Abstract
A 36-year-old female was referred to our hospital because of high fever for 5 days and abnormal behavior. She had a grade II pan-systolic murmur at the right sternal border and blood culture grew methicillin-sensitive Staphylococcus aureus. A transthorasic echocardiogram showed vegetation of the tricuspid valve and severe tricuspid regurgitation. A transesophageal echocardiogram also revealed atrial septal aneurysm and patent foramen ovale. One month after admission, elective valve replacement was performed due to refractory heart failure and uncontrolled infection. At the time of surgery, there was an anterior mitral leaflet perforation with vegetation and a destroyed tricuspid valve with huge vegetation; dual-sided infective endocarditis was disclosed.