<unk>  <unk>  or<unk> o), also<unk> lled<unk> c narrowing, is a congenital condition whereby the<unk>  is narrow, usually in the area where the ductus arteriosus (ligamentum arteriosum after regression) inserts. The word<unk> rctation means "pressing or drawing together; narrowing".<unk> rctations are most common in the<unk> c arch. The arch may be small in babies with<unk> rctations. Other heart defects may also occur when<unk> rctation is present, typically occurring on the left side of the heart. When a patient has a<unk> rctation, the left ventricle has to work harder. Since the<unk>  is narrowed, the left ventricle must generate a much higher pressure than normal in order to force enough blood through the<unk>  to deliver blood to the lower part of the body. If the narrowing is severe enough, the left ventricle may not be strong enough to push blood through the<unk> rctation, thus resulting in a lack of blood to the lower half of the body. Physiologically its complete form is manifested as interrupted<unk> c arch.
Coarctation of the aorta
Familial thoracic aortic aneurysm
Annuloaortic ectasia
Double aortic arch
Interrupted aortic arch
Aortic stenosis
Pulmonary vein stenosis
Pulmonic stenosis