Thanks for writing your query.
It will be helpful if give more information on :-
1. Age of your wife
2. What she ate in dinner and in lunch on that day?
3. Any previous history of same pain?
4. Any history of abnormal blood pressure?
5. Any medication she is taking?
The pain you have described can be due to acidity or gas or it can have a cardiac origin.
You should take her to emergency department and get an ECG done and consult a cardiologist
For acidity and gas, you can give her Omeprazole
20 mg along with Domperidone
10 mg once a day after consulting with her doctor.
Avoid spicy and oily foods .
Also get her blood investigated for Lipid profile
I hope this is helpful to you.