CET 12-Lead ECG Interpretation 2

Question 1

Which leads form the precordial (chest) leads on a standard 12-lead ECG?

Accepted Answer

V1 through V6

Answer

The precordial leads are V1 through V6, placed across the chest to view the heart in the horizontal plane.

Question 2

In a 12-lead ECG, what does a left axis deviation (LAD) most commonly indicate?

Accepted Answer

Left anterior fascicular block

Answer

Left anterior fascicular block is the most common cause of left axis deviation, shifting the QRS axis to between -30° and -90°.

Question 3

ST elevation in leads V1–V4 is most consistent with which type of STEMI?

Accepted Answer

Anterior STEMI

Answer

Leads V1–V4 overlie the anterior wall of the left ventricle, so ST elevation there indicates an anterior STEMI.

Question 4

A patient's ECG shows a QRS axis of +120°. This is classified as:

Accepted Answer

Right axis deviation

Answer

A QRS axis beyond +90° (up to +180°) is classified as right axis deviation.

Question 5

Which of the following patterns on a 12-lead ECG is associated with Wolff-Parkinson-White syndrome?

Accepted Answer

Short PR interval, delta wave, and wide QRS

Answer

WPW is characterized by a short PR interval (<120 ms), a slurred delta wave at the onset of the QRS, and a widened QRS complex.

(CET) Certified Electrocardiogram Technician Practice Test