CRAT EXAM(CERTIFIED RHYTHM ANALYSIS TECHNICIAN
PREP)2025 COMPLETE QUESTIONS AND ANSWERS ALREADY
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Question 1
Which of the following represents atrial depolarization on an electrocardiogram (ECG)?
A) T wave.
B) U wave.
C) P wave.
D) QRS complex.
E) ST segment.
Correct Answer: C) P wave.
Rationale: The P wave represents the electrical activity associated with the
depolarization of the atria, which precedes atrial contraction.
Question 2
What does the QRS complex on an ECG primarily represent?
A) Atrial repolarization.
B) Ventricular repolarization.
C) Ventricular depolarization.
D) Atrial depolarization.
E) SA node firing.
Correct Answer: C) Ventricular depolarization.
Rationale: The QRS complex signifies the rapid depolarization of the ventricles,
leading to ventricular contraction.
Question 3
A client's ECG shows a regular rhythm, a heart rate of 70 bpm, a P wave before every QRS,
and a PR interval of 0.16 seconds. This rhythm is identified as:
A) Sinus tachycardia.
B) Sinus bradycardia.
C) Normal sinus rhythm.
D) Atrial fibrillation.
E) Junctional rhythm.
Correct Answer: C) Normal sinus rhythm.
,Rationale: Normal sinus rhythm is characterized by a regular rhythm, a heart rate
between 60-100 bpm, P waves preceding every QRS, and a normal PR interval
(0.12-0.20 seconds) and QRS duration.
Question 4
What does the T wave on an ECG primarily represent?
A) Atrial depolarization.
B) Ventricular repolarization.
C) Atrial repolarization.
D) Ventricular depolarization.
E) SA node firing.
Correct Answer: B) Ventricular repolarization.
Rationale: The T wave represents the electrical activity associated with the
repolarization of the ventricles, which occurs as the ventricles relax.
Question 5
When measuring the heart rate on an ECG strip, if there are 15 small squares between two R
waves, what is the approximate heart rate? (Assume paper speed of 25 mm/sec)
A) 100 bpm.
B) 120 bpm.
C) 150 bpm.
D) 200 bpm.
E) 300 bpm.
Correct Answer: A) 100 bpm.
Rationale: At a paper speed of 25 mm/sec, each small square is 0.04 seconds. 15
small squares x 0.04 sec/square = 0.60 seconds. Heart rate = 60 seconds / 0.60
seconds = 100 bpm. Alternatively, 300 / (number of large squares) = = 100
bpm. (1 large square = 5 small squares).
Question 6
A client's ECG shows a chaotic, irregular rhythm with no discernible P waves and an irregularly
irregular ventricular rhythm. This rhythm is identified as:
A) Atrial flutter.
,B) Sinus arrhythmia.
C) Atrial fibrillation.
D) Ventricular tachycardia.
E) Junctional rhythm.
Correct Answer: C) Atrial fibrillation.
Rationale: Atrial fibrillation is characterized by disorganized electrical activity in
the atria, leading to no distinct P waves and an irregularly irregular ventricular
response.
Question 7
What is the normal duration of the PR interval on an ECG?
A) 0.04 to 0.10 seconds.
B) 0.12 to 0.20 seconds.
C) 0.20 to 0.24 seconds.
D) 0.08 to 0.12 seconds.
E) Greater than 0.20 seconds.
Correct Answer: B) 0.12 to 0.20 seconds.
Rationale: The PR interval represents the time from the beginning of atrial
depolarization to the beginning of ventricular depolarization. A normal duration is
3-5 small squares.
Question 8
A client's ECG shows a heart rate of 110 bpm, regular rhythm, and P waves preceding every
QRS complex with a normal PR interval. This rhythm is identified as:
A) Sinus bradycardia.
B) Sinus tachycardia.
C) Atrial tachycardia.
D) Junctional tachycardia.
E) Ventricular tachycardia.
Correct Answer: B) Sinus tachycardia.
Rationale: Sinus tachycardia is a normal sinus rhythm with a heart rate greater
than 100 bpm (usually 101-180 bpm).
, Question 9
What is the primary function of the SA (sinoatrial) node in the heart?
A) To delay electrical impulses to the ventricles.
B) To act as the primary pacemaker of the heart.
C) To initiate ventricular contraction directly.
D) To regulate blood pressure.
E) To conduct impulses to the bundle branches.
Correct Answer: B) To act as the primary pacemaker of the heart.
Rationale: The SA node generates electrical impulses at a regular rate, setting the
rhythm for the entire heart, hence its designation as the "natural pacemaker."
Question 10
A client's ECG shows a "sawtooth" pattern of atrial activity with a regular or irregular
ventricular rhythm. This rhythm is identified as:
A) Atrial fibrillation.
B) Atrial flutter.
C) Ventricular tachycardia.
D) Supraventricular tachycardia.
E) Multifocal atrial tachycardia.
Correct Answer: B) Atrial flutter.
Rationale: Atrial flutter is characterized by a rapid, regular atrial rhythm (typically
250-350 bpm) that creates a distinctive sawtooth pattern (F waves) on the ECG,
often with a consistent AV block (e.g., 2:1, 3:1).
Question 11
What is the normal duration of the QRS complex on an ECG?
A) 0.04 to 0.10 seconds.
B) 0.12 to 0.20 seconds.
C) 0.20 to 0.24 seconds.
D) Greater than 0.12 seconds.
E) Less than 0.04 seconds.
