Preexcited Atrial Fibrillation after a Blood Draw

Preexcited Atrial Fibrillation after a Blood Draw: A 33-year-old man presented to the emergency department with palpitations after syncope occurred while a blood sample was being obtained. He had tachycardia, with a heart rate of 192 beats per minute in an irregularly irregular rhythm. An electrocardiogram (Panel A) showed wide-complex tachycardia…