NHA EKG (CET) study guide
(2026)| 146 QUESTIONS| WITH
COMPLETE SOLUTION
Course
NHA EKG
1. What is the primary purpose of an electrocardiogram (EKG/ECG)?
A. Measure blood pressure
B. Record the electrical activity of the heart
C. Measure oxygen levels
D. Diagnose lung diseases
Correct Answer: B. Record the electrical activity of the heart
Solution:
An electrocardiogram records the electrical impulses generated by the heart as they travel
through the cardiac conduction system. It helps identify rhythm abnormalities, conduction
problems, and signs of cardiac injury.
2. Which component of the cardiac conduction system normally initiates the heartbeat?
A. Atrioventricular (AV) node
B. Bundle branches
C. Sinoatrial (SA) node
D. Purkinje fibers
Correct Answer: C. Sinoatrial (SA) node
Solution:
The SA node, located in the right atrium, is the heart’s natural pacemaker. It generates electrical
impulses that initiate atrial contraction and regulate normal heart rhythm.
3. A normal adult resting heart rate is typically:
A. 20–40 beats per minute
B. 60–100 beats per minute
C. 120–160 beats per minute
D. 160–200 beats per minute
,Correct Answer: B. 60–100 beats per minute
Solution:
A normal adult resting heart rate is generally between 60 and 100 beats per minute. Rates below
60 are called bradycardia, while rates above 100 are called tachycardia.
4. Which EKG wave represents atrial depolarization?
A. P wave
B. QRS complex
C. T wave
D. U wave
Correct Answer: A. P wave
Solution:
The P wave represents electrical activation (depolarization) of the atria before atrial contraction
occurs.
5. Which portion of the EKG represents ventricular depolarization?
A. P wave
B. PR interval
C. QRS complex
D. T wave
Correct Answer: C. QRS complex
Solution:
The QRS complex represents ventricular depolarization, which triggers ventricular contraction
and blood ejection from the heart.
6. Before applying EKG electrodes, the technician should:
A. Apply lotion to improve conductivity
B. Clean and dry the skin
C. Place electrodes over clothing
D. Ask the patient to exercise
Correct Answer: B. Clean and dry the skin
,Solution:
Proper skin preparation reduces electrical interference and improves electrode adhesion and
signal quality.
7. Which lead is considered a standard bipolar limb lead?
A. Lead II
B. V1
C. V4
D. aVR
Correct Answer: A. Lead II
Solution:
Standard bipolar limb leads include Lead I, Lead II, and Lead III. Lead II is commonly used for
rhythm monitoring because it provides a clear view of atrial activity.
8. A patient’s EKG shows a regular rhythm with a heart rate of 45 beats/minute. This
rhythm is most likely:
A. Sinus tachycardia
B. Sinus bradycardia
C. Atrial fibrillation
D. Ventricular tachycardia
Correct Answer: B. Sinus bradycardia
Solution:
Sinus bradycardia occurs when the heart rate is below 60 beats per minute while maintaining
normal sinus rhythm characteristics.
9. What is the correct placement for the V1 precordial electrode?
A. Fourth intercostal space, right of the sternum
B. Fifth intercostal space, left midclavicular line
C. Fourth intercostal space, left of sternum
D. Sixth intercostal space, left midaxillary line
Correct Answer: A. Fourth intercostal space, right of the sternum
, Solution:
V1 is placed in the fourth intercostal space at the right sternal border. Correct chest lead
placement is essential for accurate EKG interpretation.
10. What does the PR interval measure?
A. Ventricular repolarization
B. Time from atrial depolarization to ventricular depolarization
C. Duration of ventricular contraction only
D. Electrical recovery of the atria
Correct Answer: B. Time from atrial depolarization to ventricular depolarization
Solution:
The PR interval represents conduction time from the beginning of atrial depolarization through
the AV node and His-Purkinje system until ventricular depolarization begins.
11. Which structure delays the electrical impulse before it reaches the ventricles?
A. Sinoatrial (SA) node
B. Atrioventricular (AV) node
C. Purkinje fibers
D. Bundle branches
Correct Answer: B. Atrioventricular (AV) node
Solution:
The AV node briefly delays electrical conduction, allowing the atria to contract and empty blood
into the ventricles before ventricular contraction begins.
