ECG ECG Lead Placement and Equipment 3

Question 1

What is the most common cause of 60-Hz AC interference on an ECG?

Accepted Answer

Poor electrode contact or loose lead wire

Answer

Patient movement

Answer

Respiratory variation

Answer

Low battery in the ECG machine

Question 2

V3 is placed between which two leads?

Accepted Answer

V2 and V4

Answer

V1 and V2

Answer

V4 and V5

Answer

V1 and V3

Question 3

Which skin preparation step is most important before applying ECG electrodes?

Accepted Answer

Cleaning and lightly abrading the skin to reduce impedance

Answer

Applying conductive gel over hair follicles

Answer

Warming the electrode with hands before placement

Answer

Pressing the electrode for 10 seconds without preparation

Question 4

What does a wandering baseline on an ECG most commonly indicate?

Accepted Answer

Respiratory movement causing electrode motion artifact

Answer

Ventricular fibrillation

Answer

60-Hz AC interference

Answer

Lead reversal

Question 5

What is the purpose of the filter setting on an ECG machine?

Accepted Answer

To reduce artifact and electrical noise without distorting waveforms

Answer

To increase the amplitude of P waves

Answer

To speed up paper output

Answer

To calibrate the voltage standard

Question 6

Right arm and left arm lead reversal will most noticeably affect which lead's appearance?

Accepted Answer

Lead I (inverted P, QRS, and T waves)

Answer

Lead II (no change)

Answer

V1 (loss of R wave)

Answer

aVF (ST elevation)