EKG Test for Houston Methodist Exam
Latest Update 2026/2027 | 200 Questions and Verified
Answers
Complete Q&A Guide | A+ Graded
1. The standard speed of an EKG strip is:
A. 10 mm/sec
B. 25 mm/sec
C. 50 mm/sec
D. 100 mm/sec
Answer: B. 25 mm/sec
Explanation: Standard calibration for EKG rhythm interpretation is 25 mm/sec. At this speed, each small
box equals 0.04 seconds and each large box equals 0.20 seconds.
2. On EKG paper, each small box horizontally equals:
A. 0.04 seconds
B. 0.1 seconds
C. 0.2 seconds
D. 1 second
Answer: A. 0.04 seconds
,Explanation: Each small square on EKG paper represents 0.04 seconds (40 milliseconds). Five small
squares make one large square, which equals 0.20 seconds.
3. On EKG paper, each large box horizontally equals:
A. 0.04 seconds
B. 0.10 seconds
C. 0.20 seconds
D. 0.50 seconds
Answer: C. 0.20 seconds
Explanation: Each large square on EKG paper consists of five small squares and represents 0.20 seconds.
Five large boxes equal 1 second.
4. The normal PR interval duration is:
A. 0.04–0.08 seconds
B. 0.12–0.20 seconds
C. 0.20–0.28 seconds
D. >0.30 seconds
Answer: B. 0.12–0.20 seconds
Explanation: The normal PR interval reflects AV conduction time and ranges from 0.12 to 0.20 seconds
(3 to 5 small boxes).
,5. The QRS complex represents:
A. Atrial depolarization
B. Atrial repolarization
C. Ventricular depolarization
D. Ventricular repolarization
Answer: C. Ventricular depolarization
Explanation: The QRS complex reflects the electrical activation (depolarization) of the ventricles. The P
wave represents atrial depolarization, and the T wave represents ventricular repolarization.
6. The T wave represents:
A. Atrial depolarization
B. PR segment
C. Ventricular repolarization
D. Atrial repolarization
Answer: C. Ventricular repolarization
Explanation: The T wave follows the QRS complex and ST segment and represents ventricular
repolarization (recovery of the ventricles).
, 7. The P wave on an EKG represents:
A. Ventricular depolarization
B. Atrial depolarization
C. Ventricular repolarization
D. AV node conduction
Answer: B. Atrial depolarization
Explanation: The P wave represents the depolarization (contraction) of the atria. It is the first waveform
seen in a normal cardiac cycle.
8. U waves are most commonly seen with:
A. Hyperkalemia
B. Myocardial infarction
C. Hypokalemia
D. Hypoglycemia
Answer: C. Hypokalemia
Explanation: Prominent U waves are often associated with hypokalemia (low potassium levels). They are
small deflections that follow the T wave.
Latest Update 2026/2027 | 200 Questions and Verified
Answers
Complete Q&A Guide | A+ Graded
1. The standard speed of an EKG strip is:
A. 10 mm/sec
B. 25 mm/sec
C. 50 mm/sec
D. 100 mm/sec
Answer: B. 25 mm/sec
Explanation: Standard calibration for EKG rhythm interpretation is 25 mm/sec. At this speed, each small
box equals 0.04 seconds and each large box equals 0.20 seconds.
2. On EKG paper, each small box horizontally equals:
A. 0.04 seconds
B. 0.1 seconds
C. 0.2 seconds
D. 1 second
Answer: A. 0.04 seconds
,Explanation: Each small square on EKG paper represents 0.04 seconds (40 milliseconds). Five small
squares make one large square, which equals 0.20 seconds.
3. On EKG paper, each large box horizontally equals:
A. 0.04 seconds
B. 0.10 seconds
C. 0.20 seconds
D. 0.50 seconds
Answer: C. 0.20 seconds
Explanation: Each large square on EKG paper consists of five small squares and represents 0.20 seconds.
Five large boxes equal 1 second.
4. The normal PR interval duration is:
A. 0.04–0.08 seconds
B. 0.12–0.20 seconds
C. 0.20–0.28 seconds
D. >0.30 seconds
Answer: B. 0.12–0.20 seconds
Explanation: The normal PR interval reflects AV conduction time and ranges from 0.12 to 0.20 seconds
(3 to 5 small boxes).
,5. The QRS complex represents:
A. Atrial depolarization
B. Atrial repolarization
C. Ventricular depolarization
D. Ventricular repolarization
Answer: C. Ventricular depolarization
Explanation: The QRS complex reflects the electrical activation (depolarization) of the ventricles. The P
wave represents atrial depolarization, and the T wave represents ventricular repolarization.
6. The T wave represents:
A. Atrial depolarization
B. PR segment
C. Ventricular repolarization
D. Atrial repolarization
Answer: C. Ventricular repolarization
Explanation: The T wave follows the QRS complex and ST segment and represents ventricular
repolarization (recovery of the ventricles).
, 7. The P wave on an EKG represents:
A. Ventricular depolarization
B. Atrial depolarization
C. Ventricular repolarization
D. AV node conduction
Answer: B. Atrial depolarization
Explanation: The P wave represents the depolarization (contraction) of the atria. It is the first waveform
seen in a normal cardiac cycle.
8. U waves are most commonly seen with:
A. Hyperkalemia
B. Myocardial infarction
C. Hypokalemia
D. Hypoglycemia
Answer: C. Hypokalemia
Explanation: Prominent U waves are often associated with hypokalemia (low potassium levels). They are
small deflections that follow the T wave.
