Tachycardia & Sleeplessness

My two year old daughter had been diagnosed with supra ventricular tachycardia when only a couple of months old. She was on medication for over a year. Within the last year her medication was discontinued. Within the last 2 weeks she had 2 nights where she did not fall asleep until 5-6am the following morning. She was crying and was only consolable if lying with myself. I stayed up with, waiting for her to fall asleep - but she stayed awake and tossed and turned all night.

Could this be a indication that she was another having a tachycaria episode?