ECG is a graphical representation of the electrical activity of the heart during a cardiac cycle. Read following statements.
(i) Electrocardiograph machine is used to obtain an electrocardiogram (ECG).
(ii) To obtain a standard ECG, a patient is connected to the machine with three electrical leads one to each wrist and to the left ankle.
(iii) For a detailed evaluation of the heart's function, multiple leads are attached to the chest region.
(iv) The P wave represents the repolarisation of the atria, which leads to the contraction of both the atria.
(v) The QRS complex represents the depolarisation of the ventricles, which initiates the ventricular contraction.
(vi) The T wave represents the return of the ventricles from excited to normal state,
Which of the following option contain right statements ?