Re: What could this be?
Guessing VERY widely, this might be Gastritis. I had the same symptoms when it was climbing up in severity. Did he feel breathlessness too? This can accompany a gastritis attack. The issue is that most of these symptoms are sometimes similar to a heart condition but it has nothing to do with it. I don't mean to alarm you by saying this but it is hard to tell the difference between gastritis attacks and certain asthma conditions like wheezing (checking the lungs will reveal the truth) or heart attack pain. Did he have tingling in the arms? Dizziness?
I would get it checked out.