Check with your doctor first, if nothing is wrong. Maybe from too much sugar and fruit.
In Summer, more people get heart uncomfortable, in some cases when getting an abdominal massage or acupuncture for digestion, they feel better.
When sweaty, the body needs quick energy sources like glucose, so you may feel want to eat something sweet.
But we are not in a tropical area, always some chill wind under the tree, also a lot of A/C, Making the sweaty sudden stop, then the sugar stop digestion in the stomach or intestines. And start to bloat, we have limited space in the gut, so you feel your heart being pressed.
There are a famous routine 3 acupuncture points for heart problems, one for the stomach, one for the small intestine, is that interesting?