ECG ECG Lead Placement and Technique

Question 1

What is the correct placement of the V1 precordial lead?

Accepted Answer

Fourth intercostal space, right sternal border

Answer

Second intercostal space, right sternal border

Answer

Fourth intercostal space, left sternal border

Answer

Fifth intercostal space, midclavicular line

Question 2

What do limb leads I, II, and III measure?

Accepted Answer

Electrical activity in the frontal plane from three different angles of Einthoven's triangle

Answer

Only heart rate

Answer

Blood pressure changes

Answer

Respiratory patterns

Question 3

What artifact appears on an ECG when a patient is shivering?

Accepted Answer

Baseline irregularity mimicking atrial fibrillation due to muscle tremor

Answer

Flat line (asystole)

Answer

Perfectly regular sharp spikes

Answer

Large wandering baseline

Question 4

What is a 12-lead ECG and why is it called that?

Accepted Answer

A standard ECG recording using 10 electrodes that produce 12 different views of the heart's electrical activity

Answer

12 separate ECG machines

Answer

12 electrodes placed on the chest

Answer

An ECG taken over 12 minutes

Question 5

What does a normal sinus rhythm look like on an ECG?

Accepted Answer

Regular P waves before each QRS complex, consistent PR interval, rate 60-100 bpm, and upright P waves in lead II

Answer

No P waves visible

Answer

Irregular R-R intervals

Answer

QRS complexes wider than 120ms

Question 6

Why is proper skin preparation important before applying ECG electrodes?

Accepted Answer

To reduce skin impedance and ensure good electrical contact for accurate signal recording

Answer

To prevent allergic reactions to electrode gel

Answer

To sterilize the skin for surgery

Answer

It has no practical effect on the recording