In a standard ECG, one of the following functions of its components is not correctly interpreted.

(A) P is the contraction of only left atria,
ECG or Electrocardiogram records the electrical signals from heart to check for various heart conditions. The waves on ECG include P wave, R wave, S and T wave P- wave is first wave, it is a small upward deflection on the ECG It represents atrial depolarisation or excitation, which spreads from the SAN through contractile fibres in both atria and leads to their contraction. QRS complex is second wave that begins as a downward deflection, continues as a large, upright, traingular wave, and ends as a downwards wave. It represents rapid ventricular depolarisation, as the action potential spreads through contractile fibres. It makes the beginning of systole. And T-wave is the third wave, it is a dome-shaped upward deflection, and it indicates ventricular repolarisation. It occurs just as the ventricles are starting to relax. The systole ends at the end of T-wave.