Myocarditis is an inflammation of heart muscle. Inflammation can cause decrease heart ability to pump blood and cause heart failure. also heart beat irregularities which is called arrythmias.
Generally Myocarditis rare. But it can be 10 times higher among people with COVID 19 infection.
It is more common among males. Especially among older ages and among kids.
The pathophysiology of COVID-19 related myocarditis is thought to be a combination of direct viral injury and cardiac damage due to the host’s immune response.
Most patients has mild symptoms.
Symptoms and signs include:
a fast or irregular heartbeat, shortness of breath even when at rest, chest pain and fatigue.
other symptoms of a viral infection (body aches, pains, fever, sore throat). feeling tired, fluid buildup in legs, ankles and feet, fainting.
The clinical findings include changes in electrocardiogram and cardiac biomarkers, and impaired cardiac function.
Many patients do deteriorate, showing symptoms of tachycardia and acute-onset heart failure with cardiogenic shock. In these severe cases, patients may also present with signs of right-sided heart failure, including raised jugular venous pressure, peripheral edema, and right upper quadrant pain.
ventricular dysfunction and heart failure can occur within 2–3 weeks of contracting the virus.
The early signs of fulminant myocarditis usually resemble those of sepsis: the patient often presents febrile with low pulse pressure, cold or mottled extremities, and sinus tachycardia.
Laboratory elevated levels of lactate and other inflammatory markers, including C-reactive protein, erythrocyte sedimentation rate, and procalcitonin, which usually are raised in keeping with the clinical presentation of infection.
Electrocardiogram (ECG) abnormalities commonly seen with pericarditis, such as ST elevation and PR depression, may be observed in myocarditis; however, these findings are not sensitive in detecting the disease and their absence is not exclusionary.
The cardinal signs of myocarditis on echocardiogram are increased wall thickness, chamber dilation, and pericardial effusion in the background of ventricular systolic dysfunction.

The long-term impact of COVID-19 myocarditis, including the majority of mild cases, remains unknown.
Most infected patients experience mild, self-limiting symptoms; are managed in the community; and are not undergoing clinical testing such as ECG or cardiac imaging.
Typically, mild myocarditis is treated with non-steroidal anti-inflammatory drugs like ibuprofen and heart medications. such as ACE inhibitors, diuretics, beta blockers, and enzyme or receptor blockers may also be given.
In some cases, immunomodulatory treatments were given.
A recent meta-analysis on corticosteroid and intravenous immunoglobulin use in pediatric myocarditis concluded that intravenous immunoglobulin may improve ventricular systolic function but failed to find support for corticosteroid use.
However, immunosuppression might pose a risk for more severe clinical disease, especially in the presence of active viral replication.

By Patrick J. Lynch, medical illustrator - Patrick J. Lynch, medical illustrator, CC BY 2.5, https://commons.wikimedia.org/w/index...