Understanding Myocarditis: Causes | Diagnosis | Symptoms | Treatment

Jordan Nacalaban, BSN, RN

Myocarditis is an inflammatory medical condition that affects a person’s heart muscle. When your heart muscles become inflamed, it affects the ability of the heart to function well.¹

When inflammation of the heart happens, the muscle becomes enlarged, which may contribute to heart failure, heart dysfunction, or even sudden death.

Myocarditis may also affect your heart’s electrical function leading to a severe problem called arrhythmia (a heart condition in which your heart beats with an abnormal or irregular rhythm).²

It is a rare form of heart disease that affects everyone, even young individuals and children (pediatric myocarditis).

How does one get myocarditis?

When an infection occurs, which is the common cause of myocarditis, it may be caused by any of the following

Viruses:

Those from Covid-19, Influenza virus, Parvovirus B19, Human Herpesvirus 6, Enterovirus, etc. ⁶

A viral infection is the most common cause of myocarditis—one of the main reasons individuals need to be careful around known illnesses.

Bacteria:

Myocarditis can also be caused by strep, staph, and tick-borne bacteria, causing Lyme disease. In addition, other causes of myocarditis are Corynebacterium diphtheriae (Diphtheria) and Mycobacterium Tuberculosis (TB). ³

Fungus:

Those include yeast infections from candida or molds. You can also develop myocarditis from Histoplasma coming from bird droppings.

It is widely seen in persons with immunocompromised systems, including persons with HIV.

Parasites:

Some parasites that cause myocarditis include Trichinella spiralis - Tapeworms: Echinococcus from dogs, Taenia solium from pork.

One of the parasites causing myocarditis is Trypanosoma cruzi, which comes from insects and is common in Latin America.³

Other Causes of Myocarditis:

Myocarditis is primarily the result of an infection in your body, but you can also get it from other causes.

Autoimmune disease:

Lupus, Rheumatoid Arthritis, Irritable Bowel Syndrome (IBS)

Systemic Disease:

Sarcoidosis, Celiac disease

Toxins or Drug reactions:

cocaine, phenothiazine, some chemotherapeutic drugs, and other drugs

Environmental:

carbon monoxide, radiation, lead, orificenic³

Common Symptoms

Some individuals don’t have any symptoms in the early stages of myocarditis.

Some will have mild symptoms.

Each case of myocarditis greatly varies. Therefore, it’s best to get ahold of your physician and have them examine you. Below are symptoms of myocarditis, which are not limited.

Symptoms you may experience with myocarditis:

Chest Pain
Shortness of Breath (rest or activity)
Fatigue
Abnormal or Rapid Heart Rhythm
Fever
Headache
Muscle Aches
Sore Throat
Diarrhea
Joint Pain
Swelling of the legs, ankles, or feet

How do you know if you have myocarditis?

Your physician may examine you and order non-invasive testing or advanced diagnostic tests.

Those tests may include the following:

Electrocardiography (ECG): assess the electrical signals of your heart
Echocardiogram: an ultrasound of your heart and its structures
Chest X-ray: imaging can show enlargement of the heart
Blood Test: heart markers, blood cultures (viral, bacterial tests), complete blood count, etc.⁵
Cardiac MRI: indicated for people with symptoms and suspected myocarditis. It can be helpful with treatment management planning. ³
Heart Biopsy (Endomyocardial Biopsy - EMB): indicated for new-onset unknown heart failure symptoms less than two weeks of duration, unresponsive to treatment within 1-2 weeks. After the physicians had excluded all other underlying causes of myocarditis, this test is suggested.³
Cardiac Catheterization: an examination is done to visualize the heart and the extent of damage and may be used to repair the heart without surgery.

Myocarditis Treatment

There is no cure for myocarditis. However, some people with myocarditis get better on their own or with any medical treatment and may recover fully.

Your physician will recommend treatment for myocarditis based on your case, the cause of your myocarditis, and the symptoms you are experiencing.

Rest:

It can’t be stressed enough when rest is recommended to treat myocarditis. Resting will help you recover from the condition, which helps your heart heal by reducing stress on its valves to prevent further damage.

Medication:

These medications are prescribed based on individual cases and causes of myocarditis. In addition, your physician considers the severity and type of myocarditis you have.

