Relias Advanced Dysrhythmia
Exam A: The Elite Test Bank
PART I: THE PRIMER
Mastering advanced dysrhythmia interpretation is the absolute foundation of high-stakes clinical
architecture. Professional intuition must instantly decode electrical chaos into precise,
protocol-driven interventions under the strict 2026/2027 standards.
● The Atropine Mandate: The 2025/2026 AHA minimum first-line dose for symptomatic
bradycardia is exactly 1.0 mg rapid IV push, repeating every 3-5 minutes to a maximum of
3 mg.
● The Cardioversion Floor: Initial synchronized cardioversion for atrial fibrillation or flutter
with rapid ventricular response mandates a starting energy of 200 Joules biphasic.
● The Capnography Hard Deck: An ETCO2 below 10 mmHg indicates catastrophic
compression failure; an abrupt, sustained spike indicates ROSC.
● The Torsades Exception: Magnesium sulfate is exclusively reserved for polymorphic VT
(Torsades de Pointes) or verified hypomagnesemia.
PART II: THE ELITE TEST BANK
Q1: A telemetry monitor displays a regular rhythm at 78 bpm. A uniform, upright P wave
precedes every narrow QRS complex. The PR interval measures precisely 0.16 seconds,
and the QRS duration is 0.08 seconds. What is the definitive classification? A)
First-Degree Atrioventricular Block B) Normal Sinus Rhythm C) Accelerated Junctional Rhythm
D) Sinus Tachycardia
● The Answer: B (Normal Sinus Rhythm)
● Distractor Analysis: Option A is mathematically incorrect; a first-degree block requires a
PR interval strictly exceeding 0.20 seconds. Option C is anatomically flawed, as junctional
rhythms produce retrograde or absent P waves due to AV node origin. Option D ignores
the foundational 100 bpm threshold for tachycardia.
● The Mentor's Analysis: Normal sinus rhythm demands strict mathematical conformity.
The professional architect recognizes the absolute parameters: a rate of 60–100 bpm,
regular R-R intervals, upright P waves in lead II, a PR interval between 0.12–0.20
seconds, and a QRS under 0.12 seconds. The presence of normal syntax confirms intact
antegrade conduction from the sinoatrial node through the His-Purkinje system without
pathological delay.
Q2: A rhythm strip exhibits a regular rate of 52 bpm. Upright P waves are present, but the
PR interval measures a constant 0.26 seconds. The QRS duration is 0.08 seconds. What
is the diagnosis? A) Sinus Bradycardia B) First-Degree AV Block C) Second-Degree AV Block
Type I D) Third-Degree AV Block
● The Answer: B (First-Degree AV Block)
● Distractor Analysis: Option A is incomplete, addressing the rate but fatally ignoring the
prolonged conduction delay. Option C requires progressive PR lengthening culminating in
, dropped beats. Option D demands complete AV dissociation, not a constant, tracking PR
interval.
● The Mentor's Analysis: The definitive marker of a first-degree block is a fixed PR interval
exceeding 0.20 seconds (one large box) with fully intact 1:1 conduction. The electrical
impulse is delayed at the AV node, but no ventricular beats are dropped. This is generally
a benign finding but requires monitoring for progression when administering AV nodal
blocking agents.
Q3: Analysis reveals an irregular rhythm. The PR interval progressively lengthens with
each successive beat until a P wave appears without a subsequent QRS complex. The
pattern then resets. What is this rhythm? A) Second-Degree AV Block Type I (Wenckebach)
B) Second-Degree AV Block Type II C) Premature Atrial Contractions D) Third-Degree AV Block
● The Answer: A (Second-Degree AV Block Type I (Wenckebach))
● Distractor Analysis: Option B features dropped QRS complexes but maintains a strictly
constant PR interval before the drop. Option C represents early ectopic beats disrupting
the underlying rhythm, not antegrade conduction failure. Option D lacks any relationship
between atrial and ventricular depolarization.
● The Mentor's Analysis: Wenckebach is characterized by the progressive cellular fatigue
of the AV node. This manifests on the surface ECG as a progressively lengthening PR
interval, ultimately culminating in an absolute refractory state and a dropped ventricular
contraction. The R-R interval becomes irregular, but the underlying P-P interval remains
regular.
Q4: A rhythm strip demonstrates a regular atrial rate. The PR interval is constant at 0.18
seconds on conducted beats, but there are intermittent, randomly dropped QRS
complexes. What is the precise classification? A) Second-Degree AV Block Type I B)
Second-Degree AV Block Type II C) Complete Heart Block D) Non-conducted PAC
● The Answer: B (Second-Degree AV Block Type II)
● Distractor Analysis: Option A is eliminated due to the constant PR interval; Type I must
progressively lengthen. Option C is incorrect because conducted beats maintain a
consistent PR relationship, proving communication exists. Option D is an isolated atrial
event, not a persistent structural conduction block.
