Endocarditis: Symptoms, Causes, Treatment, and Prevention

Overview

Endocarditis is a rare but serious infection of the endocardium, the inner lining of the heart chambers and valves. This condition occurs when bacteria, fungi, or other germs enter the bloodstream and attach to damaged areas of the heart, leading to inflammation, infection, and potential damage to the heart valves.

While endocarditis can affect anyone, it is more common in people with:

• Pre-existing heart valve abnormalities or artificial heart valves
• A history of endocarditis
• Certain congenital heart defects
• Intravenous drug use
• Compromised immune systems

According to the American Heart Association, endocarditis affects approximately 1 in 1,000 people in the general population, but the risk increases significantly in high-risk groups. The incidence is higher in men than women and tends to occur more frequently in older adults, though it can affect individuals of any age.

Symptoms

Endocarditis symptoms can develop slowly (subacute) or suddenly (acute), depending on the cause of the infection and any underlying heart conditions. Symptoms may vary but often include:

Common Symptoms

• Fever and chills: Often persistent and unexplained, fever is one of the most common signs of endocarditis.
• Fatigue: A general feeling of tiredness or weakness that doesn’t improve with rest.
• Night sweats: Excessive sweating during sleep, often severe enough to soak clothing or bedding.
• Heart murmur: An unusual sound heard between heartbeats, often detected by a doctor during a physical exam.
• Shortness of breath: Difficulty breathing, especially during physical activity or while lying down.
• Swelling: Fluid buildup in the legs, feet, or abdomen due to heart failure.

Less Common but Serious Symptoms

• Osler’s nodes: Painful, red or purple bumps on the fingers or toes.
• Janeway lesions: Small, non-tender red spots on the palms or soles.
• Splinter hemorrhages: Tiny, painless blood spots under the fingernails or toenails.
• Petechiae: Small, pinpoint red or purple spots on the skin, mouth, or eyes caused by bleeding from broken capillaries.
• Muscle or joint pain: Aches in the arms, legs, or back without an obvious cause.
• Unexplained weight loss: Significant weight loss without changes in diet or exercise.

If you experience any of these symptoms—especially if you have a known heart condition or recent history of invasive medical procedures—seek medical attention promptly.

Causes and Risk Factors

Endocarditis occurs when germs, usually bacteria, enter the bloodstream and attach to the endocardium. Common causes include:

Bacterial Infections

• Streptococcus and Staphylococcus: These bacteria are the most common causes of endocarditis. Staphylococcus aureus, in particular, is a frequent culprit, especially in people who use intravenous drugs or have medical devices like catheters.
• Enterococcus: These bacteria, normally found in the intestines and urinary tract, can enter the bloodstream during medical procedures or infections.

Fungal Infections

Fungi such as Candida or Aspergillus can cause endocarditis, particularly in people with weakened immune systems, such as those undergoing chemotherapy or with HIV/AIDS.

Risk Factors

Certain factors increase the risk of developing endocarditis:

• Heart valve disease: People with damaged or artificial heart valves are at higher risk.
• Congenital heart defects: Some birth defects increase susceptibility to infection.
• Intravenous drug use: Using non-sterile needles can introduce bacteria directly into the bloodstream.
• Recent dental or medical procedures: Procedures that involve cutting the gums or gastrointestinal/urinary tracts can allow bacteria to enter the bloodstream.
• Poor dental hygiene: Gum disease or tooth infections can provide a pathway for bacteria.
• Chronic illnesses: Conditions like diabetes, HIV, or kidney disease weaken the immune system.
• Indwelling catheters or medical devices: Long-term use of catheters or pacemakers increases infection risk.

Diagnosis

Diagnosing endocarditis involves a combination of medical history, physical examination, and diagnostic tests. Early diagnosis is critical to prevent complications.

Medical History and Physical Exam

Your doctor will ask about your symptoms, medical history (including any heart conditions or recent procedures), and lifestyle factors (such as drug use). They will listen to your heart for murmurs and check for signs of infection, such as fever or skin abnormalities.

Diagnostic Tests

• Blood cultures: Blood samples are taken to identify the type of bacteria or fungus causing the infection. Multiple samples may be needed over 24–48 hours.
• Echocardiogram: This ultrasound of the heart helps visualize the heart valves and detect vegetations (clumps of bacteria and cells). A transesophageal echocardiogram (TEE), where a probe is passed down the esophagus, provides more detailed images than a standard echocardiogram.
• Electrocardiogram (ECG or EKG): Measures the heart’s electrical activity to check for irregularities.
• Chest X-ray: Helps assess whether the infection has spread to the lungs or caused heart failure.
• Complete blood count (CBC): Checks for signs of infection, such as an elevated white blood cell count.
• Erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP): Blood tests that measure inflammation levels in the body.

The American College of Cardiology and European Society of Cardiology provide guidelines for diagnosing endocarditis based on these tests and clinical findings.

Treatment Options

Treatment for endocarditis depends on the cause of the infection, the severity of the condition, and whether there is damage to the heart valves. The primary goals are to eliminate the infection, manage complications, and prevent long-term damage.

Antibiotics

Bacterial endocarditis is typically treated with high-dose intravenous (IV) antibiotics administered in a hospital. The type and duration of antibiotics depend on the specific bacteria identified in blood cultures:

• Streptococcal infections: Usually treated with penicillin or ceftriaxone for 4–6 weeks.
• Staphylococcal infections: Often require nafcillin, oxacillin, or vancomycin for 6 weeks or longer.
• Enterococcal infections: Treated with a combination of antibiotics, such as ampicillin and gentamicin, for 4–6 weeks.

