The heart "palpitations" may not be so benign as your cardiologist would think. I got them for years, starting in my 30s and eventually they led to a heart attack.
I would get a bubble of gas, I thought, caught in my stomach, and then the palps would start. Eventually I recognized them as tachycardia. I could get them stopped if I could get a burp up. It was a form of "valsalva maneuver" I know now. This went on for 20 years. I went through extensive testing and was pronounced "normal" for everything. I even had stress testing. A few months after that test i had the heart attack.
After that event I started keeping a food log because I noticed that my symptoms seemed to follow specific meals - like cereal for breakfast. I figured out that it might be an allergy and went to an allergist who told me to take my food list and to "challenge testing." After I got my list narrowed down (it wasn't the waffle, it was the maple sryup), I searched the internet for a connection and found my list on the sulfite allergy pages.
I don't get reflux symptoms or tachycardia as long as I steer clear of my food triggers.
I have since read a number of articles on cardioesophageal reflex, linked angina, and a new one that describes how esophageal spasms can trigger cardiac vasospasm leading to plaque rupture and heart attack.
My cardiologist believes me now, but my gastro doc doesn't. I'm no doctor, just a mom.