I'm a bit of a craft person so of course I LIVE on Pinterest and image my utter surprise and 'OMG why didn't I think to look for these before' moment when this popped up:
I asked the Lego king of the house if we had the parts to make this and just by looking at the finished image he was able to tell me exactly what pieces we needed, how many and if we could do it! (Now, what I am tempted to write is all 3 of us rummaged in the box, got the pieces out and made the heart.... What happened was) Mummy and daddy got the pieces together and junior kept taking them for his 'Wreck Ralph' house.......
After having a rummage it became quite clear we didn't have enough of 1 colour so we had a white edge to ours, but I'd have been happy with a rainbow heart too.
Here are the official tiles to use, but like 'us' (Lego King) I'm sure you can use a variation to make your heart.
Do let me know if you try this too or leave me a link to your creations.