● The Mentor's Analysis: Mobitz Type II is a highly unstable infranodal block, usually
located within the bundle branches. The constant PR interval before the dropped beat
proves the block is occurring below the AV node. This carries a severe risk of sudden
progression to complete heart block or ventricular standstill, immediately necessitating
transcutaneous pacing readiness.
Q5: A patient’s ECG shows a regular atrial rate of 80 bpm and a regular, wide-complex
ventricular rate of 35 bpm. There is absolute dissociation between the P waves and the
QRS complexes. What is this rhythm? A) Second-Degree AV Block Type II B) Idioventricular
Rhythm C) Third-Degree AV Block D) Sinus Arrest with Escape Rhythm
● The Answer: C (Third-Degree AV Block)
● Distractor Analysis: Option A requires some P waves to successfully conduct to the
ventricles. Option B lacks organized atrial activity (P waves) entirely. Option D involves a
failure of the SA node, but here the SA node is firing normally at 80 bpm.
● The Mentor's Analysis: Complete heart block is defined by total atrioventricular
dissociation. The atria are paced by the SA node, and the ventricles are paced
independently by an escape pacemaker (in this case, Purkinje fibers, evidenced by the
wide QRS and 35 bpm rate).
, AV Block Type PR Interval QRS Drop Pattern Clinical Severity
Characteristic
First-Degree Constant, > 0.20 sec None Benign
Second-Degree Type I Progressively Predictable, grouped Usually benign
lengthening beating
Second-Degree Type II Constant on conducted Unpredictable, sudden High risk
beats
Third-Degree Variable, completely Complete failure of Lethal emergency
dissociated conduction
Q6: A 6-second strip reveals an irregularly irregular rhythm with a narrow QRS complex.
There are no discernible P waves; instead, a chaotic, wavy baseline is present. What is
the rhythm? A) Atrial Flutter B) Ventricular Fibrillation C) Atrial Fibrillation D) Supraventricular
Tachycardia
● The Answer: C (Atrial Fibrillation)
● Distractor Analysis: Option A is incorrect because it features highly organized,
macro-reentrant sawtooth flutter waves. Option B is a lethal wide-complex rhythm with no
cardiac output. Option D is strictly regular.
● The Mentor's Analysis: Atrial fibrillation is defined structurally by the absolute absence
of organized atrial depolarization (no P waves), an irregularly irregular R-R interval, and a
narrow QRS complex. The clinical priority shifts immediately to assessing hemodynamic
stability, stroke risk via stagnation of blood in the left atrial appendage, and ventricular rate
control.
Q7: An ECG displays a regular ventricular response at 75 bpm. The baseline consists of
continuous, identical "sawtooth" deflections at a rate of 300 bpm. The QRS is narrow.
What is the rhythm? A) Atrial Fibrillation B) Atrial Flutter C) Ventricular Tachycardia D)
Junctional Tachycardia
● The Answer: B (Atrial Flutter)
● Distractor Analysis: Option A lacks organized atrial activity, presenting as a fibrillatory
baseline. Option C is a wide-complex rhythm originating in the ventricles. Option D
features absent or retrograde P waves, not continuous sawtooth waves.
● The Mentor's Analysis: The sawtooth morphology represents a massive
macro-reentrant circuit localized within the right atrium, typically firing at roughly 250-350
bpm. The AV node acts as a physiological gatekeeper, protecting the ventricles by
conducting impulses in a fixed mathematical ratio (e.g., 4:1 conduction yielding a
ventricular rate of 75 bpm).
Q8: A rhythm strip shows a regular rate of 48 bpm. The QRS complexes are narrow (0.08
seconds). P waves are entirely absent. Where is the primary pacemaker originating? A)
SA Node B) AV Node C) Bundle Branches D) Purkinje Fibers
● The Answer: B (AV Node)
● Distractor Analysis: Option A is incorrect; intact SA node firing produces upright P
waves. Options C and D originate below the bifurcation of the bundle of His, inherently
producing wide QRS complexes (>0.12s) indicative of ventricular escape rhythms.
● The Mentor's Analysis: When the SA node fails or is suppressed, the AV junction
assumes pacemaker control at its intrinsic, fail-safe rate of 40-60 bpm. Because the
electrical impulse originates at the AV node, atrial depolarization is either completely
absent or occurs in a retrograde fashion, resulting in missing or inverted P waves. The
narrow QRS confirms standard conduction through the ventricles.
