(p. 743) Endocarditis 

Endocarditis is defined as an inflammation of the endocardial surface of the heart. This may include heart valves, mural endocardium or the endocardium that covers implanted material, such as prosthetic valves, pacemaker/defibrillator leads and catheters. Infective and non-infective-related causes must be distinguished. In most cases, the inflammation is related to a bacterial or fungal infection with oral streptococci, group D streptococci, staphylococci and enterococci accounting for 85% of episodes. Infective endocarditis (IE) is a serious disease with an incidence ranging from 30 to 100 episodes/million patient-years. From various portals of entry (e.g. oral, digestive, cutaneous) and a subsequent bacteraemia, pathogens can adhere and colonize intracardiac foreign material or onto previously damaged endocardium due to numerous complex processes based on a unique host–pathogen interaction. Rarely, endocarditis can be related to non-infective causes, such as immunological or neoplastic. Mortality is high, with more than one-third dying within a year of diagnosis from complications such as acute heart failure or emboli. This disease still remains a diagnostic challenge with many cases being identified and subsequently treated too late. Diagnosis of IE usually relies on the association between an infectious syndrome and recent endocardial involvement. Blood cultures and echocardiography are the main diagnostic procedures, but are negative in almost 30% of cases, requiring the use of more sophisticated techniques. Computed tomography, magnetic resonance imaging and positron emission tomography are promising imaging modalities. Improved understanding of its pathophysiology and the development of relevant diagnostic strategies enables accelerated identification and treatment, and thus an improved prognosis.