You can make use of some software, it is useful if you can add multiple layer in to the graphic.
The lower layer store the background picture such as the wording;
You can add another layer, putting above the background layer, it is the part of the Heart Shape.
The Heart were consisted of six pictures, each of them had the extension of part of the heart;
By using the software that can combine several pictures into an "animated gif", it will be looked like an animation.
for example, suppose we have the 9 pictures below
[>]
[->]
[-->]
[--->]
[---->]
[------>]
[------->]
[-------->]
[--------->]
if we put them together, and out put to an animated gif, you will see an moving arrow from left to right.