ECG chest lead positions

ECG chest lead positions

Positioning chest leads in wrong locations is quite common, often due to difficulty in locating anatomical landmarks, especially in females. V in chest leads stands for voltage.

Chest lead positions are as follows:

V1: 4th right intercostal space, right sternal edge
V2: 4th left intercostal space, left sternal edge
V3: Midway between V2 and V4
V4: 5th left intercostal space, midclavicular line
V5: Anterior axillary line, in the same horizontal level as V4
V6: Mid axillary line, in the same horizontal level as V4

Right chest leads:

V3R: Midway between V1 and V4R
V4R: 5th right intercostal space, midclavicular line
V5R and V6R are not usually taken, unless there is dextrocardia. Their positions will be corresponding the left chest leads, but on opposite side.
V3R and V4R are taken along with standard 12 lead ECG when right ventricular infarction is suspected.

Posterior leads:

V7: Posterior axillary line, in the same horizontal level as V6
V8: Mid scapular line, in the same horizontal level as V6
V9: Midway between midscapular line and spine, in the same horizontal level as V6
Posterior leads [1] are useful when true posterior infarction is suspected [2]. But they are seldom taken because of the technical difficulty in placing the leads which needs prone position, in a sick patient.

References

1. Chia BL, Tan HC, Yip JW, Ang TL. Electrocardiographic patterns in posterior chest leads (V7, V8, V9) in normal subjects. Am J Cardiol. 2000 Apr 1;85(7):911-2, A10.
2. Melendez LJ, Jones DT, Salcedo JR. Usefulness of three additional electrocardiographic chest leads (V7, V8, and V9) in the diagnosis of acute myocardial infarction. Can Med Assoc J. 1978 Oct 7;119(7):745-8.