Dysrhythmia Exam Questions & Verified Answers
Comprehensive Question Study Guide for Cardiac Rhythm
Disorders
Normal Sinus Rhythm & Basic Concepts (Questions 1-10)
Question 1
Normal sinus rhythm has which characteristics? A) Rate 60-100 bpm,
regular rhythm, P wave before each QRS B) Rate 50-80 bpm, irregular
rhythm, no P waves C) Rate 100-150 bpm, regular rhythm, wide QRS D)
Rate 40-60 bpm, regular rhythm, inverted P waves
Answer: A) Rate 60-100 bpm, regular rhythm, P wave before each QRS
Rationale: NSR characteristics include rate 60-100 bpm, regular rhythm,
upright P waves in lead II before each QRS, and PR interval 0.12-0.20
seconds.
Question 2
The PR interval represents: A) Ventricular depolarization B) Atrial
depolarization and AV node delay C) Ventricular repolarization D) Atrial
repolarization
Answer: B) Atrial depolarization and AV node delay Rationale: PR
interval measures time from start of atrial depolarization through AV
nodal conduction delay.
Question 3
Normal PR interval duration is: A) 0.04-0.08 seconds B) 0.08-0.12
seconds C) 0.12-0.20 seconds D) 0.20-0.24 seconds
,Answer: C) 0.12-0.20 seconds Rationale: Normal PR interval is 0.12-
0.20 seconds (3-5 small boxes on ECG).
Question 4
The QRS complex represents: A) Atrial depolarization B) AV node
conduction C) Ventricular depolarization D) Ventricular repolarization
Answer: C) Ventricular depolarization Rationale: QRS complex
represents electrical depolarization of the ventricles.
Question 5
Normal QRS duration is: A) Less than 0.08 seconds B) 0.08-0.12 seconds
C) 0.12-0.16 seconds D) Greater than 0.20 seconds
Answer: B) 0.08-0.12 seconds Rationale: Normal QRS duration is 0.08-
0.12 seconds (2-3 small boxes).
Question 6
The T wave represents: A) Atrial depolarization B) Ventricular
depolarization C) Ventricular repolarization D) AV node conduction
Answer: C) Ventricular repolarization Rationale: T wave represents
ventricular repolarization (recovery phase).
Question 7
Each small box on ECG paper represents: A) 0.02 seconds B) 0.04
seconds C) 0.06 seconds D) 0.08 seconds
Answer: B) 0.04 seconds Rationale: Each small box (1mm) represents
0.04 seconds horizontally and 0.1 mV vertically.
Question 8
, To calculate heart rate using the 300 method: A) Count R-R intervals in
6 seconds and multiply by 10 B) Divide 300 by the number of large
boxes between R waves C) Count QRS complexes in 10 seconds and
multiply by 6 D) Measure PR interval and multiply by heart rate
Answer: B) Divide 300 by the number of large boxes between R waves
Rationale: The 300 method divides 300 by large boxes between
consecutive R waves for regular rhythms.
Question 9
Lead II is preferred for rhythm monitoring because: A) It shows the
largest P waves B) It best visualizes ventricular activity C) P waves are
most prominent and upright D) QRS complexes are widest
Answer: C) P waves are most prominent and upright Rationale: Lead II
provides the best visualization of P wave morphology for rhythm
analysis.
Question 10
The normal electrical conduction pathway is: A) SA node → AV node →
Bundle of His → Purkinje fibers B) AV node → SA node → Bundle
branches → Purkinje fibers C) SA node → Bundle of His → AV node →
Bundle branches D) Purkinje fibers → Bundle branches → AV node →
SA node
Answer: A) SA node → AV node → Bundle of His → Purkinje fibers
Rationale: Normal conduction: SA node → atria → AV node → Bundle of
His → bundle branches → Purkinje fibers → ventricles.
Sinus Dysrhythmias (Questions 11-20)
Comprehensive Question Study Guide for Cardiac Rhythm
Disorders
Normal Sinus Rhythm & Basic Concepts (Questions 1-10)
Question 1
Normal sinus rhythm has which characteristics? A) Rate 60-100 bpm,
regular rhythm, P wave before each QRS B) Rate 50-80 bpm, irregular
rhythm, no P waves C) Rate 100-150 bpm, regular rhythm, wide QRS D)
Rate 40-60 bpm, regular rhythm, inverted P waves
Answer: A) Rate 60-100 bpm, regular rhythm, P wave before each QRS
Rationale: NSR characteristics include rate 60-100 bpm, regular rhythm,
upright P waves in lead II before each QRS, and PR interval 0.12-0.20
seconds.
Question 2
The PR interval represents: A) Ventricular depolarization B) Atrial
depolarization and AV node delay C) Ventricular repolarization D) Atrial
repolarization
Answer: B) Atrial depolarization and AV node delay Rationale: PR
interval measures time from start of atrial depolarization through AV
nodal conduction delay.
Question 3
Normal PR interval duration is: A) 0.04-0.08 seconds B) 0.08-0.12
seconds C) 0.12-0.20 seconds D) 0.20-0.24 seconds
,Answer: C) 0.12-0.20 seconds Rationale: Normal PR interval is 0.12-
0.20 seconds (3-5 small boxes on ECG).
Question 4
The QRS complex represents: A) Atrial depolarization B) AV node
conduction C) Ventricular depolarization D) Ventricular repolarization
Answer: C) Ventricular depolarization Rationale: QRS complex
represents electrical depolarization of the ventricles.
Question 5
Normal QRS duration is: A) Less than 0.08 seconds B) 0.08-0.12 seconds
C) 0.12-0.16 seconds D) Greater than 0.20 seconds
Answer: B) 0.08-0.12 seconds Rationale: Normal QRS duration is 0.08-
0.12 seconds (2-3 small boxes).
Question 6
The T wave represents: A) Atrial depolarization B) Ventricular
depolarization C) Ventricular repolarization D) AV node conduction
Answer: C) Ventricular repolarization Rationale: T wave represents
ventricular repolarization (recovery phase).
Question 7
Each small box on ECG paper represents: A) 0.02 seconds B) 0.04
seconds C) 0.06 seconds D) 0.08 seconds
Answer: B) 0.04 seconds Rationale: Each small box (1mm) represents
0.04 seconds horizontally and 0.1 mV vertically.
Question 8
, To calculate heart rate using the 300 method: A) Count R-R intervals in
6 seconds and multiply by 10 B) Divide 300 by the number of large
boxes between R waves C) Count QRS complexes in 10 seconds and
multiply by 6 D) Measure PR interval and multiply by heart rate
Answer: B) Divide 300 by the number of large boxes between R waves
Rationale: The 300 method divides 300 by large boxes between
consecutive R waves for regular rhythms.
Question 9
Lead II is preferred for rhythm monitoring because: A) It shows the
largest P waves B) It best visualizes ventricular activity C) P waves are
most prominent and upright D) QRS complexes are widest
Answer: C) P waves are most prominent and upright Rationale: Lead II
provides the best visualization of P wave morphology for rhythm
analysis.
Question 10
The normal electrical conduction pathway is: A) SA node → AV node →
Bundle of His → Purkinje fibers B) AV node → SA node → Bundle
branches → Purkinje fibers C) SA node → Bundle of His → AV node →
Bundle branches D) Purkinje fibers → Bundle branches → AV node →
SA node
Answer: A) SA node → AV node → Bundle of His → Purkinje fibers
Rationale: Normal conduction: SA node → atria → AV node → Bundle of
His → bundle branches → Purkinje fibers → ventricles.
Sinus Dysrhythmias (Questions 11-20)
