Endocarditis

Original Editor - Audrey Brown
Top Contributors - Audrey Brown, Ahmed M Diab, Rachael Lowe, Vidya Acharya and Stacy Lawrence

Introduction

Endocarditis is an inflammatory condition of the endocardium, the innermost lining of the heart. It is often caused by infections, most commonly bacterial, and is known as infective endocarditis (IE) and this is another type of endocarditis, known as non-infective endocarditis or non-bacterial thrombotic endocarditis (NBTE). It is characterised by the formation of sterile vegetations on heart valves. Endocarditis can lead to severe complications, such as valve destruction, heart failure, and systemic embolisation. Early diagnosis and treatment are critical to preventing irreversible damage.

Clinically Relevant Anatomy

Endocarditis may involve the inner lining of the heart, the heart valves, and/or the heart muscle.

Etiology and Pathophysiology

Endocarditis is commonly caused by bacterial infections, with Staphylococcus aureus and Streptococcus viridans being the most frequently identified pathogens. It can also result from fungal or viral infections, although these are less common. The infection typically begins when bacteria enter the bloodstream through invasive procedures, dental infections, or intravenous drug use and adhere to damaged cardiac tissue or prosthetic valves. The formation of vegetation—a mass of fibrin, platelets, and microorganisms—is a hallmark of the disease.

Recent evidence highlights the evolving nature of infective endocarditis. According to "Infective Endocarditis: A Contemporary Update," changes in demographics, healthcare practices, and microbial profiles are influencing the disease’s presentation and management. For instance, prosthetic valve endocarditis is becoming more prevalent as the population ages and the use of intracardiac devices increases.

Clinical Presentation

Patients with the following factors are at higher risk for developing infectious endocarditis:

• Birth defects of the heart
• Heart transplant and valve problems (such as valvular stenosis or valvular regurgitation)
• Prosthetic heart valves
• Past history of endocarditis
• Dental procedures that are likely to cause bleeding
• Surgical procedures involving the breathing tract, the urinary tract system, and/or the digestive tract.
• Surgical produces on skin infections and soft tissue infections
• Hypertrophic cardiomyopathy
• Hypertension

Endocarditis is also more common in patients over the age of 50, and men are twice as likely to be affected as women.

Most patients present with fever, night sweats, fatigue, weight and appetite loss, and a rare number of them may present with a stroke.

Other symptoms of endocarditis may include:

• Small areas of bleeding under the nails (Splinter Hemorrhages)
• Red, painless skin spots on palms and soles of feet (Janeway Lesions)
• Red, painful nodes in the pads of fingers and toes (Osler nodes)
• Shortness of breath with activity
• Swelling in feet, legs, and abdomen
• Fatigue
• Weakness
• Aches and/or pains in muscles and joints
• Sacroiliitis
  

Diagnostic Procedures

Less than half of patients with endocarditis may present with a new heart murmur or a change in a past heart murmur. However, this can help localise which valve is involved.

Other testing for endocarditis involves blood cultures to identify the bacteria or fungus causing the infection, complete blood count (CBC), C-reactive protein counts (CRP), and erythrocyte sedimentation rates (ESR). An echocardiogram may also be performed to examine the heart valves.Blood testing is important to help diagnose the most effective treatment.

Management / Intervention

Endocarditis is a potentially life-threatening condition and emergency medical intervention and hospitalization may be necessary.

Patients with endocarditis require long-term antibiotic therapy for 4-6 weeks to eliminate all bacteria within the heart chambers and valves.

Surgery is often indicated in the following situations where endocarditis can cause more serious health conditions:

• The infection breaks off into small pieces, increasing the risk for strokes
• The patient develops heart failure as a result of damaged heart valves
• Severe organ damage (ex. heart damage)

The prognosis for endocarditis generally improves with time-to-treatment. If endocarditis is not treated in a timely manner, the patient may develop brain abscesses, further damage to heart valves, spread of the infection to other parts of the body, or stroke.

Prevention

Preventative measure to limit infection exposure should be taken to decrease the risk of developing endocarditis.

Patients at risk of developing endocarditis should:

• Practice good oral hygiene, especially addressing abscesses and gum disease, to minimize the risk of bacteria entering the blood stream via the mouth
• Skin Checks, including washing the skin regularly with an antibacterial soap, and addressing symptoms of skin infections

It is important to note that antibiotics should only be used when necessary to reduce the risk of VRSA and MRSA.

Resources

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