ECG

What does the P wave represent in an ECG?

Atrial contraction (atrial depolarization).

What occurs during the QRS complex in an ECG?

The ventricles contract (ventricular depolarization).

What is indicated by the T wave in an ECG?

The ventricles relax (ventricular repolarization).

What happens when the P wave is missing in an ECG?

Atria aren’t contracting properly.

What does a wide QRS complex indicate?

Ventricular contraction is slow or abnormal.

What is suggested if the T wave is abnormal?

Ventricular repolarization is off, possibly due to potassium imbalance.

P wave

The SA node fires, causing atria to contract (depolarization).

QRS complex

The signal reaches the ventricles, making them contract (depolarization).

T wave

The ventricles relax and reset (repolarization).