My daughter was feeling dizzy last night and now is complaining about a pain over her heart. she's 6 years old?

Evaluation : Provide fluids, check her temperature and treat fever. If she is not otherwise I’ll, cardiac arrhythmia may be considered as a possible cause.

Reason for exam...: There are more questions than answers that come to mind given the brief question you have asked, which is always a good indicator that it would be advisable for you to seek an evaluation with your daughter's pediatrician so there can be a complete history and physical done to determine the cause of the symptoms. If she is having any trouble breathing or significant symptoms, go to ER.