BACKGROUND: Congenital heart defects predispose patients to a significantly increased risk of infective endocarditis (IE), and the incidence is even greater in the immunocompromised population. The involvement of multiple valves leads to a higher rate of complications and thus mortality. Moreover, biventricular IE is an uncommon condition with no specific guidelines for treatment.
METHODS: In this report, we discuss a case of an immunocompetent young male with a congenital perimembranous ventricular septal defect, complicated by multivalvular and right ventricular free wall vegetations. Biventricular involvement of IE along with septic embolization to both the pulmonary and systemic circulation resulted in challenges in the management of this patient.
CONCLUSIONS: The decision regarding timing and type (surgical vs. conservative) of treatment in such a complicated and aggressive IE case should be based on individual circumstances. However, the strategy of initial antibiotic therapy followed by surgical intervention can be a suitable option in such patients.

Mural endocarditis is a very rare condition. This entity involves bacterial growth on cardiac walls. In addition, concomitant valvular endocarditis, along with mural endocarditis, is an extremely rare combination. The diagnosis of mural endocarditis is difficult and requires more advanced cardiac imaging, such as a transesophageal echocardiogram. The differential diagnoses of mural masses include vegetations, thrombi, metastasis, and benign and malignant tumors. We present a rare and unusual case of Methicillin-Resistant Staphylococcus aureus bacteremia with findings of both right ventricular outflow tract mural endocarditis and valvular endocarditis involving the mitral valve.