Hi.  My name is Kenneth.  I am frequently experiencing blackouts that last over fifteen minutes or longer.  I have been to an epilepsy testing center, and they have told me that I do not have epilepsy.  I do not understand why my blackouts keep on occuring, while getting worse.  My worst blackout lasted about four hours, which had scared me very badly.
If the epilepsy center has done a complete assessment for you and determined that you don't have epilepsy then, what you need is a cardiovascular workup. If you have a primary doctor then, I would expect this referral should be made soon. If not then, you should find a primary doctor who can help you get directed to the right specialists now to continue the workup.  Spells can also be due to many other problems such as medication side effects, low blood sugar, psychological stress, very low blood pressure from deny Chat Doctor.  That is why you need a primary medical doctor who can look at all these things and help direct you.