Many people have a pulse rate of 58 beats each minute, and no symptoms such as dizziness, weariness, and pain in the chest area may be seen in them, which is considered normal. It is good for her to have a steady pulse rate. The change in the pulse rate is not caused directly by the operation at present but it is necessary to check it frequently. If she feels okay and does not have any other problems, then she should be fine in general. You should always see a cardiologist if there are any worrying symptoms or developments.