[Infective endocarditis--still a great challenge. Two case reports].

We present two patients with aortic valve disease who developed acute infective endocarditis. In both patients the disease started with infection of the upper respiratory tract. The patients were treated with antibiotics due to pneumonia. The diagnosis of infective endocarditis was established 4 months and 9 weeks after the onset of infection. The first patient died whereas the second underwent successful aortic valve replacement.