CET Lead Placement & Recording Procedures 3

Question 1

Which lead is considered the 'ground' or reference electrode in a standard 12-lead ECG setup?

Accepted Answer

Right leg (RL)

Answer

The right leg (RL) electrode serves as the electrical ground or reference and does not contribute to any of the 12 leads.

Question 2

V4 is placed at the:

Accepted Answer

Fifth intercostal space, left midclavicular line

Answer

V4 is positioned at the fifth intercostal space at the midclavicular line, typically over the cardiac apex.

Question 3

When a technician notices AC (60 Hz) interference on the ECG tracing, the first corrective step should be:

Accepted Answer

Check and correct electrode connections and skin contact

Answer

AC interference usually results from poor electrode contact or nearby electrical equipment; checking connections and skin preparation resolves it without altering the signal.

Question 4

In right-sided ECG leads (V3R–V6R), where is V4R placed?

Accepted Answer

Mirror image of V4 on the right chest at the fifth ICS, right midclavicular line

Answer

V4R is the right-side mirror of V4, placed at the fifth intercostal space on the right midclavicular line, critical for detecting right ventricular MI.

Question 5

A patient's left arm is in a cast. Which adjustment is appropriate for the LA electrode?

Accepted Answer

Place the LA electrode as high on the left arm as possible above the cast

Answer

The electrode should be placed on the most distal accessible portion of the same limb to maintain anatomical consistency of the limb lead system.

(CET) Certified Electrocardiogram Technician Practice Test

(CET) Certified Electrocardiogram Technician Practice Test

CET Lead Placement & Recording Procedures 3