I, too, Have been down this road. My daughter was born with an extremely complex Congenital Heart Defect so we are all too familiar with getting echos. She has had 2 open heart surgeries, 3 caths and I believe her echo count is up to well over a dozen...and she is only 2!!!
My best advice...go to Target and get a Munchkin-brand sippy cup. (Get one that has a soft spout) Limit the food/ milk intake leading up to the echo...and then give him his milk during the procedure. If he isn't a big milk fan...give him juice. Yes, it's not the "best" thing to give...but if it keeps him still and quiet then it is completely worth it!!!
If you have a personal DVD player or an Mp3 player/ iPod that shows video it will be a great help!! Find a video that will keep his interest...baby einstein, elmo, barney...these worked well for us.
I am not sure what time your apointment is...but when our daughter was one her echos were usually mid-morning. We would wake her up extra early in the hopes that she might nap for the echo. The quietness of the echo room, the dim lights, and the white noise- type sound from the echo machine really relaxes her and she hets pretty sleepy everytime!!
The echo tech should be able to do the procedure with a *bit* of movement. I am hoping that the echo tech you are seeing works directly with a Pediatric Cardiologist...in which case they will be used to dealing with kids.
I will warn you...our echo tech (who is the best around...trained with the best at Children's Hospital in Milwaukee...) said that the one year echos are hard...they will get the pictures that they get and there may be a need for follow up!
If it makes you feel any better...easier echos are in sight. My little girl is 2 and very energetic and she will lie completely still for her echos now. It's a combo of bribery (suckers), distraction (seasame street) and a fascination with Jeff, the echo tech.
Best of luck!!! I hope that everything goes well.