[Repeated thrombolysis and difficulties in treatment with antivitamin K in an infant with mitral valve prosthesis].

The finding of cardiac failure in a neonate led to the diagnosis of congenital mitral regurgitation complicating dystrophic valves. After failed surgical valvuloplasty, the child underwent mitral valve replacement with a Saint-Jude medical prosthesis at the age of 4 months. The child developed four episodes of prosthetic valve thrombosis in the two years that followed. The first was treated surgically but the three others were treated by thrombolysis associating plasminogen tissue activator and urokinase. All but one of the thromboses occurred in a context of recent destabilisation of oral anticoagulant therapy despite the initiation of heparin. Repeat thrombolysis was successfully undertaken, thereby widening the indications of this type of treatment in the infant. This case also underlines the difficulties of oral anticoagulants in infants.