Atrial tachycardia

I am in my 70's as well and have had infrequent tach episodes for over 20 years. Just had another echo and will see the cardio doc next week and will ask about diet causes. No one seems too excited about it. I did a literature search for "stevia root and heart issues" and it returned "no results." One citation: "This patient had no major risk factors for SVT development other than starting an intense weight-loss regime with a ketone-based weight-loss product a few days before the development of the tachyarrhythmia." The authors stated that there is nothing in the literature on this and they will continue to investigate. A broader search with "tachycardia and diet" returned nothing of interest either. Has your medical team mentioned "ablation"? Mine have but tachycardia episodes are so infrequent, I passed.

Suger ?

It is unlikely to be related to any of those, especially since your trials are mixed. It's something else setting off your heart. I don't know a lot about your heart's condition (I have atrial fibrillation in remission after two catheter ablations).
https://www.mayoclinic.org/diseases-conditions/atrial-tachycardia/symptoms-causes/syc-20573298
https://biologyinsights.com/what-is-the-most-common-cause-of-atrial-tachycardia/
Your heart is now disordered electrically. It has rogue signalling cells in your atria/atrium if only one of them. They fire when they get 'worked up' enough to do so. As the second citation above suggests, the signals have found a re-entrant path and move in a circle-back way to re-enter the atrium endothelium and cause it to beat. It's like double-tapping on a weapon's trigger. Two for the price of one, except that the double-taps keep repeating until the pathway polarizes differently (?) and that signal is broken. Until next time. Note that I am untrained and only know a fair bit about AF, not about SVT or AT. I'm just trying to paint a picture.

Stress is what sets off paroxysmal arrhythmias. It can be poor/lack of sleep, medications, financial woes or relationship problems, illness in others or in yourself, lack of exercise, too much/too intense exercise, dietary problems that might make your gut flora troubled, bowel cramps or gas, bloating, alcohol, non-prescription substances that alter mood or reality, perhaps even Vagus nerve tone. Eating too much at one sitting can cause distension which, in turn, can bring on AF or perhaps SVT/AT if it is the cause of discomfort (stress).

There is help, though. An electrophysiologist (EP) visit is ahead of you, maybe soon, maybe in a year's time, depending on how you respond to various suggested remedies or treatments.

I have Paraxsysmal Afib. After wearing a Holter Monitor for 2 weeks, Paraxsysmal Atrial Tachycardia was diagnosed but no Afib. Either can occur sporadically or not at all for awhile. Tried to get an appointment with Mayo Clinic in Jacksonville. This is the 2nd time I was advised that they are not taking new cardiology patients for my condition. They are booked 1 1/2 years out! So disappointing that having a world class facility in Florida means nothing if you can't get an appointment.

https://www.healthgrades.com/clinical-cardiac-electrophysiology-directory/fl-florida
I can't vouch for any of the above (I'm in British Columbia, Canada), but maybe there's something useful for you in there.

This arrhythmia situation is like detecting the source of some allergies. It takes diligence and patience. Keep tracking and eliminating. Do you wear a Fitbit? I look at my bpms multiple times a day and track when it becomes elevated. My main trigger is Gerd for an episode. Google your questions. It's very enlightening. I feel your frustration. Hang in there. These days, there are options for some relief. Text your medical team with concerns as well. Please keep us posted. : )

@d050526 Thanks for your kind reply. I don't own a fitbit but I am trying to track it.

Please keep us posted. One thing, you mention being scheduled for an electrocardiogram (that's the ECG/EKG you have already had) but I assume you mean an echocardiogram. An echo uses sound waves to visualize the workings of your heart and is very commonly done, take about 30 min. and also records an ECG at the same time. Ask the tech performing the test if they can position you to see the screen; I found it fascinating to watch.

Hi for me fitbit is the best

@d050526 how (when) does your GERD show up? I query me having it OR wonder if I am developing Pulmonary fibrosis due to my cough . Am on Amiodarone