Multicenter, retrospective, observational study consisting of patients who presents with typical/atypical chest pain to the emergency department and have an ensuing negative ischemic evaluation. Planned to review the subsequent diagnostic process in these patients, including patients with CMRI (Cardiac Magnetic Resonance Imaging), PET (Positron Emission Tomography) imaging for evaluation of myocarditis with the goal of quantifying the number of patients who go on to have a proven diagnosis of myocarditis that can explain their presenting symptoms.