Case report:
A 36-year-old athletic male mountain biker with no significant past
medical or cardiac history suffered from upper respiratory symptoms 6
weeks before hospital admission. He had a positive test by polymerase
chain reaction (PCR) for COVID-19 infection at that time. The patient
had received the second dose of the Moderna vaccine at the end of May
2021. Two months later, he suffered from severe fatigue and persistent
bradycardia at the time of his positive COVID-19 testing with a heart
rate (HR) in the 30s. He was diagnosed with a breakthrough COVID-19
infection. His symptoms gradually improved but his exercise tolerance
remained very limited and he could not raise his heart rate
appropriately with activities. Due to persistent fatigue and
bradycardia, he went to urgent care where he denied any significant
dizziness or syncope.