The depolarization wave is finally conducted to the 
Purkinje
Fibers at the ends of the bundle branches. These specialized
cardiac conduction system fibers form a rapid conduction network
within the myocardium and are responsible for propagating the
depolarization wave to all cardiac muscle cells. The 
QRS
complex
of the electrocardiogram represents the ventricular
depolarization of contraction.
Following ventricular contraction and the QRS complex is a
brief period of low electrical activity. On the electrocardiogram
this appears as the 
S-T segment. Ventricular
repolarization is
represented by the 
T-wave on the electrocardiogram.
The T-wave
deflection is also in the same direction of the largest
deflection of the QRS complex because the electrical forces of
repolarization are transmitted from the epicardial surface to the
endocardial surfaces in the same direction as depolarization.