This is the pattern for the heart that I use in my profile image.
This heart pattern uses one shuttle only.
All rings have the stitch count of R(4-2-2-2-2-4) with joins made where indicated in the chart.
Ring with different stitch counts are numbered accordingly in the chart.
Reverse work to make the 8th ring.
The design would look better if you make this ring and the next seven rings in the reverse order double stitch (RODS), i.e making the second half of the double stitch first.
Also, I find that while making the ring with RODS, the closed rings look better if you drop the shuttle through the ring loop before closing it.
There is a single-shuttle split ring at the tip of the heart, shown in green in the chart above.
I don't have a link to any tutorial on single-shuttle split ring. The only one that I know was in Georgia Seitz's site and that is currently not available. But I will describe it as best as I can on how to make it in this pattern.
To make the single shuttle split ring.
Make one side of the ring as the normal ring. In this case R(4-2-2/..). Then close this ring but not fully. Leave about 2/3 (of the length of the other half of the ring) of the core thread exposed. Next, make the thrown ring at the tip of the heart R(2-2-2-2-2-2-2-2), closing it fully.
Now, to complete the other half of the split ring, use the method for making the double-stitches on a split chain. Here is the link to my tutorial for the Split Chain.