ABSTRACT
Infective endocarditis (IE) is an infection of the endocardium of one or more valves. Rarely, it may involve the mural endocardium. It currently is classified into one of the four major types: native valve endocarditis (NVE), prosthetic valve endocarditis (PVE), intravenous drug abuser IE (IVDA IE), and healthcare-associated IE (HCIE). Classically, this infection has been categorized as either acute or subacute. The clinical courses were quite different with the pathogens that were highly associated with one type or another. Acute IE was, and still is, a rapidly progressive disease that can be fatal in a few days. Without treatment, subacute IE may smolder for months or even longer than a year (Chapter 6). Until the 1980s, the vast majority of cases were subacute, caused by viridans streptococci. In this era of IE of intravascular devices (Table 1), there has been a dramatic reversal of this pattern. At times, the differences between these two may be blurred by indiscriminately prescribed antibiotic therapy. Infective endocarditis, caused by Staphylococcus aureus, may assume an indolent course when exposed to inadequate dosage regimens of antibiotics that are given on the basis of faulty diagnoses. This situation could be labeled as “muted endocarditis.” Nonetheless, the clinical classification of acute and subacute disease remains useful, as it still retains a good amount of clinical predictive value.
