My daughter is 6 years old. Sometimes she gets palpitations when she is not doing any activity while watching TV we even checked with the pediatric cardiologist and did the ECG and Echo test. The doctor did a thorough check and she said everything is normal no need to worry. But sometimes she gets palpitation or when she even runs little her heart beats increase. My daughter doesn't have much physical activity as there are no kids to play near our home. what could be the reason.