Hi Brian,
Welcome to the forum! I've had epilepsy for 37 yrs. now and just like you I will be sitting still doing nothing and all of the sudden I will get a rapid heartbeat for no reason I've told my Epileptologist about this and just like you I was checked over for heart problems but everything was fine. I found out it was all related to stress which lead to panic attacks for me and that in turn led to seizures. I took tegretol for many yrs. and it worked great for me but then right out of the blue I became allergic to the med. I also took Depakote and that was one of the best meds to control my seizures (sz.) but it lowered my platlet level so low that the Dr. thought I was bleeding enternally. check your body over and if you see bruises on you skin get a complete blood count done it could be that your platlet level is low from you med and that's what is causing the problem. Also stay away from nutra sweet or any artifical sweetner and cut back on the caffeine because that can cause problems for you while taking depakote. My best advice to you is to see a Epileptologist at an Epilepsy Center which are usually at University Hospitals I got the best help there and took the least meds seeing an Epileptologist compared to seeing a neurologist. Here's wishing you well and May God Bless You!

Sue P.S. Try taking vitamin B12 1000 mcg. a day it calms the nerves
down and reduces seizures.