Case number PHHY2012US058747, is an initial literature report received on 09 Jul 2012. The authors reported a case of post vaccination acute myopericarditis in an adolescent. This case refers to 17-years-old male patient. He had no history of angina pectoris, cocaine abuse, hyperlipidemia or congenital heart disease. He also had no history of autoimmune disorder, no previous travel and no previous flu-like illness with diarrhea and/or respiratory symptoms suggestive of an infectious syndrome. He was vaccinated with MCV4 (manufacture and batch number: unknown, conservatively considered as MENVEO), HAV-PUR (manufacture and batch number: unknown, conservatively considered as HAV-PUR), and Tdap (manufacture and batch number: unknown) on an unspecified date. This was the first time he was ever received meningococcal or hepatitis A vaccines. The following day he complained of diffuse arthralgia, chest pain and a low-grade fever. He was admitted to the PICU with intermittent, retrosternal chest pain for one-day. In the emergency department his physical examination was normal, but he was found to have diffuse ST-segment elevation on ECG and elevated serum cardiac enzyme levels as troponin I, 15.9 ng/mL, creatine kinase, 1106 U/L and creatine kinase MB, 44.4 U/L. A chest radiograph was normal and a two-dimensional echocardiogram showed no segmental wall-motion abnormalities, normal biventricular systolic function and no pericardial effusion. Other laboratory findings included a white blood cell count of 8.3 x 109/L (with 62 percentage neutrophils, 22 percentage lymphocytes and 3.7 percentage eosinophils), hemoglobin level of 14.6 g/dL, C-reactive protein level of 59 mg/L, erythrocyte sedimentation rate of 17 mm/hour, C4 level of 38 mg/dL, and C3 level of 142 mg/dL. The rectal and nasopharyngeal swabs were sent for adenovirus and entero-virus cultures and the results were negative. The lyme immunoglobulin G (IgG)/IgM antibody, cytomegalovirus IgG, Epstein-Barr virus capsid IgM antibody, antinuclear antibody and anti-DS DNA screens were also negative. The convalescent samples for the above-named infectious etiologies were not obtained. Over the following 24-hours, the patient's cardiac enzyme levels continued to raise to a maximum of 22.8 ng/mL for the troponin I. The gadolinium-enhanced cardiac MRI was positive for myocarditis as evidenced by delayed subepicardial enhancement of the basal to midanterolateral and inferolateral regions of the left ventricular wall. The chest pain was relieved with ketorolac and his serum enzyme levels gradually decreased. The patient was discharged four-days later on indomethacin 50 mg orally three-times per day with the recommendation of restricting physical activity for a total of four to six-weeks. The serum cardiac enzyme and C-reactive protein levels were all normalized one-week after the onset of the symptoms. The ECG at that time showed normalization of the ST segment and at the three-week follow-up, there was diffuse T-wave inversion. At ten-weeks, ECG findings were resolved and the follow-up cardiac MRI showed decrease in the area of contrast enhancement. The patient remained asymptomatic with normal ventricular function as assessed by echocardiogram and MRI. In this case, the possibility of a viral etiology cannot be definitely excluded however, the negative viral serology and the absence of symptoms make this a less likely possibility. Of interest is the natural progression of ECG changes that is commonly associated with myopericarditis and was observed in this patient. The authors concluded that, the case highlights the fact that pediatricians should be aware of the often-dramatic presentation of post vaccination myopericarditis and its usually benign clinical course. The diagnosis of myocarditis should be entertained when acute-onset chest pain is accompanied by ECG changes and elevated cardiac enzyme levels. In cases in which the above-described presentation is temporally related to routine immunizations, the immunizations should be considered as a possibly underlying etiology. The causality of the events was not reported.