Bicuspid aortic valve is considered to have a multifactorial origin. Some research suggests a defect in neural crest cell signalling may increase the risk of developing bicuspid aortic valve, and also impact on the proximal conduction system.

To examine electrocardiographic parameters in unselected newborns from the general population diagnosed with bicuspid aortic valve within 30 days after birth.

This is a substudy of the Copenhagen Baby Heart Study; a multicentre, prospective, population-based cohort study with prenatal inclusion. Cardiac examination, including transthoracic echocardiography and electrocardiography, were obtained within 30 days after birth. Newborns diagnosed with bicuspid aortic valve were matched 1:4 with newborns with structurally normal hearts based on age, sex, gestational age, weight, and length at examination.

A total of 127 newborns with bicuspid aortic valve (84 boys, median age 11 days) and 508 controls (336 boys, median age 11 days) were included. Newborns with bicuspid aortic valve had a significantly longer PR-interval (100 vs 96 ms, p = 0.011) and QRS duration (56 vs 54 ms, p = 0.042), and a significantly lower R-wave amplitude in V6 (759 vs 906 µV, p = 0.047) compared to controls. However, when correcting for multiple testing none of the results were significant.

Newborns from the general population with bicuspid aortic valve demonstrated a slightly longer PR-interval, a longer QRS duration, and a lower maximum R-wave amplitude in V6 than matched controls, although non-significant after correcting for multiple testing. This may represent early signs of conduction abnormalities, but longitudinal follow-up will provide further clarification.