Which ECG component corresponds to atrial depolarization?

Which ECG component corresponds to atrial depolarization?

• A. P wave
• B. QRS complex
• C. T wave
• D. ST segment

Answer: (A)

Atrial depolarization is represented by the P wave on the ECG. This wave occurs as the atrial muscle depolarizes in response to the impulse from the SA node, triggering atrial contraction. It appears at the start of the tracing and is followed by the QRS complex, which shows ventricular depolarization. The T wave corresponds to ventricular repolarization, while the ST segment is the flat interval between depolarization and repolarization. It’s also helpful to know that atrial repolarization happens during the QRS complex, but it isn’t seen as a separate deflection because it’s masked by the much larger ventricular activity.

Atrial depolarization is represented by the P wave on the ECG. This wave occurs as the atrial muscle depolarizes in response to the impulse from the SA node, triggering atrial contraction. It appears at the start of the tracing and is followed by the QRS complex, which shows ventricular depolarization. The T wave corresponds to ventricular repolarization, while the ST segment is the flat interval between depolarization and repolarization. It’s also helpful to know that atrial repolarization happens during the QRS complex, but it isn’t seen as a separate deflection because it’s masked by the much larger ventricular activity.