The QRS complex in a standard ECG represents
- Repolarisation of ventricles
- Repolarisation of auricles
- Depolarisation of auricles
- Depolarisation of ventricles
Answer
(4) Depolarisation of ventricles
Solution
As per NCERT, in a standard ECG:
P-wave ⇒ electrical excitation (depolarisation) of the atria
QRS complex ⇒ depolarisation of the ventricles, which initiates ventricular contraction
T-wave ⇒ return of the ventricles from excited to normal state (repolarisation)
∴ The QRS complex represents depolarisation of ventricles.
Answer: (4)