Which ECG wave represents ventricular depolarization and atrial repolarization?

Which ECG wave represents ventricular depolarization and atrial repolarization?

• A. P Wave
• B. QRS Complex
• C. T Wave
• D. ST Segment

Answer: (B)

Ventricular depolarization shows up as the sharp, rapid deflections of the QRS complex on the ECG. Atrial repolarization occurs at about the same time but is masked by the much larger ventricular depolarization signal, so you don’t see a separate wave for it. The P wave corresponds to atrial depolarization, the T wave to ventricular repolarization, and the ST segment is the flat interval between depolarization and repolarization. So the wave that represents ventricular depolarization (with atrial repolarization occurring during that interval but hidden) is the QRS complex.

Ventricular depolarization shows up as the sharp, rapid deflections of the QRS complex on the ECG. Atrial repolarization occurs at about the same time but is masked by the much larger ventricular depolarization signal, so you don’t see a separate wave for it. The P wave corresponds to atrial depolarization, the T wave to ventricular repolarization, and the ST segment is the flat interval between depolarization and repolarization. So the wave that represents ventricular depolarization (with atrial repolarization occurring during that interval but hidden) is the QRS complex.