12. What is the normal duration of the PR interval?
A. 0.04–0.08 seconds
B. 0.12–0.20 seconds
C. 0.24–0.30 seconds
D. 0.30–0.40 seconds
Correct Answer: B. 0.12–0.20 seconds
Solution:
(2026)| 146 QUESTIONS| WITH
COMPLETE SOLUTION
Course
NHA EKG
1. What is the primary purpose of an electrocardiogram (EKG/ECG)?
A. Measure blood pressure
B. Record the electrical activity of the heart
C. Measure oxygen levels
D. Diagnose lung diseases
Correct Answer: B. Record the electrical activity of the heart
Solution:
An electrocardiogram records the electrical impulses generated by the heart as they travel
through the cardiac conduction system. It helps identify rhythm abnormalities, conduction
problems, and signs of cardiac injury.
2. Which component of the cardiac conduction system normally initiates the heartbeat?
A. Atrioventricular (AV) node
B. Bundle branches
C. Sinoatrial (SA) node
D. Purkinje fibers
Correct Answer: C. Sinoatrial (SA) node
Solution:
The SA node, located in the right atrium, is the heart’s natural pacemaker. It generates electrical
impulses that initiate atrial contraction and regulate normal heart rhythm.
3. A normal adult resting heart rate is typically:
A. 20–40 beats per minute
B. 60–100 beats per minute
C. 120–160 beats per minute
D. 160–200 beats per minute
,Correct Answer: B. 60–100 beats per minute
Solution:
A normal adult resting heart rate is generally between 60 and 100 beats per minute. Rates below
60 are called bradycardia, while rates above 100 are called tachycardia.
4. Which EKG wave represents atrial depolarization?
A. P wave
B. QRS complex
C. T wave
D. U wave
Correct Answer: A. P wave
Solution:
The P wave represents electrical activation (depolarization) of the atria before atrial contraction
occurs.
5. Which portion of the EKG represents ventricular depolarization?
A. P wave
B. PR interval
C. QRS complex
D. T wave
Correct Answer: C. QRS complex
Solution:
The QRS complex represents ventricular depolarization, which triggers ventricular contraction
and blood ejection from the heart.
6. Before applying EKG electrodes, the technician should:
A. Apply lotion to improve conductivity
B. Clean and dry the skin
C. Place electrodes over clothing
D. Ask the patient to exercise
Correct Answer: B. Clean and dry the skin
,Solution:
Proper skin preparation reduces electrical interference and improves electrode adhesion and
signal quality.
7. Which lead is considered a standard bipolar limb lead?
A. Lead II
B. V1
C. V4
D. aVR
Correct Answer: A. Lead II
Solution:
Standard bipolar limb leads include Lead I, Lead II, and Lead III. Lead II is commonly used for
rhythm monitoring because it provides a clear view of atrial activity.
8. A patient’s EKG shows a regular rhythm with a heart rate of 45 beats/minute. This
rhythm is most likely:
A. Sinus tachycardia
B. Sinus bradycardia
C. Atrial fibrillation
D. Ventricular tachycardia
Correct Answer: B. Sinus bradycardia
Solution:
Sinus bradycardia occurs when the heart rate is below 60 beats per minute while maintaining
normal sinus rhythm characteristics.
9. What is the correct placement for the V1 precordial electrode?
A. Fourth intercostal space, right of the sternum
B. Fifth intercostal space, left midclavicular line
C. Fourth intercostal space, left of sternum
D. Sixth intercostal space, left midaxillary line
Correct Answer: A. Fourth intercostal space, right of the sternum
, Solution:
V1 is placed in the fourth intercostal space at the right sternal border. Correct chest lead
placement is essential for accurate EKG interpretation.
10. What does the PR interval measure?
A. Ventricular repolarization
B. Time from atrial depolarization to ventricular depolarization
C. Duration of ventricular contraction only
D. Electrical recovery of the atria
Correct Answer: B. Time from atrial depolarization to ventricular depolarization
Solution:
The PR interval represents conduction time from the beginning of atrial depolarization through
the AV node and His-Purkinje system until ventricular depolarization begins.
11. Which structure delays the electrical impulse before it reaches the ventricles?
A. Sinoatrial (SA) node
B. Atrioventricular (AV) node
C. Purkinje fibers
D. Bundle branches
Correct Answer: B. Atrioventricular (AV) node
Solution:
The AV node briefly delays electrical conduction, allowing the atria to contract and empty blood
into the ventricles before ventricular contraction begins.
12. What is the normal duration of the PR interval?
A. 0.04–0.08 seconds
B. 0.12–0.20 seconds
C. 0.24–0.30 seconds
D. 0.30–0.40 seconds
Correct Answer: B. 0.12–0.20 seconds
Solution:
