Myopericarditis - Symptoms, Diagnosis, Treatment, and COVID-19

Introduction

The pericardium is the fluid-filled double membranous sac surrounding the heart and major vessels. The inflammation of the pericardium is called pericarditis. The myocardium is the muscular middle layer of the heart, and the inflammation of the myocardium is called myocarditis. When both pericarditis and myocarditis occur together, the condition is called myopericarditis. Myopericarditis is a complication of pericarditis, with the inflammation extending to the myocardium. So, myopericarditis primarily presents with pericarditis symptoms with inflammation involving the myocardium.

What Are the Causes of Myopericarditis?

In most cases of myopericarditis, the actual cause is unknown. However, the following conditions can cause myopericarditis.

• Bacterial infections caused by Mycoplasma, Mycobacterium tuberculosis (causative agent of tuberculosis), etc.

• Parasitic infections.

• Viral infections caused by echovirus, Epstein-Barr virus, and Hepatitis C virus.

• Fungal infections caused by Aspergillus, Histoplasma, etc.

• Cancers that spread (metastatic cancer) like lung cancer, melanoma, etc.

• Hypothyroidism.

• Renal failure.

• Rhabdomyosarcoma (cardiac tumor).

• Following radiation therapy of the chest.

• Inflammatory conditions like rheumatic arthritis, Sjogren, lupus, inflammatory bowel disease, etc.

• Vaccines like smallpox and Covid 19 vaccines.

• Viral infections are said to be one of the common causes of myopericarditis. Myopericarditis is more prevalent in males and mostly affects those below 40 years.

What Are the Symptoms of Myopericarditis?

Initial symptoms include runny nose, low-grade fever, fatigue, dyspnea (breathing difficulty), chest pain, arthralgia (joint pain or stiffness), and palpitation (condition of abnormal heart rhythm). The chest pain is described as sharp pain, which worsens during cough and is relieved on sitting forward.

Symptoms of heart failure are also present and include pedal edema, shortness of breath, orthopnea (shortness of breath experienced in lying down position), and fatigue. Syncope (fainting) and cardiac arrest may occur in some rare cases.

What Are the Different Diagnostic Tests Done?

The different diagnostic tests done include:

1. Laboratory Investigations: Blood tests show an elevated level of ESR (erythrocyte sedimentation rate), C-reactive protein, and WBC (white blood cell). An elevated level of cardiac biomarkers is also seen, suggesting myocardial involvement. A routine blood examination is also done to rule out other conditions like Hepatitis, renal failure, and thyroid diseases.

2. ECG (Electrocardiogram): Localized changes are seen on the ECG, which depends on the extent of inflammation.

3. Radiographic Examinations: Chest X-rays are normal in most cases. However, fluid accumulation is seen in the pericardial space in some severe cases of heart failure.

4. Echocardiogram: An echocardiogram is normal in most cases. In addition, an echocardiogram rarely shows signs of pericardial effusion (increased fluid accumulation in pericardial space).

Echocardiogram is also used to examine the patient’s left and right ventricular function. In the case of patients with failure in left ventricular function mortality rate is more.

5. Endomyocardial Biopsy: Endomyocardial biopsy is done in some cases that show signs of continued inflammation even after treatment.

6. Cardiac Magnetic Resonance Imaging: CMR (cardiac magnetic resonance imaging) helps determine the extent of pericardial and myocardial involvement. Pericardial thickening with pericardial effusion is seen in CMR.

7. Coronary Angiography: This invasive test is done mostly in old-aged patients with a risk of atherosclerosis to rule out acute coronary syndrome.

How Is Myopericarditis Diagnosed?

The physical examination findings vary from patient to patient. But the common findings are fever, signs of heart failure, and pericardial friction rub (it is a medical sign, a grating sound produced due to friction of the heart against the pericardium). Blood examination shows an increased level of markers of inflammation which includes WBC, CRP, and ESR. Laboratory examination also shows increased levels of cardiac biomarkers. ECG helps in detecting LVF (left ventricular function) and pericardial involvement. CMR helps in detecting the extent of myocardial and pericardial involvement.

Acute pericarditis presents with either two or more of the following symptoms:

• Pericardial friction rub.

• Chest pain.

• Pericardial effusion.

• Changes in ECG.

Myopericarditis presents with symptoms of acute pericarditis and also one or more of the following features:

• Elevation of cardiac biomarkers.

• CMR shows myocardial inflammation.

• Echocardiography showing left ventricular systolic failure.

How Is Myopericarditis Treated?

• In the case of patients having myopericarditis with normal left ventricular function, NSAIDs (non-steroidal anti-inflammatory drugs) are the first line of treatment.

• In the case of patients who have severe myocardial involvement, only low doses of NSAIDs are to be used as they can affect myocardial function adversely.

• In severe pericardial effusion, surgical drainage is done (pericardiocentesis). The risks associated with this procedure involve the risk of injury to the lungs, stomach, liver, and heart and also the risk of infection.

• In the case of patients with signs of heart failure and myocardial involvement, treatment options include diuretics, beta-blockers, or angiotensin-converting enzyme inhibitors.

• Corticosteroids may be used in the case of inflammatory conditions, and antibiotics are used in the case of bacterial infections.

• Activities that can cause physical exertion should be restricted for a certain period of time, as suggested by the physician.

• The prognosis of the condition is good, with less chance of long-term complications.

What Is the Link Between COVID-19 and Myopericarditis?

• Studies have suggested that myopericarditis is one of the cardiac complications of COVID-19.

• Studies show that seven percent of people affected by the COVID-19 virus show signs of myocardial inflammation.

• SARS-CoV-2mRNA (Severe acute respiratory syndromes) vaccine and myopericarditis also show a relation, with those undertaking the vaccine at higher risk of developing myopericarditis. The affected were mostly males below 40 years of age, and this was more common with the booster dose vaccination. Smallpox vaccination in adults is also shown to have a similar effect.

What Are the Complications of Myopericarditis?

By early diagnosis and proper treatment, long-term complications can be avoided. The potential complications include the following:

• Constrictive Pericarditis: Constructive pericarditis occurs when the pericardium becomes thicker and gets fibrosed. In cases of bacterial infection leading to myopericarditis, the risk for constrictive pericarditis is 20% to 30%. In cases where the viral infection has been the cause of myopericarditis, the risk for the development of constrictive pericarditis is less than one percent. Constrictive pericarditis may affect the heart’s pumping activity and lead to heart failure.

• Heart Failure: In cases where myopericarditis leads to heart failure, the condition may be life-threatening.

• Left ventricular dysfunction.

• Arrhythmia (abnormal heart rhythm).

Conclusion

Myopericarditis is a cardiac condition occurring as a complication of pericarditis, leading to myocardial inflammation. The overall prognosis of the condition is good, and the condition is manageable with proper treatment and early diagnosis. The chances for potential long-term complications are rare and viral infections are the most common cause of the condition.