Advent Health EKG Question Bank (Latest 2026/2027 Edition) –
Questions, Answers & Detailed Rationales
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SECTION 1: Basic EKG Principles and Waveform Analysis
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Question 1
Standard EKG graph paper runs at 25 mm/second with a standard calibration of 1 mV =
10 mm. At this standard, each small box (1 mm) represents which measurements
horizontally and vertically?
A. 0.02 seconds horizontally; 0.1 mV vertically
B. 0.04 seconds horizontally; 0.2 mV vertically
C. 0.20 seconds horizontally; 1.0 mV vertically
D. 0.10 seconds horizontally; 0.5 mV vertically
Correct Answer:
A — 0.02 seconds horizontally; 0.1 mV vertically
Rationale:
At standard calibration, each 1 mm small box represents 0.04 seconds (actually, wait:
25 mm/sec means 1 mm = 0.04 sec? No, 25 mm/sec means 1 mm = 1/25 = 0.04
seconds. And 1 mV = 10 mm means 1 mm = 0.1 mV. But the standard is 0.04 seconds
per small box, not 0.02. A large box (5 mm) is 0.20 seconds, so a small box is 0.04
seconds. Let me correct this.
Actually, standard EKG: paper speed 25 mm/s. 1 small box = 1 mm = 0.04 seconds. 1
large box = 5 mm = 0.20 seconds. Voltage: 1 mV = 10 mm, so 1 mm = 0.1 mV.
So the correct answer should be 0.04 seconds and 0.1 mV. But that's not one of my
options. Let me fix the options.
,A. 0.04 seconds; 0.1 mV
B. 0.02 seconds; 0.2 mV
C. 0.20 seconds; 1.0 mV
D. 0.10 seconds; 0.5 mV
Correct: A
Rationale:
At standard calibration (25 mm/second, 10 mm/mV), each 1 mm small box equals 0.04
seconds horizontally and 0.1 mV vertically. Option B incorrectly halves the time interval,
while option C describes a large box (5 mm) rather than a small box.
Question 2
The P wave on a surface EKG corresponds to which physiological event in the cardiac
conduction system?
A. Ventricular depolarization
B. Atrial depolarization
C. Atrial repolarization
D. Ventricular repolarization
Correct Answer:
B — Atrial depolarization
Rationale:
The P wave represents atrial depolarization initiated by the sinoatrial node. Ventricular
depolarization produces the QRS complex, and ventricular repolarization produces the T
wave; atrial repolarization is typically obscured by the QRS complex.
Question 3
A patient is on a cardiac monitor in the ICU. The rhythm strip shows regular R-R intervals
spanning exactly 15 large boxes. Using the standard 300 method for heart rate
calculation, the ventricular rate is approximately:
,A. 20 beats per minute
B. 75 beats per minute
C. 100 beats per minute
D. 150 beats per minute
Correct Answer:
A — 20 beats per minute
Rationale:
The 300 method divides 300 by the number of large boxes between R waves to estimate
rate (300 ÷ 15 = 20 bpm). Option B (75 bpm) would require four large boxes, and option
D (150 bpm) would require two large boxes.
Question 4
A 62-year-old patient presents for preoperative evaluation. The EKG demonstrates a
regular sinus rhythm with a PR interval measured at 0.24 seconds, which is consistent
across all beats. The QRS duration is 0.08 seconds. No dropped beats are observed.
This finding is most consistent with:
A. First-degree AV block
B. Second-degree AV block type I
C. Second-degree AV block type II
D. Third-degree AV block
Correct Answer:
A — First-degree AV block
Rationale:
A fixed PR interval greater than 0.20 seconds without dropped beats defines first-degree
AV block. Option B (Wenckebach) requires progressive PR prolongation, option C
requires fixed PR with sudden non-conducted P waves, and option D requires complete
AV dissociation.
, Question 5
The normal duration of the QRS complex in adults, measured from the onset of the Q
wave to the termination of the S wave, is:
A. Less than 0.06 seconds
B. Less than 0.12 seconds
C. Less than 0.20 seconds
D. Less than 0.40 seconds
Correct Answer:
B — Less than 0.12 seconds
Rationale:
A normal QRS duration is less than 0.12 seconds (three small boxes); durations
exceeding this threshold indicate ventricular conduction delay such as bundle branch
block or ventricular rhythm. Option C describes the upper limit of a normal PR interval,
not the QRS.
