ok just got something interesting, Lukas the Trickster blood claw of the space wolves have replaced his... well ill just quote it:
Lukas had his Secondary Heart torn out by the Dark Eldar Prince Sliscus, an encounter he now laughs about, though it would have easily killed a lesser warrior. In its place he had a Stasis Grenade fitted. Should an enemy ever best him, Lukas is determined to have the last laugh.
and my question is, does this not affect him to have 1 heart instead of 2? i have my heart issues and i know everyone who have heart problems get affected somehow, and 50% of normall heart capacity cant be good for anyone. yes i know he is a space marine and super genes and everything, but still 50% is alot! any thoughts?