low blood pressure and slow heart beat is often a cause of a fit in which case it is often over diagnosed as epilesply , my pall has it , i told him to look at heart disease a thining of the heart wall , think its called bardycardio ? some thing like that , tilt test and salt are ment 2 work but am no doctor , i have cardiomyopthy dilated left . hope u get it sorted
Fainting, dizziness etc can also be signs of nervous system problems.
Autonomic nervous system problems can cause your BP and HR to drop quickly - check on Orthostatic Hypotension or Orthostatic Intolerance and Neurocardiogenic Syncope.
I have NCS and OI along with malignant heart rhythms - had to have a tilt table test to diagnose the problems (electrophysiologist EP ordered it)
Having a seizure after fainting could either be from Epilepsy or from a heart arrhythmia. Whoever this happened to should be checked out by both a neurologist and a cardiologist to rule out either problem soon.
My brother had a seizure this morning related to low blood pressure. It was so low they could not even read it until he was feeling better then it read 69/29....
If you are on blood pressure pills, standing after taking those will make you feel faint, sometimes dizzy. I think dizziness is mostly a result of low blood pressure, or inner ear problems. Simply standing up too fast does not cause fainting normally.