i have a friend that really wants to be an airline pilot, however he was recently diagnosed with a very light case of WPW syndrome after an ECG for something unrelated. he has no symptoms and no history of arrhythmia. what are his chances of getting a first class medical?

I'm no doctor; but my guess is not good. It's probably best to give your local AME or surgeon an email.

Untreated, I would think zero chance of any class medical since there is a risk of sudden incapacitation. Maybe it can be treated with beta blockers or something?

This site has some detailed medical condition info...

http://aviationmedicine.com/index.cfm?fuseaction=home

rickair7777, i got this from your site:
"The FAA Guide to Aviation Medical Examiners does not disqualify pilots with WPW who have not had a significant arrhythmia from holding any class of medical certificate. Those with arrhythmias will require control of the condition before medical certification."
So now you got me confused

apply, ame will defer to faa, they ask for records - tests, you comply and presto!

and that's good enough for the airlines?