A 85-year-old male with history of heart failure, biological aortic prosthesis and atrial fibrillation was hospitalized for urinary septic shock to Escherichia coli and was treated with empiric antibiotic. The transesophageal echocardiogram showed no dysfunction of the prosthesis. Due to clinical worsening, the patient repeated the echocardiogram which showed a vegetation on the non-coronary cusp and vegetation at the base of the mitral valve with a fistula between the implantation area of the prosthesis and the left atrium. The patient was rejected for cardiac surgery due to unfavorable surgical conditions and completed 6 weeks of directed antibiotherapy. He improved and was discharged with indication to maintain prophylactic antibiotic till echocardiographic reassessment.