New onset (<48h) should be anticoagulated with heparin to prevent atrial thrombus so that you can give them a change at cardioversion. You start the heparin immediately b/c it will limit the risk the fibrillating atrium and thus the crappy blood flow in the atrium will clot. That way, when they go for TEE cardioversion there isn't a clot and they can be shocked out of fib.
If you cannot succesfully cardiovert and your EP won't do an ablation, there really isnt a need to bridge to coumadin.
If they get cardioverted and go back into sinus, they need to be bridged b/c the risk of atrial clot after cardioversion is higher than being in a-fib for ~4 weeks after the procedure.
Now with dabigitran, no need to bridge.
Most people do.
I HATE lovenox in the hospital and I encourage everyone on this board to hate it too.
As an outpatient it is a good drug but in the hospital, I don't use it. I can't tell you how many times I have been burned with a patient on lovenox. You can't easily reverse it and the effects last much longer than heparin. Just for convenience, heparin is the way to go in the hospital.
The hospitals around us seem to love it. It's great when they send us a MICU disaster bleeding out of every orifiace who is getting lovenox...
