I honestly don't know and since it came and left before the doctors could see it on ECG, it would be guess work. From my own experience with a lifetime of arrhythmias, I know sometimes eating too fast or trying to swallow too large a bite can stimulate the vagus nerve and upset the heart rhythm for a bit. The nerve apparently runs very close to the esophagus. Some people have trouble with swallowing and rhythm problems quite often. I've only had it happen rarely.
I'm sure it was scary and very uncomfortable but I'm glad it set itself right. Let's hope it doesn't happen again.