Endocarditis

Endocarditis is a rare but life-threatening infection that attacks the inner lining of your heart’s chambers and valves. While uncommon, affecting only about 5 to 7 cases per 100,000 people each year, this serious condition requires immediate medical attention and can be fatal without proper treatment.

Table of contents

• What is endocarditis?
• What causes endocarditis?
• Signs and symptoms
• How is it diagnosed?
• Treatment approaches
• Possible complications
• Prevention and reducing your risk

What is endocarditis?

Endocarditis is an inflammation of the endocardium, which is the inner lining of your heart’s chambers and valves. This condition occurs when germs, most commonly bacteria but sometimes fungi, enter your bloodstream and attach to damaged areas in your heart^[1].

When germs settle in the heart, they form clumps called vegetations. These vegetations are made up of the infecting organisms, a protein called fibrin (which helps blood clot), and tiny cell fragments in your blood called platelets. As inflammation continues, these vegetations break down the surrounding heart tissue, which can greatly damage your heart valves^[2].

• Heart chambers
• Heart valves
• Endocardium (inner lining of heart)

There are two main types of endocarditis. Infective endocarditis (also called bacterial endocarditis) is the most common type and happens when germs attach to damaged heart tissue. Non-infective endocarditis is much rarer and involves vegetations that aren’t due to infection. This type is linked with conditions that make your blood clot too easily, such as lupus^[2].

Infective endocarditis can develop in two different ways. Acute endocarditis begins suddenly with a high fever and fast heart rate, and can become life-threatening within days. Subacute endocarditis develops gradually over weeks or several months^[2].

infective endocarditis, bacterial endocarditis

What causes endocarditis?

Most of the time, a bacterial infection causes endocarditis. The bacteria come from elsewhere in your body, such as your mouth, skin, or respiratory system, and travel through your blood to your heart^[2]. Common bacteria that cause endocarditis include Staphylococcus aureus, viridans Streptococcus, enterococci, and coagulase-negative staphylococci^[14].

Healthy heart tissue is normally very resistant to infection. However, when you already have damage to your heart, it becomes easier for bacteria to attach and grow on that damaged tissue. The bacteria produce enzymes that destroy the surrounding heart tissue^[2].

Your risk of developing endocarditis is higher if you have certain conditions or circumstances, including^[1][2][3]:

• An artificial (prosthetic) heart valve or a heart valve that has been repaired
• Damaged heart valves from heart disease or infection
• Congenital heart disease (heart defects you were born with)
• A condition called hypertrophic cardiomyopathy, where the heart muscle cells have enlarged
• Had endocarditis in the past
• An implanted heart device such as a pacemaker or defibrillator
• Injecting drugs into your veins
• Poor dental health and gum disease
• Diabetes
• A weakened immune system
• Using a hemodialysis access or central venous catheter

Endocarditis is rare, even in those with higher risk. It’s more common in older people, and twice as many men are affected as women^[3][4].

Signs and symptoms

Symptoms of endocarditis can vary widely from person to person and may be hard to notice. They may develop slowly over weeks or months, or they can appear suddenly^[1][6].

The most common symptoms of endocarditis include^[1][2][4]:

• Fever and chills
• Flu-like symptoms, such as tiredness, headaches, and body aches
• Aching joints and muscles
• Chest pain when you breathe
• Shortness of breath (feeling like you can’t get enough air)
• Night sweats (heavy sweating during sleep)
• A new or changed whooshing sound in the heart, called a heart murmur
• Fast heart rate
• Loss of appetite and unexplained weight loss
• Swelling in the feet, legs, or belly

Less common symptoms can include^[1][2]:

• Blood in the urine
• Tenderness under the left rib cage (where the spleen is located)
• Painless red, purple, or brown flat spots on the soles of the feet or palms of the hands (called Janeway lesions)
• Painful red or purple bumps on the tips of the fingers or toes (called Osler nodes)
• Tiny purple, red, or brown spots on the skin, in the whites of the eyes, or inside the mouth (called petechiae)
• Pale skin
• Cough

If you have symptoms of endocarditis, especially if you have risk factors, see your health care provider as soon as possible. If you have severe symptoms like chest pain, shortness of breath, or signs of heart failure, go to the emergency room immediately^[2].

How is it diagnosed?

To diagnose endocarditis, your health care provider will ask about your medical history, including recent illnesses, other health conditions, and any dental or surgical procedures you’ve had. They will also do a physical exam to check for signs of infection, such as a heart murmur, an enlarged spleen, and bleeding under the nails^[5][9].

