Abstract
As the most common congenital heart defect, understanding the etiology and progression of aortopathy in bicuspid aortic valve (BAV) is imperative to management of patients with BAV. A reasonable hypothesis, based on the strength of evidence for both genetic and hemodynamic causes of BAV-associated thoracic aortic disease (TAD), is that BAV is caused by genetic variant(s) that also predispose to TAD by a common mechanism; presumably by cell-signaling resulting in an embryologic defect that causes BAV and a postnatal risk of TAD that is accentuated by hemodynamic stress of abnormal flow through the BAV valve. Clinical heterogeneity seen in BAVassociated TAD is likely due to individual genetic variation and the severity of hemodynamic alteration.