Electrocardiographic patterns in posterior chest leads (V7, V8, V9) in normal subjects

The electrocardiographic patterns in leads V7, V8, and V9 were studied in 225 young, normal men (age range 17 to 21 years). The prevalence of 0.5- to 1.0-mm ST-segment elevation in leads V7, V8, and Vg 0.08 second after the J point was 8.9%, 5.8%, and 3.1%, respectively; the ST-segment elevation was not >1.0 mm in any subject.