Infective endocarditis leads to formation of bulky and friable vegetations on the valvular leaflets. The vegetations are composed of fibrin, neutrophils, and colonies of bacteria that cause erosion of underlying cardiac structures. Fragments of infected vegetations may detach and cause pulmonary or systemic septic embolism. Splinter hemorrhages in the nail bed and petechiae in skin and mucosae are also due to microscopic septic emboli. In this case, myocardial infarction was probably due to a septic embolus in the coronary circulation. If infective endocarditis is due to a virulent organism such as Staphylococcus aureus (a common cause of endocarditis in intravenous drug abusers), a tumultuous clinical course ensues, associated with high moality. With less virulent organisms, such as Streptococci viridans, Subacute infective endocarditis is the resultant clinical picture. Subacute endocarditis arises in patients with previously malformed or damaged valves and is associated with a slower course and a better prognosis. Also Know: Carcinoid hea disease is caused by serotonin-producing carcinoids in the liver or lungs. Fibrosis of the endocardium ensues, affecting the right hea in the case of hepatic carcinoids and the left hea for pulmonary carcinoids. Thickening and rigidity of valvular leaflets are characteristic gross findings. Libman-Sacks endocarditis is a non-infective form of endocarditis associated with systemic lupus erythematosus (SLE). The vegetations are small and regularly aligned along the valvular margins. Nonbacterial thrombotic endocarditis was previously known as marantic endocarditis, being associated with debilitating conditions such as disseminated neoplasms. Increased coagulability is probably the underlying pathogenesis. The lesions are small vegetations similar to Libman-Sacks endocarditis. Clinical and Laboratory Features of Infective Endocarditis (Frequency,%) Fever 80-90 Chills and sweats 40-75 Anorexia, weight loss, malaise 25-50 Myalgias, ahralgias 15-30 Back pain 7-15 Hea murmur 80-85 New/worsened regurgitant murmur 20-50 Aerial emboli 20-50 Splenomegaly 15-50 Clubbing 10-20 Neurologic manifestations 20-40 Peripheral manifestations (Osler's nodes, subungual hemorrhages, Janeway lesions, Roth's spots) 2-15 Petechiae 10-40 Anemia 70-90 Leukocytosis 20-30 Microscopic hematuria 30-50 Elevated erythrocyte sedimentation rate 60-90 Elevated C Reactive protein level >90 Rheumatoid factor 50 Circulating immune complexes 65-100 Ref: Karchmer A.W. (2012). Chapter 124. Infective Endocarditis. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.