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Potentially life-threatening emergency
Endocarditis in Adult
See also in: Nail and Distal Digit
Other Resources UpToDate PubMed
Potentially life-threatening emergency

Endocarditis in Adult

See also in: Nail and Distal Digit
Contributors: Katie Fitzgibbon MD, Sylvia Guerra MD, MTS, Neil Mendoza MD, Paritosh Prasad MD, Bruce Lo MD
Other Resources UpToDate PubMed


Emergent Care / Stabilization:
  • Initial considerations in the setting of endocarditis do not differ from other emergency hemodynamic stabilization approaches.
  • Obtain blood cultures early if endocarditis is suspected.
  • Involve the cardiac surgery team as early as possible if surgical intervention may be warranted.
Diagnosis Overview:
Endocarditis is a potentially life-threatening disease of the cardiac endothelium, most frequently involving the valves, caused by vegetations, infection, or both. Most cases of endocarditis are infectious, but it can also have noninfectious etiologies, such as in Libman-Sacks endocarditis where vegetations form secondary to autoimmune disease. Additionally, endocarditis can present as either acute or subacute disease and may be valvular or nonvalvular.

Endocarditis is a serious medical condition with an incidence rate of 15 per 100 000 people, an in-hospital mortality rate of around 20%, a 6-month mortality rate of around 30%, and a 1-year mortality rate approaching 40%. If surgery is indicated, early surgical intervention is associated with lower mortality. The incidence of endocarditis is increasing overall with more indwelling cardiovascular devices and increasing rates of intravenous (IV) drug use, which are major risk factors for this disease. Other risk factors include chronic hemodialysis, intravascular catheters, skin infections, recent dental procedures, poor dentition, prosthetic valve(s), age older than 60 years, male sex, congenital or acquired valvular heart disease, and prior infective endocarditis. Endocarditis should be considered in immunodeficient patients and patients with certain congenital or heritable heart malformations.

Community-acquired infection remains the most common cause of endocarditis, comprising up to 70% of cases, and is most commonly caused by oral, gastrointestinal (GI), and cutaneous bacteria. The most common bacterial cause in higher-income countries is Staphylococcus aureus (in up to 40% of cases).

Signs and symptoms include a sudden onset of high fever, sepsis, or systemic complications, especially in the setting of a new heart murmur. Additionally, worsening of an old murmur, hematuria, and vascular embolic events should raise concern for endocarditis. Although there are classically taught pathognomonic signs and symptoms consistent with endocarditis, such as Janeway lesions, Roth spots, and splinter hemorrhages, these are found in a minority of patients, and their absence should not eliminate endocarditis from the differential.

The risk of developing prosthetic valve endocarditis is greatest during the initial 3 months after surgery, remains high for 6 months, and then falls gradually. Infection generally occurs with equal frequency on aortic and mitral sites as well as on mechanical and bioprosthetic devices during the first postoperative year. Afterward, bioprosthetic valves have a higher risk of infection due to age-related alterations in the valves' surfaces.

Libman-Sacks endocarditis is a noninfective cardiac valve disease that was initially described in patients with systemic lupus erythematosus (SLE). This form of endocarditis might occur in patients with antiphospholipid antibody syndrome. Vegetations on cardiac valves in Libman-Sacks endocarditis are composed primarily of inflammatory cells and fibrin clots. Endocarditis is presumed to be caused by autoimmunity against a cardiac valve with concurrent hypercoagulability. Patients are often asymptomatic but may be discovered after a cardioembolism causes ischemic injury, such as stroke or peripheral embolic disease. Libman-Sacks endocarditis is most frequently seen on the mitral and/or aortic valves and may cause valve dysfunction.


I38 – Endocarditis, valve unspecified

56819008 – Endocarditis

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Differential Diagnosis & Pitfalls

Endocarditis can present with a wide range of sometimes nonspecific symptoms and can therefore be difficult to diagnose. If endocarditis presents with fever only, it may be mistaken for a febrile illness. If it presents with a murmur only, it is very important to take a detailed history to ensure that this is indeed a new murmur, raising suspicion for endocarditis.

The most common murmur heard with acute infective endocarditis is Aortic regurgitation; however, given that endocarditis can affect any valve, any new murmur should raise suspicion for endocarditis in the right clinical setting.

Other diagnoses on the differential include:

  • Cellulitis
  • Septic arthritis
  • Acute cholecystitis
  • Acute cholangitis
  • Intraabdominal abscess
  • Systemic lupus erythematosus
  • Rheumatic fever and heart disease
  • Cholesterol emboli
  • Vasculitis
  • Deep vein thrombosis (DVT)
  • Myocarditis

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Last Reviewed:01/24/2024
Last Updated:02/14/2024
Copyright © 2024 VisualDx®. All rights reserved.
Potentially life-threatening emergency
Endocarditis in Adult
See also in: Nail and Distal Digit
A medical illustration showing key findings of Endocarditis (Acute Bacterial Endocarditis)
Clinical image of Endocarditis - imageId=47822. Click to open in gallery.  caption: 'Angulated reddish and violaceous macules and thin papules on the great toe.'
Angulated reddish and violaceous macules and thin papules on the great toe.
Copyright © 2024 VisualDx®. All rights reserved.