Prosthetic cardiac valve thrombosis is a rare but serious complication of valve replacement with mechanical prostheses. The diagnosis is far from being easy because the clinical presentations are variable. Cinefluoroscopy of the prothesis and Doppler echocardiography (transthoracic and transoesophageal) are essential diagnostic investigations. The management (heparin therapy, thrombolysis, surgery) is based on individual assessment depending on the severity of prothesis obstruction and involvement of a right or left heart valve. Thrombosis of a tricuspid valve prosthesis is usually an indication for thrombolytic therapy. Massive thrombosis of a left heart prosthesis is usually an indication for surgery but thrombolysis may be considered as a salvage procedure in cases of cardiac surgery.
Cardiac sarcoidosis is often unrecognised because of the absence of specific clinical and electrical signs. The consequences are serious, the main risk being sudden death due to conduction defects (24 to 31% of cases) or ventricular arrhythmias. Any conduction defect without an obvious cause in a young patient should suggest a possible diagnosis of sarcoidosis. The confirmation is histological when giant cell non-caseuting epithelioid granuloma is demonstrated but myocardial biopsies are only positive in 20% of cases. Therefore, biopsy of accessible organs such as salivary glands is recommended. Diagnostic strategy consists in searching for signs of systemic sarcoidosis, and, when the diagnosis has been established, perform a complete work-up with echocardiography, dipyridamole myocardial scintigraphy, cardiac MRI and 24 hour ambulatory ECG recordings (Holter). The only proven treatment is steroid therapy with occasional spectacular observations of reversibility of arrhythmias or conduction defects.
Les thromboses de protheses valvulaires cardiaques representent une complication rare mais grave du remplacement valvulaire par prothese mecanique. Le diagnostic de thrombose est loin d’etre toujours aise car les presentations cliniques sont variees. L’echocardiographie transthoracique est l’examen de premiere intention qui doit etre complete au moindre doute par le radiocinema de valve et l’echocardiographie transœsophagienne. Quant a l’attitude therapeutique (heparine, fibrinolyse, chirurgie), elle doit etre discutee au cas par cas selon la localisation de la prothese et le contexte clinique. Une thrombose obstructive de prothese en position tricuspide releve classiquement de la fibrinolyse. Une thrombose massive d’une valve du cœur gauche est avant tout une indication a la chirurgie. Cependant, la fibrinolyse peut etre envisagee comme geste de sauvetage en cas de defaillance cardiocirculatoire grave et d’eloignement d’un centre de chirurgie cardiaque, de contre-indication a la chirurgie, ou en cas d’obstruction avec petit thrombus.
