Anxiety and pacemaker settings

My mother-in-law is 71 and a three time pacemaker patient.  She is a very stressful person and is always worrying about everything and everybody. All of her CAT scans and lab work look very good.  After her second and now third pacemaker replacement she will have any or all of the following;
  feel weak
   anxious
    slurred speech
     faint
      headaches
       spurts of increased energy
        Heart rate changes that she can feel

She is always going back to her pacemaker/Heart doctor at Loma Linda to have them change the settings.  They change her setting back to one that she will tell them was better. They will make the change and for a short period she will usually feel better.  They have put on heart monitors to look for problems with her heart and the pacemaker.

Her last pacemaker wore out after about 2-3 years.

Can anxiety or worrying cause her to have something that might be causing these symptoms and not be related to the pacemaker?