- V1: 4th intercostal space (ICS), RIGHT margin of the sternum
- V2: 4th ICS along the LEFT margin of the sternum
- V4: 5th ICS, mid-clavicular line
- V3: midway between V2 and V4
- V5: 5th ICS, anterior axillary line (same level as V4)
- V7: Left posterior axillary line, in the same horizontal plane as V6.
- V8: Tip of the left scapula, in the same horizontal plane as V6.
- V9: Left paraspinal region, in the same horizontal plane as V6.
