Questions, EKG Strips & Rationale
Explanations
Question 1
Description: Regular rhythm at 72 bpm. Each QRS is preceded by a normal P wave
(upright in lead II). PR interval 0.16 sec, QRS 0.08 sec.
ASCII Strip:
| P | QRS | T | P | QRS | T | P | QRS | T |
| . | .. | . | . | .. | . | . | .. | . | (regular)
Choices:
A) Sinus bradycardia
B) Normal sinus rhythm
C) Atrial fibrillation
D) Junctional rhythm
Correct Answer: B) Normal sinus rhythm – Rate 60-100, normal P waves, normal
intervals.
Question 2
Description: Regular rhythm at 48 bpm. Normal P waves, PR 0.18 sec, QRS 0.08 sec.
ASCII:
| P | QRS | T | | P | QRS | T | | (wide spacing)
Choices:
A) Sinus tachycardia
B) Sinus bradycardia
C) First-degree AV block
D) Junctional bradycardia
Correct Answer: B) Sinus bradycardia – Rate <60 with normal sinus morphology.
Question 3
Description: Regular rhythm at 115 bpm. Normal P waves, PR 0.16 sec, QRS 0.08 sec.
ASCII:
,|P|QRS|T|P|QRS|T|P|QRS|T|P|QRS|T| (close together)
Choices:
A) Sinus tachycardia
B) SVT
C) Atrial flutter
D) Normal sinus rhythm
Correct Answer: A) Sinus tachycardia – Rate >100 with normal sinus origin.
Question 4
Description: Irregularly irregular rhythm. No discernible P waves. Baseline fibrillatory
waves. Ventricular rate ~90 bpm.
ASCII:
| .. | QRS | . | ... | QRS | .. | . | QRS | ... | (chaotic baseline)
Choices:
A) Atrial flutter
B) Atrial fibrillation
C) Multifocal atrial tachycardia
D) Wandering pacemaker
Correct Answer: B) Atrial fibrillation – Irregularly irregular, no P waves.
Question 5
Description: Regular rhythm with "sawtooth" flutter waves at ~300 bpm. Ventricular
rate ~75 bpm (4:1 block).
ASCII:
| /\/\/\ | QRS | /\/\/\ | QRS | /\/\/\ | (flutter waves)
Choices:
A) Atrial fibrillation
B) Atrial flutter
C) SVT
D) Sinus tachycardia
Correct Answer: B) Atrial flutter – Sawtooth flutter waves.
Question 6
Description: Regular, narrow-complex tachycardia at 180 bpm. No visible P waves.
Rate sudden onset.
,ASCII:
| QRS | T | QRS | T | QRS | T | QRS | T | (fast, no P)
Choices:
A) Sinus tachycardia
B) Atrial fibrillation
C) SVT
D) V-tach
Correct Answer: C) SVT – Narrow, fast, no P waves, sudden onset.
Question 7
Description: Sinus rhythm at 70 bpm with an early, wide QRS (0.14 sec) that is not
preceded by a P wave. Compensatory pause follows.
ASCII:
| P | QRS | T | P | [wide] | T | P | QRS | (early wide beat)
Choices:
A) PAC
B) PVC (unifocal)
C) Junctional escape
D) Aberrant conduction
Correct Answer: B) PVC (unifocal) – Wide, early, no preceding P, same
morphology each time.
Question 8
Description: Sinus rhythm with PVCs that have at least two different morphologies in
the same lead.
ASCII:
| P QRS T | P [wide1] T | P QRS T | P [wide2] T |
Choices:
A) Unifocal PVCs
B) Multifocal PVCs
C) Bigeminy
D) Trigeminy
Correct Answer: B) Multifocal PVCs – Different QRS morphologies.
, Question 9
Description: Sinus rhythm at 80 bpm. Every other beat is a PVC (pattern: normal,
PVC, normal, PVC).
ASCII:
| N | PVC | N | PVC | N | PVC | (alternating)
Choices:
A) Trigeminy
B) Couplet
C) Bigeminy
D) Multifocal
Correct Answer: C) Bigeminy – PVC every other beat.
Question 10
Description: Sinus rhythm at 75 bpm. Every third beat is a PVC (pattern: normal,
normal, PVC, normal, normal, PVC).
ASCII:
| N | N | PVC | N | N | PVC |
Choices:
A) Bigeminy
B) Trigeminy
C) Couplet
D) Quadrigeminy
Correct Answer: B) Trigeminy – PVC every third beat.
Question 11
Description: Sinus rhythm with two consecutive PVCs occurring together.
ASCII:
| N | N | PVC | PVC | N | N |
Choices:
A) Bigeminy
B) Trigeminy
C) Couplet
D) Run of V-tach
Correct Answer: C) Couplet – Two PVCs in a row.