Myocarditis is an inflammatory disease of the myocardium. Its manifestations depend on the extent and location of the condition; mild cases may have no symptoms, while severe cases can lead to cardiogenic shock and sudden death. Most patients experience precursor symptoms of viral infection one to three weeks before onset, such as fever, general fatigue, and muscle soreness, or gastrointestinal symptoms like nausea and vomiting. Subsequently, they may experience palpitations, chest tightness, difficulty breathing, and potentially fainting or sudden death. Clinically diagnosed myocarditis is mostly due to arrhythmias as the primary complaint, or patients seek treatment for common symptoms.