Eustachian Valve Endocarditis in an Intravenous Drug User

Abstract

Case Description: We present the case of an intravenous drug user(IVDU) who presented with back pain. Initial Investigations and Management: His blood cultures demonstrated Staphylococcus aureus bacteraemia. He was diagnosed with a psoas abscess on CT scan, which was drained. He developed septic shock post operatively. CT chest demonstrated bilateral multifocal cavitating pneumonia with an inferior vena cava(IVC) thrombus for which patient had an IVC filter inserted. Transthoracic echocardiogram(TTE) demonstrated normal left and right ventricular function. The aortic and mitral valve were unremarkable, however there were vegetations visualised on the anterior(1.2 cm) and septal(1.0 cm) leaflets of the tricuspid valve with moderate regurgitation. Cardiothoracic surgical opinion was of conservative management at the time as there was no urgent indication for surgery. Despite a combination of broad spectrum antibiotics guided by the infectious disease specialists, our patient remained febrile with persistently positive blood cultures, elevated inflammatory markers and fluctuating levels of consciousness. Key Investigation: Transoesophageal echocardiogram(TOE) demonstrated anterior tricuspid valve vegetation, with aneurysm formation, localised perforation and eccentric severe regurgitation. The anteriorly directed tricuspid regurgitant jet had resulted in an infective seeding of the Eustachian valve, where a vegetation was visualised. The patient was transferred to ICU for further management of septic shock. He subsequently underwent tricuspid valve replacement, resection of the Eustachian valve, and completed the course of antibiotics, achieving a full recovery. The Eustachian valve vegetation was verified at surgery. Conclusion: This case demonstrates a rare form of endocarditis, with seeding of the Eustachian valve from a tricuspid valve jet lesion.