I should note that if you have an elevated "sed rate" (ESR), you should get other, more specific tests as this is a very broad indication of something going on within your body.
I think the OP is referring to the erythrocyte sedimentation rate (ESR), also called a sedimentation rate. It is the rate at which red blood cells sediment in a period of one hour. It is a common hematology test, and is a non-specific measure of inflammation.
Unfortunately, you posted this in the Heart Rhythm Community. I can tell you that elevated ESR is found in instances of pregnancy, inflammation, anemia or rheumatoid arthritis, with lower readings found in polycythemia, sickle cell anemia, hereditary spherocytosis, and congestive heart failure.
I do not know what "ESR" is... suppose that means I don't have what you're looking for. Still, it may be something I and others would recognize if you spelled it our, maybe said something about any symptoms you feel, that sort of information.
I assume you do believe "ESR" is related to heart rhythm, or problems with heart rhythm. That's what we "do" here.
I have not done a search on "ESR", sorry if I should know given I have heart rhythm problems, but I don't.