Hi,
I'm a Scoundrel, but I get it fairly consistently now. I'm in near full champ.
The key stat is surge. You obviously need a big crit for this.
I pop either a 15% pvp adrenal, or a 440 surge adrenal, and my 220 crit/surge relic then start using my big heal. If I'm healing myself, then I'll also pop defense screen which gives me 15% more healing to self when talented.
I get around 6200 usually when I crit.