Basic Arrhythmia Course Final Exam | Comprehensive
Practice Questions & Detailed Rationales 2026/2027
QUESTION 1
What is the inherent pacing rate of the AV junction (junctional
pacemaker)?
A. 40 to 60 beats per minute
B. 60 to 100 beats per minute
C. 20 to 40 beats per minute
D. 100 to 150 beats per minute
Correct Answer: A. 40 to 60 beats per minute
Detailed Rationale: The AV junction serves as a secondary backup
pacemaker with an inherent firing rate of 40 to 60 beats per minute
when the SA node fails to fire.
QUESTION 2
Which criterion distinguishes a Mobitz Type I from a Mobitz Type II
second-degree AV block?
A. Mobitz I features progressive PR interval lengthening prior to a
dropped beat, whereas Mobitz II has a constant PR interval on
conducted beats with sudden dropped beats.
B. Mobitz I features wide QRS complexes; Mobitz II has narrow
complexes.
,C. Mobitz I occurs exclusively in the bundle branches, while Mobitz II
occurs in the SA node.
D. There is no electrocardiographic distinction between the two types.
Correct Answer: A. Mobitz I features progressive PR interval
lengthening prior to a dropped beat, whereas Mobitz II has a constant
PR interval on conducted beats with sudden dropped beats.
Detailed Rationale: Wenckebach (Mobitz I) involves progressive slowing
of AV nodal conduction until a beat is dropped, whereas Mobitz II
involves intermittent, sudden failure of conduction below the AV node
with fixed PR intervals.
QUESTION 3
In the setting of an acute inferior wall myocardial infarction, which
contiguous ECG leads typically display ST-segment elevation?
A. Leads II, III, and aVF
B. Leads V1 through V4
C. Leads I, aVL, and V5-V6
D. Leads V7, V8, and V9
Correct Answer: A. Leads II, III, and aVF
Detailed Rationale: Leads II, III, and aVF view the inferior wall of the left
ventricle and consistently show ST elevation during an acute inferior
STEMI.
QUESTION 4
,What is the primary rhythm mechanism when an ECG displays regular
wide QRS complexes at 160 beats per minute with evidence of AV
dissociation and capture beats?
A. Ventricular Tachycardia (VTach)
B. Supraventricular Tachycardia with aberrant conduction
C. Atrial Fibrillation with rapid ventricular response
D. Accelerated idioventricular rhythm
Correct Answer: A. Ventricular Tachycardia (VTach)
Detailed Rationale: The presence of AV dissociation, capture beats, and
wide QRS complexes (>0.14 seconds) during a regular wide-complex
tachycardia are diagnostic hallmarks confirming Ventricular Tachycardia.
QUESTION 5
What is the primary danger associated with an "R-on-T" premature
ventricular contraction (PVC)?
A. It falls on the relative refractory period (T wave peak), potentially
triggering lethal ventricular fibrillation or polymorphic VT.
B. It immediately causes severe sinus bradycardia.
C. It shortens the PR interval permanently.
D. It converts atrial flutter into normal sinus rhythm.
Correct Answer: A. It falls on the relative refractory period (T wave
peak), potentially triggering lethal ventricular fibrillation or polymorphic
VT.
, Detailed Rationale: The peak of the T wave represents a vulnerable
window of repolarization where an ectopic impulse can spark chaotic
reentrant arrhythmias like ventricular fibrillation.
QUESTION 6
Which medication is considered the first-line pharmacologic treatment
for stable Monomorphic Ventricular Tachycardia or acute ventricular
arrhythmias?
A. Amiodarone
B. Atropine
C. Adenosine
D. Digoxin
Correct Answer: A. Amiodarone
Detailed Rationale: Amiodarone is a Class III antiarrhythmic agent used
widely in ACLS protocols to treat stable ventricular tachycardia and
control refractory ventricular arrhythmias.
QUESTION 7
What is the correct initial drug dose and administration method for
treating symptomatic Supraventricular Tachycardia (SVT) via rapid IV
push?
