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Noninfective Endocarditis


Guy P. Armstrong

, MD, Waitemata District Health Board and Waitemata Cardiology, Auckland

Reviewed/Revised Jul 2022 | Modified Sep 2022
Topic Resources

Noninfective endocarditis is formation of blood clots on heart valves and the lining of the heart.

  • Symptoms occur when a blood clot breaks loose and blocks arteries elsewhere in the body.

  • Diagnosis is by echocardiography and blood cultures.

  • Treatment is with anticoagulants.

Endocarditis usually involves infection of the inner lining of the heart (endocardium) and/or heart valves (infective endocarditis Infective Endocarditis Infective endocarditis is an infection of the lining of the heart (endocardium) and usually also of the heart valves. Infective endocarditis occurs when bacteria enter the bloodstream and travel... read more Infective Endocarditis ). However, endocarditis also can occur without infection. This form is called noninfective endocarditis.

Noninfective endocarditis develops when fibrous blood clots without microorganisms (sterile vegetations) form on damaged heart valves. Damage may be due to a birth defect, rheumatic fever Rheumatic Fever Rheumatic fever is inflammation of the joints, heart, skin, and nervous system, resulting from a complication of untreated streptococcal infection of the throat. Rheumatic fever is a reaction... read more Rheumatic Fever , or an autoimmune disorder Autoimmune Disorders An autoimmune disorder is a malfunction of the body's immune system that causes the body to attack its own tissues. What triggers an autoimmune disorder is not known. Symptoms vary depending... read more (in which antibodies attack the heart valves). Rarely, damage results from insertion of a catheter into the heart. People most at risk include those with the following:

Noninfective endocarditis, like infective endocarditis, may cause heart valves to leak or not open normally. Arteries may become blocked if vegetations break loose (becoming emboli), travel through the bloodstream to other parts of the body, and lodge in an artery, blocking it. Sometimes blockage can have serious consequences. Blockage of an artery to the brain can cause a stroke Overview of Stroke A stroke occurs when an artery to the brain becomes blocked or ruptures, resulting in death of an area of brain tissue due to loss of its blood supply (cerebral infarction). Symptoms occur suddenly... read more , and blockage of an artery to the heart can cause a heart attack Acute Coronary Syndromes (Heart Attack; Myocardial Infarction; Unstable Angina) Acute coronary syndromes result from a sudden blockage in a coronary artery. This blockage causes unstable angina or a heart attack (myocardial infarction), depending on the location and amount... read more Acute Coronary Syndromes (Heart Attack; Myocardial Infarction; Unstable Angina) . Organs that are often affected include the lungs, kidneys, spleen, and brain. Fingers and toes may also be affected. Emboli also often travel to the skin and back of the eye (retina).

Symptoms of noninfectious endocarditis occur when emboli form. The symptoms depend on what part of the body is affected.

The Heart

Diagnosis of Noninfective Endocarditis

  • Echocardiography

  • Blood cultures

Distinguishing between noninfective and infective endocarditis is difficult but important because treatment differs. Noninfective endocarditis may be diagnosed when echocardiography Echocardiography and Other Ultrasound Procedures Ultrasonography is a type of medical imaging that uses high-frequency (ultrasound) waves to produce a moving image of internal organs and other tissues. Echocardiography is ultrasonography of... read more Echocardiography and Other Ultrasound Procedures detects vegetations on the heart valves. Echocardiography cannot determine whether vegetations are infected. In order to detect whether microorganisms are present, blood cultures Culture of Microorganisms Infectious diseases are caused by microorganisms, such as bacteria, viruses, fungi, and parasites. Doctors suspect an infection based on the person's symptoms, physical examination results,... read more are done. If no bacteria or other microorganisms are detected by blood culture, it is more likely that the endocarditis is noninfectious. Blood tests for substances that may indicate the cause of noninfective endocarditis may be needed.

Treatment of Noninfective Endocarditis

  • Treatment of underlying disease

  • Anticoagulants

Anticoagulants, such as warfarin and heparin, may be used to prevent clotting, but their benefits have not been confirmed. Any underlying disease that has contributed to the development of noninfective endocarditis should be treated.

Prognosis is generally poor, more because of the seriousness of the underlying disorder than because of the heart problem.

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