Certified Rhythm Analysis Technician (CRAT) Practice Exam 2026 – All-in-One Study Guide for Exam Success!

The three types of leads used in a 12-lead ECG consist of standard leads, augmented leads, and chest leads.

Standard leads refer to the limb leads, which include the bipolar leads that measure the electrical potential differences between two points (for example, between the right arm and left arm or left leg). Augmented leads are unipolar leads that enhance the signals from specific limb placements by combining readings from different limb electrodes. The chest leads, also known as precordial leads, are placed on the chest and provide a view of the heart's electrical activity from the horizontal plane.

This combination of leads is essential for obtaining a comprehensive view of the heart's electrical function, allowing for a thorough analysis during an ECG recording. Each type of lead contributes to the overall assessment by providing different perspectives of cardiac activity.

As for the other options, they do not accurately group the leads into the accepted classifications commonly used in ECG interpretation.