APEX EKG TEST EXAM WITH
CORRECT ANSWERS &
RATIONALES MASTER ECG
INTERPRETATION FOR NURSIN |
APEX EKG TEST EXAM WITH CORRECT ANSWERS |
Comprehensive Examination
APEX EKG TEST EXAM WITH CORRECT ANSWERS &
RATIONALES MASTER ECG INTERPRETATION FOR
NURSIN actual exam preparation document with verified
INTRODUCTION
This document is an important and very helpful preparation
resource for APEX EKG TEST EXAM WITH CORRECT
ANSWERS & RATIONALES MASTER ECG
INTERPRETATION FOR NURSIN. Every item uses a focused
exam stem, four response options, a keyed response, and a clear
rationale, making it easier to understand the subject, spot
distractors, and build real exam confidence.
Page 1
, Question 1
A patient presents with palpitations and a regular, narrow-complex tachycardia
at 150 bpm. The rhythm strip reveals a 2:1 relationship between atrial and
ventricular activity. Which maneuver or finding is most specific for
differentiating atrial flutter from AVNRT in this context?
A. Vagal maneuvers resulting in abrupt termination of the tachycardia.
B. Presence of a pseudo-R' wave in lead V1.
C. Identification of discrete, negative sawtooth waves in the inferior
leads.
D. Beat-to-beat variability in the RR interval.
Correct Answer: C - Identification of discrete, negative sawtooth
waves in the inferior leads.
RATIONALE
Atrial flutter with 2:1 conduction typically displays characteristic
negative sawtooth flutter waves (F waves) in the inferior leads (II, III,
aVF) at a rate of ~300 bpm. AVNRT, even when regular and narrow,
lacks these discrete flutter waves and often terminates abruptly with
vagal maneuvers or adenosine, while flutter typically does not
terminate but may slow conduction. Pseudo-R' waves are seen in
AVNRT, not flutter.
Question 2
Which ECG finding is most indicative of a high-risk Brugada pattern requiring
immediate electrophysiology referral in an asymptomatic patient?
A. Type 2 saddleback ST elevation in V2 with a positive terminal T wave.
B. Type 1 coved ST elevation 2 mm in V1-V2 with negative T wave.
C. Early repolarization pattern in the lateral leads.
D. Epsilon waves in the right precordial leads.
Correct Answer: B - Type 1 coved ST elevation 2 mm in V1-V2
with negative T wave.
Page 2
, RATIONALE
The Type 1 Brugada pattern (coved ST elevation 2 mm in V1-V2 with
a negative T wave) is diagnostic of Brugada syndrome and carries a
high risk of sudden cardiac death, even in asymptomatic individuals.
Type 2 patterns are not diagnostic and require drug challenge for
confirmation. Epsilon waves are associated with arrhythmogenic right
ventricular cardiomyopathy (ARVC), not Brugada.
Question 3
A 12-lead ECG shows a wide-complex tachycardia with a regular rate of 180
bpm. Which finding most strongly supports a ventricular origin over a
supraventricular origin with aberrancy?
A. RS interval >100 ms in any precordial lead.
B. Presence of a right bundle branch block pattern.
C. A preceding P wave with a short PR interval.
D. Beat-to-beat variability in the RR interval.
Correct Answer: A - RS interval >100 ms in any precordial lead.
RATIONALE
An RS interval (from onset of R to nadir of S) greater than 100 ms in
any precordial lead is a highly specific criterion for ventricular
tachycardia (VT) according to the Brugada criteria. RBBB pattern can
occur in both VT and SVT with aberrancy. A preceding P wave with
short PR is more indicative of pre-excitation. RR variability suggests
atrial fibrillation with aberrancy.
Question 4
Which electrolyte abnormality is most likely to produce the ECG findings of
flattened T waves, prominent U waves, and a prolonged QT interval?
A. Hyperkalemia
B. Hypokalemia
C. Hypercalcemia
Page 3
, D. Hypomagnesemia
Correct Answer: B - Hypokalemia
RATIONALE
Hypokalemia classically causes flattened T waves, ST depression,
prominent U waves, and QT prolongation. Hyperkalemia leads to
peaked T waves, widened QRS, and a sine wave pattern.
Hypercalcemia shortens the QT interval. Hypomagnesemia can cause
similar changes but less consistently prominent U waves.
Question 5
In the setting of an acute inferior myocardial infarction, which ECG finding
suggests concurrent right ventricular involvement and mandates cautious use of
nitrates?
A. ST elevation in lead V1 and V2.
B. ST elevation in lead V4R.
C. Reciprocal ST depression in lead aVL.
D. Pathologic Q waves in lead III.
Correct Answer: B - ST elevation in lead V4R.
RATIONALE
Right ventricular infarction is best identified by ST elevation in
right-sided precordial leads, particularly V4R. This finding is
associated with inferior MI and indicates a high risk of hypotension
with nitrates due to preload dependence. ST elevation in V1-V2
suggests anterior or septal involvement, not right ventricular.
Reciprocal changes in aVL are common in inferior MI but do not
specifically indicate RV involvement.
Question 6
Which of the following best explains the mechanism of action of adenosine in
terminating paroxysmal supraventricular tachycardia (PSVT)?
