Oh, yes. The good old stomach can and often does mimic heart problems. But make sure you've seen the cardiologist recently first, to make sure it's not really the heart. The bad aftertaste sounds like gastric reflux.
If you go to the GERD forum you can look up in the searchbox all sorts of posts like yours.
It's not always one or the other either. The stomach can trigger the heart and vice versa. I've long had a problem called cardioesophageal reflex (with an E), aka linked angina. When I eat a food trigger I get rapid heartbeats (tachycardia), usually preceeded by my stomach misbehaving.
To find out if you have food triggers, keep a food log/journal. Write down the time, what you eat or drink, and the reactions/symptoms after half an hour, 1 and 2 hours. When you get a list you have to break down the foods into ingredients. For me it wasn't the waffle, it was the maple syrup. Honey was OK. It wasn't the hamburger, it ws the condiments. It wasn't the oatmeal, it ws the brown sugar. I knew I had a problem with gelatin and pork, gravy and stews. I'd always hated onions. When I googled my food list and the words "food allergy" or "food intolerances" I found all my foods on a sulfite sensitivity/intolerance list. Other people may be sensitive to MSG or fruit or just about
anything. Start the journal!
Don't expect your doctors to have ever heard of cardioesophageal reflex or linked angina. My cardiologist and gastroenterologist don't believe me. (I couldn't posibly know anything because I'm an old woman, grandma, not an MD, although I do have a degree in Biology.) I started researching scientific papers when this gave me a heart attack in 2006. My heart attack had only a tiny bit of elevated enzymes. It was just a spasm of the LAD coronary artery, but wouldn't stop and needed a stent.