👉 Myocarditis, also known as myocardial inflammation or myocardial edema, is a condition that affects the heart muscle. It can occur due to various factors such as bacterial infections, viral infections, or inflammatory conditions like rheumatoid arthritis, which causes swelling in the joints and muscles. Myocarditis can lead to severe symptoms including chest pain, shortness of breath, fever, nausea, and fatigue. Treatment depends on the cause and severity of the condition.