Heart Infection

Overview

What is a heart infection?

A heart infection can happen when microbes or other irritants invade your heart. The infections are most commonly caused by bacteria, viruses, and less commonly, by fungi. A heart infection can damage or inflame your heart. The parts of the heart most often damaged by infection include the:

  • Heart muscle (myocardium).
  • Heart valves.
  • Inner lining (endocardium).
  • Outer membrane or sac (pericardium).

What are the types of heart infection?

Three main types of infection can affect your heart. These heart infections are:

  • Endocarditis, infection of the lining of your heart valves (also called bacterial endocarditis or infective endocarditis).
  • Myocarditis, inflammation of your heart muscle.
  • Pericarditis, inflammation of the sac covering your heart’s outer surface.

Who might get a heart infection?

Serious heart infections are rare for most people. But heart infections are more common for people who:

  • Are older than 65 years of age.
  • Have had heart surgery.
  • Use injected recreational drugs.

Symptoms and Causes

Causes of a heart infection vary by type. The most common causes for each include:

Endocarditis causes:

  • Poor dental hygiene, when your gums bleed and bacteria enter your bloodstream.
  • Dental procedures, when your gums become cut and bacteria travel to your bloodstream.
  • Catheters, when bacteria enter your body through the tube your provider inserts to remove fluid from your body or inject fluids.
  • IV drug use, especially if you share needles or syringes to inject drugs.

Pericarditis causes:

  • Viral infection, such as a respiratory tract virus or gastrointestinal virus (viral pericarditis).
  • Bacterial infection, such as tuberculosis (more common in developing countries) (bacterial pericarditis).
  • Fungal infection (fungal pericarditis).
  • Parasite infection (parasitic pericarditis).
  • Autoimmune diseases, including lupus, rheumatoid arthritis and scleroderma.

Less common causes of pericarditis include:

  • Chest injury, such as during a car accident (traumatic pericarditis).
  • Kidney failure (uremic pericarditis).
  • Tumors.
  • Genetic diseases, such as familial Mediterranean fever (FMF).
  • Immune system-suppressing medications.

Myocarditis causes:

  • Viral infections, such as SARS-CoV-2 (which causes COVID-19), coxsackievirus (which affects the intestines and leads to stomach flu), parvovirus, adenovirus and hepatitis C.
  • Bacterial infections, such as streptococcus, staphylococcus, tick-borne bacteria and tuberculosis.
  • Fungal infections, such as from yeast, mold and bird droppings.
  • Parasite infection, more common in Central and South America.
  • Autoimmune diseases, including rheumatoid arthritis.

Less common causes of myocarditis include:

  • Allergic reactions to medications, such as antibiotics, anti-seizure medications and cancer drugs.
  • Allergic reactions to recreational drugs.
  • Radiation.

What are the symptoms of a heart infection?

Heart infection symptoms vary from person to person, depending upon the disease. Many heart infections include these common symptoms:

Endocarditis symptoms

Endocarditis is the only type of heart infection that has a heart murmur as a symptom. Your provider can hear a specific sound when blood flows through your heart. Less common symptoms of endocarditis include:

  • Blood in your urine (hematuria).
  • Red or purple spots on your skin, inside your mouth or on the whites of your eyes (petechiae).
  • Red spots on the bottoms of your feet and palms of your hands (Janeway lesions).
  • Red spots under the skin on your toes or fingers (Osler’s nodes).
  • Spleen tenderness.
  • Unexplained weight loss.

Diagnosis and Tests

How is a heart infection diagnosed?

To help diagnose your condition, your healthcare provider will ask about your symptoms and family history. Your provider will listen to your heart with a stethoscope to check for a heart murmur. You may have:

  • Blood tests: Blood samples show the levels of inflammatory proteins in your blood. Higher-than-usual levels of inflammatory proteins can indicate active inflammation in your heart muscle. For certain infections, they can also show whether you’ve developed antibodies against viruses that may cause an infection. Blood tests may also show elevated white blood cell counts to identify signs of infection.
  • Chest X-ray: Your healthcare provider can see changes to the shape and size of your heart. They can also look for swelling or excess fluid.
  • CT (computed tomography) scan or magnetic resonance imaging (MRI): Your provider can view images of your heart to look for inflammation, thickening or other changes.
  • Cardiac catheterization/heart biopsy: In some instances, your provider inserts a small tube (catheter) into your vein to reach your heart. They may take a sample (biopsy) of heart muscle tissue to look for a heart infection or inflammation.

