HOAG ECG Exam UPDATED ACTUAL
Exam Questions and CORRECT Answers
Comprehensive ECG Practice Exam
Part 1 (Questions 1–20)
Question 1
A patient's ECG shows:
• Rate: 72 bpm
• Regular rhythm
• Upright P wave before every QRS
• PR interval: 0.16 sec
• QRS: 0.08 sec
What rhythm is present?
A. Junctional rhythm
B. Sinus bradycardia
C. Normal sinus rhythm
D. Atrial flutter
Answer: C. Normal sinus rhythm
,Rationale:
Normal sinus rhythm (NSR) requires:
• Rate 60–100 bpm
• Regular rhythm
• One upright P wave before each QRS
• PR interval 0.12–0.20 sec
• QRS <0.12 sec
All criteria are met.
Why the others are incorrect
• A: Junctional rhythms often have absent or inverted P
waves.
• B: Bradycardia is <60 bpm.
• D: Atrial flutter has sawtooth flutter waves.
Clinical Pearl: Evaluate ECGs systematically: rate, rhythm, P
waves, PR interval, QRS duration.
Question 2
Which structure is the heart's normal pacemaker?
A. AV node
B. Bundle branches
C. SA node
D. Purkinje fibers
,Answer: C. SA node
Rationale:
The sinoatrial (SA) node normally initiates impulses at 60–100
bpm, making it the primary pacemaker.
Incorrect Answers
• A: AV node is a backup pacemaker (40–60 bpm).
• B: Bundle branches conduct impulses.
• D: Purkinje fibers pace at 20–40 bpm if higher pacemakers
fail.
Clinical Pearl: The fastest intrinsic pacemaker usually controls
the rhythm.
Question 3
A PR interval measures 0.24 seconds.
This finding indicates:
A. Normal conduction
B. First-degree AV block
C. Second-degree AV block Type II
D. Ventricular tachycardia
Answer: B. First-degree AV block
Rationale:
A PR interval greater than 0.20 seconds with every P wave
conducted defines first-degree AV block.
, Incorrect Answers
• A: Normal PR is 0.12–0.20 sec.
• C: Type II has dropped QRS complexes.
• D: VT is a wide-complex tachycardia.
Clinical Pearl: First-degree AV block often requires monitoring
rather than treatment if asymptomatic.
Question 4
Which ECG component represents ventricular depolarization?
A. P wave
B. QRS complex
C. T wave
D. PR interval
Answer: B. QRS complex
Rationale:
The QRS complex represents electrical activation of the ventricles.
Incorrect Answers
• A: P wave = atrial depolarization.
• C: T wave = ventricular repolarization.
• D: PR interval = AV conduction time.
Question 5
Exam Questions and CORRECT Answers
Comprehensive ECG Practice Exam
Part 1 (Questions 1–20)
Question 1
A patient's ECG shows:
• Rate: 72 bpm
• Regular rhythm
• Upright P wave before every QRS
• PR interval: 0.16 sec
• QRS: 0.08 sec
What rhythm is present?
A. Junctional rhythm
B. Sinus bradycardia
C. Normal sinus rhythm
D. Atrial flutter
Answer: C. Normal sinus rhythm
,Rationale:
Normal sinus rhythm (NSR) requires:
• Rate 60–100 bpm
• Regular rhythm
• One upright P wave before each QRS
• PR interval 0.12–0.20 sec
• QRS <0.12 sec
All criteria are met.
Why the others are incorrect
• A: Junctional rhythms often have absent or inverted P
waves.
• B: Bradycardia is <60 bpm.
• D: Atrial flutter has sawtooth flutter waves.
Clinical Pearl: Evaluate ECGs systematically: rate, rhythm, P
waves, PR interval, QRS duration.
Question 2
Which structure is the heart's normal pacemaker?
A. AV node
B. Bundle branches
C. SA node
D. Purkinje fibers
,Answer: C. SA node
Rationale:
The sinoatrial (SA) node normally initiates impulses at 60–100
bpm, making it the primary pacemaker.
Incorrect Answers
• A: AV node is a backup pacemaker (40–60 bpm).
• B: Bundle branches conduct impulses.
• D: Purkinje fibers pace at 20–40 bpm if higher pacemakers
fail.
Clinical Pearl: The fastest intrinsic pacemaker usually controls
the rhythm.
Question 3
A PR interval measures 0.24 seconds.
This finding indicates:
A. Normal conduction
B. First-degree AV block
C. Second-degree AV block Type II
D. Ventricular tachycardia
Answer: B. First-degree AV block
Rationale:
A PR interval greater than 0.20 seconds with every P wave
conducted defines first-degree AV block.
, Incorrect Answers
• A: Normal PR is 0.12–0.20 sec.
• C: Type II has dropped QRS complexes.
• D: VT is a wide-complex tachycardia.
Clinical Pearl: First-degree AV block often requires monitoring
rather than treatment if asymptomatic.
Question 4
Which ECG component represents ventricular depolarization?
A. P wave
B. QRS complex
C. T wave
D. PR interval
Answer: B. QRS complex
Rationale:
The QRS complex represents electrical activation of the ventricles.
Incorrect Answers
• A: P wave = atrial depolarization.
• C: T wave = ventricular repolarization.
• D: PR interval = AV conduction time.
Question 5
