Inclusion Criteria:

1. All patients eligible for vaccination with a COVID-19 vaccine,

2. At least one cardiac symptom of suspected myocarditis/pericarditis within 42 days of receiving a COVID-19 vaccination. The clinical symptoms include chest pain, pressure, or discomfort; dyspnea, shortness of breath/dyspnea/pain with breathing, palpitations, diaphoresis, syncope, or sudden death.

   OR At least two non-specific symptoms within 42 days of receiving a COVID-19 vaccination. These symptoms include fatigue, abdominal pain, dizziness or syncope, edema, or cough.

   OR No symptoms, but abnormal histopathology or a combination of abnormal cardiac biomarkers with abnormal cardiac imaging (echo or MRI)

3. At least one of the following:

   1. Elevations in Troponin T, Troponin I, or CK-MB (above threshold of normal)
   2. Abnormal MRI (per Brighton Criteria Case Definitions)
   3. Any new or worsening cardiac arrhythmias on ECG or telemetry or Holter monitor (per Brighton Criteria Case Definitions) including those that normalize on recovery.
   4. Abnormal Echocardiographic findings (per Brighton Criteria Case Definitions, see Appendix 2 and 3)
   5. Physical exam finding: Pericardial friction rub or pulsus paradoxus
   6. Pericardial fluid or inflammation by imaging (echo, MRI, or CT) or at least one of the following elevated biomarkers of inflammation: ESR, CRP, hs-CRP, or D-Dimer.
   7. Enlarged heart on chest radiograph.
   8. Histopathologic examination of myocardial tissue (autopsy or endomyocardial biopsy) showed myocardial inflammation

Exclusion Criteria:

1. Clear alternative diagnosis or explanation for the symptoms and findings (e.g. infectious myocarditis such as Lyme carditis). Note: Work-up of alternative diagnosis is dependent on clinical presentation e.g. Lyme carditis (e.g. endemic area, season, bullseye rash) or autoimmune heart disease (e.g. arthritis, rash, recurrence).
2. Symptoms after 42 days of vaccination.