A Pilot for a U.S. airline

You are a pilot for a U.S. airline, flying international routes. On a layover in a third-world country, you experience crushing chest pain and become violently ill. You are taken to a crude local medical clinic, where the doctor tells you that you suffered a heart attack. The next morning,
you feel fine, so you are convinced the doctor’s diagnosis was in error. The doctor, however,
adamantly stands by his diagnosis.

a. Is it legal for you to act as a pilot or other required flight crew member on the return flight
to the U.S.? Why?

b. Are you required to report this event and diagnosis to the FAA? If so, to whom and when?