Precordial (chest) leads
Also calledchest leads · V leads · unipolar chest leads · horizontal plane leads · precordial leads
Definition
The six chest leads (V1 through V6) that view the heart in the horizontal plane, each recording the potential at its chest electrode relative to Wilson's central terminal. Standard positions: V1 fourth intercostal space at the right sternal border, V2 fourth intercostal space at the left sternal border, V3 midway between V2 and V4, V4 fifth intercostal space in the midclavicular line, V5 in the horizontal plane of V4 at the anterior axillary line, and V6 in the horizontal plane of V4 at the midaxillary line. Leads V1 to V4 view the anterior surface of the heart and V5 to V6 the lateral surface.
Clinical noteOnly V4 is anchored to the 5th intercostal space; V5 (anterior axillary line) and V6 (midaxillary line) are placed at V4's horizontal level, not independently to the 5th ICS.
Sources
- Meek S, Morris F. ABC of clinical electrocardiography. Introduction. I: Leads, rate, rhythm, and cardiac axis. BMJ. 2002;324(7334):415-418. doi.org/10.1136/bmj.324.7334.415
- Kligfield P, Gettes LS, Bailey JJ, et al. Recommendations for the standardization and interpretation of the electrocardiogram: part I: the electrocardiogram and its technology. Circulation. 2007;115(10):1306-1324. doi.org/10.1161/CIRCULATIONAHA.106.180200
Last reviewed 2 October 2026. Every definition in the EKG Dictionary cites the guideline, consensus statement or original paper it comes from.