Isolated Pulmonic Valve Endocarditis Causing Septic Pulmonary Embolism

Abstract

INTRODUCTION: Isolated pulmonic valve endocarditis without tricuspid valve involvement is a very rare entity, affecting less then 1.5% of all patients with infective endocarditis (1). Although it is uncommon, it can result in another uncommon but serious disorder, septic pulmonary embolism (2). We are presenting a case of isolated pulmonic valve endocarditis who presented as septic pulmonary embolism with multiple cavitary lesions and fever but no identifiable precipitating risk factors for right sided endocarditis. CASE PRESENTATION: 48 years old man with past medical history of coronary artery disease and congestive heart failure who works as a hospital employee presented with fever, weight loss, nonproductive cough, orthopnea, diarrhea and back pain for 2 weeks. He denied any intravenous drug abuse. The chest X-ray showed some linear markings. Computed tomography of the chest showed bilateral multiple cavitary lesions. Mycobacterium tuberculosis was ruled out, with initial negative blood cultures. Magnetic resonance imaging of the spine did not show any abnormal enhancement. Later, the bronchoscopic alveolar lavage and blood cultures grew methicillin-sensitive staphylococcus aureus. Transesophageal echocardiogram revealed a vegetation on the pulmonic valve, moderate pulmonic valve insufficiency with a reduced ejection fraction of 25-30%. Patient had no other clinical manifestations or other complications. He was treated with intravenous Nafcillin with symptomatic and clinical improvement then was discharged home on continuous oxacillin infusion for 4 weeks. DISCUSSION: In our case,although there was a clinical suspicion for septic pulmonary embolism, the initial transthoracic echocardiogram did not reveal any vegetations. The right sided endocarditis, which involves mostly the tricuspid valve alone or the pulmonic valve along with the tricuspid valve is more frequent in males with risk factors like intravenous drug abuse, central venous catheterization, pacemaker leads or congenital heart malformations but our patient did not have any of these except for heart failure with reduced ejection fraction and did not have tricuspid valve involvement. CONCLUSIONS: Septic pulmonary embolism should be considered in the differential diagnosis of multiple cavitary lesions and fever, even in patients with no significant risk factors for right sided endocarditis and the transesophageal echocardiogram should be the next step which has a better sensitivity for isolated pulmonic valve involvement which is an extremely rare finding.