Correct Answer: A) 0.04 to 0.10 seconds.
PREP)2025 COMPLETE QUESTIONS AND ANSWERS ALREADY
SOLVED 100%
Question 1
Which of the following represents atrial depolarization on an electrocardiogram (ECG)?
A) T wave.
B) U wave.
C) P wave.
D) QRS complex.
E) ST segment.
Correct Answer: C) P wave.
Rationale: The P wave represents the electrical activity associated with the
depolarization of the atria, which precedes atrial contraction.
Question 2
What does the QRS complex on an ECG primarily represent?
A) Atrial repolarization.
B) Ventricular repolarization.
C) Ventricular depolarization.
D) Atrial depolarization.
E) SA node firing.
Correct Answer: C) Ventricular depolarization.
Rationale: The QRS complex signifies the rapid depolarization of the ventricles,
leading to ventricular contraction.
Question 3
A client's ECG shows a regular rhythm, a heart rate of 70 bpm, a P wave before every QRS,
and a PR interval of 0.16 seconds. This rhythm is identified as:
A) Sinus tachycardia.
B) Sinus bradycardia.
C) Normal sinus rhythm.
D) Atrial fibrillation.
E) Junctional rhythm.
Correct Answer: C) Normal sinus rhythm.
,Rationale: Normal sinus rhythm is characterized by a regular rhythm, a heart rate
between 60-100 bpm, P waves preceding every QRS, and a normal PR interval
(0.12-0.20 seconds) and QRS duration.
Question 4
What does the T wave on an ECG primarily represent?
A) Atrial depolarization.
B) Ventricular repolarization.
C) Atrial repolarization.
D) Ventricular depolarization.
E) SA node firing.
Correct Answer: B) Ventricular repolarization.
Rationale: The T wave represents the electrical activity associated with the
repolarization of the ventricles, which occurs as the ventricles relax.
Question 5
When measuring the heart rate on an ECG strip, if there are 15 small squares between two R
waves, what is the approximate heart rate? (Assume paper speed of 25 mm/sec)
A) 100 bpm.
B) 120 bpm.
C) 150 bpm.
D) 200 bpm.
E) 300 bpm.
Correct Answer: A) 100 bpm.
Rationale: At a paper speed of 25 mm/sec, each small square is 0.04 seconds. 15
small squares x 0.04 sec/square = 0.60 seconds. Heart rate = 60 seconds / 0.60
seconds = 100 bpm. Alternatively, 300 / (number of large squares) = = 100
bpm. (1 large square = 5 small squares).
Question 6
A client's ECG shows a chaotic, irregular rhythm with no discernible P waves and an irregularly
irregular ventricular rhythm. This rhythm is identified as:
A) Atrial flutter.
,B) Sinus arrhythmia.
C) Atrial fibrillation.
D) Ventricular tachycardia.
E) Junctional rhythm.
Correct Answer: C) Atrial fibrillation.
Rationale: Atrial fibrillation is characterized by disorganized electrical activity in
the atria, leading to no distinct P waves and an irregularly irregular ventricular
response.
Question 7
What is the normal duration of the PR interval on an ECG?
A) 0.04 to 0.10 seconds.
B) 0.12 to 0.20 seconds.
C) 0.20 to 0.24 seconds.
D) 0.08 to 0.12 seconds.
E) Greater than 0.20 seconds.
Correct Answer: B) 0.12 to 0.20 seconds.
Rationale: The PR interval represents the time from the beginning of atrial
depolarization to the beginning of ventricular depolarization. A normal duration is
3-5 small squares.
Question 8
A client's ECG shows a heart rate of 110 bpm, regular rhythm, and P waves preceding every
QRS complex with a normal PR interval. This rhythm is identified as:
A) Sinus bradycardia.
B) Sinus tachycardia.
C) Atrial tachycardia.
D) Junctional tachycardia.
E) Ventricular tachycardia.
Correct Answer: B) Sinus tachycardia.
Rationale: Sinus tachycardia is a normal sinus rhythm with a heart rate greater
than 100 bpm (usually 101-180 bpm).
, Question 9
What is the primary function of the SA (sinoatrial) node in the heart?
A) To delay electrical impulses to the ventricles.
B) To act as the primary pacemaker of the heart.
C) To initiate ventricular contraction directly.
D) To regulate blood pressure.
E) To conduct impulses to the bundle branches.
Correct Answer: B) To act as the primary pacemaker of the heart.
Rationale: The SA node generates electrical impulses at a regular rate, setting the
rhythm for the entire heart, hence its designation as the "natural pacemaker."
Question 10
A client's ECG shows a "sawtooth" pattern of atrial activity with a regular or irregular
ventricular rhythm. This rhythm is identified as:
A) Atrial fibrillation.
B) Atrial flutter.
C) Ventricular tachycardia.
D) Supraventricular tachycardia.
E) Multifocal atrial tachycardia.
Correct Answer: B) Atrial flutter.
Rationale: Atrial flutter is characterized by a rapid, regular atrial rhythm (typically
250-350 bpm) that creates a distinctive sawtooth pattern (F waves) on the ECG,
often with a consistent AV block (e.g., 2:1, 3:1).
Question 11
What is the normal duration of the QRS complex on an ECG?
A) 0.04 to 0.10 seconds.
B) 0.12 to 0.20 seconds.
C) 0.20 to 0.24 seconds.
D) Greater than 0.12 seconds.
E) Less than 0.04 seconds.
Correct Answer: A) 0.04 to 0.10 seconds.
