Endocarditis

Infective endocarditis is an infection of the endocardial surface of the heart, most often a valve. It is uncommon, it is frequently missed early, and untreated it is close to uniformly fatal — which is why a patient with unexplained fever and a reason to have a susceptible heart deserves active suspicion rather than reassurance. What makes it distinctive is that it is an endovascular infection. The organism is not walled off in a tissue abscess; it is sitting on a surface washed by every litre of blood the heart moves. That single fact explains almost everything else about the disease: the persistent bacteraemia, the need for prolonged intravenous therapy, the fever that does not settle, and the sudden catastrophic complications when a fragment breaks free. This lesson is written for Canadian nurse-practitioner practice. It covers diagnostic reasoning under the modified Duke framework, culture strategy including culture-negative disease, imaging escalation, prosthetic valve and cardiac device infection, antimicrobial principles, surgical referral thresholds and current Canadian prophylaxis guidance. Laboratory values follow SI units.