Symptoms mimicking COVID-19 infection, pulmonary emboli, or septicemia delayed diagnosis of aortic bioprosthesis failure. A 71-year-old man was admitted emergently with shortness of breath, fever, cough, and chest pain. Echocardiography performed after 2 days showed diastolic regurgitation in an aortic perimount pericardial bioprosthesis implanted 12 years previously. An urgent reoperation disclosed that one pericardial cusp was torn from the stent of the valve. We have not previously encountered sudden pericardial leaflet dehiscence of an internally mounted pericardial valve that caused heart failure and found no literature report like our finding.