Certified Rhythm Analysis Technician (CRAT) Practice Exam 2025 – All-in-One Study Guide for Exam Success!

Idioventricular rhythm is characterized by a heart rate that typically falls between 20 and 40 beats per minute, and it is often considered a rhythm originating from the ventricles when the primary pacemaker in the heart (the sinoatrial node) fails to initiate impulses. In idioventricular rhythm, the rhythm is almost always regular, which means the intervals between beats are consistent.

This rhythm is marked by the absence of P waves, which indicates that there are no atrial contractions being conducted through to the ventricles. Instead, the heart rate is reflected in the ventricular response, which is captured by a wide QRS complex. The wide QRS is a direct result of the ventricular depolarization occurring in an abnormal manner, as the impulses are generated within the ventricles rather than the usual conduction pathways through the atrioventricular (AV) node.

As such, the choice that describes idioventricular rhythm accurately highlights these characteristics: a heart rate of 20-40 bpm, nearly regular rhythm, absence of P waves, and a preceding wide QRS complex.