I was trying the heart out using white yarn just because I happened to have some on the table. I normally like more colourful things but I like the white heart too!
Here is a chart for crocheting the heart. A few times I have used Photoshop or Illustrator for making charts but it is far too slow! This I just drew with a pencil!
So you start in the middle by chaining 5. I marked the starts of rows on yellow pen.
This is how to make the group of raised trebles: