I believe the term is vasovagal syncope, and just because you passed out does not mean you have it. The biggest mistake pilots make is chosing an AME on the basis of price and whether or not a prostrate exam is done. What happens is that your AME is probably practicing in a main area and doing flight physicals on the side. As a result, he or she has very little idea how best to pursue a deferral. You could be grounded for a long time while you and your AME are educated on the proccess. (Your paperwork going back and forth and eating up months or being needlessly disapproved because your AME is probably not aware of exactly what the feds want to see along with your diagnosis!) Please, please, take the following advice:
Do not contact your AME concerning this matter, and do not fly!
What you need is a diagnosis from a doctor. Your primary care physician should be your first call Monday morning if you havn't done that already. Once you have a diagnosis in hand, please consider calling Dr. Stacy Vereen in Atlanta. Doc Veren is board certified in aerospace medicine, former head of the Civil Aeromedical Institute, and a free-lance corporate pilot. (PM me for his phone number.) He is on YOUR side, and maintains a close working relationship with the Federal Air Surgeon and all of the FAA staff doctors up at OKC. He'll be able to tell you exactly what documentaion you'll need to gather in addition to your diagnosis. He will also do a phone consultation with you for a nominal fee to explain how your specific situation will play out. Dr. Vereen maintains contacts with other AME's around the country who are also board-certified in aerospace medicine and attend all of the CAMI conferences. He will most likely refer you to one of these individuals close to you. Because you contacted him first and he is doing the recommending, he'll be able to ethically consult with the other AME concerning your specific issues and give them his reccommedations. Trust me here, this is going to take a lot of the stress out of the whole process and speed things along greatly in regards to you returning to the cockpit. (If possible.) Doc Vereen is a big voice in the aerospace medicine community.
Best of luck man, I truly do hope it's something completely benign and innocent!