Hi, thank you for approaching. Currently your mother s blood pressure and heart rate are still withing the normal range but on the lower end of it. Typically pacemakers are implanted because of either low or irregular heart rate, and they frequently require adjustment of their rate after the initial implantation. The purpose of the medication she receives is to slow down the natural heart rate. The best thing to do right now if your mother is presenting symptoms of tiredness and lightheartedness is to interrogate the pacemaker and see whether increasing the pacing rate has any beneficial influence of her. I would attempt not to change the medication dose right now, since i do not know why is she receiving the metoprolol.