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. Posttes
Question 1
An ECG rhythm shows a regular rate of 72 bpm with upright P
waves preceding each QRS complex and a normal PR interval.
Which cardiac structure is primarily responsible for initiating
this rhythm?
A. Atrioventricular (AV) node
B. Bundle of His
C. Sinoatrial (SA) node
D. Purkinje fibers
,Correct Answer: C
Rationale:
The SA node is the primary pacemaker of the heart and initiates
normal sinus rhythm. The ECG characteristics—regular rhythm,
rate 60–100 bpm, upright P waves before each QRS—indicate
sinus origin.
• A is incorrect: AV node delays conduction but does not
initiate normal rhythm.
• B and D are part of ventricular conduction, not pacemaker
initiation.
Source: ECG Workout: Exercises in Arrhythmia Interpretation,
8th Edition – Chapter 1
Question 2
An ECG shows delayed conduction from the atria to the
ventricles, evidenced by a prolonged PR interval. Which
structure is responsible for this delay under normal conditions?
A. SA node
B. AV node
C. Bundle branches
D. Purkinje fibers
Correct Answer: B
Rationale:
The AV node slows conduction to allow ventricular filling,
, reflected as the PR interval. A prolonged PR interval indicates
delayed conduction through the AV node.
• A initiates impulses, not delays them.
• C and D conduct impulses rapidly, not slowly.
Source: ECG Workout: Exercises in Arrhythmia Interpretation,
8th Edition – Chapter 1
Question 3
An ECG tracing shows a normal P wave followed by a QRS
complex. Which physiological event does the P wave
represent?
A. Ventricular depolarization
B. Atrial depolarization
C. Ventricular repolarization
D. Atrial repolarization
Correct Answer: B
Rationale:
The P wave represents atrial depolarization, corresponding to
electrical activation of the atria.
• A corresponds to QRS complex
• C corresponds to T wave
• D is not visible on ECG
Source: ECG Workout: Exercises in Arrhythmia Interpretation,
8th Edition – Chapter 1
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. Posttes
Question 1
An ECG rhythm shows a regular rate of 72 bpm with upright P
waves preceding each QRS complex and a normal PR interval.
Which cardiac structure is primarily responsible for initiating
this rhythm?
A. Atrioventricular (AV) node
B. Bundle of His
C. Sinoatrial (SA) node
D. Purkinje fibers
,Correct Answer: C
Rationale:
The SA node is the primary pacemaker of the heart and initiates
normal sinus rhythm. The ECG characteristics—regular rhythm,
rate 60–100 bpm, upright P waves before each QRS—indicate
sinus origin.
• A is incorrect: AV node delays conduction but does not
initiate normal rhythm.
• B and D are part of ventricular conduction, not pacemaker
initiation.
Source: ECG Workout: Exercises in Arrhythmia Interpretation,
8th Edition – Chapter 1
Question 2
An ECG shows delayed conduction from the atria to the
ventricles, evidenced by a prolonged PR interval. Which
structure is responsible for this delay under normal conditions?
A. SA node
B. AV node
C. Bundle branches
D. Purkinje fibers
Correct Answer: B
Rationale:
The AV node slows conduction to allow ventricular filling,
, reflected as the PR interval. A prolonged PR interval indicates
delayed conduction through the AV node.
• A initiates impulses, not delays them.
• C and D conduct impulses rapidly, not slowly.
Source: ECG Workout: Exercises in Arrhythmia Interpretation,
8th Edition – Chapter 1
Question 3
An ECG tracing shows a normal P wave followed by a QRS
complex. Which physiological event does the P wave
represent?
A. Ventricular depolarization
B. Atrial depolarization
C. Ventricular repolarization
D. Atrial repolarization
Correct Answer: B
Rationale:
The P wave represents atrial depolarization, corresponding to
electrical activation of the atria.
• A corresponds to QRS complex
• C corresponds to T wave
• D is not visible on ECG
Source: ECG Workout: Exercises in Arrhythmia Interpretation,
8th Edition – Chapter 1
