Causes Of Myocarditis, and How to Reduce Your Risk

Myocarditis is a heart condition that affects an estimated 1.5 million people a year or 10 to 20 per 100,000 people. It can permanently damage the heart muscle to increase the risk for complications, including heart failure, stroke, and sudden cardiac death.

Early diagnosis and treatment of myocarditis may help you avoid long-term heart damage and improve your condition. Knowing what causes myocarditis and how to reduce your risk can empower you to take the necessary steps to stay healthy and live your life to its fullest.

What Is Myocarditis?

Myocarditis is inflammation of the heart muscle. Inflammation of the heart muscle can make it more difficult for your heart to pump blood and causes a range of symptoms, including chest pain, shortness of breath, and rapid heart rate. It may also cause lightheadedness, fatigue, and flu-like symptoms that affect your day-to-day activities and quality of life.

When not treated, myocarditis can get severe to the point that your heart is so weakened it can no longer pump blood to the rest of your body. When this happens, blood clots can form in the heart to cause other serious conditions like heart attack and stroke. Myocarditis can often be effectively treated with medications and/or surgery.

What Causes Myocarditis?

The most common causes of myocarditis are viruses, bacterial infections, parasites, and fungal infections. These types of illnesses can cause body-wide inflammation that also affects the heart. Non-infectious autoimmune disorders, such as lupus, may also cause myocarditis.

Illnesses and parasites that are linked to myocarditis include:

• Common cold
• COVID-19
• Hepatitis B and C
• Herpes
• Staphylococcus (staph infections)
• Streptococcus (strep throat)
• Toxoplasma
• Yeast infections

The use of certain medications has also been linked to myocarditis, which is known as drug-induced myocarditis. Medications that may cause this heart condition, according to a 2022 study published in Nature, include but are not limited to:

• Antipsychotics (such as clozapine)
• Salicylates (such as aspirin)
• Chemotherapy drugs
• Immunotherapy drugs
• Vaccines (including smallpox and COVID-19 vaccines)

Is There a Link Between Myocarditis and COVID-19?

The American Heart Association reports that several recent studies show that the COVID-19 virus and vaccines may cause myocarditis. It says that people may develop this heart condition after receiving the first or second vaccine dosage and that an estimated three in every 1,000 patients hospitalized due to a COVID-19 infection may be at risk for developing acute myocarditis.

Consult with your doctor to learn more about your risk for myocarditis if you are diagnosed with COVID-19 or have received one or more vaccines for this infection. Your doctor can answer any questions you have, perform an evaluation, and talk to you in more detail about the benefits vs. the risks of getting COVID-19 vaccines.

Ways To Reduce Your Risk for Myocarditis

Myocarditis occurs when the heart muscle becomes inflamed. Therefore, the best way to reduce your risk for this condition is to avoid practicing behaviors that expose you to illnesses, foods, and other sources of toxins that contribute to inflammation.

Reduce Your Sodium Intake

Eating high amounts of salt can increase your blood pressure. This is why many doctors recommend cutting back on high-sodium foods to reduce your risk for heart disease. Research also shows that a high-sodium diet causes your body to produce more pro-inflammatory cytokines (proteins) that trigger inflammation and autoimmune disorders.

Start eating less salt to reduce your risk for myocarditis. Stop adding table salt to your foods, especially processed foods that already contain lots of salt. Try eating fewer processed foods and more whole foods like fruits, vegetables, whole grains, nuts, and sources of lean protein.

Don’t Smoke

Cigarettes are loaded with thousands of chemicals that can cause swelling and inflammation of the blood vessels. This can make your blood vessels more narrow, causing a wide range of heart conditions. In addition to myocarditis, smoking can increase your risk for coronary heart disease, stroke, and peripheral artery disease.

Don’t start smoking if you are a non-smoker. If you currently smoke or think you may be addicted to nicotine, ask your doctor about treatments that can help you quit. Medications and forms of nicotine replacement, like gum and patches, are some of the many effective treatments that can help you stop smoking.

