EKG Challenge No. 11 - Mmmm.... That looks sort of fast...

You are working one evening in the emergency department when a 60-something year old female is slotted for a room.  Her chief complaint?  "Fever, weakness, vomiting".    Seeing that her triage heart rate was 157, you leave your granola bar where it is and immediately walk into the room to assess her.  You see an elderly-appearing female in moderate respiratory distress.  Her temperature is 38.2,  blood pressure is 125/87, RR is 32, oxygen saturation is 93% on 5L NC.  She has a history of a bone-marrow transplant and is chronically immunosuppressed. She endorses poor PO intake and several episodes of emesis over the last few days.  She says that she came in today when she developed some shortness of breath as well.  She denies any chest pain or palpitations.  On exam, her mucous membranes are dry, her abdomen non-tender, and her breath sounds are decreased in the right base.  You are a bit disturbed by the looks of her rhythm strip on the monitor so you get a 12-lead EKG:

Interpret the EKG.  What is your differential?  What would you do next?  

See the case conclusion here