A 42-year-old man was presented to the emergency department with palpitations and shortness of breath that started a few minutes before his arrival. The patient had a momentary period of asystole, but his rapid heart rate returned. He was subsequently given adenosine 0.6 mg en route to the hospital. He denies having any chest pain, nausea, vomiting, diaphoresis, light-headedness, or recent illness.
He also denies having any symptoms of infection, such as fever, cough, vomiting, diarrhoea, anorexia, or dysuria. He reports increased stress at work and is drinking up to 4 cups of coffee a day. Past Medical History: He reports no notable history of medical conditions except for a similar episode of a rapid heart rate about 4 years ago for which he was treated with an unknown drug for 2 years. His family history is significant for a father who died of a myocardial infarction at age 45…
