Myocarditis occurs when part of the heart (the myocardium) becomes inflamed. The myocardium is the thick muscular layer of the heart. Symptoms range from mild to severe, including fatigue, fever, lightheadedness, chest pain, shortness of breath, fast or irregular heartbeat, and flu-like body aches. Some people experience no symptoms at all, while others feel like they are having a heart attack.1Myocarditis. Accessed September 1, 2023. https://www.heart.org/en/health-topics/myocarditis
Myocarditis affects about 1.5 million people worldwide each year. In acute cases, symptoms dissipate after two weeks; in chronic cases, they continue longer. Children, pregnant women, and those who are immunocompromised are most at risk for myocarditis, but this condition also affects generally healthy people. Because there is a risk of progressive heart failure with severe myocarditis, timely diagnosis is a priority. A qualified healthcare practitioner will assess symptoms and diagnose the condition.
Potential Causes and Complications of Myocarditis
In 50% to 80% of myocarditis cases, there is no clear cause. However, infections, viruses, autoimmune disorders, and medications may contribute.
Viral and Bacterial Infections
In North America, viral infections are the leading cause of myocarditis. Common culprits are coxsackieviruses, parvovirus B-19, and human herpesviruses. Up to 5% of acute viral infections involve the myocardium.2Kang M, Chippa V, An J. Viral Myocarditis. In: StatPearls. StatPearls Publishing; 2023. Accessed September 1, 2023. https://www.ncbi.nlm.nih.gov/books/NBK459259
COVID-19 is a well-known virus making myocarditis headlines. The virus itself can induce mild to severe symptoms. Vaccine-induced myocarditis is usually rare, but young males appear more vulnerable.3Rout A, Suri S, Vorla M, Kalra DK. Myocarditis associated with COVID-19 and its vaccines — a systematic review. Prog Cardiovasc Dis. 2022;74:111-121. https://doi.org/10.1016/j.pcad.2022.10.004 The Centers for Disease Control and Prevention notes the benefits of mRNA COVID-19 vaccination outweigh myocarditis risk, adding that most patients who reported myocarditis after vaccination responded well to medicine and rest and swiftly recovered.4CDC. COVID-19 Vaccination. Centers for Disease Control and Prevention. Published February 11, 2020. Accessed September 1, 2023. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/adverse-events.html
But how does a virus cause myocarditis? The virus invades the myocardium and makes copies of itself, destroying normal heart cells. When the immune system attempts to fight the virus, severe cardiac damage can result. Although most people fully recover from viral myocarditis, some cases worsen. Myocarditis can enter a chronic phase characterized by scar tissue formation and persistent heart inflammation. The heart becomes enlarged (dilated cardiomyopathy) and weakens, eventually leading to end-stage heart failure.5Martens CR, Accornero F. Viruses in the heart: Direct and indirect routes to myocarditis and heart failure. Viruses. 2021;13(10):1924. https://doi.org/10.3390/v13101924
Autoimmune Disorders
Autoimmune disorders such as systemic lupus erythematosus (SLE), Wegener’s granulomatosis, and giant cell arteritis are associated with myocarditis.6Kang M, Chippa V, An J. Viral Myocarditis. In: StatPearls. StatPearls Publishing; 2023. Accessed September 1, 2023. https://www.ncbi.nlm.nih.gov/books/NBK459259 According to a 2023 review, SLE increases the risk of myocarditis, coronary artery disease, and pericarditis.7Nor MA, Ogedegbe OJ, Barbarawi A, et al. Systemic lupus erythematosus and cardiovascular diseases: A systematic review. Cureus. 2023;15(5):e39284. https://doi.org/10.7759/cureus.39284
Medications and Recreational Drugs
Behavioral health medications such as tricyclic antidepressants, some antipsychotic drugs, and lithium (often prescribed for patients with bipolar disorder) may cause myocarditis over time. Experts believe drug-induced toxic myocarditis permanently changes the heart. Patients become more susceptible to abnormal heart rhythms, which may lead to cardiac arrest or sudden death.
