DOI: https://doi.org/10.36347/sjmcr.2026.v14i11.030

Pages: 2536-2542

Right-sided infective endocarditis (IE) most often affects the tricuspid valve and can be difficult to confirm when antimicrobial therapy begins before blood cultures are obtained. We report a 39-year-old man with no known structural heart disease or injection drug use who developed tricuspid valve IE after severe thoracoabdominal trauma, emergency abdominal surgery, and a complicated postoperative course. Serial echocardiography showed the new appearance and subsequent enlargement of two mobile tricuspid vegetations, from 15 × 5 mm and 16 × 6 mm to 24 × 4 mm and 22 × 5 mm, with severe tricuspid regurgitation. Blood cultures were repeatedly negative after prior antibiotic exposure. Computed tomography later showed bilateral peripheral pulmonary micronodules, several with cavitation, consistent with septic pulmonary emboli. The diagnosis was clinically considered blood culture-negative infective endocarditis and met the 2023 Duke-International Society for Cardiovascular Infectious Diseases definition of possible IE. The patient received ceftriaxone for 21 days with gentamicin during the first 14 days, followed by 42 days of vancomycin. At the end of treatment, the vegetations had partially regressed and the patient remained clinically stable. He was still asymptomatic two months later, with no documented recurrence. The case shows the value of serial echocardiography when the initial study is normal, the limitations of cultures obtained after antibiotics, and the importance of evaluating pulmonary embolic complications in suspected right-sided IE.