RELIAS DYSRHYTHMIA BASIC TEST – EXAM QUESTIONS AND
CORRECT ANSWERS (VERIFIED ANSWERS) PLUS RATIONALE | 2027
Q&A | INSTANT DOWNLOAD PDF
1. A patient’s ECG shows a regular rhythm at 78 beats/minute. Each QRS complex
is preceded by an upright P wave, and the PR interval remains constant. Which
interpretation is most appropriate?
A. Atrial flutter
B. Normal sinus rhythm
C. Junctional rhythm
D. Ventricular tachycardia
Rationale: Normal sinus rhythm originates from the sinoatrial node and is characterized by a
regular rate generally between 60 and 100 beats/minute, a consistent P wave before every QRS
complex, and a stable PR interval.
2. When assessing an ECG strip, which interval represents the time from the
beginning of atrial depolarization to the beginning of ventricular depolarization?
A. QT interval
B. ST segment
C. QRS interval
D. PR interval
Rationale: The PR interval extends from the beginning of the P wave to the beginning of the QRS
complex and reflects conduction through the atria, AV node, and His-Purkinje system.
3. At the standard ECG paper speed of 25 mm/second, one small box represents
approximately:
A. 0.04 second
B. 0.08 second
C. 0.12 second
D. 0.20 second
Rationale: Each small horizontal ECG box represents 0.04 second at the standard paper speed.
Five small boxes make one large box, equal to 0.20 second.
4. A rhythm strip contains four large boxes between consecutive R waves. Using
the 300 method, approximately what is the ventricular rate?
A. 60 beats/minute
B. 75 beats/minute
C. 75 beats/minute
D. 100 beats/minute
,Rationale: For a regular rhythm, divide 300 by the number of large boxes between R waves.
Four large boxes give 300 ÷ 4 = 75 beats/minute.
5. Which ECG component represents ventricular depolarization?
A. P wave
B. QRS complex
C. T wave
D. U wave
Rationale: The QRS complex represents ventricular depolarization. The P wave represents atrial
depolarization, while the T wave represents ventricular repolarization.
6. A patient has a heart rate of 48 beats/minute. The rhythm is regular, P waves are
present before every QRS, and the PR interval is constant. Which rhythm is
present?
A. Junctional bradycardia
B. Atrial fibrillation
C. Sinus arrest
D. Sinus bradycardia
Rationale: Sinus bradycardia maintains normal sinus conduction but has a rate below 60
beats/minute. The presence of consistent P waves before QRS complexes supports a sinus origin.
7. A patient becomes anxious and develops a regular rhythm at 126 beats/minute.
P waves remain upright and precede each QRS complex. Which rhythm is most
likely?
A. Sinus tachycardia
B. Atrial fibrillation
C. Ventricular tachycardia
D. Junctional rhythm
Rationale: Sinus tachycardia is a sinus rhythm with a rate above 100 beats/minute. The
preserved P-QRS relationship indicates that the sinus node remains the pacemaker.
8. Which assessment is most important when a monitor first displays a new
dysrhythmia?
A. Determine whether the patient has eaten recently
B. Obtain the patient's weight
C. Assess the patient’s clinical condition and pulse
D. Silence the monitor alarm and continue observation
, Rationale: The monitor provides electrical information, but treatment decisions depend on the
patient’s condition. Responsiveness, pulse, blood pressure, symptoms, and perfusion should be
assessed promptly.
9. A premature atrial contraction occurs when:
A. The ventricles fail to depolarize
B. The AV node becomes the permanent pacemaker
C. The SA node stops producing impulses
D. An atrial focus depolarizes prematurely
Rationale: A premature atrial contraction originates from an ectopic atrial focus that fires
earlier than expected, producing an early atrial depolarization.
10. Which finding most strongly supports the presence of a premature ventricular
contraction?
A. Early narrow QRS preceded by a normal P wave
B. Premature wide and bizarre QRS complex without a preceding normal P wave
C. Regular sawtooth atrial activity
D. Constant PR intervals with dropped beats
Rationale: PVCs originate in ventricular tissue and therefore commonly produce premature,
wide, abnormal QRS complexes that are not preceded by a normal conducted P wave.
11. A patient’s rhythm is irregularly irregular, and no consistent P waves can be
identified. Which dysrhythmia is most consistent with these findings?
A. Sinus arrhythmia
B. Atrial flutter
C. Atrial fibrillation
D. First-degree AV block
Rationale: Atrial fibrillation is characterized by chaotic atrial activity, absence of organized P
waves, and an irregularly irregular ventricular response.
12. An ECG demonstrates repetitive atrial activity with a characteristic sawtooth
appearance. The finding is most consistent with:
A. Atrial flutter
B. Atrial fibrillation
C. Junctional rhythm
D. Ventricular fibrillation
Rationale: Atrial flutter produces organized but rapid atrial depolarizations that commonly
appear as repetitive sawtooth flutter waves.
