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Diploma in ECG Interpretation Exam Questions
And Correct Answers (Verified Answers) Plus
Explanation 2026 Q&A | Instant Download
Pdf.
Q1. Which structure is known as the "pacemaker" of the heart?
A) Atrioventricular (AV) node
B) Sinoatrial (SA) node
C) Purkinje fibers
D) Bundle of His
Answer: B
Rationale: The SA node generates electrical impulses at a rate
of 60–100 bpm, setting the normal heart rhythm.
Q2. The normal intrinsic firing rate of the AV node is:
A) 60–100 bpm
B) 40–60 bpm
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C) 20–40 bpm
D) 100–150 bpm
Answer: B
Rationale: The AV junction has an intrinsic rate of 40–60 bpm,
acting as a secondary pacemaker if the SA node fails.
Q3. Which part of the conduction system has the fastest intrinsic
firing rate?
A) AV node
B) Purkinje fibers
C) SA node
D) Bundle branches
Answer: C
Rationale: The SA node has the highest intrinsic rate (60–100
bpm) and overrides lower pacemakers by suppressing their
automaticity.
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Q4. The P wave on the ECG represents:
A) Ventricular depolarization
B) Atrial depolarization
C) Ventricular repolarization
D) AV nodal delay
Answer: B
Rationale: The P wave reflects the spread of electrical activity
through the atria. It is typically upright in leads I and II.
Q5. The QRS complex represents:
A) Atrial depolarization
B) Ventricular depolarization
C) Atrial repolarization
D) Ventricular repolarization
Answer: B
Rationale: The QRS complex represents rapid ventricular
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depolarization. Ventricular repolarization is represented by the T
wave.
Q6. The T wave represents:
A) Atrial repolarization
B) Ventricular repolarization
C) Ventricular depolarization
D) AV nodal conduction
Answer: B
Rationale: The T wave corresponds to ventricular repolarization.
Atrial repolarization is usually not visible because it occurs during
the QRS.
Q7. The PR interval measures the time from:
A) Start of P wave to start of QRS
B) End of P wave to start of QRS
C) Start of QRS to end of T wave
D) R wave to R wave
Diploma in ECG Interpretation Exam Questions
And Correct Answers (Verified Answers) Plus
Explanation 2026 Q&A | Instant Download
Pdf.
Q1. Which structure is known as the "pacemaker" of the heart?
A) Atrioventricular (AV) node
B) Sinoatrial (SA) node
C) Purkinje fibers
D) Bundle of His
Answer: B
Rationale: The SA node generates electrical impulses at a rate
of 60–100 bpm, setting the normal heart rhythm.
Q2. The normal intrinsic firing rate of the AV node is:
A) 60–100 bpm
B) 40–60 bpm
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C) 20–40 bpm
D) 100–150 bpm
Answer: B
Rationale: The AV junction has an intrinsic rate of 40–60 bpm,
acting as a secondary pacemaker if the SA node fails.
Q3. Which part of the conduction system has the fastest intrinsic
firing rate?
A) AV node
B) Purkinje fibers
C) SA node
D) Bundle branches
Answer: C
Rationale: The SA node has the highest intrinsic rate (60–100
bpm) and overrides lower pacemakers by suppressing their
automaticity.
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Q4. The P wave on the ECG represents:
A) Ventricular depolarization
B) Atrial depolarization
C) Ventricular repolarization
D) AV nodal delay
Answer: B
Rationale: The P wave reflects the spread of electrical activity
through the atria. It is typically upright in leads I and II.
Q5. The QRS complex represents:
A) Atrial depolarization
B) Ventricular depolarization
C) Atrial repolarization
D) Ventricular repolarization
Answer: B
Rationale: The QRS complex represents rapid ventricular
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depolarization. Ventricular repolarization is represented by the T
wave.
Q6. The T wave represents:
A) Atrial repolarization
B) Ventricular repolarization
C) Ventricular depolarization
D) AV nodal conduction
Answer: B
Rationale: The T wave corresponds to ventricular repolarization.
Atrial repolarization is usually not visible because it occurs during
the QRS.
Q7. The PR interval measures the time from:
A) Start of P wave to start of QRS
B) End of P wave to start of QRS
C) Start of QRS to end of T wave
D) R wave to R wave
