Certified Rhythm Analysis Technician (CRAT) Practice Exam 2026 - Free CRAT Practice Questions and Study Guide

In a patient with an AV sequential pacemaker, the presence of a normal QRS complex without a ventricular spike on an ECG suggests that the patient's intrinsic conduction system has resumed its function. This indicates that the heart's natural electrical impulses are firing effectively enough to activate the ventricles, essentially "kicking in" the patient's own conduction pathways.

When the pacemaker is functioning correctly, it sends electrical signals to stimulate the heart, which would typically result in noticeable ventricular spikes on the ECG. However, if the intrinsic conduction system is properly conducting impulses, the pacemaker can effectively be bypassed – hence, the absence of ventricular spikes. The normal QRS complex is indicative of proper ventricular depolarization occurring due to these intrinsic signals rather than pacemaker activity.

This scenario highlights the ability of the heart to autonomously self-regulate its rhythm even in the presence of a pacemaker, demonstrating the remarkable resilience and adaptability of cardiac conduction systems.