Hello
Sudden wake up after 1-2 hours after sleep , with clammy , rigid , fast heart beat , all these symptoms may be due to , these includes .
1 Hyper acidity or
gastritis , due to over eating or due to un adjustable food , so following measures will help.
Try raising the head of your daughter about 4 inches with blocks.It also might help to avoid EATING or Drinking for 2 hours before she lie down.To help control stomach acid one should not drink with caffeine in them or eat chocolates or spicy or greasy foods . Also take some
antacid but if symptoms are sever she may need drugs like
proton pump inhibitors like pantoloc -D one or twice in day till complete cure.
The 2nd reason of such symptoms may be
anxiety or tension or fear ( of any thing ) , so , if think such things please
consult psychiatrist and get his help.
In my opinion all these symptoms are due to over eating or due to as above mentioned . Rapid heart beat , clammy , rigidity are due to hyper acidity .
But just for precaution get in an E K G and consult a physician .
Good luck.