Symptomatic Bradycardia in a Young Adult After Camping

Scenario: An 18-year-old man with no significant medical history arrived at the emergency department via ambulance after a sudden syncopal episode of unknown cause. He had just returned from camping a few days prior. At the time of the episode, the patient was performing chores and his mother found him down and disoriented. En route to the hospital, emergency medical services reported a heart rate of 48/min and a blood pressure of 72/33 mm Hg; he was treated with a 500-mL saline bolus. During examination, he recalled the event and stated that he had felt dizzy so he had lain down. At this time, he reported no shortness of breath, chest pain, nausea, vomiting, changes in vision or hearing, or headache. Vital signs upon his arrival at the emergency department were recorded as heart rate 67/min, blood pressure 97/64 mm Hg, body temperature 38 °C (100.7 °F), respiratory rate...