sounds more like your heart dont like the zantac.
i too have reflux quite often,eat pepcid,and never had an issue with palp with the reflux.
i do get palps though too,,,now wether that in itself is related i cannot say,but one thing i can say is we both get palps,and we both have reflux.,,i just cannot link mine with each other.
I get heart palpitations when my GERD acts up. I was able to stop taking the reflux medications altogether when I changed my diet for the better. It turned out that I have a laundry list of food sensitivities. Here are the ones that bother my gastro issues the most (some of them might be the same for you): Dairy (lactose), gluten (especially wheat), corn (closely tied to gluten and lactose intolerance), and the entire nightshade family. Also, no foods with any form of sugar (natural or otherwise), which includes all fruits 'til you determine which ones bother you the most--citrus is the worst culprit for me. Bananas are a close second, but they bother the intestines more than the reflux.
Another big one for me is psyllium fiber, which aggravates my GERD like no one's business. I started using flaxseed meal and no longer have to deal with this issue. It's just a different kind of fiber that seems to be gentler on the system. The naturopath suggested it, and it does work without aggravating the GERD. Apparently, psyllium bothers a lot of other people, so it's like a food sensitivity, too.
My heart simply doesn't like the whole GERD thing. Sure, I still get some occasional palpitations, but they're caused by something else. I was in the e.r. with the palpitations connected to the GERD, so I know what I'm talking about. Maalox with some kind of numbing medicine is what they used. I still get some occasional GERD, too, but I usually know it's caused by some kind of food issue I haven't quite got figured out. But, I was able to get off of those dangerous reflux medications. AND, I ended up losing the weight that just didn't want to come off before.
Other things that you might not associate with foods that are problems for both me and many others: Coffee, real tea (black, green and white are all from the same plant), fruit juices (especially citrus), milk, soy milk, certain herbal teas (not all, thank goodness), ALL soda pops and other beverages sold near the soda pop (The majority of them contain high fructose corn syrup which is bad on all fronts for me since it's made from corn and I can't handle corn. I also can't handle any form of sugar).
I think it's worth getting so strict with the diet, since I lost most of the weight I needed to lose and feel a lot better overall because of that. I only get occasional PVC's (palpitations) now. I try not to panic, because I know that the medical establishment can't measure the kind that I get and I've learned that they'll go away almost as suddenly as they appear. I found out they're called PVC's and are probably benign in my case. But, I'm not getting the kind associated with GERD anymore, so I do know what you're talking about.
I think you'll find that it's worth checking out food sensitivities for yourself. There is a right way and a wrong way to do it. The best way is to find a naturopath or a nutritionist who can help you figure out an elimination diet food challenge. The basic overview is to avoid everything on the list they hand to you for a minimum of two weeks. This is when you find out that even though it seems hard at first that you can find foods that don't contain wheat and other glutens in them. Most people are sensitive to wheat in particular, which is why it's on the list. The naturopath or the nutritionist will help explain the process to you in a way that you can understand. The only one who you have to answer to is yourself and how your own body feels with each of the foods on the list. Not all nightshade family is on the list I was given, but it was clear that all nightshades bother my GERD or cause me joint and muscle pain, so the naturopath nixed all the nightshades, too. Too bad, because I was starting to really like eggplant, now that I know how to cook it correctly. I knew she was right, though, because I knew that peppers and tomatoes irritated my GERD.
Give it a try. With the right guidance, you can be free of the GERD and the palpitations that come with the GERD or the medications for GERD. My brother has similar food issues, he found out, so now he feels better with his GERD, too. I don't think he has as many food sensitivities as I do, but he has found out that most of the people in his immediate family have some of the same issues with the biggest items on the elimination diet list.
I can relate to your condition very much. I've had recurrent GERD before, but not the SVT. Last year, after several years, I was confined in the hospital for SVT, with accompanying LBP (low blood pressure of, sometimes, 70/50).
I noticed that my palpitations come from the area below my sternum, at the time my stomach is bloated (usually when I had a heavy meal), or when I am tense, subjected to heat or cold extremes. When I try to avoid the above conditions, or when I change position, I usually skip the SVT.
The doctors seem not to be listening when I tell them that my SVT gets triggered by the aforesaid factors, except one who was sympathetic with my situation.
Thanks for your time.