14 year old female athlete with exertional tachycardia (>200 bpm) during exercise

[djmodracek]

My 14 y/o daughter is very athletic and plays multiple sports. Recently her club soccer team began utilizing exercise monitors to gauge each athletes exercise parameters (HR, %max HR, etc). After a few practices we noticed a trend where her HR would increase up above 200 bpm (100% max) during exertion, then slowly come back down to a reasonable rate when recovering.  She states she is assymptomatic.  Her resting HR is usually 60-70. This has occurred during practices, training runs, etc.  We were alittle concerned about this so we started a basic work up. Physical exam is unremarkable without any murmurs or pathological heart sounds. She was mildly iron deficient, but not anemic. Remainder of lab work was WNL. Her EKG did show an incomplete RBBB, but no evidence of LVH or other abnormalities. Our next step is gonna be a pediatric cardiology referral where I’m sure she’ll need to get an Echo. I just wanted to reach out to this community to see how concerned we should be with all of this. She is currently training with her HS team and her pediatrician doesn’t want to limit her at this point.  Thx so much for your help.