“What could cause a fast heartbeat in a child?”

Great question and an important one. First and foremost, anytime the rapid heart beat occurs Acutely along with difficulty breathing, disturbing color changes And altered alertness, this is a true medical emergency and should be treated as such. assuming that this observation is non acute but is one that is still Recurrent it should be investigated. It is a relatively common occurrence in kids. some non cardiac conditions that may increase heart rate are things like fever, exercise, dehydration and maybe a benign condition called POTS which happens when the heart rate increases when the child goes from sitting or lying down to standing. in any case assuming that the rapid heart beat is not an emergency, the child should certainly be seen by his or her regular pediatrician have a relatively extensive physical exam and tests like an EKG, Maybe a chest X-ray, some laboratory tests like electrolytes and Thyroid levels. this kind of attention will most likely result in Deciding if the episodes of tachycardia range from benign Childhood sinus tachycardia to more serious diagnoses.