Depolarization of human ventricular muscle starts from

Order of depolarization in the heart. -        First- Left side of the interventricular septum -        Moves to right across the mid portion of the septum -        Apex of heart -        Along ventricular walls to AV groove (Endocardium to epicardium) -        Last- Posterobasal portion of the left ventricle, pulmonary conus, uppermost portion of the septum.