NCCT Electrocardiography Technician Fundamentals

Question 1

The P wave on an ECG represents:

Accepted Answer

Atrial depolarization

Answer

The P wave reflects the electrical depolarization of the atria, initiating atrial contraction.

Question 2

A normal PR interval duration on an adult ECG is:

Accepted Answer

0.12–0.20 seconds

Answer

A normal PR interval is 0.12–0.20 seconds, representing conduction from the SA node through the AV node.

Question 3

The QRS complex on an ECG represents:

Accepted Answer

Ventricular depolarization

Answer

The QRS complex represents the electrical depolarization of the ventricles, triggering ventricular contraction.

Question 4

In a standard 12-lead ECG, how many chest (precordial) leads are there?

Accepted Answer

6

Answer

A 12-lead ECG includes 6 precordial (chest) leads: V1 through V6.

Question 5

Which of the following is the primary pacemaker of the heart?

Accepted Answer

SA node

Answer

The sinoatrial (SA) node, located in the right atrium, is the heart's primary pacemaker, normally firing at 60–100 bpm.

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