Herbs and Supplements for Myocarditis
Astragalus Root
Astragalus root has long been used in Traditional Chinese Medicine for stress management and heart conditions. Research shows cardioprotective Astragalus fights viruses and reduces inflammation, oxidation, and scar tissue formation.8Zheng Q, Zhuang Z, Wang ZH, et al. Clinical and preclinical systematic review of Astragalus membranaceus for viral myocarditis. Oxid Med Cell Longev. 2020;2020:1560353. https://doi.org/10.1155/2020/1560353
Hawthorn Berry
Hawthorn berry is a potent herb that supports heart health. This wild berry can improve circulation, control heart palpitations, and increase coronary artery blood flow. It may even protect against congestive heart failure, which can occur with untreated myocarditis.9Nawrot J, Gornowicz-Porowska J, Budzianowski J, Nowak G, Schroeder G, Kurczewska J. Medicinal herbs in the relief of neurological, cardiovascular, and respiratory symptoms after COVID-19 infection a literature review. Cells. 2022;11(12):1897. https://doi.org/10.3390/cells11121897
Green Tea
Superfood green tea is a protective powerhouse for the heart. Epigallocatechin-3-gallate (EGCG), a polyphenol in green tea, could alleviate viral myocarditis by slowing the virus’s ability to replicate.10He X, Gao B, Zhou L, Xiong S. Green tea polyphenol epigallocatechin-3-gallate-alleviated coxsackievirus B3-induced myocarditis through inhibiting viral replication but not through inhibiting inflammatory responses. J Cardiovasc Pharmacol. 2017;69(1):41-47. https://doi.org/10.1097/FJC.0000000000000439
Reishi Mushrooms
Reishi (Ganoderma lucidum) has been used throughout China, Japan, and Korea for more than 2,000 years. The mushroom’s potent antioxidant properties may reduce the risk of heart disease, lower blood pressure, and increase the efficacy of heart medications.11Shaito A, Thuan DTB, Phu HT, et al. Herbal medicine for cardiovascular diseases: Efficacy, mechanisms, and safety. Front Pharmacol. 2020;11:422. doi:10.3389/fphar.2020.00422
Conventional Treatments for Myocarditis
Conventional myocarditis treatments include supplemental oxygen and fluids management (as the heart may be unable to pump fluid out of the body quickly). With a second- or third-degree heart block, a doctor may implant a pacemaker to control the heartbeat. ACE inhibitors are commonly used to treat heart failure. In the most severe cases, a heart transplant may be needed.
Footnotes
- 1Myocarditis. Accessed September 1, 2023. https://www.heart.org/en/health-topics/myocarditis
- 2Kang M, Chippa V, An J. Viral Myocarditis. In: StatPearls. StatPearls Publishing; 2023. Accessed September 1, 2023. https://www.ncbi.nlm.nih.gov/books/NBK459259
- 3Rout A, Suri S, Vorla M, Kalra DK. Myocarditis associated with COVID-19 and its vaccines — a systematic review. Prog Cardiovasc Dis. 2022;74:111-121. https://doi.org/10.1016/j.pcad.2022.10.004
- 4CDC. COVID-19 Vaccination. Centers for Disease Control and Prevention. Published February 11, 2020. Accessed September 1, 2023. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/adverse-events.html
- 5Martens CR, Accornero F. Viruses in the heart: Direct and indirect routes to myocarditis and heart failure. Viruses. 2021;13(10):1924. https://doi.org/10.3390/v13101924
- 6Kang M, Chippa V, An J. Viral Myocarditis. In: StatPearls. StatPearls Publishing; 2023. Accessed September 1, 2023. https://www.ncbi.nlm.nih.gov/books/NBK459259
- 7Nor MA, Ogedegbe OJ, Barbarawi A, et al. Systemic lupus erythematosus and cardiovascular diseases: A systematic review. Cureus. 2023;15(5):e39284. https://doi.org/10.7759/cureus.39284
- 8Zheng Q, Zhuang Z, Wang ZH, et al. Clinical and preclinical systematic review of Astragalus membranaceus for viral myocarditis. Oxid Med Cell Longev. 2020;2020:1560353. https://doi.org/10.1155/2020/1560353
- 9Nawrot J, Gornowicz-Porowska J, Budzianowski J, Nowak G, Schroeder G, Kurczewska J. Medicinal herbs in the relief of neurological, cardiovascular, and respiratory symptoms after COVID-19 infection a literature review. Cells. 2022;11(12):1897. https://doi.org/10.3390/cells11121897
- 10He X, Gao B, Zhou L, Xiong S. Green tea polyphenol epigallocatechin-3-gallate-alleviated coxsackievirus B3-induced myocarditis through inhibiting viral replication but not through inhibiting inflammatory responses. J Cardiovasc Pharmacol. 2017;69(1):41-47. https://doi.org/10.1097/FJC.0000000000000439
- 11Shaito A, Thuan DTB, Phu HT, et al. Herbal medicine for cardiovascular diseases: Efficacy, mechanisms, and safety. Front Pharmacol. 2020;11:422. doi:10.3389/fphar.2020.00422