A. Adenosine 6 milligrams rapid IV push followed by a 20 mL normal
saline flush
B. Atropine 1 milligram IV push
C. Amiodarone 150 milligrams over 10 minutes
Practice Questions & Detailed Rationales 2026/2027
QUESTION 1
What is the inherent pacing rate of the AV junction (junctional
pacemaker)?
A. 40 to 60 beats per minute
B. 60 to 100 beats per minute
C. 20 to 40 beats per minute
D. 100 to 150 beats per minute
Correct Answer: A. 40 to 60 beats per minute
Detailed Rationale: The AV junction serves as a secondary backup
pacemaker with an inherent firing rate of 40 to 60 beats per minute
when the SA node fails to fire.
QUESTION 2
Which criterion distinguishes a Mobitz Type I from a Mobitz Type II
second-degree AV block?
A. Mobitz I features progressive PR interval lengthening prior to a
dropped beat, whereas Mobitz II has a constant PR interval on
conducted beats with sudden dropped beats.
B. Mobitz I features wide QRS complexes; Mobitz II has narrow
complexes.
,C. Mobitz I occurs exclusively in the bundle branches, while Mobitz II
occurs in the SA node.
D. There is no electrocardiographic distinction between the two types.
Correct Answer: A. Mobitz I features progressive PR interval
lengthening prior to a dropped beat, whereas Mobitz II has a constant
PR interval on conducted beats with sudden dropped beats.
Detailed Rationale: Wenckebach (Mobitz I) involves progressive slowing
of AV nodal conduction until a beat is dropped, whereas Mobitz II
involves intermittent, sudden failure of conduction below the AV node
with fixed PR intervals.
QUESTION 3
In the setting of an acute inferior wall myocardial infarction, which
contiguous ECG leads typically display ST-segment elevation?
A. Leads II, III, and aVF
B. Leads V1 through V4
C. Leads I, aVL, and V5-V6
D. Leads V7, V8, and V9
Correct Answer: A. Leads II, III, and aVF
Detailed Rationale: Leads II, III, and aVF view the inferior wall of the left
ventricle and consistently show ST elevation during an acute inferior
STEMI.
QUESTION 4
,What is the primary rhythm mechanism when an ECG displays regular
wide QRS complexes at 160 beats per minute with evidence of AV
dissociation and capture beats?
A. Ventricular Tachycardia (VTach)
B. Supraventricular Tachycardia with aberrant conduction
C. Atrial Fibrillation with rapid ventricular response
D. Accelerated idioventricular rhythm
Correct Answer: A. Ventricular Tachycardia (VTach)
Detailed Rationale: The presence of AV dissociation, capture beats, and
wide QRS complexes (>0.14 seconds) during a regular wide-complex
tachycardia are diagnostic hallmarks confirming Ventricular Tachycardia.
QUESTION 5
What is the primary danger associated with an "R-on-T" premature
ventricular contraction (PVC)?
A. It falls on the relative refractory period (T wave peak), potentially
triggering lethal ventricular fibrillation or polymorphic VT.
B. It immediately causes severe sinus bradycardia.
C. It shortens the PR interval permanently.
D. It converts atrial flutter into normal sinus rhythm.
Correct Answer: A. It falls on the relative refractory period (T wave
peak), potentially triggering lethal ventricular fibrillation or polymorphic
VT.
, Detailed Rationale: The peak of the T wave represents a vulnerable
window of repolarization where an ectopic impulse can spark chaotic
reentrant arrhythmias like ventricular fibrillation.
QUESTION 6
Which medication is considered the first-line pharmacologic treatment
for stable Monomorphic Ventricular Tachycardia or acute ventricular
arrhythmias?
A. Amiodarone
B. Atropine
C. Adenosine
D. Digoxin
Correct Answer: A. Amiodarone
Detailed Rationale: Amiodarone is a Class III antiarrhythmic agent used
widely in ACLS protocols to treat stable ventricular tachycardia and
control refractory ventricular arrhythmias.
QUESTION 7
What is the correct initial drug dose and administration method for
treating symptomatic Supraventricular Tachycardia (SVT) via rapid IV
push?
A. Adenosine 6 milligrams rapid IV push followed by a 20 mL normal
saline flush
B. Atropine 1 milligram IV push
C. Amiodarone 150 milligrams over 10 minutes
