Vegetation on the tricuspid valve by echocardiography. Arrow denotes the vegetation. In general, the Duke criteria should be fulfilled in order to establish the diagnosis of endocarditis. Although the Duke criteria are widely used, they have significant limitations. For example, the sensitivity of the Duke criteria for detecting<unk>  decreases when prosthetic heart valves are present. As the Duke criteria rely heavily on the results of echocardiography, research has addressed when to order an echocardiogram by using signs and symptoms to predict occult endocarditis among people who inject drugs and among non drug-abusing patients. However, this research is over twenty years old and it is possible that changes in the epidemiology of endocarditis and bacteria such as staphylococci make the following estimates incorrect. The blood tests C reactive protein (CRP) and procalcitonin have not been found to be particularly useful in helping make or rule out the diagnosis. Ultrasound Echocardiography is the main type of diagnostic imaging used to establish the diagnosis of<unk> . There are two main types of echocardiography used to assist with the diagnosis of<unk> : transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE). The transthoracic echocardiogram has a sensitivity and specificity of approximately 65% and 95% if the echocardiographer believes there is 'probable' or 'almost certain' evidence of endocarditis. However, in endocarditis involving a prosthetic valve, TTE has a sensitivity of approximately 50%, whereas TEE has a sensitivity exceeding 90%. The TEE also has an important diagnostic role when the TTE does not reveal<unk>  but diagnostic suspicion remains high, since TEE is more sensitive for<unk>  and is better able to characterize infection-related damage to the heart valves and surrounding tissues. Guidelines support the initial use of TTE over TEE in people with abnormal blood cultures, a new heart murmur, and suspected<unk> . TEE is the preferred initial form of imaging in people with suspected<unk>  who have a moderate to high pretest probability of<unk> , including people with prosthetic heart valves, blood cultures growing Staphylococcus, or have an intracardiac device (such as a pacemaker). File:UOTW 27 - Ultrasound of the Week 1.Ultrasound showing infectious endocarditis File:UOTW 27 - Ultrasound of the Week 2.Ultrasound showing infectious endocarditis File:UOTW 27 - Ultrasound of the Week 3.Ultrasound showing infectious endocarditis File:UOTW 60 - Ultrasound of the Week 1.Ultrasound showing another case of infectious endocarditis Modified Duke criteria Established in 1994 by the Duke Endocarditis Service and revised in 2000, the Duke criteria are a collection of major and minor criteria used to establish a diagnosis of<unk> . According to the Duke criteria, diagnosis of<unk>  can be definite, possible, or rejected. A diagnosis of<unk>  is definite if either the following pathological or clinical criteria are met: One of these pathological criteria: * Histology or culture of cardiac vegetation, embolized vegetation, or intracardiac abscess from the heart finds microorganisms * Active endocarditis One of these combinations of clinical criteria * Two major clinical criteria * One major and three minor criteria * Five minor criteria Diagnosis of<unk>  is possible if one of the following combinations of clinical criteria is met: * One major and one minor criteria * Three minor criteria are fulfilled Major criteria Positive blood culture with typical<unk>  microorganism, defined as one of the following: * Typical microorganism consistent with<unk>  from two separate blood cultures, as noted below: * Viridans-group streptococci, or * Streptococcus bovis including nutritional variant strains, or * HACEK group, or * Staphylococcus aureus, or * Community-acquired enterococci, in the absence of a primary focus * Microorganisms consistent with<unk>  from persistently positive blood cultures defined as: * Two positive cultures of blood samples drawn >12 hours apart, or * Three or a majority of ≥four separate blood cultures (with first and last sample drawn at least one hour apart) * Coxiella burnetii detected by at least one positive blood culture or IgG antibody titer for Q fever phase 1 antigen >1:800. This was previously a minor criterion Evidence of endocardial involvement with positive echocardiogram is defined as * Oscillating intracardiac mass on valve or supporting structures, in the path of regurgitant jets, or on implanted material in the absence of an alternative anatomic explanation, or * Abscess, or * New partial dehiscence of prosthetic valve or new valvular regurgitation (worsening or changing of preexisting murmur not sufficient) Minor criteria * Predisposing factor: known cardiac lesion, recreational drug injection * Fever >38 °C * Vascular phenomena: arterial emboli, pulmonary infarcts, Janeway lesions, conjunctival hemorrhage * Immunological phenomena: glomerulonephritis, Osler's nodes, Roth's spots, Rheumatoid factor * Microbiologic evidence: Positive blood culture (that doesn't meet a major criterion) or serologic evidence of infection with organism consistent with<unk>  but not satisfying major criterion Risk Among people who do not use intravenous drugs and have a fever in the emergency department, there is a less than 5% chance of occult endocarditis. Mellors in 1987 found no cases of endocarditis nor of staphylococcal bacteremia among 135 febrile patients in the emergency room. The upper confidence interval for 0% of 135 is 5%, so for statistical reasons alone, there is up to a 5% chance of endocarditis among these patients. In contrast, Leibovici found that among 113 non-selected adults admitted to the hospital because of fever there were two cases (1.8% with 95%CI: 0% to 7%) of endocarditis. Among people who do use intravenous drugs and have a fever in the emergency department, there is about a 10% to 15% prevalence of endocarditis. This estimate is not substantially changed by whether the doctor believes the patient has a trivial explanation for their fever. Weisse found that 13% of 121 patients had endocarditis. Marantz also found a prevalence of endocarditis of 13% among such patients in the emergency department with fever. Samet found a 6% incidence among 283 such patients, but after excluding patients with initially apparent major illness to explain the fever (including 11 cases of manifest endocarditis), there was a 7% prevalence of endocarditis. Among people with staphylococcal bacteremia (SAB), one study found a 29% prevalence of endocarditis in community-acquired SAB versus 5% in nosocomial SAB. However, only 2% of strains were resistant to methicillin and so these numbers may be low in areas of higher resistance.
Infective endocarditis
Libman–Sacks endocarditis
Loeffler endocarditis
Nonbacterial thrombotic endocarditis
Subacute bacterial endocarditis
Tuberculous pericarditis
Nocardiosis
Ischemic cardiomyopathy