Not dyspn-OHHHH-ea, Cuts?
I guess there should not be much trouble in following either dictionary. After all the British only add an occasional o or an a here and there. Once you get the hang of the few terms that are different, then I guess it should be smooth sailing. What you usually need the dictionary for is to look up what 'torsades de pointes' means, and that being a French term, would spell the same on both sides of the Atlantic.
Btw, Cuts, did you learn medicine in Hungarian there?