATIONALE
QUESTION 1: What does the P wave on an ECG represent?
A) Ventricular depolarization
B) Ventricular repolarization
C) Atrial repolarization
D) Bundle of His conduction
E) Atrial depolarization
EXPERT RATIONALE: The P wave represents the electrical activity associated with atrial
depolarization — the wave of electricity that spreads through both atria, causing them
to contract and push blood into the ventricles.
QUESTION 2: What does the QRS complex represent?
A) Atrial depolarization
B) Atrial repolarization
,C) SA node firing
D) Ventricular depolarization
E) Ventricular repolarization
EXPERT RATIONALE: The QRS complex represents ventricular depolarization — the
electrical activation that spreads through the ventricles causing them to contract and
eject blood. It normally lasts 0.06–0.10 seconds.
QUESTION 3: What does the T wave represent?
A) Atrial depolarization
B) Ventricular depolarization
C) SA node automaticity
D) AV node conduction delay
E) Ventricular repolarization
EXPERT RATIONALE: The T wave represents ventricular repolarization — the recovery
phase of the ventricles as they prepare for the next contraction. It follows the QRS
complex and is normally upright in most leads.
QUESTION 4: What is the normal duration of the PR interval?
A) 0.04–0.06 seconds
B) 0.06–0.08 seconds
C) 0.12–0.20 seconds
D) 0.20–0.28 seconds
E) 0.28–0.36 seconds
EXPERT RATIONALE: The normal PR interval is 0.12–0.20 seconds (3–5 small squares on
ECG paper). It represents the time from atrial depolarization to the onset of ventricular
depolarization, including normal conduction delay through the AV node.
,QUESTION 5: What is the normal duration of the QRS complex?
A) 0.04–0.06 seconds
B) 0.06–0.10 seconds
C) 0.12–0.20 seconds
D) 0.20–0.24 seconds
E) 0.24–0.30 seconds
EXPERT RATIONALE: The normal QRS duration is 0.06–0.10 seconds (less than 3 small
squares). A QRS wider than 0.12 seconds suggests a bundle branch block or ventricular
conduction abnormality.
QUESTION 6: How fast does standard ECG paper move?
A) 10 mm/sec
B) 15 mm/sec
C) 20 mm/sec
D) 25 mm/sec
E) 50 mm/sec
EXPERT RATIONALE: Standard ECG paper runs at 25 mm/sec. This is the universal
standard speed used in interpreting ECGs. Each small square (1 mm) equals 0.04
seconds and each large square (5 mm) equals 0.20 seconds.
QUESTION 7: What does each large box on ECG paper represent in time?
A) 0.04 seconds
B) 0.08 seconds
C) 0.10 seconds
, D) 0.20 seconds
E) 0.40 seconds
EXPERT RATIONALE: Each large box on standard ECG paper is 5 mm wide and at 25
mm/sec represents 0.20 seconds. Each large box contains 5 small boxes, each
representing 0.04 seconds.
QUESTION 8: What is the primary pacemaker of the heart?
A) AV node
B) Bundle of His
C) Purkinje fibers
D) Left bundle branch
E) Sinoatrial (SA) node
EXPERT RATIONALE: The SA node is the primary pacemaker of the heart, located in the
right atrium near the superior vena cava. It normally fires at a rate of 60–100 beats per
minute and initiates each cardiac cycle.
QUESTION 9: What is the normal intrinsic rate of the AV node?
A) 20–40 bpm
B) 40–60 bpm
C) 60–100 bpm
D) 100–120 bpm
E) 120–150 bpm
EXPERT RATIONALE: The AV node has an intrinsic firing rate of 40–60 bpm. It serves as a
secondary pacemaker if the SA node fails. If the AV node takes over, the resulting rhythm
is called a junctional rhythm.
(2026 Updated) | Real Practice Questions,
Answers & Detailed Rationales, ECG
Interpretation Study Guide & Passing
Review
• This prep guide contains 200 exam-style questions covering all core EKG
Technician Certification topics — use it by attempting each question first before
checking the correct answer and EXPERT RATIONALE.
