Don't wear your heart on your sleeve, hang it on the wall. I took emmett's exploitable heart and exploited it by slicing it in half and boolean punching a screw hanger and an LED holder into the back. Et voila! A heart which hangs on the wall and glows.
It hangs by itself with no visible hardware. If you want to make it glow you will need a 2032 battery and a standard 5 mm (T-1 3/4) LED. Red filament with a red LED is the usual choice, but a blinking red LED is even better. But you can make any combination your sick little heart desires. Try yellow glow in the dark fillament with a UV LED for a special alien glow heart. If you make one now it will still be glowing strong on Valentines day.