I have actually had problems twice at restaurants. The first time was well before my surgery, the second not too long ago. The first time my blood pressure got very low and the ambulance technicians couldn't get it up, so I was transported to the emergency department. After spending a few hours there, things straightened out on their own and nothing was discovered to be wrong, and I was released.
The second time I felt the same, but it wasn't quite as bad. I ended up going home in the car and later in the night learned that it was actually a stomach bug. I vomited, and that sealed the diagnosis.
Both times my blood pressure went way down after eating large meals. You would think that blood pressure would go up under those circumstances, wouldn't you? I've always suspected the vagus nerve, but have never had confirmation of that involvement.
I never had the rapid heart rate you're describing, but I can tell you my "unwrapped" mother had the problem often enough to go to a heart specialist, who treated the rapid heartbeat with medication. They had difficulty getting it into control without fairly high doses, so implanted a pacemaker to pick up the slack.
Have you been to a heart specialist, or at least your PCP? My husband has atrial fibrillation, which causes his heart to race. He's on medication that keeps it in pretty good control. The heart doctor says it's not dangerous, but it is disconcerting, so he treats it with medication.
If you're suffering with this problem, you ought to get to your PCP and consider seeing a specialist as well. I don't think it is related to the surgery at all.
Nissen Fundoplication 2/09
"Whatever you fight, you strengthen, and what you resist, persists.”
“Worry pretends to be necessary but serves no useful purpose”
“Accept - then act. Whatever the present moment contains, accept it as if you had chosen it. Always work with it, not against it.”