Myocarditis: Causes, Signs and Symptoms, Diagnosis and Treatment

Introduction

Myocardium refers to the muscles of the heart. When the heart muscles or the myocardium undergo any inflammation or inflammatory change, it results in myocarditis. Myocarditis occurs due to certain immune disorders or some kind of infection in the body. The myocardium does not contract and relax as efficiently as it is supposed to if it gets inflamed. This leads to an overall decrease in cardiac output and hampers the normal functioning of the heart. In cases where myocarditis goes undiagnosed, the body may react disparagingly and cause acute heart failure or even permanent damage to the heart.

How Does Myocarditis Affect the Heart?

Myocarditis is a condition that results in the swelling of the heart muscles. This swelling or inflammation expands as well as exhausts the heart. It generates scar tissue and compels the heart to work vigorously to smoothly circulate oxygen and blood all through the body. Myocarditis can affect the elderly and young adults, children, and newborns. It is prevalent in males and surprisingly in young athletes in their early thirties. It is one of the main reasons for sudden death in young adults and children.

What Are the Causes of Myocarditis?

The principal reason for myocarditis is a viral infection in the body. During the viral infection, inflammatory changes occur in the body. This leads to an extra amount of stress on the heart, and this extra pressure does not decrease unless the viral infection is cured completely. Additionally, bacterial infection or cancer can also put the heart at risk of developing myocarditis. A parasitic or fungal infection can also possibly lead to myocarditis as well as some autoimmune conditions such as rheumatoid arthritis (RA), inflammatory bowel disease, or lupus. Below are the causes that lead to myocarditis.

• During a viral infection, the body releases cells to kill the virus. In case these cells enter the heart, they may inflame the heart tissues leading to myocarditis.

• Coxsackie B virus.

• EBV or Epstein-Barr virus.

• Cytomegalovirus (CMV).

• Herpes simplex virus.

• Human immunodeficiency virus.

• Hepatitis C.

• Parvovirus.

• Chlamydia.

• Streptococcal bacterial infection.

• Mycoplasma infection.

• Treponema infection.

• Borrelia infection.

• Toxins such as alcohol and drugs- cocaine.

• Lead toxin.

• Toxins released after spider bites.

• Wasp stings.

• Toxins after a snakebite.

• Chemotherapy.

• Radiation therapy.

• Allergies to certain medications and antibiotics.

• Graves disease (an autoimmune disorder that causes overactivity of the thyroid gland, leading to symptoms such as hyperthyroidism and an enlarged thyroid)

• Postpartum cardiomyopathy (a rare form of heart failure that occurs in women during late pregnancy or in the months following childbirth).

• Allergic reaction to tetanus toxoid.

• Toxoplasmosis (a parasitic infection caused by the Toxoplasma gondii parasite, which can be contracted through contaminated food or contact with infected animals).

• Giant cell myocarditis (a rare inflammatory disease of the heart characterized by the infiltration of the heart muscle by immune cells called giant cells).

What Are the Signs and Symptoms of Myocarditis?

Generally, myocarditis has no symptoms as such, and many people recover without even knowing they have suffered from myocarditis. Nevertheless, there are some clinical manifestations that do signify the presence of myocarditis. Patients suffering from myocarditis tend to experience the following mentioned signs and symptoms.

• Fainting.

• Abnormal heartbeat.

• Dizziness.

• Sharp stabbing kind of pain in the chest.

• Shortness of breath.

• Palpitations.

• Swelling in the ankles, legs, and feet.

• Fatigue.

• Pressure in the chest.

• Fever.

• Tachycardia (increased heart rate).

• Bradycardia (decreased heart rate).

• Atrial fibrillation.

• Diarrhea.

• Sore throat.

• Muscle aches.

• Joint pain.

• Extended neck veins.

• Decreased urinary output.

How to Diagnose Myocarditis?

The correct diagnosis of myocarditis is made after the healthcare provider has taken a thorough medical history, especially cardiovascular history. In addition, understanding the patient’s symptoms and conducting physical examinations as well as several tests are necessary to diagnose a case of myocarditis. Mentioned below are some of the go-to diagnostic tools for myocarditis.

• Electrocardiogram.

• Cardiac enzyme markers.

• Complete blood picture.

• Echocardiogram.

• Rheumatological screening tests.

• Viral blood tests.

• Heart muscle biopsy.

• Chest X-rays.

• Lung and other chest structures examination.

• MRI (magnetic resonance imaging) of the heart or magnetic resonance imaging of the heart.

How Is Myocarditis Treated?

To treat myocarditis, it is essential to know the underlying condition. Once the cause is cured, it is most likely that myocarditis and related symptoms shall be treated eventually. The healthcare provider and team will take measures to reduce any extra workload on the heart so that any further complications can be kept at bay. To aid in better functioning of the heart, the doctor may prescribe some medications such as:

• Diuretics.

• Beta-blockers.

• Angiotensin-converting enzyme inhibitors.

• Antibiotic therapy.

• Aggressive removal of the toxin.

After a critical evaluation of the entire cardiovascular system, the healthcare professional may suggest the insertion of a pacemaker or an implantable loop recorder. The best person to make this decision is the cardiologist and a team of multidisciplinary doctors. The decision is purely based on the outcome of myocarditis episodes and the underlying cause. Reexamination and reevaluation of the patient's cardiovascular system are highly recommended in order to ensure full recovery of heart function.

What Are the Complications of Myocarditis?

Myocarditis must never be left undiagnosed and untreated. There are recorded cases of myocarditis leading to heart failure if not treated according to the underlying condition. In rare cases, the cardiac output is lost, and complications such as cardiomyopathy and pericarditis emerge. Cardiomyopathy is when the muscles of the heart become weak due to a change in cellular structure. Pericarditis is the infection leading to inflammation of the protective sac like the envelope of the heart. This envelope is called the pericardium. Myocarditis can lead to death or permanent heart damage if left untreated in sporadic cases.

Conclusion

Myocarditis is the inflammation of the heart, or cardiac muscles called the myocardium. Prompt treatment and diagnosis are critical. Post-treatment, the majority of the patients live a long healthy life, free from the after-effects of myocarditis. However, a handful of patients have been diagnosed with myocarditis and have required a heart transplant or lifelong cardiovascular medication. Healthy lifestyle changes and a balanced diet full of vegetables and fruits can support the functioning of the heart. It is suggested to decrease the sodium intake in the diet and quit smoking. Vigorous exercise and participating in competitive sports can be resumed but only after a time period set by the healthcare provider.