3D bio printing has come a long way and printing a simple single direction pumping 2 chamber heart Like a fishes is definitely possible within 5 years. Provided these hearts functioned well, implanting said hearts into my veins should increase my vo2 max and add a redundancy factor. Even if the primary heart failed as well as 2 of the smaller ones, a single small heart should keep me “alive” (not moving or conscious) long enough for me to be resuscitated. Seems like an absolute win to me?