Abstract 13195: A Case of Ebstein Anomaly Diagnosed Following Tricuspid and Pulmonic Valve Infective Endocarditis in an Adult Patient

Abstract

Background: We present a rare case of infective endocarditis (IE) involving both tricuspid (TV) and pulmonic valves (PV) in the setting of newly diagnosed Ebstein anomaly (EA) with isolated, small membranous VSD. Case: A 48 yo woman with no known medical history presented with two weeks of fever, flu-like symptoms, and dyspnea. Vitals showed fever, tachycardia, and tachypnea. Poor dentition, grade III systolic murmur, and S3 gallop were noted on physical exam. EKG showed sinus tachycardia and right bundle branch block. Laboratory studies showed leukocytosis and elevated CRP. A chest CT revealed bilateral lung infiltrates in a rounded configuration concerning for septic emboli. Blood cultures grew Streptococcus mitis , and IV antibiotics were initiated. TTE revealed 3.2cm apical displacement of the TV resulting in right ventricular atrialization, diagnostic for EA. TTE also found a 26x17mm vegetation on the septal and anterior leaflets of the TV with moderate tricuspid regurgitation and an 11x6mm vegetation on the PV, confirmed by TEE. Cardiac MRI also noted a focal aneurysm of the membranous interventricular septum with a hemodynamically insignificant shunt. Discussion: While interatrial communications are seen in a majority of EA patients (80-94% of cases), this patient presented solely with a small membranous VSD and absence of ASD and PFO. Moreover, this patient had no PDA to depend on for pulmonary flow. Remarkably, she had an asymptomatic course with EA until the development of endocarditis. It is believed the presence of an isolated VSD in this patient’s severe EA likely promoted forward pulmonic flow in an already inadequate right ventricle. Right-sided IE is itself rare (5-10% of cases) with isolated PV involvement being even rarer (2% of cases). This patient’s uncorrected EA with redundant TV and PV leaflet tissue likely contributed as a nidus for simultaneous infection of both valves.