Which part of the EKG represents ventricular depolarization?

Which part of the EKG represents ventricular depolarization?

• A. P wave
• B. QRS complex
• C. T wave
• D. PR interval

Answer: (B)

The QRS complex is the part of the EKG that represents ventricular depolarization. This phase occurs when the electrical impulse travels through the ventricles, causing them to contract and pump blood to the lungs and the rest of the body. The QRS complex is typically the most visually prominent part of the EKG tracing, reflecting the rapid depolarization of the right and left ventricles.

During this part of the cardiac cycle, the P wave, which precedes the QRS complex, represents atrial depolarization—a different process that occurs prior to ventricular contraction. The T wave, following the QRS complex, indicates ventricular repolarization, which is the recovery phase after contraction. The PR interval represents the time taken for the electrical impulse to travel from the atria to the ventricles but does not represent any depolarization itself. Therefore, when identifying the EKG component associated with ventricular depolarization, the QRS complex is the clear choice.