ECG ECG Lead Placement and Equipment 2 — Questions and Answers
Question 1: What does the standard calibration signal on ECG paper look like?
- 1 mV = 10 mm tall square wave (Correct answer)
- 1 mV = 5 mm tall square wave
- 2 mV = 10 mm tall square wave
- 0.5 mV = 10 mm tall square wave
Correct answer: 1 mV = 10 mm tall square wave
Standard ECG calibration is 1 mV = 10 mm (two large boxes) in amplitude.
Question 2: Which leads are referred to as the augmented limb leads?
- aVR, aVL, aVF (Correct answer)
- I, II, III
- V1, V2, V3
- V4, V5, V6
Correct answer: aVR, aVL, aVF
aVR, aVL, and aVF are the three augmented unipolar limb leads.
Question 3: What is the recommended minimum number of leads monitored continuously in a telemetry unit?
- 2 (Correct answer)
- 1
- 6
- 12
Correct answer: 2
Continuous telemetry monitoring typically requires at least 2 leads to improve arrhythmia detection.
Question 4: When a patient has a limb amputation preventing standard lead placement, where can the arm lead be repositioned?
- On the shoulder or upper torso near the limb stump (Correct answer)
- On the chest near the sternum
- On the opposite arm
- On the abdomen
Correct answer: On the shoulder or upper torso near the limb stump
When a limb is absent, the electrode is placed as close to the original site as possible, such as on the shoulder stump.
Question 5: What is the voltage gain setting used in half-standardization on an ECG?
- 5 mm/mV (Correct answer)
- 10 mm/mV
- 20 mm/mV
- 2.5 mm/mV
Correct answer: 5 mm/mV
Half-standardization sets gain to 5 mm/mV, used when waveforms are too tall at normal gain.
Question 6: Which ECG artifact pattern is commonly caused by patient movement or shivering?
- Muscle tremor artifact (high-frequency irregular baseline) (Correct answer)
- 60 Hz AC interference (thick regular baseline)
- Loose electrode artifact (intermittent flat line)
- Respiratory artifact (slow undulation)
Correct answer: Muscle tremor artifact (high-frequency irregular baseline)
Patient movement or shivering creates high-frequency, irregular baseline noise called muscle tremor artifact.
ECG ECG Lead Placement and Equipment 2
What does the standard calibration signal on ECG paper look like?