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

V1 is placed at the fourth intercostal space at the right sternal border. Correct lead placement is crucial for accurate ECG interpretation.

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

Limb leads I, II, and III measure cardiac electrical activity in the frontal plane, forming Einthoven's triangle: Lead I (RA to LA), Lead II (RA to LL), Lead III (LA to LL).

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

Muscle tremor from shivering creates an irregular, jagged baseline that can mimic atrial fibrillation or obscure the underlying rhythm, requiring patient warming and stillness.

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

A 12-lead ECG uses 10 physical electrodes (4 limb, 6 precordial) to create 12 different electrical viewpoints of the heart, providing a comprehensive picture of cardiac electrical activity.

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

Normal sinus rhythm shows regular rhythm with each P wave followed by a QRS complex, PR interval 0.12-0.20 seconds, QRS duration <0.12 seconds, and rate between 60-100 bpm.

ECG (Electrocardiogram) Practice Test

ECG (Electrocardiogram) Practice Test

ECG ECG Lead Placement and Technique