NHA CET Exam Prep 2026: 400 Most Tested
EKG Technician Practice Questions with
Verified Answers & Detailed Rationales –
Complete Study Guide
SECTION 1: EKG FUNDAMENTALS AND EQUIPMENT (Questions 1–
80)
1. What is the primary pacemaker of the heart?
A. AV Node
B. SA Node
C. Bundle of His
D. Purkinje Fibers
Answer: B
Rationale: The SA (sinoatrial) node is the primary pacemaker of the
heart, located in the upper right atrium. It initiates electrical
impulses at a rate of 60-100 bpm. The AV node (A) is the secondary
pacemaker (40-60 bpm). The Bundle of His (C) and Purkinje fibers
(D) are lower pacemakers (20-40 bpm).
,2. What is a more medically correct term for the clotting of an
artery?
A. Stenosis
B. Occlusion
C. Embolism
D. Thrombosis
Answer: B
Rationale: Occlusion refers to the complete or partial blockage of a
blood vessel. Stenosis (A) is narrowing. Embolism (C) is a clot that
travels. Thrombosis (D) is clot formation at the site.
3. When the atria depolarize (or contract), what is shown on the EKG
tracing?
A. QRS complex
B. T wave
C. P wave
D. PR segment
Answer: C
Rationale: The P wave represents atrial depolarization (contraction).
The QRS complex (A) represents ventricular depolarization. The T
wave (B) represents ventricular repolarization. The PR segment (D)
is the isoelectric line between atrial depolarization and ventricular
depolarization.
,4. An irregular heartbeat that is common among children is called
_____.
A. Sinus Arrhythmia
B. Atrial Fibrillation
C. Sinus Tachycardia
D. Sinus Bradycardia
Answer: A
Rationale: Sinus arrhythmia is a normal variation in heart rate that
occurs with breathing, commonly seen in children and young
adults. Atrial fibrillation (B) is an irregularly irregular rhythm. Sinus
tachycardia (C) is a fast regular rhythm. Sinus bradycardia (D) is a
slow regular rhythm.
5. 1 small box on an EKG strip denotes 0.04 seconds of time. How
long is this represented in millimeters?
A. 0.5 mm
B. 1 mm
C. 2 mm
D. 5 mm
Answer: B
Rationale: One small box on EKG paper is 1 mm by 1 mm and
represents 0.04 seconds. Five small boxes (5 mm) equal 0.20
seconds. Option B is correct.
, 6. What is the term used to describe the amount of blood pumped by
the heart per minute?
A. Stroke volume
B. Cardiac output
C. Ejection fraction
D. Preload
Answer: B
Rationale: Cardiac output is the amount of blood pumped by the
heart per minute (heart rate × stroke volume). Stroke volume (A) is
the amount of blood pumped per beat. Ejection fraction (C) is the
percentage of blood ejected from the ventricle. Preload (D) is the
volume of blood in the ventricle at end-diastole.
7. Leads I, II, and III are collectively known as:
A. Precordial leads
B. Augmented leads
C. Standard leads
D. Chest leads
Answer: C
Rationale: Leads I, II, and III are the standard bipolar limb leads.
Precordial leads (A) are V1-V6. Augmented leads (B) are aVR, aVL,
and aVF. Chest leads (D) is another term for precordial leads.
EKG Technician Practice Questions with
Verified Answers & Detailed Rationales –
Complete Study Guide
SECTION 1: EKG FUNDAMENTALS AND EQUIPMENT (Questions 1–
80)
1. What is the primary pacemaker of the heart?
A. AV Node
B. SA Node
C. Bundle of His
D. Purkinje Fibers
Answer: B
Rationale: The SA (sinoatrial) node is the primary pacemaker of the
heart, located in the upper right atrium. It initiates electrical
impulses at a rate of 60-100 bpm. The AV node (A) is the secondary
pacemaker (40-60 bpm). The Bundle of His (C) and Purkinje fibers
(D) are lower pacemakers (20-40 bpm).
,2. What is a more medically correct term for the clotting of an
artery?
A. Stenosis
B. Occlusion
C. Embolism
D. Thrombosis
Answer: B
Rationale: Occlusion refers to the complete or partial blockage of a
blood vessel. Stenosis (A) is narrowing. Embolism (C) is a clot that
travels. Thrombosis (D) is clot formation at the site.
3. When the atria depolarize (or contract), what is shown on the EKG
tracing?
A. QRS complex
B. T wave
C. P wave
D. PR segment
Answer: C
Rationale: The P wave represents atrial depolarization (contraction).
The QRS complex (A) represents ventricular depolarization. The T
wave (B) represents ventricular repolarization. The PR segment (D)
is the isoelectric line between atrial depolarization and ventricular
depolarization.
,4. An irregular heartbeat that is common among children is called
_____.
A. Sinus Arrhythmia
B. Atrial Fibrillation
C. Sinus Tachycardia
D. Sinus Bradycardia
Answer: A
Rationale: Sinus arrhythmia is a normal variation in heart rate that
occurs with breathing, commonly seen in children and young
adults. Atrial fibrillation (B) is an irregularly irregular rhythm. Sinus
tachycardia (C) is a fast regular rhythm. Sinus bradycardia (D) is a
slow regular rhythm.
5. 1 small box on an EKG strip denotes 0.04 seconds of time. How
long is this represented in millimeters?
A. 0.5 mm
B. 1 mm
C. 2 mm
D. 5 mm
Answer: B
Rationale: One small box on EKG paper is 1 mm by 1 mm and
represents 0.04 seconds. Five small boxes (5 mm) equal 0.20
seconds. Option B is correct.
, 6. What is the term used to describe the amount of blood pumped by
the heart per minute?
A. Stroke volume
B. Cardiac output
C. Ejection fraction
D. Preload
Answer: B
Rationale: Cardiac output is the amount of blood pumped by the
heart per minute (heart rate × stroke volume). Stroke volume (A) is
the amount of blood pumped per beat. Ejection fraction (C) is the
percentage of blood ejected from the ventricle. Preload (D) is the
volume of blood in the ventricle at end-diastole.
7. Leads I, II, and III are collectively known as:
A. Precordial leads
B. Augmented leads
C. Standard leads
D. Chest leads
Answer: C
Rationale: Leads I, II, and III are the standard bipolar limb leads.
Precordial leads (A) are V1-V6. Augmented leads (B) are aVR, aVL,
and aVF. Chest leads (D) is another term for precordial leads.
