Native and Prosthetic Aortic Valve Endocarditis

1.1 Definitions Infective endocarditis (IE) is an endovascular, microbial infection of intracardiac structures facing the blood, including infections of the large intrathoracic vessels and of intracardiac foreign bodies. The early characteristic lesion is a variably sized vegetation, although destruction, ulceration, or abscess formation may be seen earlier by echocardiography (Habib et al, 2009). Prosthetic valve endocarditis (PVE) is classified as early or late, depending on when infection is diagnosed: early PVE (within 12 months after surgery) and late PVE (12 months or more after surgery). Nosocomial IE is defined as an infection occurring > 72 h after admission to the hospital or IE acquired in association with a significant invasive procedure performed during a recent hospitalization ≤ 8 weeks before the onset of symptoms. Persistent infection is defined as a repeat episode of IE caused by the same microorganism developing < 1 year after the first episode (Hill et al, 2007).