The exception is when you're below zero HP; in that instance any effect that lets you spend a healing surge will give you a single hit point if you have no healing surges remaining.
Best way to do it is to be a half-elf, take Eldritch Strike as your dilettante power, and base it off CON, then grab Versatile Master at Paragon. If you can manage to swing Lightning damage, you also take Lyrandar Wind-rider as your PP. And Quickened Spellcasting at Epic.
But you should be...