A 61-year-old man presents with “fluttering” in his chest for one hour. No other symptoms are present. In particular, he did not feel dizzy or faintish at any point. He had three similar episodes during the past two months. He was diagnosed with essential hypertension 10 years ago, but defaulted on follow-up soon afterwards. His surgical history is unremarkable. He is not on any medications currently. He does not smoke. He has between two to three standard drinks per week, in social settings. There is no history of allergies. A full blood count and serum sodium, potassium, and chloride levels are within normal parameters.