precedes heart attack
in about 16% of cases and is a fairly common phenomenon.
The chest pain
which your husband is having off and on could be due to the following reasons;
1- Local inflammatory injury
on the chest due to the shocks.
(This can be confirmed by pressing on the area of chest which has pain, if doing so increases the pain, it means that the chest pain is due to the shocks delivered).
2- The chest pain could be due to Post Heart Attack Angina (simply means progression of disease).
( This can be confirmed firstly, if the pain doesn't increase by applying local pressure, if the pain is associated with sinking of heart, cold sweating, radiation
of the chest pain to right arm, both arms, neck or jaw, OR if it is precipitated while walking, jogging, exertion and relieved by taking rest or by taking sublingual angised).
3- Sometimes the "feeling of gas in stomach" is another symptom of Angina.
If you have any queries further, do not hesitate to ask.