Page 4
CORRECT ANSWERS &
RATIONALES MASTER ECG
INTERPRETATION FOR NURSIN |
APEX EKG TEST EXAM WITH CORRECT ANSWERS |
Comprehensive Examination
APEX EKG TEST EXAM WITH CORRECT ANSWERS &
RATIONALES MASTER ECG INTERPRETATION FOR
NURSIN actual exam preparation document with verified
INTRODUCTION
This document is an important and very helpful preparation
resource for APEX EKG TEST EXAM WITH CORRECT
ANSWERS & RATIONALES MASTER ECG
INTERPRETATION FOR NURSIN. Every item uses a focused
exam stem, four response options, a keyed response, and a clear
rationale, making it easier to understand the subject, spot
distractors, and build real exam confidence.
Page 1
, Question 1
A patient presents with palpitations and a regular, narrow-complex tachycardia
at 150 bpm. The rhythm strip reveals a 2:1 relationship between atrial and
ventricular activity. Which maneuver or finding is most specific for
differentiating atrial flutter from AVNRT in this context?
A. Vagal maneuvers resulting in abrupt termination of the tachycardia.
B. Presence of a pseudo-R' wave in lead V1.
C. Identification of discrete, negative sawtooth waves in the inferior
leads.
D. Beat-to-beat variability in the RR interval.
Correct Answer: C - Identification of discrete, negative sawtooth
waves in the inferior leads.
RATIONALE
Atrial flutter with 2:1 conduction typically displays characteristic
negative sawtooth flutter waves (F waves) in the inferior leads (II, III,
aVF) at a rate of ~300 bpm. AVNRT, even when regular and narrow,
lacks these discrete flutter waves and often terminates abruptly with
vagal maneuvers or adenosine, while flutter typically does not
terminate but may slow conduction. Pseudo-R' waves are seen in
AVNRT, not flutter.
Question 2
Which ECG finding is most indicative of a high-risk Brugada pattern requiring
immediate electrophysiology referral in an asymptomatic patient?
A. Type 2 saddleback ST elevation in V2 with a positive terminal T wave.
B. Type 1 coved ST elevation 2 mm in V1-V2 with negative T wave.
C. Early repolarization pattern in the lateral leads.
D. Epsilon waves in the right precordial leads.
Correct Answer: B - Type 1 coved ST elevation 2 mm in V1-V2
with negative T wave.
Page 2
, RATIONALE
The Type 1 Brugada pattern (coved ST elevation 2 mm in V1-V2 with
a negative T wave) is diagnostic of Brugada syndrome and carries a
high risk of sudden cardiac death, even in asymptomatic individuals.
Type 2 patterns are not diagnostic and require drug challenge for
confirmation. Epsilon waves are associated with arrhythmogenic right
ventricular cardiomyopathy (ARVC), not Brugada.
Question 3
A 12-lead ECG shows a wide-complex tachycardia with a regular rate of 180
bpm. Which finding most strongly supports a ventricular origin over a
supraventricular origin with aberrancy?
A. RS interval >100 ms in any precordial lead.
B. Presence of a right bundle branch block pattern.
C. A preceding P wave with a short PR interval.
D. Beat-to-beat variability in the RR interval.
Correct Answer: A - RS interval >100 ms in any precordial lead.
RATIONALE
An RS interval (from onset of R to nadir of S) greater than 100 ms in
any precordial lead is a highly specific criterion for ventricular
tachycardia (VT) according to the Brugada criteria. RBBB pattern can
occur in both VT and SVT with aberrancy. A preceding P wave with
short PR is more indicative of pre-excitation. RR variability suggests
atrial fibrillation with aberrancy.
Question 4
Which electrolyte abnormality is most likely to produce the ECG findings of
flattened T waves, prominent U waves, and a prolonged QT interval?
A. Hyperkalemia
B. Hypokalemia
C. Hypercalcemia
Page 3
, D. Hypomagnesemia
Correct Answer: B - Hypokalemia
RATIONALE
Hypokalemia classically causes flattened T waves, ST depression,
prominent U waves, and QT prolongation. Hyperkalemia leads to
peaked T waves, widened QRS, and a sine wave pattern.
Hypercalcemia shortens the QT interval. Hypomagnesemia can cause
similar changes but less consistently prominent U waves.
Question 5
In the setting of an acute inferior myocardial infarction, which ECG finding
suggests concurrent right ventricular involvement and mandates cautious use of
nitrates?
A. ST elevation in lead V1 and V2.
B. ST elevation in lead V4R.
C. Reciprocal ST depression in lead aVL.
D. Pathologic Q waves in lead III.
Correct Answer: B - ST elevation in lead V4R.
RATIONALE
Right ventricular infarction is best identified by ST elevation in
right-sided precordial leads, particularly V4R. This finding is
associated with inferior MI and indicates a high risk of hypotension
with nitrates due to preload dependence. ST elevation in V1-V2
suggests anterior or septal involvement, not right ventricular.
Reciprocal changes in aVL are common in inferior MI but do not
specifically indicate RV involvement.
Question 6
Which of the following best explains the mechanism of action of adenosine in
terminating paroxysmal supraventricular tachycardia (PSVT)?
Page 4