Question 6
A 12-lead EKG shows a predominantly positive QRS complex in lead I and a
predominantly negative QRS complex in lead aVF. The electrical axis of the heart is
most likely:
A. Normal axis
B. Left axis deviation
C. Right axis deviation
D. Extreme axis deviation
Correct Answer:
B — Left axis deviation
Rationale:
Questions, Answers & Detailed Rationales
──────────────────────────────
SECTION 1: Basic EKG Principles and Waveform Analysis
──────────────────────────────
Question 1
Standard EKG graph paper runs at 25 mm/second with a standard calibration of 1 mV =
10 mm. At this standard, each small box (1 mm) represents which measurements
horizontally and vertically?
A. 0.02 seconds horizontally; 0.1 mV vertically
B. 0.04 seconds horizontally; 0.2 mV vertically
C. 0.20 seconds horizontally; 1.0 mV vertically
D. 0.10 seconds horizontally; 0.5 mV vertically
Correct Answer:
A — 0.02 seconds horizontally; 0.1 mV vertically
Rationale:
At standard calibration, each 1 mm small box represents 0.04 seconds (actually, wait:
25 mm/sec means 1 mm = 0.04 sec? No, 25 mm/sec means 1 mm = 1/25 = 0.04
seconds. And 1 mV = 10 mm means 1 mm = 0.1 mV. But the standard is 0.04 seconds
per small box, not 0.02. A large box (5 mm) is 0.20 seconds, so a small box is 0.04
seconds. Let me correct this.
Actually, standard EKG: paper speed 25 mm/s. 1 small box = 1 mm = 0.04 seconds. 1
large box = 5 mm = 0.20 seconds. Voltage: 1 mV = 10 mm, so 1 mm = 0.1 mV.
So the correct answer should be 0.04 seconds and 0.1 mV. But that's not one of my
options. Let me fix the options.
,A. 0.04 seconds; 0.1 mV
B. 0.02 seconds; 0.2 mV
C. 0.20 seconds; 1.0 mV
D. 0.10 seconds; 0.5 mV
Correct: A
Rationale:
At standard calibration (25 mm/second, 10 mm/mV), each 1 mm small box equals 0.04
seconds horizontally and 0.1 mV vertically. Option B incorrectly halves the time interval,
while option C describes a large box (5 mm) rather than a small box.
Question 2
The P wave on a surface EKG corresponds to which physiological event in the cardiac
conduction system?
A. Ventricular depolarization
B. Atrial depolarization
C. Atrial repolarization
D. Ventricular repolarization
Correct Answer:
B — Atrial depolarization
Rationale:
The P wave represents atrial depolarization initiated by the sinoatrial node. Ventricular
depolarization produces the QRS complex, and ventricular repolarization produces the T
wave; atrial repolarization is typically obscured by the QRS complex.
Question 3
A patient is on a cardiac monitor in the ICU. The rhythm strip shows regular R-R intervals
spanning exactly 15 large boxes. Using the standard 300 method for heart rate
calculation, the ventricular rate is approximately:
,A. 20 beats per minute
B. 75 beats per minute
C. 100 beats per minute
D. 150 beats per minute
Correct Answer:
A — 20 beats per minute
Rationale:
The 300 method divides 300 by the number of large boxes between R waves to estimate
rate (300 ÷ 15 = 20 bpm). Option B (75 bpm) would require four large boxes, and option
D (150 bpm) would require two large boxes.
Question 4
A 62-year-old patient presents for preoperative evaluation. The EKG demonstrates a
regular sinus rhythm with a PR interval measured at 0.24 seconds, which is consistent
across all beats. The QRS duration is 0.08 seconds. No dropped beats are observed.
This finding is most consistent with:
A. First-degree AV block
B. Second-degree AV block type I
C. Second-degree AV block type II
D. Third-degree AV block
Correct Answer:
A — First-degree AV block
Rationale:
A fixed PR interval greater than 0.20 seconds without dropped beats defines first-degree
AV block. Option B (Wenckebach) requires progressive PR prolongation, option C
requires fixed PR with sudden non-conducted P waves, and option D requires complete
AV dissociation.
, Question 5
The normal duration of the QRS complex in adults, measured from the onset of the Q
wave to the termination of the S wave, is:
A. Less than 0.06 seconds
B. Less than 0.12 seconds
C. Less than 0.20 seconds
D. Less than 0.40 seconds
Correct Answer:
B — Less than 0.12 seconds
Rationale:
A normal QRS duration is less than 0.12 seconds (three small boxes); durations
exceeding this threshold indicate ventricular conduction delay such as bundle branch
block or ventricular rhythm. Option C describes the upper limit of a normal PR interval,
not the QRS.
Question 6
A 12-lead EKG shows a predominantly positive QRS complex in lead I and a
predominantly negative QRS complex in lead aVF. The electrical axis of the heart is
most likely:
A. Normal axis
B. Left axis deviation
C. Right axis deviation
D. Extreme axis deviation
Correct Answer:
B — Left axis deviation
Rationale:
