hypnoctopus

So I had Clover, my small 2019 female corn snake out for some handling two days ago. While holding her, I noticed a marking on her lower neck that resembled the 'belly button' scar that snakes have on their belly, like a line. After looking at it more closely, I noticed there was also a slight bulge in that area and I could actually see her heart beating. Today I thought I would do a little test and compare her heart rate to my other snakes' heart rates and see if hers was higher than average. Her heart rate could easily be felt and it ended up being 76 bpm. However, I tried to get the heart rate on literally every other snake I own and could not feel any of them. So now I have nothing to compare to. Does anyone know what the average heart rate for corn snakes is? I imagine it might be affected by things like size/age, maybe gender, or stress. I have no other reason to be concerned about her. She has always been a fantastic eater, has regular good sheds, normal corn snake behavior. And when I took her out for feeding today, I could no longer see a bulge in her heart. She did recently develop follicles, but reabsorbed them. Nothing else in her environment has changed. Any insight is welcome!