Heart Inflammation Causes and Risk Factors

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Infections

Viruses, bacteria, fungi, and parasites can cause heart  inflammation .

• Viruses are the most common cause of myocarditis and pericarditis. These may include SARS-CoV-2 (the virus that causes COVID-19), adenovirus, coxsackievirus (including hand, foot, and mouth disease), herpes virus, influenza (flu) virus, and parvovirus B19 (which causes an infection common in children known as fifth disease). Viruses may infect the heart muscle tissue, causing the body’s immune system to react.

• Bacteria are the most common cause of endocarditis, which occurs when bacteria and blood cells form clumps, most often on the heart valves. In many advanced countries, Staphylococcus aureus (staph infection) is the most common type of bacteria that causes endocarditis. Bacteria can enter the blood in many ways, including during a medical or dental procedure or through drug use, when drugs are injected into the veins by needle. Streptococcus (strep) bacteria can also cause endocarditis, but this is more common in less developed countries.
• Parasites are another cause of infection leading to myocarditis. One example is the parasite that causes Chagas disease, a serious health problem in Latin America. The parasite can affect the heart and may lead to the need for a pacemaker.
• Fungi, such as yeast or mold, are rare causes of myocarditis and pericarditis. These infections are more common in people who have immune systems that are weak from conditions such as HIV/AIDS, cancer, or diabetes.

Autoimmune diseases

Autoimmune diseases, such as rheumatoid arthritis and lupus, may cause pericarditis or myocarditis. They can also damage the heart valves, which can lead to endocarditis.

Medicines

Medicines can cause side effects that may lead to myocarditis, pericarditis, or both. These include:

• Antibiotics
• Antidepressants
• Benzodiazepines, also known as tranquilizers
• Diuretics, which are medicines that help your body get rid of extra fluid
• Heart medicines
• Psychiatric medicines
• Seizure medicines
• Weight-loss medicines

Rarely, an allergic reaction to a vaccine can lead to myocarditis.

Age

Different age groups are at risk for different types of heart inflammation.

• Although they can affect all ages, myocarditis and pericarditis occur more often in young adults. Pericarditis also affects middle-aged adults.
• Older adults are more at risk for endocarditis caused by bacteria.

Sex

Heart inflammation from endocarditis, myocarditis, and pericarditis is more common in men than in women. This is true except when the inflammation is caused by  autoimmune  diseases, such as lupus and rheumatoid arthritis, which are more common in women. Endocarditis and pericarditis occur twice as often in men as in women.

Family history and genetics

Genetics play a role in the risk for all three types of heart inflammation.

• Your  genes  may play a role in how your body responds to infection and inflammation and whether you contract myocarditis or pericarditis.
• People who have structural or congenital heart defects, such as problems with the heart valves, may be at higher risk for infections that can cause endocarditis.
• Certain  inherited  conditions can affect your risk of heart inflammation. For example, you may be at higher risk for myocarditis and pericarditis if you have familial Mediterranean fever or tumor necrosis factor receptor-associated periodic syndrome (TRAPS). These rare conditions affect how the body controls inflammation.

Lifestyle choices

Your risk may be higher if you:

• Drink too much alcohol, which could also lower heart function and heart failure
• Use cocaine, amphetamines, or recreational drugs injected intravenously (into the veins)

Medical conditions

Medical conditions that can raise your risk include:

• Diabetes, which can make you more likely to contract infections
• Eating disorders, such as anorexia
• HIV/AIDS, which may lead to myocarditis from infections, poor nutrition, and certain treatments
• Skin disorders, such as burns or  chronic  infections
• Poor dental health

Procedures to treat other medical conditions also carry a risk of infection, which can lead to heart inflammation. These include implanting a pacemaker or defibrillator in the heart.

Medicines

Certain medications used to treat cancer and other conditions by lowering your body’s natural defense system may damage the heart muscle, resulting in myocarditis.

You may not be able to prevent heart inflammation.

If you have risk factors for endocarditis, your healthcare provider may share steps to prevent bacterial growth on the endocardium.

• Avoid using recreational intravenous (IV) drugs.
• Wash your hands and skin regularly and wash cuts or scrapes right away to help prevent infection.
• Brush and floss your teeth every day and see your dentist regularly.

Many causes of myocarditis and pericarditis are hard or impossible to avoid or prevent. Managing some risk factors for diseases, such as HIV, and avoiding substances, such as amphetamines and cocaine, may help prevent myocarditis.

Fact Sheet

Taking Care of Our Hearts, Together

Learn more about how healthy lifestyle changes can help prevent heart disease.

View the fact sheet