An 18-year- old female presents to ED with sudden onset of rapid, irregular palpitations and is found to be in fast atrial fibrillation. She denies chest pain or shortness of breath, has no significant past medical history and is not taking any prescription medications or illicit drugs. She has an interesting family history. Her mother, brother and maternal grandfather have all suffered previous episodes of paroxysmal atrial fibrillation. She had an uncle who died of a sudden cardiac arrest at the age of 30 and a sister who died in infancy from presumed sudden infant death syndrome (SIDS). She undergoes electrical cardioversion and successfully reverts to sinus rhythm.
CXR is unremarkable. Bloods reveal normal levels of potassium, magnesium, calcium and TSH. Her ECG is attached here with. What would be the likely diagnosis for this condition? *This case is from the Docplexus Editorial…
