Generalized Weakness After Heavy Drinking: Your Dx?

A 38-year-old man with a history of hypertension, depression, and alcohol abuse presented with total body weakness after drinking heavily the night before. Vital signs were normal, except for blood pressure of 158/94 mm Hg. His medications included hydrochlorothiazide and fluoxetine, but he had not been taking either drug recently. His ECG is shown here.

What diagnosis does this ECG indicate?