Heart Failure medications - to help reduce your heart’s workload ³
Anti-inflammatory drugs - you may receive medications to decrease inflammation in your heart
Anti-viral treatment - if you have myocarditis caused by a virus, you may be given these medications to combat viral infections
Immunosuppressive therapy (corticosteroids) - supports your immune system by lowering inflammation. Medications that suppress your immune system have treatment benefits for people who have acute lymphocytic myocarditis and giant cell myocarditis.³
Antiarrhythmic medications - intended to control the rhythm of your heart
Immunoglobulin IV therapy (IVIG) - enhances immune system support; IVIG contains anti-viral and anti-inflammatory effects on myocarditis.⁴

Addressing your underlying conditions

Your physician will also look at any present medical conditions when planning treatment.

Procedures

Implanted Cardioverter Defibrillator (ICD) pacemaker
Ventricular assistive device (VAD)
Repeat imaging exams
Cardiac Catheterization

Surgery

Heart transplant

Lifestyle changes

Your physician may recommend limiting physical activity such as contact sports for a specified time (3 to 6 months). The focus is to help your heart heal. Ask questions concerning exercise, activity restrictions, and when to resume them.⁶

To promote heart health, your physician may recommend:

Quitting smoking.
Limiting your sodium intake.
Monitoring your fluids.
Avoiding alcohol and other health modifiers.

Complications of Myocarditis

When myocarditis is left untreated, complications may happen even when under treatment.

Listed below are complications of myocarditis:

Heart Failure
Cardiomyopathy
Abnormal or Irregular Heartbeat
Heart attack
Stroke
Sudden death

What to do to reduce the chance of getting myocarditis?

Although there is no known, full-proof preventive method against myocarditis, these simple tips may help you not get myocarditis.

Avoid people who are sick with viral or flu-like symptoms.
Follow a healthy lifestyle for overall health.
Reduce your risk of getting other illnesses. If you feel sick, stay at home to prevent a possible spread of infection.
Continue good hygiene - wash hands, use sanitizers, clean surfaces
Avoid risky behavior: illegal drugs, practice safe sex, cook food to the appropriate temperature.
Be prepared when going hiking. Prevent ticks exposure by wearing long sleeves and pants during your hikes.
Get vaccinated to prevent illness and diseases.
Prioritize your immune system.
Obtain accurate and current information regarding myocarditis from reputable sources.

Summary:

Myocarditis affects your heart’s ability to function well. Your physician may order tests to determine the severity of your condition and map out treatment.

It can occur to people who aren’t aware of the symptoms they’re experiencing. The goal is to get an early diagnosis of myocarditis. When myocarditis is suspected, it’s important to see your physician without delay.

One may acquire a mild case of myocarditis, and you recover. Another may be severe, leading to intensive care and life-threatening situations. It’s important to remember that it may come back even though myocarditis has resolved.

Health outcomes may depend on your body’s response to treatment and timely diagnostics to set a clinical route for treating myocarditis.

Your physician prioritizes the timely diagnosis of myocarditis and a treatment care plan that may help you recover.

Most persons with myocarditis can recover from uncomplicated medical interventions to multi-approach treatment. Unfortunately, however, some people’s conditions deteriorate quickly, even dying from myocarditis.

If you suspect you are experiencing symptoms that point to myocarditis, you should talk to your physician immediately.

When you’re recovering from myocarditis, it’s crucial to seek follow-up care with your physician.

References

1. Johns Hopkins Medicine | Myocarditis (n.d.)

2. MedlinePlus | Arrhythmia | Irregular Heartbeat (July 09, 2021)

3. Blauwet, Lori A, and Leslie T Cooper. “Myocarditis.” Progress in cardiovascular diseases (2010) doi:10.1016/j.pcad.2009.11.006

4. Huang, Xin et al. “Intravenous Immunoglobulin Therapy for Acute Myocarditis in Children and Adults.” International heart journal vol. 60,2 (2019): 359-365. doi:10.1536/ihj.18-299

5. Kang M, An J. Viral Myocarditis. [Updated 2022 Jan 5]. In: StatPearls [Internet]. Treasure Island (FL). StatPearls Publishing

6. National Heart Lung and Blood Institute | Heart Inflammation (n.d.)