Exam A: The Elite Test Bank
PART I: THE PRIMER
Mastering advanced dysrhythmia interpretation is the absolute foundation of high-stakes clinical
architecture. Professional intuition must instantly decode electrical chaos into precise,
protocol-driven interventions under the strict 2026/2027 standards.
● The Atropine Mandate: The 2025/2026 AHA minimum first-line dose for symptomatic
bradycardia is exactly 1.0 mg rapid IV push, repeating every 3-5 minutes to a maximum of
3 mg.
● The Cardioversion Floor: Initial synchronized cardioversion for atrial fibrillation or flutter
with rapid ventricular response mandates a starting energy of 200 Joules biphasic.
● The Capnography Hard Deck: An ETCO2 below 10 mmHg indicates catastrophic
compression failure; an abrupt, sustained spike indicates ROSC.
● The Torsades Exception: Magnesium sulfate is exclusively reserved for polymorphic VT
(Torsades de Pointes) or verified hypomagnesemia.
PART II: THE ELITE TEST BANK
Q1: A telemetry monitor displays a regular rhythm at 78 bpm. A uniform, upright P wave
precedes every narrow QRS complex. The PR interval measures precisely 0.16 seconds,
and the QRS duration is 0.08 seconds. What is the definitive classification? A)
First-Degree Atrioventricular Block B) Normal Sinus Rhythm C) Accelerated Junctional Rhythm
D) Sinus Tachycardia
● The Answer: B (Normal Sinus Rhythm)
● Distractor Analysis: Option A is mathematically incorrect; a first-degree block requires a
PR interval strictly exceeding 0.20 seconds. Option C is anatomically flawed, as junctional
rhythms produce retrograde or absent P waves due to AV node origin. Option D ignores
the foundational 100 bpm threshold for tachycardia.
● The Mentor's Analysis: Normal sinus rhythm demands strict mathematical conformity.
The professional architect recognizes the absolute parameters: a rate of 60–100 bpm,
regular R-R intervals, upright P waves in lead II, a PR interval between 0.12–0.20
seconds, and a QRS under 0.12 seconds. The presence of normal syntax confirms intact
antegrade conduction from the sinoatrial node through the His-Purkinje system without
pathological delay.
Q2: A rhythm strip exhibits a regular rate of 52 bpm. Upright P waves are present, but the
PR interval measures a constant 0.26 seconds. The QRS duration is 0.08 seconds. What
is the diagnosis? A) Sinus Bradycardia B) First-Degree AV Block C) Second-Degree AV Block
Type I D) Third-Degree AV Block
● The Answer: B (First-Degree AV Block)
● Distractor Analysis: Option A is incomplete, addressing the rate but fatally ignoring the
prolonged conduction delay. Option C requires progressive PR lengthening culminating in
, dropped beats. Option D demands complete AV dissociation, not a constant, tracking PR
interval.
● The Mentor's Analysis: The definitive marker of a first-degree block is a fixed PR interval
exceeding 0.20 seconds (one large box) with fully intact 1:1 conduction. The electrical
impulse is delayed at the AV node, but no ventricular beats are dropped. This is generally
a benign finding but requires monitoring for progression when administering AV nodal
blocking agents.
Q3: Analysis reveals an irregular rhythm. The PR interval progressively lengthens with
each successive beat until a P wave appears without a subsequent QRS complex. The
pattern then resets. What is this rhythm? A) Second-Degree AV Block Type I (Wenckebach)
B) Second-Degree AV Block Type II C) Premature Atrial Contractions D) Third-Degree AV Block
● The Answer: A (Second-Degree AV Block Type I (Wenckebach))
● Distractor Analysis: Option B features dropped QRS complexes but maintains a strictly
constant PR interval before the drop. Option C represents early ectopic beats disrupting
the underlying rhythm, not antegrade conduction failure. Option D lacks any relationship
between atrial and ventricular depolarization.
● The Mentor's Analysis: Wenckebach is characterized by the progressive cellular fatigue
of the AV node. This manifests on the surface ECG as a progressively lengthening PR
interval, ultimately culminating in an absolute refractory state and a dropped ventricular
contraction. The R-R interval becomes irregular, but the underlying P-P interval remains
regular.
Q4: A rhythm strip demonstrates a regular atrial rate. The PR interval is constant at 0.18
seconds on conducted beats, but there are intermittent, randomly dropped QRS
complexes. What is the precise classification? A) Second-Degree AV Block Type I B)
Second-Degree AV Block Type II C) Complete Heart Block D) Non-conducted PAC
● The Answer: B (Second-Degree AV Block Type II)
● Distractor Analysis: Option A is eliminated due to the constant PR interval; Type I must
progressively lengthen. Option C is incorrect because conducted beats maintain a
consistent PR relationship, proving communication exists. Option D is an isolated atrial
event, not a persistent structural conduction block.
