Case report: septic embolism through patent foramen ovale in mitral valve endocarditis

Background Infective endocarditis with septic emboli is a well-recognized sequala. However, emboli almost invariably are found 'downstream' to the vegetation. In the absence of congenital heart disease, the embolization from the left heart to the pulmonary circulation has never been described.Case summary A 4-year-old boy presents with a background history of pharyngitis treated with antibiotics. Upon ambulatory review, he is noted to have a new murmur. Transthoracic echocardiogram demonstrated mitral valve vegetation with severe mitral regurgitation; in addition, there was a patent foramen ovale (PFO), and there were no congenital heart defects. The patient was treated for infective endocarditis on high clinical suspicion. He subsequently developed septic pulmonary emboli in the absence of right-sided vegetation. Subsequent mitral valve vegetectomy, resection of infected native anterior mitral valve leaflet, mitral valve repair, and valvuloplasty. The patient made an excellent recovery following the completion of antibiotic therapy.Discussion Although not possible to confirm with certainty, this case demonstrates the most plausible explanation for this child's presentation being septic pulmonary emboli originating from left-sided heart vegetation migrating through a PFO.