Relias-style Dysrhythmia Practice — 35 Questions
1. Rhythm strip shows regular narrow QRS complex tachycardia at ~180 bpm
with abrupt onset and termination. Patient is stable. Best immediate action?
A. IV amiodarone
B. Vagal maneuvers (e.g., Valsalva), then IV adenosine if needed
C. Immediate synchronized cardioversion
D. Start dopamine infusion
Rationale: Regular, narrow-complex SVT in a stable patient → try vagal
maneuvers first; adenosine is the next step if vagal maneuvers fail.
Test tip: For narrow regular tachycardia → vagal → adenosine; if unstable →
cardioversion.
2. 12-lead ECG: Irregularly irregular rhythm, absent P waves, variable R–R
intervals. Best interpretation?
A. Multifocal atrial tachycardia
B. Atrial fibrillation
C. Atrial flutter with variable block
D. Sinus arrhythmia
Rationale: Irregularly irregular with no discernible P waves = atrial fibrillation.
Test tip: “Irregularly irregular = AFib” is a high-yield phrase.
3. Patient in atrial fibrillation becomes hypotensive and diaphoretic. Best
immediate management?
A. IV rate control with diltiazem
B. Synchronized cardioversion
C. Start oral anticoagulation now
D. Observe and repeat ECG in 30 min
Rationale: Hemodynamic instability from any arrhythmia → immediate
synchronized cardioversion.
Test tip: Unstable = electricity, not meds.
, 4. Rhythm: wide QRS tachycardia, patient is pulseless. What is the correct
action?
A. Synchronized cardioversion
B. IV amiodarone while monitoring pulse
C. Immediate unsynchronized defibrillation (shock) and CPR
D. IV adenosine
Rationale: Pulseless ventricular tachycardia is a shockable rhythm —
immediate defibrillation and CPR per ACLS.
Test tip: Pulseless VT/VF → defib + CPR.
5. ECG shows prolonged PR interval (>200 ms), each QRS preceded by a P wave,
all conducted. Diagnosis?
A. Mobitz type I AV block
B. First-degree AV block
C. Complete heart block
D. Mobitz type II AV block
Rationale: Prolonged but constant PR interval with 1:1 conduction = first-
degree AV block.
Test tip: Long PR but every P followed by QRS → 1st degree.
6. Rhythm: progressive PR lengthening until a dropped QRS, then cycle repeats.
Diagnosis?
A. Mobitz type I (Wenckebach) AV block
B. Mobitz type II AV block
C. Complete heart block
D. First-degree AV block
Rationale: Progressive PR prolongation with eventual nonconducted P wave =
Mobitz I.
Test tip: “Longer, longer, longer, drop — then you’ve got Wenckebach.”
7. Rhythm: constant PR intervals with sudden dropped QRS complexes, no
progressive prolongation. Likely diagnosis?
A. Sinus arrest
1. Rhythm strip shows regular narrow QRS complex tachycardia at ~180 bpm
with abrupt onset and termination. Patient is stable. Best immediate action?
A. IV amiodarone
B. Vagal maneuvers (e.g., Valsalva), then IV adenosine if needed
C. Immediate synchronized cardioversion
D. Start dopamine infusion
Rationale: Regular, narrow-complex SVT in a stable patient → try vagal
maneuvers first; adenosine is the next step if vagal maneuvers fail.
Test tip: For narrow regular tachycardia → vagal → adenosine; if unstable →
cardioversion.
2. 12-lead ECG: Irregularly irregular rhythm, absent P waves, variable R–R
intervals. Best interpretation?
A. Multifocal atrial tachycardia
B. Atrial fibrillation
C. Atrial flutter with variable block
D. Sinus arrhythmia
Rationale: Irregularly irregular with no discernible P waves = atrial fibrillation.
Test tip: “Irregularly irregular = AFib” is a high-yield phrase.
3. Patient in atrial fibrillation becomes hypotensive and diaphoretic. Best
immediate management?
A. IV rate control with diltiazem
B. Synchronized cardioversion
C. Start oral anticoagulation now
D. Observe and repeat ECG in 30 min
Rationale: Hemodynamic instability from any arrhythmia → immediate
synchronized cardioversion.
Test tip: Unstable = electricity, not meds.
, 4. Rhythm: wide QRS tachycardia, patient is pulseless. What is the correct
action?
A. Synchronized cardioversion
B. IV amiodarone while monitoring pulse
C. Immediate unsynchronized defibrillation (shock) and CPR
D. IV adenosine
Rationale: Pulseless ventricular tachycardia is a shockable rhythm —
immediate defibrillation and CPR per ACLS.
Test tip: Pulseless VT/VF → defib + CPR.
5. ECG shows prolonged PR interval (>200 ms), each QRS preceded by a P wave,
all conducted. Diagnosis?
A. Mobitz type I AV block
B. First-degree AV block
C. Complete heart block
D. Mobitz type II AV block
Rationale: Prolonged but constant PR interval with 1:1 conduction = first-
degree AV block.
Test tip: Long PR but every P followed by QRS → 1st degree.
6. Rhythm: progressive PR lengthening until a dropped QRS, then cycle repeats.
Diagnosis?
A. Mobitz type I (Wenckebach) AV block
B. Mobitz type II AV block
C. Complete heart block
D. First-degree AV block
Rationale: Progressive PR prolongation with eventual nonconducted P wave =
Mobitz I.
Test tip: “Longer, longer, longer, drop — then you’ve got Wenckebach.”
7. Rhythm: constant PR intervals with sudden dropped QRS complexes, no
progressive prolongation. Likely diagnosis?
A. Sinus arrest
