Abstract Introduction infective endocarditis(IE) is a high morbidity and mortality disease, and heart failure,central nervous system embolization and annular abscess account for common complications.Nevertheless,intracardiac fistula is rare and predicts higher mortality and urgency for surgery. Case 84years old male patient,with an aortic bioprosthesis valve Perimount n23 since 2015,was admitted to internal medicine ward 3months before,due to Enterococcus faecalis bacteremia.at that time,transoesophageal echocardiography(TEE) revealed moderate to severe mitral valve(MV) regurgitation(vena contracta 0.7cm) and trivial tricuspid regurgitation,but did not showed any suggestive images of endocarditis.the patient was treated with 14days of amoxicillin-clavulanate. On the current presentation,due to fadigue to mild physical activity and fever for 2weeks,he was admitted to cardiology ward for further investigation.blood cultures were positive for the previous agent,so antibiotherapy with ampicillin 12g/day and gentamicin 240mg id was started.TEE revealed thickening of aortic bioprosthesis’ leaflets with preserved systolic opening.aortic valve annulus thickening,mainly near the non-coronary cusp,was evident, without characteristic features of peri-annular abscess.on ventricular side of the prosthesis,there was a vegetation(10.7x10.8mm). a small nodule lesion,coherent with a second vegetation,was present on the MV’s posterior leaflet,without regurgitation’s worsening. a third one was observed on the septal leaflet of the tricuspid valve(7.3x6.5mm),which also caused an increasement in severity of the regurgitation,quantified as moderate. On the sixth day,the patient presented with right arm paresis,so a brain CT was performed,showing an ischemic lesion on the left middle cerebral artery.Reevaluation,5days later,owing to new neurological changes,showed multiple acute vertebrobasilar embolic strokes. As a result of poor medical response and embolic strokes,the patient was referred to surgical treatment. however, due to prohibitive surgical risk (euroscore 59%), the patient was refused. After 6weeks of blood culture driven antibiotherapy,a reevaluation TEE revealed a periprosthetic pseudoaneurysm with small aorta-to-right atrium fistula.no vegetations were found. Conclusion rate complication of cardiac fistulae is high,60%of the patients develop heart failure and mortality rate is higher than 40%.although conservative treatment was addressed,after 8months discharge,the patient remains with few heart failure symptoms(NYHA classII).