Conversation: The conversation between human and AI assistant.
[|Human|] My 16 year old daughter, who is a competitive swimmer, started having a rapid heartbeat while working out. It happened about 4-5 times over the course of 2-3 weeks and now hasn t happened again for 3 weeks. All tests came back normal, except she is low on Vitamin D. Cardiologist wondered if she has/had SVT but she has been unable to capture the heart rate using a portable heart monitor since it usually only happens when she is swimming (she has to get out of pool, get monitor, etc and by that time heart rate seemed to have slowed down). Could this be caused by low Vitamin D? or a virus? She had complained about being really tired too but feels less tired now than she did a few weeks ago. Mono test came back negative too.
[|AI|]  Vit d deficiency is not directly associated with increased risk of SVT.there are meta analysis of its supplementation decreasing cardiovascular risk in elderly, but many have contrary results. Any myocarditis due to viral etiology can have this presentation, but your cardiologist seems to reliably rule out those. She may need holder monitoring to see for episodes and a loop recorder which may capture the rhythm during swimming which may give a better idea.