A baffle is a surgically-created tunnel or wall within the heart or major blood vessels used to redirect the flow of blood. They are used in some types of heart abnormalities that a child is born with known as congenital heart defects. Baffles are usually constructed, at least in part, from a person's own heart tissue, while other methods of redirecting blood using artificial material are known by the more generic term 'conduits'. Baffle does not refer to surgical techniques that redirect blood outside the heart or blood vessels such as coronary artery bypass grafting.