Relias Dysrhythmia Basic A Test 2026/2027 – Verified
Questions & Rationales | ECG Rhythm Interpretation, Heart
Blocks, ACLS Interventions | Pass Guaranteed
,1. Which structure normally serves as the primary pacemaker of the heart?
A. AV node
B. SA node
C. Bundle of His
D. Purkinje fibers
Answer: SA node
Rationale: The SA node has the fastest intrinsic rate, 60 to 100 bpm, so it
normally initiates the cardiac impulse.
2. What is the normal intrinsic rate of the SA node?
A. 20 to 40 bpm
B. 40 to 60 bpm
C. 60 to 100 bpm
D. 100 to 150 bpm
Answer: 60 to 100 bpm
Rationale: The SA node normally fires at 60 to 100 bpm, defining normal
sinus rhythm.
3. Which rhythm has regular P waves before every QRS, a rate of 60 to 100
bpm, a PR interval of 0.12 to 0.20 seconds, and a QRS less than 0.12
seconds?
A. Sinus bradycardia
B. Normal sinus rhythm
C. Junctional rhythm
D. Atrial flutter
Answer: Normal sinus rhythm
, Rationale: NSR meets all criteria: regular, rate 60 to 100, upright P before
each QRS, normal PR and QRS.
4. What is the rate in sinus bradycardia?
A. Less than 60 bpm
B. 60 to 100 bpm
C. 100 to 150 bpm
D. Greater than 150 bpm
Answer: Less than 60 bpm
Rationale: Sinus bradycardia has normal sinus morphology but a rate below
60 bpm.
5. What is the first-line medication for symptomatic sinus bradycardia with
hypotension?
A. Atropine
B. Adenosine
C. Amiodarone
D. Defibrillation
Answer: Atropine
Rationale: Atropine increases heart rate by blocking vagal effects and is
first-line for symptomatic bradycardia.
6. What is the typical rate range for sinus tachycardia?
A. 40 to 60 bpm
B. 60 to 100 bpm
C. 100 to 150 bpm
D. 150 to 250 bpm
Questions & Rationales | ECG Rhythm Interpretation, Heart
Blocks, ACLS Interventions | Pass Guaranteed
,1. Which structure normally serves as the primary pacemaker of the heart?
A. AV node
B. SA node
C. Bundle of His
D. Purkinje fibers
Answer: SA node
Rationale: The SA node has the fastest intrinsic rate, 60 to 100 bpm, so it
normally initiates the cardiac impulse.
2. What is the normal intrinsic rate of the SA node?
A. 20 to 40 bpm
B. 40 to 60 bpm
C. 60 to 100 bpm
D. 100 to 150 bpm
Answer: 60 to 100 bpm
Rationale: The SA node normally fires at 60 to 100 bpm, defining normal
sinus rhythm.
3. Which rhythm has regular P waves before every QRS, a rate of 60 to 100
bpm, a PR interval of 0.12 to 0.20 seconds, and a QRS less than 0.12
seconds?
A. Sinus bradycardia
B. Normal sinus rhythm
C. Junctional rhythm
D. Atrial flutter
Answer: Normal sinus rhythm
, Rationale: NSR meets all criteria: regular, rate 60 to 100, upright P before
each QRS, normal PR and QRS.
4. What is the rate in sinus bradycardia?
A. Less than 60 bpm
B. 60 to 100 bpm
C. 100 to 150 bpm
D. Greater than 150 bpm
Answer: Less than 60 bpm
Rationale: Sinus bradycardia has normal sinus morphology but a rate below
60 bpm.
5. What is the first-line medication for symptomatic sinus bradycardia with
hypotension?
A. Atropine
B. Adenosine
C. Amiodarone
D. Defibrillation
Answer: Atropine
Rationale: Atropine increases heart rate by blocking vagal effects and is
first-line for symptomatic bradycardia.
6. What is the typical rate range for sinus tachycardia?
A. 40 to 60 bpm
B. 60 to 100 bpm
C. 100 to 150 bpm
D. 150 to 250 bpm
