I do not have SVT, but I get plenty of PVCs. Mine can be worsened by anxiety, excitement, adrenaline rushes, any kind of upset, vagus nerve irritation, GERD .... lots of possible reasons, lots of PVCs. although, the last few days have been better. but check with your doctor if your anxiety gets too bad. the best to you.
Anxiety and associated adrenaline can be a trigger for SVT. Body positional changes; twisting of the torso, bending over, etc. can I initiate an event. Caffeine and stimulents along wtih smoking at triggers too. PVC's occuring at the correct moment can initiate an event. 140 is on the low side of SVT with most of us in the range of 200 up to 260 or so.
There are others here with SVT, I'm sure they'll be able to help you out. It's usually considered benign, though like so many other benign heart rhythm anomalies, benign often terrorizes those of us with them despite the strongest reassurances by the doctor and others.
I'd have to guess that anxiety is can be a trigger, as well as stimulants, such as caffeine, cold and diet medications (prescription or over-the-counter), alcohol, and some prescription and illicit drugs. I have experienced PVCs for 40 years, the last thing I want to do is make them mad, I can't even smoke, eat chocolate, drink coffee, etc., I'd rather avoid the PVCs, compared to the anxiety I suffer over PVCs, I had no trouble giving up the those things.
If you're not sure if something is OK to eat or use, ask your Doctor or Pharmacist.