Drink Less Alcohol

High amounts of alcohol have long been associated with increased inflammation throughout the body. Research even shows that binge drinking, or drinking heavily over a short period, is linked to an increased risk for myocarditis. The CDC defines binge drinking as having five or more drinks on a single occasion if you’re a man and four or more drinks on a single occasion if you’re a woman.

Start drinking less alcohol or consider abstaining from alcohol completely. Alcohol can interfere with your sleep, contribute to weight gain, and weaken your immune system. High blood pressure, liver disease, stroke, and cancer are other serious health conditions linked to high alcohol intake.

Learn About Your Medications

Many types of medications have been linked to myocarditis—including medications used to treat depression, anxiety, and cancer. Studies have also linked vaccines to this heart condition, including the COVID-19 vaccines.

Read all the warnings, labels, and package inserts that come with your medications to learn more about their potential side effects. Talk to your doctor if you are using one or more medications linked to myocarditis. Your doctor may switch your medications or talk to you about whether the benefits of using your medication outweigh the potential risks.

Your provider can also talk to you in more detail about any risks associated with vaccines and help you make informed healthcare decisions for you and your family.

Wash Your Hands Regularly

Washing your hands regularly can reduce your exposure to harmful bacteria and viruses that increase your risk for myocarditis. Wash your hands after coming into contact with surfaces in public places, such as doorknobs and stair railings, and after shaking hands with others. Also, avoid touching your face or any foods if you haven’t recently washed your hands.

The CDC provides five steps for washing your hands properly:

1. Wet your hands using clean, running water and apply soap.
2. Rub your hands together to lather them with the soap, making sure to lather between your fingers, the backs of your hands, and under your nails as well.
3. Scrub and wash your hands for at least 20 seconds.
4. Rinse your hands under clean, running water to remove all traces of soap.
5. Dry the water off your hands using a clean towel or air dryer.

Distance Yourself From Those Who Are Sick

Many viruses and infections can easily spread to others when you cough, sneeze, laugh, breathe, and talk. Some can also spread by touch if you recently wiped your nose or touched your mouth.

If a coworker, friend, or relative is sick, avoid coming into close contact with that person to reduce your risk for illness and complications like myocarditis. If you are sick, keep your distance from others and consider staying home from work or school to avoid spreading your illness.

Reduce Your Exposure To Toxins and Radiation

Insecticides, pesticides, carbon monoxide, and radiation therapy are some of the many toxins and chemicals that may increase your risk for heart inflammation and myocarditis. Reduce your exposure to these substances as best as possible, such as by using eco-friendly insecticides that lack harmful toxins and eating organic fruits and vegetables. If you have a condition that can be treated with radiation therapy, ask your doctor about other treatments that aren’t linked to myocarditis.

If you work around harmful toxins and chemicals, practice work safety guidelines and regulations to the best of your ability. Wear protective gear at all times and change out of your work clothes before you come home to avoid exposing toxins to your family.

Practice Safer Sex

Sexually transmitted diseases (STDs) such as herpes, hepatitis, and chlamydia have been linked to heart inflammation and may increase your risk for myocarditis. Be open with your partner about STDs and suggest getting tested together, so you know more about your risk for these conditions. Also, practice safer sex by wearing a condom to reduce your risk for these and other STDs that can lead to serious health complications.

Avoid Sharing Needles

Intravenous use of drugs such as heroin and methamphetamine is an independent risk factor for myocarditis—especially if you are sharing needles with others. Contaminated needles often contain harmful bacteria that can cause inflammation of your blood vessels and heart muscle. Sharing needles can also increase your risk for HIV and hepatitis—the latter of which can also contribute to myocarditis.

Avoid sharing needles with others at all costs. If you use injection drugs, consider visiting a supervised drug injection site to gain access to clean, sterile needles, or talk to your doctor about professional treatment for drug misuse and substance use disorders. Your doctor may refer you to a specialist who can help.

When To See a Doctor

Make an appointment with your healthcare provider if you think you may have myocarditis or have symptoms of myocarditis, such as chest pain and shortness of breath. Your doctor can perform an evaluation and run a series of tests to properly diagnose and treat your condition.

If your symptoms are severe, seek emergency medical treatment right away.

Dr. Khawar Gul, a Lompoc-based cardiologist, contributed this article. Learn more.