We still don't know what is causing this

Emily still has a very rapid pulse. I've been purposely not reporting the numbers on the blog because they are scary. Her heart was in the 160's when she was admitted to the hospital. When they let her out it was 140. Last night and this morning at remained at 132. We were hoping it had slowed down but I asked Tracy to take her pulse and it's still really high. Today marks a week that her heart has been working really hard. Emily also had another low grade fever last night, with one reading above 100.4. Something is wrong, for her heart to be beating that fast and for fevers to be on and off. I can't stand not knowing what is up and have asked her to have Emily seen today. The doctors still may not be able to figure it out, but I want to make sure they know it is still going on.