Lead Site V4

**Semantic type:** Spatial Concept

**Definition:** A unipolar electrocardiogram lead site; the electrode is placed at the fifth intercostal space on the anterior chest wall (between ribs 5 and 6) at the left midclavicular line. In small animals it corresponds to V4-V6 where it is placed at the 6th left intercostal space near the costochondral junction. In large animals it is placed over the 6th rib at the level of a horizontal line drawn through the scapulohumeral articulation on the left side of the thorax.

**Synonyms:** - LEAD V4 - Lead C4