ECG Workout
Exercises in Arrhythmia Interpretation
8th Edition
Author(s)Jane Huff
,TEST BANK
Table of Contents — ECG Workout: Exercises in Arrhythmia Interpretation, 8th Edition
1. Anatomy and Physiology of the Heart
2. Electrophysiology
3. Waveforms, Complexes, Intervals, and Segments
4. Cardiac Monitors
5. Analyzing a Rhythm Strip
6. Sinus Rhythms
7. Atrial Rhythms
8. Junctional Rhythms and AV Blocks
9. Ventricular Rhythms and Bundle-Branch Block
10. Pacemakers
11. Posttest
Question 1
An ECG rhythm strip shows a regular rhythm at 72 bpm. Each
QRS complex is preceded by a uniform upright P wave, and the
PR interval is consistent. Which cardiac structure is responsible
for initiating this rhythm?
A. Atrioventricular (AV) node
B. Sinoatrial (SA) node
C. Bundle of His
D. Purkinje fibers
Correct Answer: B
,Rationale:
The SA node is the natural pacemaker of the heart and initiates
impulses that produce normal sinus rhythm. The presence of
upright, uniform P waves preceding each QRS confirms sinus
origin.
• A: AV node delays conduction, not initiates rhythm
• C & D: Conduct impulses but do not initiate normal rhythm
Source: ECG Workout, 8th Edition – Chapter 1
Question 2
An ECG shows normal sinus rhythm. Which ECG component
represents atrial depolarization initiated by the SA node?
A. QRS complex
B. T wave
C. P wave
D. PR interval
Correct Answer: C
Rationale:
The P wave represents atrial depolarization triggered by the SA
node.
• A: Ventricular depolarization
• B: Ventricular repolarization
• D: Conduction time from atria to ventricles
, Source: ECG Workout, 8th Edition – Chapter 1
Question 3
A rhythm strip shows consistent P waves followed by QRS
complexes. The PR interval is 0.16 seconds. What does this
indicate about AV node function?
A. Conduction is delayed abnormally
B. Conduction is normal
C. Conduction is blocked
D. Conduction bypasses the AV node
Correct Answer: B
Rationale:
A normal PR interval (0.12–0.20 seconds) indicates proper
conduction through the AV node.
• A: Would show prolonged PR
• C: Would show dropped QRS
• D: Not consistent with normal ECG pattern
Source: ECG Workout, 8th Edition – Chapter 1
Question 4
An ECG tracing shows a normal sinus rhythm. Which structure
is responsible for delaying the impulse before ventricular
depolarization?
Exercises in Arrhythmia Interpretation
8th Edition
Author(s)Jane Huff
,TEST BANK
Table of Contents — ECG Workout: Exercises in Arrhythmia Interpretation, 8th Edition
1. Anatomy and Physiology of the Heart
2. Electrophysiology
3. Waveforms, Complexes, Intervals, and Segments
4. Cardiac Monitors
5. Analyzing a Rhythm Strip
6. Sinus Rhythms
7. Atrial Rhythms
8. Junctional Rhythms and AV Blocks
9. Ventricular Rhythms and Bundle-Branch Block
10. Pacemakers
11. Posttest
Question 1
An ECG rhythm strip shows a regular rhythm at 72 bpm. Each
QRS complex is preceded by a uniform upright P wave, and the
PR interval is consistent. Which cardiac structure is responsible
for initiating this rhythm?
A. Atrioventricular (AV) node
B. Sinoatrial (SA) node
C. Bundle of His
D. Purkinje fibers
Correct Answer: B
,Rationale:
The SA node is the natural pacemaker of the heart and initiates
impulses that produce normal sinus rhythm. The presence of
upright, uniform P waves preceding each QRS confirms sinus
origin.
• A: AV node delays conduction, not initiates rhythm
• C & D: Conduct impulses but do not initiate normal rhythm
Source: ECG Workout, 8th Edition – Chapter 1
Question 2
An ECG shows normal sinus rhythm. Which ECG component
represents atrial depolarization initiated by the SA node?
A. QRS complex
B. T wave
C. P wave
D. PR interval
Correct Answer: C
Rationale:
The P wave represents atrial depolarization triggered by the SA
node.
• A: Ventricular depolarization
• B: Ventricular repolarization
• D: Conduction time from atria to ventricles
, Source: ECG Workout, 8th Edition – Chapter 1
Question 3
A rhythm strip shows consistent P waves followed by QRS
complexes. The PR interval is 0.16 seconds. What does this
indicate about AV node function?
A. Conduction is delayed abnormally
B. Conduction is normal
C. Conduction is blocked
D. Conduction bypasses the AV node
Correct Answer: B
Rationale:
A normal PR interval (0.12–0.20 seconds) indicates proper
conduction through the AV node.
• A: Would show prolonged PR
• C: Would show dropped QRS
• D: Not consistent with normal ECG pattern
Source: ECG Workout, 8th Edition – Chapter 1
Question 4
An ECG tracing shows a normal sinus rhythm. Which structure
is responsible for delaying the impulse before ventricular
depolarization?