• Each question includes 5 options (A–E), a highlighted correct answer, and a
detailed EXPERT RATIONALE to reinforce your understanding and build exam
confidence.
EKG TECHNICIAN CERTIFICATION EXAM PREP (2026)
200 Real Practice Questions | Answers & Detailed EXPERT RATIONALE
QUESTION 1: What does the P wave on an ECG represent?
A) Ventricular depolarization
B) Ventricular repolarization
C) Atrial repolarization
D) Bundle of His conduction
E) Atrial depolarization
EXPERT RATIONALE: The P wave represents the electrical activity associated with atrial
depolarization — the wave of electricity that spreads through both atria, causing them
to contract and push blood into the ventricles.
QUESTION 2: What does the QRS complex represent?
A) Atrial depolarization
B) Atrial repolarization
,C) SA node firing
D) Ventricular depolarization
E) Ventricular repolarization
EXPERT RATIONALE: The QRS complex represents ventricular depolarization — the
electrical activation that spreads through the ventricles causing them to contract and
eject blood. It normally lasts 0.06–0.10 seconds.
QUESTION 3: What does the T wave represent?
A) Atrial depolarization
B) Ventricular depolarization
C) SA node automaticity
D) AV node conduction delay
E) Ventricular repolarization
EXPERT RATIONALE: The T wave represents ventricular repolarization — the recovery
phase of the ventricles as they prepare for the next contraction. It follows the QRS
complex and is normally upright in most leads.
QUESTION 4: What is the normal duration of the PR interval?
A) 0.04–0.06 seconds
B) 0.06–0.08 seconds
C) 0.12–0.20 seconds
D) 0.20–0.28 seconds
E) 0.28–0.36 seconds
EXPERT RATIONALE: The normal PR interval is 0.12–0.20 seconds (3–5 small squares on
ECG paper). It represents the time from atrial depolarization to the onset of ventricular
depolarization, including normal conduction delay through the AV node.
,QUESTION 5: What is the normal duration of the QRS complex?
A) 0.04–0.06 seconds
B) 0.06–0.10 seconds
C) 0.12–0.20 seconds
D) 0.20–0.24 seconds
E) 0.24–0.30 seconds
EXPERT RATIONALE: The normal QRS duration is 0.06–0.10 seconds (less than 3 small
squares). A QRS wider than 0.12 seconds suggests a bundle branch block or ventricular
conduction abnormality.
QUESTION 6: How fast does standard ECG paper move?
A) 10 mm/sec
B) 15 mm/sec
C) 20 mm/sec
D) 25 mm/sec
E) 50 mm/sec
EXPERT RATIONALE: Standard ECG paper runs at 25 mm/sec. This is the universal
standard speed used in interpreting ECGs. Each small square (1 mm) equals 0.04
seconds and each large square (5 mm) equals 0.20 seconds.
QUESTION 7: What does each large box on ECG paper represent in time?
A) 0.04 seconds
B) 0.08 seconds
C) 0.10 seconds
, D) 0.20 seconds
E) 0.40 seconds
EXPERT RATIONALE: Each large box on standard ECG paper is 5 mm wide and at 25
mm/sec represents 0.20 seconds. Each large box contains 5 small boxes, each
representing 0.04 seconds.
QUESTION 8: What is the primary pacemaker of the heart?
A) AV node
B) Bundle of His
C) Purkinje fibers
D) Left bundle branch
E) Sinoatrial (SA) node
EXPERT RATIONALE: The SA node is the primary pacemaker of the heart, located in the
right atrium near the superior vena cava. It normally fires at a rate of 60–100 beats per
minute and initiates each cardiac cycle.
QUESTION 9: What is the normal intrinsic rate of the AV node?
A) 20–40 bpm
B) 40–60 bpm
C) 60–100 bpm
D) 100–120 bpm
E) 120–150 bpm
EXPERT RATIONALE: The AV node has an intrinsic firing rate of 40–60 bpm. It serves as a
secondary pacemaker if the SA node fails. If the AV node takes over, the resulting rhythm
is called a junctional rhythm.
