Kaiser EKG Test Study Guide: 50 Questions with Correct
Answers (2026/2027 Edition)
SECTION 1: Cardiac Anatomy, Physiology, and EKG Waveform Components
Question 1.
A 62-year-old patient presents for a routine EKG. The tracing shows a regular rhythm
with a rate of 72 bpm. Each QRS complex is preceded by an upright P wave in lead II.
The PR interval measures 0.16 seconds, and the QRS duration is 0.08 seconds. Which
cardiac structure is primarily responsible for the initial depolarization that produces the
P wave?
A. AV node
B. SA node
C. Bundle of His
D. Purkinje fibers
Correct Answer: B. SA node
Rationale: The P wave represents atrial depolarization, which is initiated by the sinoatrial
(SA) node, the primary pacemaker of the heart located in the right atrium near the
superior vena cava. The SA node has an intrinsic firing rate of 60-100 bpm and
generates the electrical impulse that spreads through the atria, producing the P wave.
Option A (AV node) is incorrect because the AV node delays the impulse but does not
produce the P wave; it is responsible for the PR segment delay. Option C (Bundle of His)
is incorrect because it conducts the impulse from the AV node to the bundle branches
and does not initiate atrial depolarization. Option D (Purkinje fibers) is incorrect because
they are responsible for rapid ventricular depolarization, producing the QRS complex,
not the P wave.
,Question 2.
During a 12-lead EKG interpretation class, an instructor asks students to identify the
normal duration of the PR interval in an adult with normal conduction. Which
measurement falls within the accepted normal range?
A. 0.08 seconds
B. 0.12 seconds
C. 0.24 seconds
D. 0.30 seconds
Correct Answer: B. 0.12 seconds
Rationale: The normal PR interval in adults ranges from 0.12 to 0.20 seconds (3 to 5
small boxes on standard EKG paper). This interval represents the time from the
beginning of atrial depolarization (P wave) to the beginning of ventricular depolarization
(QRS complex), including conduction through the atria, AV node, Bundle of His, and
bundle branches. Option A (0.08 seconds) is incorrect because it is below the normal
range and would suggest an accelerated conduction pathway such as
Wolff-Parkinson-White syndrome or a junctional rhythm with retrograde conduction.
Option C (0.24 seconds) is incorrect because it exceeds the normal upper limit and
represents first-degree AV block. Option D (0.30 seconds) is incorrect because it
indicates significant AV conduction delay consistent with advanced first-degree AV
block.
Question 3.
A telemetry nurse is reviewing the normal electrical conduction pathway of the heart. In
a healthy individual, after the impulse leaves the SA node, which structure serves as the
critical gatekeeper that delays the electrical impulse before it reaches the ventricles?
A. Bundle of His
B. AV node
,C. Left bundle branch
D. Interventricular septum
Correct Answer: B. AV node
Rationale: The atrioventricular (AV) node is located in the right atrium near the interatrial
septum and serves as the critical gatekeeper that delays the electrical impulse for
approximately 0.10 seconds. This delay allows time for atrial contraction (kick) to
complete ventricular filling before ventricular systole begins. Option A (Bundle of His) is
incorrect because it conducts the impulse rapidly from the AV node to the bundle
branches without significant delay. Option C (Left bundle branch) is incorrect because it
is a rapid conduction pathway within the ventricles and does not provide AV delay.
Option D (Interventricular septum) is incorrect because it is an anatomical structure, not
a specialized conduction tissue, though it is the site where the bundle branches divide.
Question 4.
A patient has a 12-lead EKG performed. The QT interval is measured from the beginning
of the QRS complex to the end of the T wave. Which of the following best describes the
physiological significance of the QT interval?
A. Time of atrial depolarization and repolarization
B. Time of ventricular depolarization and repolarization
C. Time of AV nodal conduction delay only
D. Time of ventricular depolarization only
Correct Answer: B. Time of ventricular depolarization and repolarization
Rationale: The QT interval represents the total duration of ventricular electrical activity,
encompassing both ventricular depolarization (QRS complex) and ventricular
repolarization (ST segment and T wave). It is a critical measurement because
prolongation can predispose to life-threatening ventricular dysrhythmias such as
, Torsades de Pointes. Option A is incorrect because atrial depolarization and
repolarization are represented by the P wave and PR segment, not the QT interval.
Option C is incorrect because AV nodal conduction delay is represented by a portion of
the PR interval, not the QT interval. Option D is incorrect because ventricular
depolarization alone is represented by the QRS complex only; the QT interval includes
repolarization as well.
Question 5.
During a cardiac monitoring in-service, a nurse is asked about the normal amplitude of
the P wave in lead II. Which statement is most accurate regarding normal P wave
characteristics?
A. The P wave should not exceed 2.5 mm in amplitude in lead II.
B. The P wave should not exceed 5.0 mm in amplitude in lead II.
C. The P wave should not exceed 1.0 mm in amplitude in lead II.
D. The P wave amplitude is not clinically significant in lead II.
Correct Answer: A. The P wave should not exceed 2.5 mm in amplitude in lead II.
Rationale: In lead II, the normal P wave amplitude should not exceed 2.5 mm (2.5 small
boxes). P waves taller than 2.5 mm in the inferior leads (II, III, aVF) suggest right atrial
enlargement (P pulmonale), often associated with pulmonary hypertension or chronic
lung disease. Option B is incorrect because 5.0 mm would represent significant right
atrial enlargement. Option C is incorrect because 1.0 mm is below the normal upper
limit and would not account for normal physiological variation. Option D is incorrect
because P wave amplitude is clinically significant; abnormalities can indicate atrial
enlargement, electrolyte imbalances, or ectopic atrial rhythms.
