CCMA EKG Administration 4 — Questions and Answers
Question 1: A patient's EKG shows a prolonged QT interval. Which condition is this finding most commonly associated with?
- Hypokalemia (Correct answer)
- Hypernatremia
- Polycythemia
- Thrombocytopenia
Correct answer: Hypokalemia
Hypokalemia (low potassium) prolongs the QT interval and can predispose the patient to life-threatening arrhythmias such as torsades de pointes.
Question 2: When placing a V4 precordial lead, the correct anatomical position is:
- 5th intercostal space, midclavicular line (Correct answer)
- 4th intercostal space, right sternal border
- 5th intercostal space, anterior axillary line
- 4th intercostal space, left sternal border
Correct answer: 5th intercostal space, midclavicular line
V4 is placed at the 5th intercostal space at the midclavicular line on the left side of the chest.
Question 3: Which of the following is the correct sequence of electrical conduction in the heart?
- SA node → AV node → Bundle of His → Purkinje fibers (Correct answer)
- AV node → SA node → Bundle of His → Purkinje fibers
- SA node → Bundle of His → AV node → Purkinje fibers
- Purkinje fibers → SA node → AV node → Bundle of His
Correct answer: SA node → AV node → Bundle of His → Purkinje fibers
Normal cardiac conduction begins at the SA node, travels to the AV node, then through the Bundle of His and Purkinje fibers to depolarize the ventricles.
Question 4: A medical assistant notices the EKG tracing shows a flat, wandering baseline. The MOST likely cause is:
- Patient movement or breathing (Correct answer)
- Reversed limb leads
- Low battery in the EKG machine
- Incorrect paper speed setting
Correct answer: Patient movement or breathing
A wandering baseline is most commonly caused by patient movement, muscle tremor, or breathing artifact during the recording.
Question 5: On a standard EKG strip, the paper speed in the United States is:
- 25 mm/sec (Correct answer)
- 50 mm/sec
- 10 mm/sec
- 100 mm/sec
Correct answer: 25 mm/sec
Standard US EKG paper speed is 25 mm per second, which means each small square represents 0.04 seconds.
Question 6: Which EKG finding is characteristic of ventricular fibrillation?
- Chaotic, irregular waveforms with no identifiable P waves or QRS complexes (Correct answer)
- Regular narrow QRS complexes at a rate of 150 bpm
- Wide QRS complexes occurring every other beat
- Sawtooth P waves at a rate of 300 bpm
Correct answer: Chaotic, irregular waveforms with no identifiable P waves or QRS complexes
Ventricular fibrillation produces chaotic, disorganized electrical activity with no discernible P waves, QRS complexes, or T waves.
Question 7: To reduce somatic tremor artifact caused by an elderly or anxious patient during an EKG, a medical assistant should:
- Ask the patient to lie still, relax muscles, and breathe normally (Correct answer)
- Increase the sensitivity setting on the EKG machine
- Apply electrodes over bony prominences instead of soft tissue
- Speed up the paper to 50 mm/sec
Correct answer: Ask the patient to lie still, relax muscles, and breathe normally
Instructing the patient to relax all muscles and breathe normally is the primary intervention to reduce somatic muscle tremor artifact.
CCMA EKG Administration 4
A patient's EKG shows a prolonged QT interval.
Which condition is this finding most commonly associated with?