Relias Dysrhythmia Basic B Test 2026 Study
Guide | Verified Questions & Answers for
Cardiac Rhythm Interpretation Success
Relias Dysrhythmia Basic B Test 2026 Study Guide
• This comprehensive study guide contains verified exam questions with detailed
EXPERT RATIONALE to master cardiac dysrhythmia interpretation and clinical
management.
• Use this material by reviewing each question, attempting to identify the correct
rhythm/answer before revealing the solution, and studying the EXPERT
RATIONALE to reinforce key concepts and exam success.
1. A 68-year-old patient presents with a regular rhythm at 72 bpm. The ECG
shows upright P waves before each QRS complex in leads II, III, and aVF. What
rhythm is this?
A) Atrial fibrillation
B) Normal sinus rhythm
C) Atrial flutter
D) Junctional rhythm
E) Wandering atrial pacemaker
B) Normal sinus rhythm
EXPERT RATIONALE: Normal sinus rhythm is characterized by a regular rate (60-
100 bpm), upright P waves in leads II, III, aVF (indicating normal sinus atrial
depolarization), a constant PR interval (0.12-0.20 seconds), and a QRS duration less
than 0.12 seconds. All criteria are met in this case. Atrial fibrillation lacks P waves;
atrial flutter shows sawtooth waves; junctional rhythm shows absent or inverted P
waves; wandering atrial pacemaker shows varying P wave morphology.
2. An ECG demonstrates a rate of 152 bpm with a regular rhythm and a
sawtooth baseline between QRS complexes. What is this dysrhythmia?
,A) Atrial fibrillation
B) Atrial flutter
C) Supraventricular tachycardia
D) Sinus tachycardia
E) Ventricular tachycardia
B) Atrial flutter
EXPERT RATIONALE: Atrial flutter is characterized by a regular ventricular rate
(typically 120-220 bpm), a "sawtooth" or "picket fence" baseline created by
continuous atrial depolarization, and a regular R-R interval. The atrial rate is
typically 250-350 bpm. Common conduction ratios are 2:1 (rate ~150), 3:1 (~100), or
4:1 (~75). Atrial fibrillation is chaotic and irregular; SVT may present regularly but
lacks sawtooth waves; sinus tachycardia shows normal P waves; ventricular
tachycardia has wide QRS complexes.
3. A patient with chronic atrial fibrillation is on digoxin. The ECG shows an
irregular rhythm at 68 bpm with no visible P waves. What finding might
indicate digoxin toxicity in this patient?
A) Increased ventricular rate
B) Regularization of the rhythm
C) Increased PR interval
D) Flattened T waves
E) ST segment elevation
B) Regularization of the rhythm
EXPERT RATIONALE: Digoxin toxicity in atrial fibrillation can produce a regular
ventricular rate due to increased AV block creating a regular "dropped beat" pattern
(atrial fibrillation with complete AV block resulting in junctional rhythm). This
regularization is a classic sign of digoxin toxicity. Other signs include junctional
rhythms, PACs, and potentially dangerous dysrhythmias. Increased ventricular rate
,indicates inadequate digoxin effect. Increased PR interval alone is not specific for
toxicity. Flattened T waves and ST elevation are non-specific findings.
4. An ECG shows premature beats occurring at regular intervals before every
other normal beat (bigeminy). The premature beats have a different
morphology than the normal complexes and originate above the AV node.
What is this dysrhythmia?
A) Premature ventricular contractions in bigeminy
B) Premature atrial contractions in bigeminy
C) Sinus arrhythmia
D) Wandering atrial pacemaker
E) Atrial fibrillation with frequent aberrancy
B) Premature atrial contractions in bigeminy
EXPERT RATIONALE: Premature atrial contractions (PACs) in bigeminy occur when
an ectopic atrial focus fires prematurely in a regular pattern before every other
beat. PACs show an abnormal P wave with different morphology than sinus beats,
may have a shortened PR interval depending on location, and the QRS is usually
narrow (unless aberrantly conducted). The rhythm is termed bigeminy because the
pattern repeats every two beats. PVCs in bigeminy would show wide QRS
complexes. Wandering atrial pacemaker shows varying P wave morphology with
normal conduction. Sinus arrhythmia shows normal P waves with variable rate.
