Acute Myopericarditis; This literature-study case was reported in a literature article and describes the occurrence of MYOCARDITIS (Acute Myopericarditis) in a 25-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.     No Medical History information was reported.   On an unknown date, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On an unknown date, received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On an unknown date,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced MYOCARDITIS (Acute Myopericarditis) (seriousness criteria hospitalization and medically significant). The patient was hospitalized for 1 day due to MYOCARDITIS. The patient was treated with COLCHICINE for Myopericarditis, at an unspecified dose and frequency. At the time of the report, MYOCARDITIS (Acute Myopericarditis) outcome was unknown. Possible    DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Bacterial test: negative (Negative) Negative. On an unknown date, Body mass index: 28 kg/m2 Body mass index28 kg/m2. On an unknown date, C-reactive protein (0-10mg/dl): 96 mg/dl (abnormal) C-reactive protein was elevated at 96 mg/dl.. On an unknown date, Echocardiogram: - 21.0% TTE Global longitudinal strain - 21.0%. On an unknown date, Ejection fraction: 60% (normal) TTE showed an LVEF of 60% and no pericardial effusion.. On an unknown date, Electrocardiogram: abnormal (abnormal) 12-lead ECG showed diffuse PR segment depression and PR segment elevation in lead aVR, consistent with acute pericarditis.. On an unknown date, Magnetic resonance imaging heart: abnormal (abnormal) CMR performed 1 week after hospital discharge showed subepicardial LGE and myocardial edema in the lateral LV segments, - 19.6% (normal) GLS by TTE and CMR was normal (< -18%). and 59% CMR LVEF 59%. On an unknown date, Red blood cell sedimentation rate (0-15 mm/hr): 24 mm/hr (High) Erythrocyte sedimentation rate 24 mm/hr. On an unknown date, SARS-CoV-2 test: negative (Negative) Negative. On an unknown date, Troponin I (0.006 ng/ml-0.060 ng/ml): 17 pg/ml (abnormal) serum cardiac troponin was elevated at 17 pg/ml. On an unknown date, Viral test: negative (Negative) Other Viral Serologies including Adenovirus, Rhinovirus, influenza/ Parainfluenza, Respiratory Syncytial Virus, Mycoplasma pneumoniae, Chlamydia pneumoniae not detected.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered MYOCARDITIS (Acute Myopericarditis) to be possibly related.    Patient had no coronary artery disease risk factors or cardiac comorbidities.  Patient with no known prior health problems presented to the emergency department 3 days after receiving his second dose of the Moderna COVID-19 vaccine with chest pain and dyspnea. Other symptoms included generalized body aches, nausea, headache, chills, and fatigue.  No cardiac rub was reported.  CMR findings of the patient met updated  criteria for acute myocarditis.  Patient's length of stay at hospital was reported as 1 day and was discharged home in stable clinical condition.  Author stated that longer clinical follow-up may help understand if the CMR abnormalities observed are temporary in the setting of a high inflammatory state or longer-lasting, and whether they help predict any clinically-relevant adverse events or deterioration in cardiac function.  Author concluded that in conjunction with other recently published case series and national vaccine safety surveillance data, this case series suggests an association between acute myocarditis and COVID-19 vaccination in young males and highlights a potential pattern in accompanying CMR abnormalities.  This case concerns literature review of a 25 year old male who experienced the serious listed event of Myocarditis 3 days after the second dose of Moderna COVID-19 vaccine. Re-challenge is not applicable as it is the second dose and causality is possible in the article. Benefit-risk relationship of Moderna COVID-19 vaccine is not affected by this report..; Sender's Comments: This case concerns literature review of a 25 year old male who experienced the serious listed event of Myocarditis 3 days after the second dose of Moderna COVID-19 vaccine. Re-challenge is not applicable as it is the second dose and causality is possible in the article. Benefit-risk relationship of Moderna COVID-19 vaccine is not affected by this report.