2026 CCRN Practice Test – Complete Study Resource

The correct choice is the T wave, which represents the repolarization of the ventricles on an electrocardiogram (EKG). During the cardiac cycle, after the ventricles have depolarized and contracted, they must return to their resting state to prepare for the next heartbeat. This process of ventricular repolarization is reflected on the EKG as the T wave.

The T wave's shape is generally smooth and rounded, indicating the ventricular muscle cells returning to their resting potential. Proper interpretation of the T wave is essential in monitoring cardiac health, as abnormalities in its morphology or timing can suggest underlying conditions such as ischemia or electrolyte imbalances.

In contrast, the P wave corresponds to atrial depolarization, while the QRS complex indicates ventricular depolarization. The PR interval does not represent either depolarization or repolarization; instead, it measures the time it takes for electrical impulses to travel from the atria to the ventricles. Understanding the timing and characteristics of each component of the EKG is crucial for critical care nurses in assessing cardiac function and identifying potential abnormalities.