The blood pressure should NOT be high - You have to follow it up and need treatment.
Considering you are young, you need extensive investigations to find a cause - a treatable cause in particular - the chances of finding one may not be high, bit it is worth it.
A normal ECHOcardiogram
(one of those machine) and blood test
What was the ECG finding? Did they do one after exercise or 24-hour monitoring?
Atypical pain and relation to food suggest stomach and/or food pipe - an upper GI Endoscopy
(a small tube put through the mouth to see the stomach) can shed some light.
Avoid fatty or junk food - even if they are not causing anything obvious at the moment, in the long run, they rise the cholesterol
and block the blood vessels.
Follow up with your Internist or Cardiologist