5. A 55-year-old patient presents with chest pain and dyspnea. The ECG shows
a rate of 198 bpm with a regular rhythm and a narrow QRS complex. No P
waves are visible. What is the most likely diagnosis?
A) Atrial flutter with rapid ventricular response
B) Supraventricular tachycardia
C) Sinus tachycardia secondary to anxiety
, D) Ventricular tachycardia
E) Atrial fibrillation with rapid ventricular response
B) Supraventricular tachycardia
EXPERT RATIONALE: Supraventricular tachycardia (SVT) presents with a regular
narrow complex tachycardia (typically 140-250 bpm), absent or buried P waves
(often in or after the QRS or T wave), and an abrupt onset. SVT is most commonly
atrioventricular reentrant tachycardia (AVRT) or atrioventricular nodal reentrant
tachycardia (AVNRT). The regularity and rate are key distinguishing features. Atrial
flutter would show sawtooth waves; sinus tachycardia would show visible sinus P
waves; ventricular tachycardia shows wide QRS complexes; atrial fibrillation is
irregular.
6. On telemetry, a patient shows occasional wide QRS complexes (0.14
seconds) that occur prematurely and have a different morphology than the
underlying rhythm. The underlying rhythm is regular at 78 bpm. What is this
dysrhythmia?
A) Bundle branch block
B) Premature ventricular contraction
C) Aberrantly conducted PAC
D) Ventricular tachycardia
E) Atrial fibrillation with aberrancy
B) Premature ventricular contraction
EXPERT RATIONALE: Premature ventricular contractions (PVCs) are ectopic beats
originating from ventricular tissue that occur before the next expected sinus beat.
They are characterized by wide QRS complexes (>0.12 seconds), abnormal T wave
(opposite direction from QRS), and absence of a preceding P wave. PVCs occur
prematurely relative to the underlying rhythm and have different morphology. A
bundle branch block would be consistently present; aberrant PACs would have
Guide | Verified Questions & Answers for
Cardiac Rhythm Interpretation Success
Relias Dysrhythmia Basic B Test 2026 Study Guide
• This comprehensive study guide contains verified exam questions with detailed
EXPERT RATIONALE to master cardiac dysrhythmia interpretation and clinical
management.
• Use this material by reviewing each question, attempting to identify the correct
rhythm/answer before revealing the solution, and studying the EXPERT
RATIONALE to reinforce key concepts and exam success.
1. A 68-year-old patient presents with a regular rhythm at 72 bpm. The ECG
shows upright P waves before each QRS complex in leads II, III, and aVF. What
rhythm is this?
A) Atrial fibrillation
B) Normal sinus rhythm
C) Atrial flutter
D) Junctional rhythm
E) Wandering atrial pacemaker
B) Normal sinus rhythm
EXPERT RATIONALE: Normal sinus rhythm is characterized by a regular rate (60-
100 bpm), upright P waves in leads II, III, aVF (indicating normal sinus atrial
depolarization), a constant PR interval (0.12-0.20 seconds), and a QRS duration less
than 0.12 seconds. All criteria are met in this case. Atrial fibrillation lacks P waves;
atrial flutter shows sawtooth waves; junctional rhythm shows absent or inverted P
waves; wandering atrial pacemaker shows varying P wave morphology.
2. An ECG demonstrates a rate of 152 bpm with a regular rhythm and a
sawtooth baseline between QRS complexes. What is this dysrhythmia?
,A) Atrial fibrillation
B) Atrial flutter
C) Supraventricular tachycardia
D) Sinus tachycardia
E) Ventricular tachycardia
B) Atrial flutter
EXPERT RATIONALE: Atrial flutter is characterized by a regular ventricular rate
(typically 120-220 bpm), a "sawtooth" or "picket fence" baseline created by
continuous atrial depolarization, and a regular R-R interval. The atrial rate is
typically 250-350 bpm. Common conduction ratios are 2:1 (rate ~150), 3:1 (~100), or
4:1 (~75). Atrial fibrillation is chaotic and irregular; SVT may present regularly but
lacks sawtooth waves; sinus tachycardia shows normal P waves; ventricular
tachycardia has wide QRS complexes.
