Certified Rhythm Analysis Technician (CRAT) Practice Exam 2025 - Free CRAT Practice Questions and Study Guide

The identification of rhythms where P-P and R-R intervals are regular but occur at different rates corresponds to a specific conduction abnormality, commonly seen in complete heart block. In cases of complete heart block, the atria and ventricles are electrically dissociated, meaning that they beat independently of each other. This results in consistent P waves (regular P-P intervals) generated by the atrial activity at one rate, while the ventricles (R waves) contract at a different, usually slower rate due to a separate intrinsic pacemaker (regular R-R intervals).

A key characteristic of complete heart block is that the atrial and ventricular rhythms do not synchronize, leading to the phenomenon where P waves can appear regularly, yet they bear no relation to the QRS complexes (ventricular contractions). This dissociation is what ultimately supports the presence of regularity in each interval while highlighting that they are functioning at different rates, aligning with the outlined features of complete heart block.

In contrast, other rhythms such as Wenckebach, atrial fibrillation, or first-degree heart block exhibit variations in P-P or R-R intervals, thus making them unsuitable for this particular description.