Complex EKG Technician Practice Questions
with Verified Answers & Detailed Rationales –
Most Tested Questions|| Latest Update 2026-
2027
1. A 68-year-old male with a history of hypertension and diabetes presents
with palpitations. His EKG shows a heart rate of 145 bpm, narrow QRS
complexes, and no visible P waves. The rhythm is irregularly irregular. Which
of the following is the MOST likely diagnosis?**
A. Sinus tachycardia
B. Atrial flutter
C. Atrial fibrillation
D. Supraventricular tachycardia
Answer: C
Rationale: Atrial fibrillation is characterized by an irregularly irregular rhythm,
narrow QRS complexes, and no visible P waves. Sinus tachycardia (A) has
regular P waves. Atrial flutter (B) typically has sawtooth waves. SVT (D) is
usually regular.
,2. A patient's EKG shows a PR interval that progressively lengthens over three
beats until a QRS complex is dropped. This pattern repeats. What is the
correct interpretation?
A. First-degree heart block
B. Second-degree heart block Type I (Mobitz I)
C. Second-degree heart block Type II (Mobitz II)
D. Third-degree heart block
Answer: B
Rationale: Second-degree Type I (Wenckebach) is characterized by progressive
PR prolongation until a QRS is dropped. First-degree (A) has a constant
prolonged PR. Type II (C) has a constant PR with dropped beats. Third-degree
(D) has complete AV dissociation.
3. A 55-year-old female is scheduled for a stress test. She reports taking
metoprolol this morning. What is the MOST appropriate action?
A. Proceed with the stress test as scheduled
B. Hold the metoprolol and reschedule the test
C. Administer atropine before the test
D. Increase the speed of the treadmill
Answer: B
Rationale: Beta-blockers like metoprolol blunt the heart rate response to
exercise, making the stress test less reliable. The test should be rescheduled
after holding the medication as directed by the provider. Options A, C, and D
are inappropriate.
,4. During a Holter monitor application, the technician places electrodes near
V1 and V5. What is the primary reason for these specific locations?
A. To minimize artifact from skeletal muscle
B. To detect ischemia in the left ventricle
C. To provide a modified chest lead view
D. To ensure proper grounding
Answer: C
Rationale: Holter monitors use modified chest leads (near V1 and V5) to
provide a two-channel view of the heart, similar to V1 and V5 on a standard
12-lead EKG. Options A, B, and D are not the primary reason.
5. A patient's EKG shows a heart rate of 38 bpm, no P waves, and wide QRS
complexes. What is the MOST likely rhythm?
A. Sinus bradycardia
B. Junctional rhythm
C. Idioventricular rhythm
D. Third-degree heart block
Answer: C
Rationale: Idioventricular rhythm is characterized by a rate of 20–40 bpm, no
P waves, and wide QRS complexes. Sinus bradycardia (A) has P waves.
Junctional rhythm (B) has narrow QRS. Third-degree (D) may have P waves
with AV dissociation.
, 6. Which of the following is a correct statement regarding the use of limb
electrodes?
A. The right leg electrode is always the ground
B. The left leg electrode is always positive
C. The right arm electrode is always negative
D. All limb electrodes are used for recording
Answer: A
Rationale: The right leg electrode is used as the ground electrode for all leads.
The left leg (B) is not always positive. The right arm (C) can be negative or
positive depending on the lead. Not all limb electrodes are used for recording
(D).
7. A patient with a pacemaker presents for an EKG. What should the
technician do to minimize interference from the pacemaker?
A. Place the electrodes closer to the pacemaker
B. Use a different lead configuration
C. Ensure the pacemaker is turned off
D. Apply the electrodes in standard positions and monitor for spikes
Answer: D