Infective Endocarditis of the Mitral Valve in a Patient with Congenital RCA to LV Fistula

Abstract

A 26-year-old female recent nursing graduate from the Philippines presented to the Emergency Department with 4-week history of intermittent fevers. This occurred following dental root canal and filling 5 months earlier. Physical examination revealed a pansystolic murmur in the left sternal edge. Blood cultures were positive for Streptococcus anginosus (one of the Milleri group Streptococci) with penicillin MIC of 0.125. Transthoracic echocardiography (TTE) demonstrated markedly dilated right coronary artery (RCA) with RCA fistula noted between the distal RCA and entering the basal inferior LV wall. Left ventricle (LV) was mildly dilated with normal systolic function (EF 58%). A transoesophageal echocardiogram revealed a strand-like echodensity (3.3 mm length) associated with the posterior mitral valve leaflet tip. There was significant dilation of the RCA (ostial RCA 1.5 cm) visualised traversing over the RV outflow tract and connecting into the basal inferior LV cavity. High turbulent diastolic flow was demonstrated consistent with RCA to LV fistula. Cardiac MRI revealed RCA to LV fistula flow representing 28% of aortic flow. A partial anomalous pulmonary venous drainage of the right upper lobe to the superior vena cava was detected. The patient was treated with 42 days of intravenous penicillin. Repeat TTE showed mild posterior mitral valve leaflet thickening with grade 0-1/4 mitral regurgitation. A 3D printed model (Fig. 1) was presented at a multidisciplinary team meeting. As LV fistulae pose a risk for rupture, a decision was made for elective percutaneous closure six months after demonstration of clearance from infection and normal inflammatory markers.