3. A patient with chronic atrial fibrillation is on digoxin. The ECG shows an
irregular rhythm at 68 bpm with no visible P waves. What finding might
indicate digoxin toxicity in this patient?
A) Increased ventricular rate
B) Regularization of the rhythm
C) Increased PR interval
D) Flattened T waves
E) ST segment elevation
B) Regularization of the rhythm
EXPERT RATIONALE: Digoxin toxicity in atrial fibrillation can produce a regular
ventricular rate due to increased AV block creating a regular "dropped beat" pattern
(atrial fibrillation with complete AV block resulting in junctional rhythm). This
regularization is a classic sign of digoxin toxicity. Other signs include junctional
rhythms, PACs, and potentially dangerous dysrhythmias. Increased ventricular rate
,indicates inadequate digoxin effect. Increased PR interval alone is not specific for
toxicity. Flattened T waves and ST elevation are non-specific findings.
4. An ECG shows premature beats occurring at regular intervals before every
other normal beat (bigeminy). The premature beats have a different
morphology than the normal complexes and originate above the AV node.
What is this dysrhythmia?
A) Premature ventricular contractions in bigeminy
B) Premature atrial contractions in bigeminy
C) Sinus arrhythmia
D) Wandering atrial pacemaker
E) Atrial fibrillation with frequent aberrancy
B) Premature atrial contractions in bigeminy
EXPERT RATIONALE: Premature atrial contractions (PACs) in bigeminy occur when
an ectopic atrial focus fires prematurely in a regular pattern before every other
beat. PACs show an abnormal P wave with different morphology than sinus beats,
may have a shortened PR interval depending on location, and the QRS is usually
narrow (unless aberrantly conducted). The rhythm is termed bigeminy because the
pattern repeats every two beats. PVCs in bigeminy would show wide QRS
complexes. Wandering atrial pacemaker shows varying P wave morphology with
normal conduction. Sinus arrhythmia shows normal P waves with variable rate.
5. A 55-year-old patient presents with chest pain and dyspnea. The ECG shows
a rate of 198 bpm with a regular rhythm and a narrow QRS complex. No P
waves are visible. What is the most likely diagnosis?
A) Atrial flutter with rapid ventricular response
B) Supraventricular tachycardia
C) Sinus tachycardia secondary to anxiety
, D) Ventricular tachycardia
E) Atrial fibrillation with rapid ventricular response
B) Supraventricular tachycardia
EXPERT RATIONALE: Supraventricular tachycardia (SVT) presents with a regular
narrow complex tachycardia (typically 140-250 bpm), absent or buried P waves
(often in or after the QRS or T wave), and an abrupt onset. SVT is most commonly
atrioventricular reentrant tachycardia (AVRT) or atrioventricular nodal reentrant
tachycardia (AVNRT). The regularity and rate are key distinguishing features. Atrial
flutter would show sawtooth waves; sinus tachycardia would show visible sinus P
waves; ventricular tachycardia shows wide QRS complexes; atrial fibrillation is
irregular.
6. On telemetry, a patient shows occasional wide QRS complexes (0.14
seconds) that occur prematurely and have a different morphology than the
underlying rhythm. The underlying rhythm is regular at 78 bpm. What is this
dysrhythmia?
A) Bundle branch block
B) Premature ventricular contraction
C) Aberrantly conducted PAC
D) Ventricular tachycardia
E) Atrial fibrillation with aberrancy
B) Premature ventricular contraction
EXPERT RATIONALE: Premature ventricular contractions (PVCs) are ectopic beats
originating from ventricular tissue that occur before the next expected sinus beat.
They are characterized by wide QRS complexes (>0.12 seconds), abnormal T wave
(opposite direction from QRS), and absence of a preceding P wave. PVCs occur
prematurely relative to the underlying rhythm and have different morphology. A
bundle branch block would be consistently present; aberrant PACs would have
