COVID-19
Long COVID

Matilda (65 years old)

Matilda is a 65-year-old woman with no significant medical history who contracted COVID-19 disease 1 year ago with symptoms that had been mild at that time. For the past 4 weeks she has been experiencing intermittent chest pain that is worsened with exertion, followed by fatigue. She denies any shortness of breath, cough, or fever. On physical examination, her vital signs are within normal range, and lungs are clear to auscultation. An electrocardiogram is unremarkable.

Which is the most likely diagnosis for this patient?