Management and Treatment

How is a heart infection treated?

Treatment for a heart infection depends on the cause and severity of your symptoms. Providers often treat heart infections with medications. Depending on the type of heart infection, treatments may include:

People with severe heart infections may need heart surgery if other treatments don’t help. The type of surgery depends on the kind of heart infection you have. The most serious infections may require a heart transplant or heart valve surgery.

Prevention

How can I reduce my risk of a heart infection?

You may not be able to prevent a heart infection, but you can lower your risk by staying healthy. Steps you can take include:

  • Avoid contact with people with viral infections.
  • Get recommended vaccines, including for COVID-19 and the flu vaccines.
  • Not using recreational drugs.
  • Reduce your exposure to tick-infested areas and bird droppings.
  • Schedule regular dental care.
  • Take antibiotics before medical and dental procedures as your provider advises, especially if you’ve had heart valve repair and unrepaired congenital heart disease.
  • Wash your hands regularly.

Are there other conditions that put me at higher risk?

You are at higher risk for a heart infection if you have a history of:

  • Long-term catheter use.
  • Heart attack (myocardial infarction).
  • Implanted heart device, heart valve disease or heart valve surgery.
  • Problems with your dental health.
  • Radiation therapy.
  • Suppressed immune system.
  • Using IV or injectable drugs.

Outlook / Prognosis

What can I expect if I have a heart infection?

The prognosis for people with heart infections varies depending on the specific disease and severity of the disease. Many types of heart infection can cause complications over time, especially if not treated promptly. Complications can include:

Getting the right treatment and support for a heart infection can lead to a longer, healthier life. Treatment can also help you manage your symptoms and improve your quality of life.

Living With

When should I see my healthcare provider?

See your provider if you have any new symptoms or if your symptoms worsen. Seek medical treatment immediately if you have:

  • A cut or skin infection that doesn’t heal.
  • Extreme fatigue.
  • Loss of consciousness.
  • Shortness of breath or difficulty breathing.

What else should I ask my doctor about heart infections?

To understand this condition, you may want to ask:

  • What’s the most appropriate treatment for me?
  • Can my heart infection come back after I’m treated?
  • Will I have any side effects from my treatment?

How do I take care of myself?

If you see a new doctor or dentist, always tell them if you have a heart infection. This will help them to better monitor your heart health and overall wellness.

A note from Cleveland Clinic

If you or a loved one has a heart infection, talk to your healthcare provider about the best ways to manage your symptoms and improve your quality of life. You can often control a heart infection with medications and sometimes with surgery. If you have a cut or skin infection that doesn’t heal, loss of consciousness or shortness of breath, seek help immediately.

Last reviewed by a Cleveland Clinic medical professional on 11/08/2021.

References

  • American Heart Association. Infectious Endocarditis. (https://www.heart.org/en/health-topics/infective-endocarditis) Accessed 11/10/2021.
  • American Heart Association. What is Pericarditis? (https://www.heart.org/en/health-topics/pericarditis/what-is-pericarditis) Accessed 11/10/2021.
  • Murillo H, Santiago Restrepo C, Marmol-Velez JA, et al. Infectious Diseases of the Heart: Pathophysiology, Clinical and Imaging Overview. (https://pubs.rsna.org/doi/10.1148/rg.2016150225?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub++0pubmed&) Radiographics. 2016 Jul-Aug;36(4):963-83. Accessed 11/10/2021.
  • Myocarditis Foundation. Discover Myocarditis Causes, Symptoms, Diagnosis and Treatment. (https://www.myocarditisfoundation.org/about-myocarditis/) Accessed 11/10/2021.
  • Myocarditis Foundation. Types of Heart Infections. (https://www.myocarditisfoundation.org/types-of-heart-infections/) Accessed 11/10/2021.
  • Tschöpe C, Ammirati E, Bozkurt B, et al. Myocarditis and inflammatory cardiomyopathy: current evidence and future directions. (https://www.nature.com/articles/s41569-020-00435-x) Nature. 2020 Oct 12;18:169-193. Accessed 11/10/2021.

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy