ADVENTHEALTH EKG INTERPRETATION
COMPETENCY: 200 PRACTICE QUESTIONS
WITH ANSWERS AND RATIONALES FOR
UNIVERSITY-LEVEL NURSING
PROFESSIONALS (2026/2027)
Section 1: Cardiac Anatomy & Electrophysiology
Q1: The electrical impulse that initiates each normal heartbeat originates in
which anatomical structure?
• A. Bundle of His
• B. Atrioventricular (AV) node
• C. Sinoatrial (SA) node (Correct)
• D. Purkinje fibers
Rationale: The sinoatrial (SA) node, located in the right atrium, is the natural
pacemaker of the heart, with an intrinsic firing rate of 60-100 beats per minute .
Q2: During ventricular depolarization, which EKG waveform is produced?
• A. P wave
• B. T wave
• C. QRS complex (Correct)
• D. PR segment
Rationale: The QRS complex represents the electrical activation and contraction of the
ventricles (depolarization). The P wave represents atrial depolarization, and the T wave
represents ventricular repolarization .
Q3: The normal PR interval duration is:
• A. 0.08–0.10 seconds
• B. 0.12–0.20 seconds (Correct)
• C. 0.20–0.30 seconds
• D. 0.5–0.8 seconds
,Rationale: The PR interval measures the time from the beginning of atrial
depolarization to the beginning of ventricular depolarization. The normal range is
0.12–0.20 seconds (3-5 small boxes) .
Q4: The primary function of the AV node is to:
• A. Generate the initial electrical impulse
• B. Slow down the electrical impulse to allow ventricular filling (Correct)
• C. Conduct impulses rapidly to the ventricles
• D. Terminate abnormal electrical pathways
Rationale: The AV node delays the electrical impulse, allowing time for the atria to
contract and fill the ventricles before ventricular contraction begins .
Q5: The intrinsic firing rate of the Atrioventricular (AV) junctional pacemaker
cells is:
• A. 20 to 40 beats per minute
• B. 40 to 60 beats per minute (Correct)
• C. 60 to 100 beats per minute
• D. 100 to 150 beats per minute
Rationale: If the primary SA node pacemaker fails, the AV junction steps in as the
secondary pacemaker with a natural rate between 40 and 60 beats per minute .
Section 2: Rhythm Recognition
Q6: A patient's EKG shows a regular rhythm with a heart rate of 45 bpm, normal
P waves, and a normal PR interval. What is the most appropriate interpretation?
• A. Normal Sinus Rhythm
• B. Sinus Bradycardia (Correct)
• C. Junctional Rhythm
• D. First-Degree AV Block
Rationale: Sinus bradycardia meets all the criteria of a normal sinus rhythm, except the
intrinsic firing rate of the SA node drops below 60 beats per minute .
Q7: Which dysrhythmia is characterized by a totally irregular rhythm, no
discernible P waves, and a chaotic baseline?
• A. Atrial Flutter
• B. Atrial Fibrillation (Correct)
, • C. Ventricular Tachycardia
• D. Wandering Atrial Pacemaker
Rationale: Atrial fibrillation occurs due to disorganized electrical circuits in the atria,
causing a chaotic baseline without distinct P waves and an irregularly irregular
ventricular response .
Q8: Which EKG finding is the hallmark characteristic of a Third-Degree
(Complete) AV Block?
• A. Progressively lengthening PR intervals
• B. Completely independent P waves and QRS complexes (Correct)
• C. Fixed PR intervals with dropped QRS complexes
• D. A PR interval longer than 0.20 seconds with a 1:1 conduction ratio
Rationale: In a third-degree AV block, there is a total lack of conduction between the
atria and ventricles, causing the P waves and QRS complexes to be completely
independent .
Q9: A progressive lengthening of the PR interval until a QRS complex is
completely dropped is indicative of which rhythm?
• A. Mobitz Type I (Wenckebach) Second-Degree Block (Correct)
• B. Mobitz Type II Second-Degree Block
• C. First-Degree AV Block
• D. Third-Degree AV Block
Rationale: Mobitz Type I (Wenckebach) is characterized by a cyclical, progressive
elongation of the PR interval culminating in a single non-conducted P wave .
Q10: What does ST-segment elevation in leads II, III, and aVF strongly indicate?
• A. Lateral wall myocardial infarction
• B. Inferior wall myocardial infarction (Correct)
• C. Anterior wall myocardial infarction
• D. Posterior wall myocardial infarction
Rationale: The inferior wall of the heart is viewed by leads II, III, and aVF. ST-segment
elevation in these leads is the classic presentation of an acute inferior wall MI .
Section 3: EKG Acquisition & Patient Preparation
COMPETENCY: 200 PRACTICE QUESTIONS
WITH ANSWERS AND RATIONALES FOR
UNIVERSITY-LEVEL NURSING
PROFESSIONALS (2026/2027)
Section 1: Cardiac Anatomy & Electrophysiology
Q1: The electrical impulse that initiates each normal heartbeat originates in
which anatomical structure?
• A. Bundle of His
• B. Atrioventricular (AV) node
• C. Sinoatrial (SA) node (Correct)
• D. Purkinje fibers
Rationale: The sinoatrial (SA) node, located in the right atrium, is the natural
pacemaker of the heart, with an intrinsic firing rate of 60-100 beats per minute .
Q2: During ventricular depolarization, which EKG waveform is produced?
• A. P wave
• B. T wave
• C. QRS complex (Correct)
• D. PR segment
Rationale: The QRS complex represents the electrical activation and contraction of the
ventricles (depolarization). The P wave represents atrial depolarization, and the T wave
represents ventricular repolarization .
Q3: The normal PR interval duration is:
• A. 0.08–0.10 seconds
• B. 0.12–0.20 seconds (Correct)
• C. 0.20–0.30 seconds
• D. 0.5–0.8 seconds
,Rationale: The PR interval measures the time from the beginning of atrial
depolarization to the beginning of ventricular depolarization. The normal range is
0.12–0.20 seconds (3-5 small boxes) .
Q4: The primary function of the AV node is to:
• A. Generate the initial electrical impulse
• B. Slow down the electrical impulse to allow ventricular filling (Correct)
• C. Conduct impulses rapidly to the ventricles
• D. Terminate abnormal electrical pathways
Rationale: The AV node delays the electrical impulse, allowing time for the atria to
contract and fill the ventricles before ventricular contraction begins .
Q5: The intrinsic firing rate of the Atrioventricular (AV) junctional pacemaker
cells is:
• A. 20 to 40 beats per minute
• B. 40 to 60 beats per minute (Correct)
• C. 60 to 100 beats per minute
• D. 100 to 150 beats per minute
Rationale: If the primary SA node pacemaker fails, the AV junction steps in as the
secondary pacemaker with a natural rate between 40 and 60 beats per minute .
Section 2: Rhythm Recognition
Q6: A patient's EKG shows a regular rhythm with a heart rate of 45 bpm, normal
P waves, and a normal PR interval. What is the most appropriate interpretation?
• A. Normal Sinus Rhythm
• B. Sinus Bradycardia (Correct)
• C. Junctional Rhythm
• D. First-Degree AV Block
Rationale: Sinus bradycardia meets all the criteria of a normal sinus rhythm, except the
intrinsic firing rate of the SA node drops below 60 beats per minute .
Q7: Which dysrhythmia is characterized by a totally irregular rhythm, no
discernible P waves, and a chaotic baseline?
• A. Atrial Flutter
• B. Atrial Fibrillation (Correct)
, • C. Ventricular Tachycardia
• D. Wandering Atrial Pacemaker
Rationale: Atrial fibrillation occurs due to disorganized electrical circuits in the atria,
causing a chaotic baseline without distinct P waves and an irregularly irregular
ventricular response .
Q8: Which EKG finding is the hallmark characteristic of a Third-Degree
(Complete) AV Block?
• A. Progressively lengthening PR intervals
• B. Completely independent P waves and QRS complexes (Correct)
• C. Fixed PR intervals with dropped QRS complexes
• D. A PR interval longer than 0.20 seconds with a 1:1 conduction ratio
Rationale: In a third-degree AV block, there is a total lack of conduction between the
atria and ventricles, causing the P waves and QRS complexes to be completely
independent .
Q9: A progressive lengthening of the PR interval until a QRS complex is
completely dropped is indicative of which rhythm?
• A. Mobitz Type I (Wenckebach) Second-Degree Block (Correct)
• B. Mobitz Type II Second-Degree Block
• C. First-Degree AV Block
• D. Third-Degree AV Block
Rationale: Mobitz Type I (Wenckebach) is characterized by a cyclical, progressive
elongation of the PR interval culminating in a single non-conducted P wave .
Q10: What does ST-segment elevation in leads II, III, and aVF strongly indicate?
• A. Lateral wall myocardial infarction
• B. Inferior wall myocardial infarction (Correct)
• C. Anterior wall myocardial infarction
• D. Posterior wall myocardial infarction
Rationale: The inferior wall of the heart is viewed by leads II, III, and aVF. ST-segment
elevation in these leads is the classic presentation of an acute inferior wall MI .
Section 3: EKG Acquisition & Patient Preparation
