Thank you for your query,
The chest pain
in your child looks like some musculo skeletal pain related to muscle and ribs.
Pain will increase the heart rate
by the physiological changes of the body.
Give him rest and if there is significant pain you can give Tylenol or ibuprofen in prescribed dosage.
And you can apply an analgesic
cream or a spray.
If there is no relief, consult your Pediatrician
to examine and advise the treatment.
Hope I have answered your query.