on effort - in a setting of family history of heart problem and history of Bypass surgery
before 18 years - recurrence of the heart problem is the most likely diagnosis and must be excluded before considering any other possibility...That the symptom does not occur every time is a bit misleading - may mean added component of 'spasm'
Anybody can have belching
, but with the chest pain
, it may point to inferior wall ischemia
(lower wall of heart and generally the right artery)
You should see your cardiologist and get investigated - at the earliest