PCT EKG Basics 5 ā Questions and Answers
Question 1: When a PCT applies EKG electrodes, what should be done to the skin before electrode placement to ensure quality tracings?
- Apply lotion to moisturize the skin
- Clean and dry the skin, clip excess hair if necessary (Correct answer)
- Apply a thick gel layer to all sites
- Warm the electrodes under hot water
Correct answer: Clean and dry the skin, clip excess hair if necessary
Proper skin preparationācleaning with alcohol, drying, and removing excess hairāreduces impedance and artifact for a quality EKG tracing.
Question 2: Which EKG finding is associated with hypokalemia (low potassium)?
- Peaked T waves
- Shortened QT interval
- Prominent U waves (Correct answer)
- Widened QRS complex
Correct answer: Prominent U waves
Hypokalemia classically produces prominent U waves (a positive deflection after the T wave), flattened T waves, and a prolonged QU interval.
Question 3: What is the significance of a delta wave on an EKG?
- It indicates myocardial ischemia
- It is associated with Wolff-Parkinson-White syndrome and pre-excitation (Correct answer)
- It represents normal septal depolarization
- It is seen only in athletes
Correct answer: It is associated with Wolff-Parkinson-White syndrome and pre-excitation
A delta wave (slurred upstroke of the QRS) indicates ventricular pre-excitation through an accessory pathway, characteristic of Wolff-Parkinson-White (WPW) syndrome.
Question 4: A PCT observes 60-cycle interference (electrical artifact) on the EKG tracing. The BEST first step is to:
- Repeat the EKG immediately without any changes
- Check all electrode connections and ensure cables are not near electrical equipment (Correct answer)
- Increase the paper speed to 50 mm/sec
- Apply extra conductive gel to electrodes
Correct answer: Check all electrode connections and ensure cables are not near electrical equipment
60-Hz artifact is most commonly caused by poor electrode contact or nearby electrical equipment; checking connections and repositioning cables usually resolves it.
Question 5: Which lead records electrical activity between the right arm and left arm?
- Lead I (Correct answer)
- Lead II
- Lead III
- Lead aVF
Correct answer: Lead I
Lead I measures the potential difference between the left arm (positive) and right arm (negative).
Question 6: Sinus arrhythmia on an EKG is characterized by:
- Irregular P waves with varying morphology
- Regular rate that varies with breathing but normal P-QRS relationship (Correct answer)
- Dropped QRS complexes after normal P waves
- P waves buried in the QRS complex
Correct answer: Regular rate that varies with breathing but normal P-QRS relationship
Sinus arrhythmia is a normal variant where the heart rate increases with inhalation and decreases with exhalation, but P wave morphology and PR interval remain normal.
Question 7: On a rhythm strip, a patient has regular P waves at 80 bpm but only some P waves are followed by QRS complexes and the PR interval progressively lengthens before a dropped beat. This describes:
- First-degree AV block
- Mobitz Type I (Wenckebach) block (Correct answer)
- Mobitz Type II block
- Complete heart block
Correct answer: Mobitz Type I (Wenckebach) block
Mobitz Type I (Wenckebach) second-degree AV block is identified by a progressively lengthening PR interval until a P wave fails to conduct and a QRS is dropped.
PCT EKG Basics 5
When a PCT applies EKG electrodes, what should be done to the skin before electrode placement to ensure quality tracings?