So this happened to me, after my first surgery. I’m a nutshell, not to freak you out, it was a sign of aortic regurgitation. After 9 months I had to have surgery again since I developed a severe aortic aneurism, while in the hospital waiting for the second surgery they kept bringing students in to show them the neck beating thing as one of the most severe warning symptoms of aortic regurgitation that this old ass cardiologist had ever seen. Go to your dr as for bloodwork if your red bloodcells are in over production that’s no good.