How big a plot point was Tony Stark's injured heart in the first few years of if Stark has problems in Europe (or is the Iron Man suit universal). I notice that at few times the writer is confusing what the armour actually does. The movie doesn't really explain how the device works or where it attaches. However, the movie tells us the device is to keep metal fragments from. Since his first appearance in the '60s, Iron Man has gone through a huge a device in his chest to keep the shrapnel in his body out of his heart. . any power source would do the same (but wouldn't be nearly as cool!).