This case was reported in a literature article and described the occurrence of myopericarditis in a 28-year-old male subject who was vaccinated with Tdap (manufacturer unspecified). The subject was reported to have been healthy before the event. He denied having any contact with sick people, previous vaccine reactions or any cardiac risk factors apart from a history of 10 packages of tobacco per year. No further information regarding the subject's medical, family history or concurrent medication has been provided. On an unspecified date, the subject received an unspecified dose of Tdap (intramuscular, unknown injection site). 1 day after vaccination with Tdap, the subject experienced tactile fevers and myalgias. 2 days after vaccination with Tdap, the subject experienced severe substernal chest pain with sudden onset that was not associated with inspiration and improved by leaning forward. The authors reported that the clinical examination and vital signs were within normal limits at this point. An electrocardiogram (ECG) showed diffuse upsloping ST segment elevations. Laboratory studies revealed a white blood count of 13.3/mm3, troponin of 9.1 ng/mL, creatinine kinase 372 IU/L and C-reactive protein (CRP) of 79.3 mg/L. A two-dimensional echocardiography showed normal left ventricle size and function and no effusion. Initial diagnosis was pericarditis. Treatment was started with high dose Aspirin and colchicine. The subject became febrile overnight (38.1C) his troponin level increased to 30.5ng/mL and his chest pain persisted. A cardiac catheterization was performed that showed normal coronary arteries. His chest pain worsened a few hours later, and new marked ST elevations appeared in leads I, AVL and V1-V6. Repeat angiography showed a newly dissected and occluded left anterior descending coronary artery, which was stented achieving a restoration of TIMI 3 grade flow (normal flow). He was discharged with an ejection fraction of 45% and on colchicine, clopidogrel and Aspirin. Infectious screening tests that included Coxsackie B virus, echovirus and adenovirus were ultimately negative, as were the determination of antinuclear antibodies and rheumatoid factor. He presented again several times over the following few months with atypical chest pain but with normal cardiac enzymes and CRP. He underwent a Myoview-exercise treadmill test and was able to exercise 10 min without ECG changes. Nuclear imaging showed a medium-to large partially reversible perfusion defect in the apex and anteroseptal wall, but repeat catheterization showed a patent left anterior descending coronary artery stent and distal vasospasm. Treatment for the vasospasm included isosorbide mononitrate and diltiazem. Final diagnosis was myopericarditis. At the time of reporting, the outcomes of the events were unspecified. Author's conclusion: "Most cases of myocarditis result from viral infection, although other pathogens, drugs, hypersensitivity, and autoimmune disorders are occasionally implicated. Cardiovascular complications due to vaccination are rare. Only two case reports of myopericarditis after Tdap vaccination exist, and of 20 million doses distributed from 2005 to 2007, three cases were reported post-licensure safety surveillance. While it is impossible to definitely exclude a viral etiology for this case, negative viral serologies and absence of symptoms prior to vaccination make it less likely. While early post-vaccination prodrome favors a hypersensitivity reaction, hypersensitivity myocarditis is usually a retrospective, circumstantial diagnosis. The diagnostic accuracy of endomyocardial biopsy remains poor and was not indicated. Coronary angiography may be performed if there is significant uncertainty as to whether the clinical picture reflects acute coronary syndrome versus myopericarditis. Cardiac MRI has been shown to be a highly sensitive (76%) and specific (96%) alternative for myocarditis detection and differentiation from infarction. However, it is not available in many resource-limited settings, including the hospital to which this patient presented."