Infective endocarditisBMJ 2010; 341 doi: https://doi.org/10.1136/bmj.c6596 (Published 01 December 2010) Cite this as: BMJ 2010;341:c6596
- Mark Connaughton, consultant cardiologist1,
- John G Rivett, general practitioner2
- 1Cardiology Department, St Mary’s Hospital, Newport, Isle of Wight PO30 5TG, UK
- 2Martins Oak Surgery, Battle TN33 0EA UK
- Correspondence to: M Connaughton
Infective endocarditis is caused by microbial infection of the endocardial surface or of prosthetic material in the heart. More than 80% of cases are caused by Staphylococcus aureus or by species of Streptococcus or Enterococcus. The total incidence of infective endocarditis has remained relatively constant, but the epidemiology has changed markedly in recent years. Proportionately more cases are now seen in association with prosthetic valves and as a result of hospital acquired infections.1
Four months after prostate surgery that had been complicated by a urinary infection, a 65 year old man presented with lethargy, malaise, and mild anaemia. No further specific abnormalities were found over the next two weeks. He developed night sweats, and a new systolic murmur was heard. C reactive protein was raised at 90 mg/l. Infective endocarditis was considered as a diagnosis. Blood cultures were ordered and he was referred to hospital. Enterococcus faecalis was grown from all culture bottles. Transthoracic echocardiography showed mitral valve vegetations, confirming the diagnosis of bacterial endocarditis.
How common is infective endocarditis?
The annual incidence is 3-10 cases per 100 000
A general practitioner is unlikely to see more than one case every 8-10 years
Why is infective endocarditis missed?
Infective endocarditis is a rare disease with varied presentations. Symptoms such as loss of appetite, weight loss, arthralgia, and night sweats overlap with much more common conditions, including occult malignancy. Fever is almost invariable,2 but many patients may initially experience only a general malaise. Given the diagnostic difficulty, some 25% of patients take longer than one month to be admitted to hospital after their first clinical signs become evident.2
Why does this matter?
Data from the pre-antibiotic era suggest that infective endocarditis is almost always fatal if untreated.3 Delayed diagnosis in some groups is associated with a substantial increase in mortality.4 Even with timely recognition and treatment, the outcome may sometimes …