There are two different users on here I remember seeing in the past 2 months who personally had accidentally shot into a vein and they both described the experience. Chest pain, trouble breathing, incapacitated for 20-30 minutes. After that they were fine, they both said that breathing really deep would hurt for a day or so afterwards, but besides that they recovered. Both of them had the same account. This wasn't a "street myth," this was a real-life account. I'm not saying it'll kill you. But from all counts that I've heard, it was a lot more than some "dizziness." I don't deny your heart is a powerful beast, but it's really not used to having oil hitting it, especially in a higher quantity (I'm assuming OP was injecting a full ml). Also, I hate to be that guys, but I would certainly say that long-term risks of viscous oils hitting your heart could very well exist.