Ten electrodes, one on each limb and six on the chest, are routinely employed to record the electrocardiogram in the clinical setting. The information recorded by these electrodes is displayed in 12 individual leads: leads I, II, III, aVR, aVL, aVF, and leads V1 through V6. Leads I, II and III are referred to as the limb leads. Leads aVR, aVL and aVF are referred to as the augmented limb leads and leads V1 through V6 are referred to as the chest leads.