<s>[INST] I just had a nephrectomy, six weeks ago, never had heart problems that I am aware of. Inmediatly after surgery developed tachycardia, my restin g heart rate is on the mid 90s... every time I move, standup,lay down, or do minimum exertion my heart goes up...my hemoglobin is normal. could there be a relationship between kidney/ heart? [/INST] Hello I have gone through your question.Thanks for using HCM.Actually normal heart rate fluctuates between 60 to 100 per minute.so 90 is not abnormal .usually in postoperative mild pain and weakness push up the heart rate .since it is less than 100 you need not worry at all and it does not need any treatment.My best wishedDr.Teli,MD </s>