6 Interesting Facts of Infectious endocarditis
- Infection of heart valves and myocardium
- Mitral valvular vegetations (eg, accretions of bacteria, fibrin, and platelets) on rare occasion can be large enough to impede blood flow, mimicking mitral stenosis
- Presents with dyspnea, congestive cardiac failure, heart murmurs, palpitations, systemic embolism, and low-grade fever
- Most commonly seen in rheumatic heart disease
- Blood culture results are positive in almost 90% of cases 4
- Differentiated with echocardiography; helps to confirm the diagnosis by detecting valvular vegetations, valvular dehiscence, periannular tissue destruction, and leaflet perforation
- Endocarditis due to MRSA is usually acute in onset and progresses rapidly to severe disease; differential diagnosis includes the following:
- Sepsis Staphylococcus aureus
- Syndrome of organ dysfunction in conjunction with a dysregulated host response
- Characterized by fever, hemodynamic instability, and toxic appearance
- Other potential sources may be identified (eg, abdominal pain, pyuria, infiltrate on chest radiograph)
- Distinguished by blood culture results and echocardiographic criteria
- Myocardial infarction (Related: Acute coronary syndromes)
- Myocardial necrosis resulting from occlusion of a coronary artery
- Presenting features may include dyspnea and fatigue
- Usually can be differentiated by presence of retrosternal chest pain and/or pressure radiating to neck, jaw, shoulder, and/or arm
- Diagnosed by ECG showing ST elevation, ST depression, or T wave inversion; elevated cardiac troponin level
- Myocardial infarction can occur concurrently with endocarditis, owing to embolization of vegetation into a coronary artery
- Pulmonary embolism
- Sudden occlusion of a pulmonary artery, most often due to a dislodged thrombus
- As with endocarditis, presenting symptoms may include dyspnea and tachypnea
- Onset of symptoms is abrupt, and pleuritic chest pain is common
- Diagnosed by multidetector-row CT angiography or CT pulmonary angiography; D-dimer levels are usually elevated
- May occur concurrently with tricuspid endocarditis, owing to embolization of a vegetation
- Sepsis Staphylococcus aureus
- Endocarditis due to MRSE usually is somewhat more indolent; differential includes subacute or chronic systemic conditions, as follows:
- Lymphoma
- Heterogeneous group of lymphoproliferative disorders characterized by aberrant proliferation of lymphocytes
- Clinical features may include fevers, weight loss, and night sweats
- Unlike with endocarditis, regional or diffuse lymphadenopathy can usually be detected
- Diagnosis is by biopsy
- Primary cardiac tumors
- Although atrial myxoma is most common, other malignant or benign tumors can develop in the heart
- May present with symptoms of embolization, intracardiac obstruction (heart failure or syncope), and constitutional symptoms
- Chest radiograph may show tumor calcification
- Echocardiography is diagnostic and finds tumors such as the following:
- Atrial myxoma as a well-defined, pedunculated, mobile mass attached to atrial septum, near fossa ovalis
- Malignant tumor as invasive sessile mass with broad-based attachment
- Histologic examination of the tumor is confirmatory
- Systemic lupus erythematosus
- Chronic multisystem disease of autoimmune origin affecting joints and skin (and sometimes other systems)
- Clinical manifestations may include malar rash, arthritis, renal dysfunction, and neurologic involvement
- Positive results for antinuclear antibody and anti-dsDNA antibody testing confirm the diagnosis
- Echocardiography may show broad-based Libman-Sacks vegetations less than 1 cm in diameter, without independent motion characteristics, unlike vegetations of infective endocarditis
- Lymphoma