What are the waves in a normal ECG?

What are the waves in a normal ECG?

The waves in a normal ECG are the P wave, QRS complex and T wave. Occasionally there can be a U wave in a normal ECG as well. The P wave occurs when the atria (upper thin walled chambers of the heart) are activated (depolarized). QRS complex represents the electrical activation (depolarization) of the ventricles and the T wave represents the inactivation (repolarization) of the electrical activity of the ventricles. The repolarization of the atria is not usually visible in the ECG and it is called the Ta wave.