Palpitations in a young man: how to manage?

A man who appears to be around 30 years of age bangs on the door of your metropolitan general practice insisting that the receptionist, who is closing up for the evening, re-opens the practice urgently. He looks flushed and is sweating, has a marked tremor and is very agitated. He smells of alcohol, and says he has chest pains and palpitations. Waving caution, your receptionist lets him in and calls you urgently.