It sounds like it could be autonomic dysfunction or siezures. You should start by seeking another opinion from a good cardiologist. You would benefit from both a holter monitor to document the episodes and/or an event recorder that can be sent over the phone for immediate results/interpretation. A tilt table test would also be a good idea.

If you are having autonomic dysfunction resulting in syncope episodes, there are several options to help control the symptoms, to include medicine and possibly even a pacemaker even if your passing out from low heart rates.

If these events are seizure related, then an EEG would be a helpful test to consider.

What 'monitor' was used by the doctor you mentioned and what showed on the monitor to confirm your symptoms?

How often are these happening...daily, weekly, etc?