Diagnostic criteria and problems in infective endocarditis.

O sler’s portentous words are as relevant now as when originally published. Despite improved preventive strategies, rational antibiotic prescribing, advances in imaging, and increasing use of early life saving cardiac surgery, the incidence of infective endocarditis remains high at 1.7–6.2 per 100 000 person years in the USA and Europe, with a one year mortality approaching 40%. The classical patient with infective endocarditis described in textbooks no longer represents the majority of cases in practice. The emergence of staphylococcal infection, often associated with indwelling devices, co-existent medical conditions and resistant to conventional antibiotic regimes, a variety of other atypical organisms, and the persistent syndrome of culture negative endocarditis make diagnosis and treatment as great a challenge as ever.