Heart Clinic

Hospital ABC in Mexico City is amazing (certified by he Joint Commission, if that helps).

They have a cardiac clinic: https://centromedicoabc.com/en/cardiovascular-center/

I do not have a specific doctor to recommend, but hands down the ABC is the best.

The other private hospital certified by the Joint Commission is Médica Sur: https://medicasurmexico.com/en/cardiology-center.html

Good luck!