Complete depolarization of the normal ventricles requires 80 to 100 msec (0.08 to 0.10 seconds) in the adult. It is influenced by gender and body size; being slightly longer in males than in females and in larger vs. smaller individuals. The characteristics of ventricular depolarization, i.e. its sequence, vectorial direction and duration, are reflected on the body surface electrocardiogram by the characteristics of the QRS complex.