Several tests are used to help confirm or rule out endocarditis^[5][10]:

• Blood culture tests: These tests look for bacteria or fungi in your bloodstream. It’s important to obtain at least two separate blood cultures from two different sites before starting antibiotics. Results help determine which antibiotic to use for treatment^[10].
• Complete blood count: This test can show if there are a lot of white blood cells, which can be a sign of infection. It can also help diagnose anemia (low levels of healthy red blood cells), which can be a sign of endocarditis^[10].
• Echocardiogram: This test uses sound waves to create images of your beating heart. It shows how well your heart’s chambers and valves pump blood and can reveal vegetations on the heart valves. Two types may be used: a standard echocardiogram (done on the chest) or a transesophageal echocardiogram (where a flexible tube with a device is guided down your throat for more detailed pictures)^[10].
• Electrocardiogram (ECG or EKG): This quick test measures the electrical activity of your heart to check if endocarditis is affecting your heart rhythm^[5][10].
• Chest X-ray: This shows the size and shape of your heart and can reveal if endocarditis has caused heart enlargement or if infection has spread to your lungs^[10].
• CT scan or MRI: These imaging tests may be done to check for complications or to see if infection has spread to other organs^[5][10].

Diagnosis is made using specific criteria that combine clinical findings, laboratory results, and imaging findings to classify endocarditis as definite, possible, or rejected^[14].

Treatment approaches

Endocarditis is usually treated with antibiotics given through a vein (intravenously or I.V.). You will need to be admitted to the hospital so antibiotics can be delivered this way. Treatment typically lasts several weeks, often between 2 to 6 weeks^[5][12].

At first, you will be treated in the hospital. After your fever is gone and you are stable, you may be able to continue I.V. antibiotics at home with help from a home health nurse. In some cases, after I.V. treatment, your doctor may want you to take antibiotic pills. If so, take them exactly as prescribed until they are completely gone, even if you feel better^[5][12].

The choice of antibiotic depends on the type of bacteria or fungi causing the infection and whether you have a natural or artificial heart valve. Your doctor will use blood culture results to select the most effective antibiotic^[10][13].

Some people who have endocarditis need surgery to repair or replace a damaged heart valve or to prevent complications. Surgery may be recommended if^[12][14]:

• Your symptoms or test results suggest heart failure
• You continue to have a high fever despite antibiotic treatment
• The infection is caused by particularly aggressive fungi or drug-resistant bacteria
• You experience blood clots despite treatment
• You have an artificial heart valve
• Test results show an abscess (collection of pus) or abnormal passageway has developed in your heart muscle

With quick, aggressive treatment, many people survive endocarditis. Without treatment, endocarditis can be fatal^[2]. You will need follow-up visits for months or years to check the health of your heart^[5].

Possible complications

Without quick treatment, endocarditis can damage or destroy the heart valves. When germs are in your heart, they can clump together with blood cells. These clumps can break off and travel through your bloodstream, blocking blood flow, spreading infection, or damaging your organs, including your brain, lungs, kidneys, and spleen^[1][9].

Endocarditis can lead to serious complications, including^[5][9]:

• Heart failure, where the heart is unable to pump enough blood around the body
• Stroke, where the supply of blood to the brain becomes disrupted
• Heart valve damage or rupture
• Arrhythmia (problems with heart rate or rhythm)
• Heart attack
• Abscess (collection of pus) in the heart
• Sepsis, a medical emergency that happens when your body has an extreme response to infection
• Infections in other organs

Prevention and reducing your risk

If you have had endocarditis in the past or have certain high-risk heart conditions, you may need to take antibiotics before certain dental and medical procedures to prevent another infection. Talk to your doctor about whether you need this preventive treatment^[5][14].

You are at higher risk and may need preventive antibiotics before procedures if you^[5]:

• Have had a heart valve replaced or repaired
• Have had endocarditis before
• Have a congenital heart defect
• Have heart valve problems after a heart transplant

Other important steps to reduce your risk of endocarditis include^[5][18]:

• Practice good dental hygiene by brushing and flossing your teeth daily
• Visit your dentist regularly, at least twice a year
• Make sure your dentist knows if you have had endocarditis or have heart conditions that increase your risk
• Avoid using illegal drugs that are injected
• Take care of any skin infections promptly
• Seek medical care for symptoms that could indicate an infection

After you have been successfully treated for endocarditis, you can return to your normal life. Endocarditis is not contagious, so you don’t have to stay away from other people. You can use household items like utensils, toys, or clothes just like any other family member^[18].