Almost 2 weeks ago I had a bad case of diarrhea, followed a few hours later by bad tachycardia (168) for 5 hours. I thought the whole works was brought on by eating a pudding that had a sulfited flavoring (allergy to sulfites). I couldn't get it stopped with the usual Valsalva and cough execises, so I had to go to the ER, where they hit me with adenosine to reset the heart.
Several hours later I started having severe belly pain - right side, and I have no appendix. Back to the ER for admission. Doc wanted to remove my sigmoid colon and leave me with a stoma. I said no! So I spent a week and a half
with IV antibiotics and a drain tube. Better than months of recovery from surgery.
The point is that the heart problem may have been caused, at least in part, by the abscessed diverticulum, which may have perforated, as there was some peritonitis and air under diaphragm.
I 've had a heart attack brought on by eating sulfited food. It started as gastric reflux, which often has triggered tachycardia for me. That time I had some coronary vasospasm which caused a plaque rupture, occluding the LAD 95%. It's called cardio-esophageal reflex. I had no idea the other end of the gut could also cause this problem.