The standard position of the exploring chest electrode in adults is as follows:
Lead V1 is in the fourth intercostal space to the right of the sternum
Lead V2 is in the fourth intercostal space to the left of the sternum
Lead V3 lies between V2 and V4,
Lead V4 is in the fifth intercostal space in the mid-clavicular line
Lead V5 is in the fifth intercostal space in the anterior axillary line
Lead V6 is in the fifth intercostal space in the mid-axillary line
In women, the exploring electrode should be placed beneath the breast.