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

The indication of lead reversal in lead II can be determined by the presence of an inverted QRS complex. In normal physiological conditions, lead II typically shows a positive deflection for the QRS complex, as it records the electrical activity from the right arm to the left leg which generally aligns with the heart's depolarization direction.

When lead reversal occurs, the leads are incorrectly placed, leading to an altered view of the heart's electrical activity. This results in the QRS complex appearing inverted, as the electric signals are detected coming from a different angle than intended. An inverted QRS in lead II often signals lead misplacement or reversal, indicating the need to verify the electrode positions for accurate cardiac assessment.

While ST elevation, an upright T-wave, and a prolonged QRS complex can indicate various cardiac conditions or abnormalities, they do not specifically denote lead reversal. The inverted QRS complex is the key feature that highlights the unusual configuration due to incorrect lead placement.