CORRECT ANSWERS (VERIFIED ANSWERS) PLUS RATIONALE | 2027
Q&A | INSTANT DOWNLOAD PDF
1. A patient’s ECG shows a regular rhythm at 78 beats/minute. Each QRS complex
is preceded by an upright P wave, and the PR interval remains constant. Which
interpretation is most appropriate?
A. Atrial flutter
B. Normal sinus rhythm
C. Junctional rhythm
D. Ventricular tachycardia
Rationale: Normal sinus rhythm originates from the sinoatrial node and is characterized by a
regular rate generally between 60 and 100 beats/minute, a consistent P wave before every QRS
complex, and a stable PR interval.
2. When assessing an ECG strip, which interval represents the time from the
beginning of atrial depolarization to the beginning of ventricular depolarization?
A. QT interval
B. ST segment
C. QRS interval
D. PR interval
Rationale: The PR interval extends from the beginning of the P wave to the beginning of the QRS
complex and reflects conduction through the atria, AV node, and His-Purkinje system.
3. At the standard ECG paper speed of 25 mm/second, one small box represents
approximately:
A. 0.04 second
B. 0.08 second
C. 0.12 second
D. 0.20 second
Rationale: Each small horizontal ECG box represents 0.04 second at the standard paper speed.
Five small boxes make one large box, equal to 0.20 second.
4. A rhythm strip contains four large boxes between consecutive R waves. Using
the 300 method, approximately what is the ventricular rate?
A. 60 beats/minute
B. 75 beats/minute
C. 75 beats/minute
D. 100 beats/minute
,Rationale: For a regular rhythm, divide 300 by the number of large boxes between R waves.
Four large boxes give 300 ÷ 4 = 75 beats/minute.
5. Which ECG component represents ventricular depolarization?
A. P wave
B. QRS complex
C. T wave
D. U wave
Rationale: The QRS complex represents ventricular depolarization. The P wave represents atrial
depolarization, while the T wave represents ventricular repolarization.
6. A patient has a heart rate of 48 beats/minute. The rhythm is regular, P waves are
present before every QRS, and the PR interval is constant. Which rhythm is
present?
A. Junctional bradycardia
B. Atrial fibrillation
C. Sinus arrest
D. Sinus bradycardia
Rationale: Sinus bradycardia maintains normal sinus conduction but has a rate below 60
beats/minute. The presence of consistent P waves before QRS complexes supports a sinus origin.
7. A patient becomes anxious and develops a regular rhythm at 126 beats/minute.
P waves remain upright and precede each QRS complex. Which rhythm is most
likely?
A. Sinus tachycardia
B. Atrial fibrillation
C. Ventricular tachycardia
D. Junctional rhythm
Rationale: Sinus tachycardia is a sinus rhythm with a rate above 100 beats/minute. The
preserved P-QRS relationship indicates that the sinus node remains the pacemaker.
8. Which assessment is most important when a monitor first displays a new
dysrhythmia?
A. Determine whether the patient has eaten recently
B. Obtain the patient's weight
C. Assess the patient’s clinical condition and pulse
D. Silence the monitor alarm and continue observation
, Rationale: The monitor provides electrical information, but treatment decisions depend on the
patient’s condition. Responsiveness, pulse, blood pressure, symptoms, and perfusion should be
assessed promptly.
9. A premature atrial contraction occurs when:
A. The ventricles fail to depolarize
B. The AV node becomes the permanent pacemaker
C. The SA node stops producing impulses
D. An atrial focus depolarizes prematurely
Rationale: A premature atrial contraction originates from an ectopic atrial focus that fires
earlier than expected, producing an early atrial depolarization.
10. Which finding most strongly supports the presence of a premature ventricular
contraction?
A. Early narrow QRS preceded by a normal P wave
B. Premature wide and bizarre QRS complex without a preceding normal P wave
C. Regular sawtooth atrial activity
D. Constant PR intervals with dropped beats
Rationale: PVCs originate in ventricular tissue and therefore commonly produce premature,
wide, abnormal QRS complexes that are not preceded by a normal conducted P wave.
11. A patient’s rhythm is irregularly irregular, and no consistent P waves can be
identified. Which dysrhythmia is most consistent with these findings?
A. Sinus arrhythmia
B. Atrial flutter
C. Atrial fibrillation
D. First-degree AV block
Rationale: Atrial fibrillation is characterized by chaotic atrial activity, absence of organized P
waves, and an irregularly irregular ventricular response.
12. An ECG demonstrates repetitive atrial activity with a characteristic sawtooth
appearance. The finding is most consistent with:
A. Atrial flutter
B. Atrial fibrillation
C. Junctional rhythm
D. Ventricular fibrillation
Rationale: Atrial flutter produces organized but rapid atrial depolarizations that commonly
appear as repetitive sawtooth flutter waves.
