Introduction: Isolated tricuspid valve infective en-docarditis is an infrequent diagnosis, the incidence accounting for 5% and up to 15% of IE cases. TVIE is strongly associated with intravenous drug use, pacema-kers and dialysis. Patients with uncorrected congenital heart disease are also at increased risk for RSIE 92.7%. S. aureus is the predominant causative microorganism for TVIE, occurring in 60–90% of cases in some stu-dies, irrespective of associated risk factors. Current cli-nical guidelines for the diagnosis recommend the use of modified Duke criteria. Prognosis of TVIE is rela-tively good. Non-operative management of TVIE with antibiotics alone clears the bacteremia in 70–85% of cases and is associated with 7–11% in-hospital morta-lity. Between 5–16% of RSIE cases eventually require surgical intervention, with reported operative morta-lity between 0–15% for patients with isolated TVIE de caractere

Methods: We report the case of a 43-year-old male patient, chronic alcohol abuser, who denies the ad-ministration of intravenous drugs, without any medi-cal treatment or significant personal or heredocolate-ral medical records, who presented to the emergency room of a territorial hospital in bad general condition, confused, with a 7-day history of intermittent high fe-ver. No treatment was performed prior to the admissi-on. He is transferred to the cardiology clinic after the echocardiography reveals a hyperecogene vegetation in the tricuspid valve, the presence of pericardial fluid and a right pulmonary mass on Rx.

Results: Physical examination revealed bilateral coar-se breath sounds, edema of the lower limbs, and a 3/6 pan systolic heart murmur, decreased blood pressure (116/78 mmHG). Laboratory analysis revealed impor-tant inflammatory syndrome (Leucocyte=25000/mm³ VSH=125mm/h, Fibrinogen=947mg/dl). The echocar-diography reveals enlargement of the right atrium and ventricle, a hyperecogene vegetation in the tricuspid valve, a 3cm large atrial septal defect, hyperecogene ve-getations on the anterior and septal leaflet of the tricus-pid valve and the presence of pericardial fluid in me-dium quantity. Electrocardiogram reveals ST segment elevation of 1-2 mm in DII, DIII and 2-4 mm in v2-v6, minor right bundle branch block. The case was complicated by multiple lung abscesses and thoracic emp-yema due to Acinetobacter baumannii complex and Candida albicans present in sputum.In consequence of nitrate retention (creatinine 6 mg / dl, urea 225 mg / dl), dialysis was required. After improvement of renal function, the patient is readmitted in ICU with acute pulmonary edema, paroxysmal atrial flutter and pul-monary hypertension. Surgery is required in order to replace the tricuspid valve with a biological prosthesis and to close the atrial septal defect. The bioptic sample indicates the presence of S. aureus. After antiobiothe-rapy and long-term inotropic support it is retransfered under hemodynamic stability conditions Conclusions: The specificity of the case consists in the occurrence of infectious endocarditis in a patient with no record of invasive maneuvers on the right atrium or ventricle, intravenous drug administration or di-alysis treatment. Paradoxical embolism from a primary pulmonary source with secondary infection of the tri-cuspid valve remains, in this case, the most plausible pathological mechanism of endocarditis. Large vegeta-tions, septic pulmonary embolism and failed medical therapies are more important reasons to operate than severe TV regurgitation. Earlier surgical intervention will prevent further embolism and destruction of TV leaflet tissue, in addition to increasing the likelihood of TV repair and decreasing the likelihood of extension to other anatomical structures.