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Infective endocarditis: Difference between revisions
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* Acute IE – [[Staphylococcus aureus|S. aureus]] | * Acute IE – [[Staphylococcus aureus|S. aureus]] | ||
* Subacute IE – [[Streptococcus viridans]] | * Subacute IE – [[Streptococcus viridans]], other streptococci | ||
* Blood culture negative IE (BCNIE) | * Blood culture negative IE (BCNIE) | ||
** Brucella | ** Brucella | ||
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[[Rheumatic heart disease]] used to be a common cause but is now rare. | [[Rheumatic heart disease]] used to be a common cause but is now rare. | ||
== | == Pathology == | ||
Intact endothelium is resistant to bacteraemia, and so endothelial damage must be present for bacteria to colonize. Bacterial colonization results in: | Intact endothelium is resistant to bacteraemia, and so endothelial damage must be present for bacteria to colonize. Bacterial colonization results in: | ||
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* Formation of [[Immune complex|immune complexes]] -> deposit in organs | * Formation of [[Immune complex|immune complexes]] -> deposit in organs | ||
IE can also lead to acute regurgitation or valve obstruction, possibly causing acute heart failure or cardiogenic shock. | IE can also lead to acute destruction of the valves leading to acute regurgitation or valve obstruction, possibly causing acute heart failure or cardiogenic shock. | ||
Endocarditis almost always causes continous [[bacteraemia]]. | |||
=== Embolisation === | |||
Embolisation occurs in 20-50% of cases of infective endocarditis, as parts of the vegetation loosens and travels elsewhere, causing infarction. These are so-called ''septic emboli''. For left-sided endocarditis, embolisation occurs to the brain and spleen, while embolisation to the lungs is most common for right-sided endocarditis. Embolisation to vascular lumen or to the vasa vasorum causes characteristic aneurysms called ''mycotic aneurysms'', which can rupture and cause bleeds. These most commonly occur intracerebrally. Septic embolisation of the kidney may cause acute kidney injury. Janeway lesions occur from septic emboli. | |||
=== Immune complex formation === | |||
Immune complexes frequently form in infective endocarditis. These may cause glomerulonephritis, Osler nodes as well as Roth spots. | |||
== Classification == | == Classification == | ||
* Left sided endocarditis | * According to affected side of heart | ||
* Right sided endocarditis – especially in IV drug users, unusual in others | ** Left sided endocarditis | ||
* Native valve infective endocarditis (NVIE) | ** Right sided endocarditis – especially in IV drug users, unusual in others | ||
* Prosthetic valve endocarditis (PVE) | * According to risk factors | ||
** Native valve infective endocarditis (NVIE) | |||
** Prosthetic valve endocarditis (PVE) | |||
** Endocarditis in association with implants (ICD and pacemaker) | |||
** Endocarditis in IV drug users (usually right sided) | |||
Right sided endocarditis generally has a better prognosis than left-sided, but is much less common (5-10%). | |||
== Clinical features == | == Clinical features == | ||
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In case of blood culture negative IE, [[Polymerase chain reaction (PCR)|PCR]] and [[serology]] may assist in detecting the pathogen. [[Inflammatory marker|Inflammatory markers]] are elevated. | In case of blood culture negative IE, [[Polymerase chain reaction (PCR)|PCR]] and [[serology]] may assist in detecting the pathogen. [[Inflammatory marker|Inflammatory markers]] are elevated. | ||
If echocardiography fails to show signs of valvular vegetations despite high likelihood of the diagnosis, PET-CT can be used to assess perivalvular infection. | |||
=== Duke criteria === | |||
Diagnosis is based on the Duke criteria. There are major criteria and minor criteria, and the diagnosis is made when either of the following combinations are present: | Diagnosis is based on the Duke criteria. There are major criteria and minor criteria, and the diagnosis is made when either of the following combinations are present: | ||
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== Treatment == | == Treatment == | ||
Empirical antibiotic treatment is initiated after taking blood cultures, followed by specific antibiotics when results arrive. Antibiotic treatment for IE usually lasts 4 – 8 weeks. [[Penicillin]]/[[amoxicillin]] for [[streptococci]], cloxacillin for [[staphylococci]]. | Empirical intravenous antibiotic treatment is initiated after taking blood cultures, followed by specific antibiotics when results arrive. The specific empiric antibiotic regimen depends on local recommendations and the patient's risk factors (native or prosthetic valve, pacemaker/ICD, IV drug use, etc.). Antibiotic treatment for IE usually lasts 4 – 8 weeks, usually counted from the first day of definite improvement or from the day of the first negative blood culture. [[Penicillin]]/[[amoxicillin]] for [[streptococci]], cloxacillin for [[staphylococci]], depending on local resistance patterns. | ||
Surgery is often necessary in IE, in as much as 50% of cases. | Surgery is often necessary in IE, in as much as 50% of cases. Surgery is indicated for heart failure, uncontrolled infection, and in case of severe septic embolisation. Surgery is usually performed urgently. In case of [[cardiogenic shock]], emergency surgery is indicated. If there is infected material (pacemaker/ICD leads), they should be removed. | ||
== Prophylaxis == | == Prophylaxis == | ||