Ventricles
As the electrical impulse leaves the AV node, it passes into the bundle of His and then
down the bundle branches simultaneously. The first section of the ventricles to begin
depolarization is the mid portion of the interventricular septum from the left side, giving
rise to the normal Qwave on the 12-lead ECG. The walls of the left and right ventricles
are depolarized simultaneously. The speed of conduction through the ventricular Purkinje
network is rapid, about 4000 mm/s. Conduction in the ventricular muscle itself is considerably siowerabout400mm/s)