Fungal endocarditis may require antifungal medications like amphotericin B or fluconazole.

Surgery

Surgery may be necessary if:

• The infection damages heart valves, leading to severe valve dysfunction or heart failure.
• The infection persists despite antibiotic treatment.
• Large vegetations (clumps of bacteria) increase the risk of stroke or embolism.
• The infection spreads to other parts of the heart or body (e.g., abscesses).

Surgical options include:

• Valve repair: The damaged valve is reconstructed to restore normal function.
• Valve replacement: The infected valve is removed and replaced with a mechanical valve or a biological valve (from a pig, cow, or human donor).

Lifestyle and Supportive Care

• Rest: Adequate rest is essential for recovery, especially during IV antibiotic treatment.
• Hydration and nutrition: A balanced diet and proper hydration support the immune system.
• Pain management: Over-the-counter pain relievers like acetaminophen (Tylenol) may help with fever or discomfort. Avoid nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen unless approved by your doctor.
• Avoiding alcohol and tobacco: These can interfere with healing and increase complications.

Living with Endocarditis

Recovering from endocarditis requires careful management to prevent recurrence and complications. Here are some tips for daily living:

Medication Adherence

• Take all prescribed antibiotics or antifungals exactly as directed, even if you start feeling better.
• If you’ve had valve replacement surgery, take blood thinners (if prescribed) to prevent clots.

Regular Follow-Up Care

• Attend all follow-up appointments with your cardiologist or infectious disease specialist.
• Undergo regular echocardiograms or blood tests to monitor heart function and detect any signs of recurrence.

Dental and Medical Precautions

• Inform all healthcare providers (including dentists) about your history of endocarditis. You may need to take antibiotics before certain dental or surgical procedures to prevent reinfection (known as antibiotic prophylaxis).
• Maintain excellent oral hygiene to reduce the risk of bacteria entering the bloodstream.

Lifestyle Adjustments

• Avoid intravenous drug use. If you struggle with substance use, seek help from a healthcare provider or support program.
• Stay active with light exercise as approved by your doctor, but avoid strenuous activities until fully recovered.
• Monitor for symptoms of recurrence, such as fever, fatigue, or unexplained weight loss, and report them to your doctor immediately.

Prevention

Preventing endocarditis is especially important for people at high risk. Key strategies include:

Good Hygiene Practices

• Brush and floss your teeth daily to prevent gum disease.
• Visit your dentist regularly for cleanings and check-ups.
• Avoid body piercings or tattoos from unlicensed facilities, as they can introduce bacteria into the bloodstream.

Antibiotic Prophylaxis

The American Heart Association (AHA) recommends antibiotic prophylaxis before certain procedures for people at highest risk of endocarditis, including those with:

• Artificial heart valves
• A history of endocarditis
• Certain congenital heart defects
• Heart transplant with valve abnormalities

Procedures that may require prophylaxis include:

• Dental procedures involving manipulation of gum tissue or the root of a tooth.
• Invasive respiratory tract procedures (e.g., bronchoscopy with biopsy).
• Procedures on infected skin or musculoskeletal tissue.

Avoiding High-Risk Behaviors

• Do not use intravenous drugs. Seek treatment for substance use disorders if needed.
• Avoid unnecessary invasive procedures or ensure they are performed in sterile conditions.

Managing Chronic Conditions

• Control conditions like diabetes, HIV, or kidney disease to reduce infection risk.
• Follow your doctor’s recommendations for managing heart conditions or artificial valves.

Complications

If left untreated, endocarditis can lead to serious, life-threatening complications. These may include:

Heart Damage

• Heart valve damage: The infection can destroy valve tissue, leading to valve regurgitation (leaking) or stenosis (narrowing).
• Heart failure: Damaged valves can impair the heart’s ability to pump blood effectively, leading to fluid buildup in the lungs or body.
• Heart abscesses: Pockets of pus can form in the heart muscle, further damaging heart function.

Embolism

Pieces of vegetations (clumps of bacteria and cells) can break off and travel through the bloodstream, causing blockages in other organs. This can lead to:

• Stroke: If an embolism blocks a blood vessel in the brain.
• Pulmonary embolism: If a clot travels to the lungs.
• Infections in other organs: Such as the kidneys, spleen, or brain.

Sepsis

If the infection spreads throughout the body, it can lead to sepsis, a life-threatening condition characterized by widespread inflammation, organ failure, and dangerously low blood pressure.

Other Complications

• Glomerulonephritis: Inflammation of the kidneys, which can lead to kidney failure.
• Myocarditis: Inflammation of the heart muscle, which can weaken the heart.
• Pericarditis: Inflammation of the sac surrounding the heart.

According to the Centers for Disease Control and Prevention (CDC), complications from endocarditis can be severe, with mortality rates ranging from 10% to 30%, depending on the cause and timely treatment.

When to Seek Emergency Care

Additional Resources

For more information about endocarditis, visit these reputable sources:

• Mayo Clinic – Endocarditis
• American Heart Association – Infective Endocarditis
• CDC – Endocarditis
• National Heart, Lung, and Blood Institute (NHLBI) – Endocarditis