Answer: The Ventricular systole is represented in the ECG by the R wave.
Explanation:
The P Wave represents the Atrial Systole.
The R Wave represents the Ventricular Systole.
The T Wave represents the Ventricular Diastole.
Which is why the R-R complex is one of the methods used to determine the Heart Rate on the ECG. The Atrial Diastole usually is not shown on the ECG, but in some patients may be normal.