SECTION 2: Normal Sinus Rhythms and Variations
Answers (2026/2027 Edition)
SECTION 1: Cardiac Anatomy, Physiology, and EKG Waveform Components
Question 1.
A 62-year-old patient presents for a routine EKG. The tracing shows a regular rhythm
with a rate of 72 bpm. Each QRS complex is preceded by an upright P wave in lead II.
The PR interval measures 0.16 seconds, and the QRS duration is 0.08 seconds. Which
cardiac structure is primarily responsible for the initial depolarization that produces the
P wave?
A. AV node
B. SA node
C. Bundle of His
D. Purkinje fibers
Correct Answer: B. SA node
Rationale: The P wave represents atrial depolarization, which is initiated by the sinoatrial
(SA) node, the primary pacemaker of the heart located in the right atrium near the
superior vena cava. The SA node has an intrinsic firing rate of 60-100 bpm and
generates the electrical impulse that spreads through the atria, producing the P wave.
Option A (AV node) is incorrect because the AV node delays the impulse but does not
produce the P wave; it is responsible for the PR segment delay. Option C (Bundle of His)
is incorrect because it conducts the impulse from the AV node to the bundle branches
and does not initiate atrial depolarization. Option D (Purkinje fibers) is incorrect because
they are responsible for rapid ventricular depolarization, producing the QRS complex,
not the P wave.
,Question 2.
During a 12-lead EKG interpretation class, an instructor asks students to identify the
normal duration of the PR interval in an adult with normal conduction. Which
measurement falls within the accepted normal range?
A. 0.08 seconds
B. 0.12 seconds
C. 0.24 seconds
D. 0.30 seconds
Correct Answer: B. 0.12 seconds
Rationale: The normal PR interval in adults ranges from 0.12 to 0.20 seconds (3 to 5
small boxes on standard EKG paper). This interval represents the time from the
beginning of atrial depolarization (P wave) to the beginning of ventricular depolarization
(QRS complex), including conduction through the atria, AV node, Bundle of His, and
bundle branches. Option A (0.08 seconds) is incorrect because it is below the normal
range and would suggest an accelerated conduction pathway such as
Wolff-Parkinson-White syndrome or a junctional rhythm with retrograde conduction.
Option C (0.24 seconds) is incorrect because it exceeds the normal upper limit and
represents first-degree AV block. Option D (0.30 seconds) is incorrect because it
indicates significant AV conduction delay consistent with advanced first-degree AV
block.
Question 3.
A telemetry nurse is reviewing the normal electrical conduction pathway of the heart. In
a healthy individual, after the impulse leaves the SA node, which structure serves as the
critical gatekeeper that delays the electrical impulse before it reaches the ventricles?
A. Bundle of His
B. AV node
,C. Left bundle branch
D. Interventricular septum
Correct Answer: B. AV node
Rationale: The atrioventricular (AV) node is located in the right atrium near the interatrial
septum and serves as the critical gatekeeper that delays the electrical impulse for
approximately 0.10 seconds. This delay allows time for atrial contraction (kick) to
complete ventricular filling before ventricular systole begins. Option A (Bundle of His) is
incorrect because it conducts the impulse rapidly from the AV node to the bundle
branches without significant delay. Option C (Left bundle branch) is incorrect because it
is a rapid conduction pathway within the ventricles and does not provide AV delay.
Option D (Interventricular septum) is incorrect because it is an anatomical structure, not
a specialized conduction tissue, though it is the site where the bundle branches divide.
Question 4.
A patient has a 12-lead EKG performed. The QT interval is measured from the beginning
of the QRS complex to the end of the T wave. Which of the following best describes the
physiological significance of the QT interval?
A. Time of atrial depolarization and repolarization
B. Time of ventricular depolarization and repolarization
C. Time of AV nodal conduction delay only
D. Time of ventricular depolarization only
Correct Answer: B. Time of ventricular depolarization and repolarization
Rationale: The QT interval represents the total duration of ventricular electrical activity,
encompassing both ventricular depolarization (QRS complex) and ventricular
repolarization (ST segment and T wave). It is a critical measurement because
prolongation can predispose to life-threatening ventricular dysrhythmias such as
, Torsades de Pointes. Option A is incorrect because atrial depolarization and
repolarization are represented by the P wave and PR segment, not the QT interval.
Option C is incorrect because AV nodal conduction delay is represented by a portion of
the PR interval, not the QT interval. Option D is incorrect because ventricular
depolarization alone is represented by the QRS complex only; the QT interval includes
repolarization as well.
Question 5.
During a cardiac monitoring in-service, a nurse is asked about the normal amplitude of
the P wave in lead II. Which statement is most accurate regarding normal P wave
characteristics?
A. The P wave should not exceed 2.5 mm in amplitude in lead II.
B. The P wave should not exceed 5.0 mm in amplitude in lead II.
C. The P wave should not exceed 1.0 mm in amplitude in lead II.
D. The P wave amplitude is not clinically significant in lead II.
Correct Answer: A. The P wave should not exceed 2.5 mm in amplitude in lead II.
Rationale: In lead II, the normal P wave amplitude should not exceed 2.5 mm (2.5 small
boxes). P waves taller than 2.5 mm in the inferior leads (II, III, aVF) suggest right atrial
enlargement (P pulmonale), often associated with pulmonary hypertension or chronic
lung disease. Option B is incorrect because 5.0 mm would represent significant right
atrial enlargement. Option C is incorrect because 1.0 mm is below the normal upper
limit and would not account for normal physiological variation. Option D is incorrect
because P wave amplitude is clinically significant; abnormalities can indicate atrial
enlargement, electrolyte imbalances, or ectopic atrial rhythms.
SECTION 2: Normal Sinus Rhythms and Variations
