I would add that it looks like you may have started out a little too hard going by the way you heart rate goes pretty high in the first mile, then drops somewhat before heading back up.
Here's my first and only time trial. I made a point to throttle back at the beginning. There was a huge tail wind on the backstretch and opposing headwind at the front stretch. Looking at the HR chart you can sort of see what bwunger is refering to about going harder on the hill(or headwind).
