BayCare EKG Test – 2025/2026.
QUESTION 1
The ECG paper speed is 25 mm/s. One small square horizontally represents:
A. 20 ms
B. 40 ms
C. 60 ms
D. 80 ms
Correct Answer: B. 40 ms
Rationale: 25 mm/s ÷ 25 squares/second = 1 mm/40 ms.
QUESTION 2
Which lead records the electrical signal between the right arm and the left leg?
A. aVR
B. Lead II
C. Lead I
D. Lead III
Correct Answer: B. Lead II
Rationale: Lead II = RA (−) to LL (+); best for viewing atrial activity and regularity.
QUESTION 3
Normal P-wave axis in adults is typically:
A. −30° to +60°
B. 0° to +75°
C. +15° to +75°
D. −60° to +90°
Correct Answer: C. +15° to +75°
Rationale: P-wave axis reflects atrial depolarization vector; outside this range suggests atrial
ectopy or lead misplacement.
QUESTION 4
The QRS width that defines complete bundle-branch block is:
,A. ≥100 ms
B. ≥110 ms
C. ≥120 ms
D. ≥140 ms
Correct Answer: C. ≥120 ms
Rationale: ≥120 ms with appropriate morphology (rabbit-ear, slurred) is diagnostic for LBBB or
RBBB.
QUESTION 5
Artifact on lead V2 resembling ventricular tachycardia disappears when the patient holds still.
The most likely cause is:
A. Patient movement
B. Loose electrode
C. 60-Hz interference
D. Lead wire fracture
Correct Answer: A. Patient movement
Rationale: Movement artifact produces wide, irregular deflections that resolve with stillness;
loose electrode (B) usually causes baseline drift or loss of signal.
QUESTION 6
The normal upper limit for the QTc interval (Bazett) in adult males is:
A. 440 ms
B. 460 ms
C. 480 ms
D. 500 ms
Correct Answer: B. 460 ms
Rationale: QTc >460 ms in males and >470 ms in females is considered prolonged and risks
torsades.
QUESTION 7
Which electrolyte abnormality most commonly causes peaked T-waves?
A. Hypokalemia
B. Hyperkalemia
C. Hypocalcemia
D. Hypernatremia
, Correct Answer: B. Hyperkalemia
Rationale: Serum K+ >5.5 mEq/L classically produces tall, peaked, symmetric T-waves in
precordial leads.
QUESTION 8
In lead aVL, the QRS complex is predominantly negative. This suggests the cardiac axis is:
A. Normal
B. Leftward
C. Rightward
D. Extreme right
Correct Answer: C. Rightward
Rationale: Negative QRS in aVL indicates the mean vector is moving away from the left upper
quadrant → right-axis deviation (>+90°).
QUESTION 9
The rhythm strip shows regular P-P and R-R intervals, 1:1 conduction, PR 0.28 s, QRS 0.10 s,
rate 70/min. The diagnosis is:
A. First-degree AV block
B. Second-degree Mobitz I
C. Third-degree AV block
D. Sinus bradycardia
Correct Answer: A. First-degree AV block
Rationale: PR >200 ms with maintained 1:1 conduction and narrow QRS defines first-degree
block.
QUESTION 10
A patient on digoxin presents with nausea and a rhythm strip showing regular atrial fibrillation
with ventricular rate of 48 bpm and bigeminal PVCs. The most likely diagnosis is:
A. Digoxin toxicity
B. Hyperthyroidism
C. Hypokalemia
D. Pulmonary embolism
Correct Answer: A. Digoxin toxicity
Rationale: Slow ventricular response with regularized AF and frequent PVCs is classic for
digoxin excess; serum digoxin and K+ levels should be checked.
QUESTION 1
The ECG paper speed is 25 mm/s. One small square horizontally represents:
A. 20 ms
B. 40 ms
C. 60 ms
D. 80 ms
Correct Answer: B. 40 ms
Rationale: 25 mm/s ÷ 25 squares/second = 1 mm/40 ms.
QUESTION 2
Which lead records the electrical signal between the right arm and the left leg?
A. aVR
B. Lead II
C. Lead I
D. Lead III
Correct Answer: B. Lead II
Rationale: Lead II = RA (−) to LL (+); best for viewing atrial activity and regularity.
QUESTION 3
Normal P-wave axis in adults is typically:
A. −30° to +60°
B. 0° to +75°
C. +15° to +75°
D. −60° to +90°
Correct Answer: C. +15° to +75°
Rationale: P-wave axis reflects atrial depolarization vector; outside this range suggests atrial
ectopy or lead misplacement.
QUESTION 4
The QRS width that defines complete bundle-branch block is:
,A. ≥100 ms
B. ≥110 ms
C. ≥120 ms
D. ≥140 ms
Correct Answer: C. ≥120 ms
Rationale: ≥120 ms with appropriate morphology (rabbit-ear, slurred) is diagnostic for LBBB or
RBBB.
QUESTION 5
Artifact on lead V2 resembling ventricular tachycardia disappears when the patient holds still.
The most likely cause is:
A. Patient movement
B. Loose electrode
C. 60-Hz interference
D. Lead wire fracture
Correct Answer: A. Patient movement
Rationale: Movement artifact produces wide, irregular deflections that resolve with stillness;
loose electrode (B) usually causes baseline drift or loss of signal.
QUESTION 6
The normal upper limit for the QTc interval (Bazett) in adult males is:
A. 440 ms
B. 460 ms
C. 480 ms
D. 500 ms
Correct Answer: B. 460 ms
Rationale: QTc >460 ms in males and >470 ms in females is considered prolonged and risks
torsades.
QUESTION 7
Which electrolyte abnormality most commonly causes peaked T-waves?
A. Hypokalemia
B. Hyperkalemia
C. Hypocalcemia
D. Hypernatremia
, Correct Answer: B. Hyperkalemia
Rationale: Serum K+ >5.5 mEq/L classically produces tall, peaked, symmetric T-waves in
precordial leads.
QUESTION 8
In lead aVL, the QRS complex is predominantly negative. This suggests the cardiac axis is:
A. Normal
B. Leftward
C. Rightward
D. Extreme right
Correct Answer: C. Rightward
Rationale: Negative QRS in aVL indicates the mean vector is moving away from the left upper
quadrant → right-axis deviation (>+90°).
QUESTION 9
The rhythm strip shows regular P-P and R-R intervals, 1:1 conduction, PR 0.28 s, QRS 0.10 s,
rate 70/min. The diagnosis is:
A. First-degree AV block
B. Second-degree Mobitz I
C. Third-degree AV block
D. Sinus bradycardia
Correct Answer: A. First-degree AV block
Rationale: PR >200 ms with maintained 1:1 conduction and narrow QRS defines first-degree
block.
QUESTION 10
A patient on digoxin presents with nausea and a rhythm strip showing regular atrial fibrillation
with ventricular rate of 48 bpm and bigeminal PVCs. The most likely diagnosis is:
A. Digoxin toxicity
B. Hyperthyroidism
C. Hypokalemia
D. Pulmonary embolism
Correct Answer: A. Digoxin toxicity
Rationale: Slow ventricular response with regularized AF and frequent PVCs is classic for
digoxin excess; serum digoxin and K+ levels should be checked.