● The Mentor's Analysis: Mobitz Type II is a highly unstable infranodal block, usually
located within the bundle branches. The constant PR interval before the dropped beat
proves the block is occurring below the AV node. This carries a severe risk of sudden
progression to complete heart block or ventricular standstill, immediately necessitating
transcutaneous pacing readiness.
Q5: A patient’s ECG shows a regular atrial rate of 80 bpm and a regular, wide-complex
ventricular rate of 35 bpm. There is absolute dissociation between the P waves and the
QRS complexes. What is this rhythm? A) Second-Degree AV Block Type II B) Idioventricular
Rhythm C) Third-Degree AV Block D) Sinus Arrest with Escape Rhythm
● The Answer: C (Third-Degree AV Block)
● Distractor Analysis: Option A requires some P waves to successfully conduct to the
ventricles. Option B lacks organized atrial activity (P waves) entirely. Option D involves a
failure of the SA node, but here the SA node is firing normally at 80 bpm.
● The Mentor's Analysis: Complete heart block is defined by total atrioventricular
dissociation. The atria are paced by the SA node, and the ventricles are paced
independently by an escape pacemaker (in this case, Purkinje fibers, evidenced by the
wide QRS and 35 bpm rate).
, AV Block Type PR Interval QRS Drop Pattern Clinical Severity
Characteristic
First-Degree Constant, > 0.20 sec None Benign
Second-Degree Type I Progressively Predictable, grouped Usually benign
lengthening beating
Second-Degree Type II Constant on conducted Unpredictable, sudden High risk
beats
Third-Degree Variable, completely Complete failure of Lethal emergency
dissociated conduction
Q6: A 6-second strip reveals an irregularly irregular rhythm with a narrow QRS complex.
There are no discernible P waves; instead, a chaotic, wavy baseline is present. What is
the rhythm? A) Atrial Flutter B) Ventricular Fibrillation C) Atrial Fibrillation D) Supraventricular
Tachycardia
● The Answer: C (Atrial Fibrillation)
● Distractor Analysis: Option A is incorrect because it features highly organized,
macro-reentrant sawtooth flutter waves. Option B is a lethal wide-complex rhythm with no
cardiac output. Option D is strictly regular.
● The Mentor's Analysis: Atrial fibrillation is defined structurally by the absolute absence
of organized atrial depolarization (no P waves), an irregularly irregular R-R interval, and a
narrow QRS complex. The clinical priority shifts immediately to assessing hemodynamic
stability, stroke risk via stagnation of blood in the left atrial appendage, and ventricular rate
control.
Q7: An ECG displays a regular ventricular response at 75 bpm. The baseline consists of
continuous, identical "sawtooth" deflections at a rate of 300 bpm. The QRS is narrow.
What is the rhythm? A) Atrial Fibrillation B) Atrial Flutter C) Ventricular Tachycardia D)
Junctional Tachycardia
● The Answer: B (Atrial Flutter)
● Distractor Analysis: Option A lacks organized atrial activity, presenting as a fibrillatory
baseline. Option C is a wide-complex rhythm originating in the ventricles. Option D
features absent or retrograde P waves, not continuous sawtooth waves.
● The Mentor's Analysis: The sawtooth morphology represents a massive
macro-reentrant circuit localized within the right atrium, typically firing at roughly 250-350
bpm. The AV node acts as a physiological gatekeeper, protecting the ventricles by
conducting impulses in a fixed mathematical ratio (e.g., 4:1 conduction yielding a
ventricular rate of 75 bpm).
Q8: A rhythm strip shows a regular rate of 48 bpm. The QRS complexes are narrow (0.08
seconds). P waves are entirely absent. Where is the primary pacemaker originating? A)
SA Node B) AV Node C) Bundle Branches D) Purkinje Fibers
● The Answer: B (AV Node)
● Distractor Analysis: Option A is incorrect; intact SA node firing produces upright P
waves. Options C and D originate below the bifurcation of the bundle of His, inherently
producing wide QRS complexes (>0.12s) indicative of ventricular escape rhythms.
● The Mentor's Analysis: When the SA node fails or is suppressed, the AV junction
assumes pacemaker control at its intrinsic, fail-safe rate of 40-60 bpm. Because the
electrical impulse originates at the AV node, atrial depolarization is either completely
absent or occurs in a retrograde fashion, resulting in missing or inverted P waves. The
narrow QRS confirms standard conduction through the ventricles.
