What is the intervention for atrial fibrillation of paramedics?

Medications vs shock: If atrial fibrillation is seen, and heart rate is very rapid, medications are first given by ems which usually slow it down. If, however, the heart rate doesn't respond to medications, or the person is critically ill and the blood pressure is extremely low, they need emergent cardioversion (electrical shock) to restart the heart into normal rhythm.

Meds, Cardioversion: Treatment depends on the patient's presentation. For someone with rapid atrial fibrillation who has a stable blood pressure the treatment is often IV medications used to slow the heart rate. The first drug is usually IV diltiazem/cardizem or a beta blocker. For patients with rapid a-fib and low blood pressure, immediate cardioversion may be needed.