V 1: the fourth intercostal space at the right edge of sternum.
V2: the fourth intercostal space of the left sternum.
V3: the midpoint of the connection between V2 and v4.
V4: the intersection of the left clavicle midline and the fifth intercostal space.
V5: The left axillary front line is on the same horizontal line as v4.
V6: The left axillary midline is level with v4.
V7: The left posterior axillary line is level with v4.
V8: Paravertebral level is the same as v4.