An appointment with the cardiologist sounds like a very good idea. Pacemaker syndrome does not typically cause disorientation, but it does cause fatigue, dizziness and lightheadedness. I am not sure that a 24 EKG will help, but it can't hurt. The pacemaker itself holds information about the amount of time he is paced. Sinus node dysfunction with a working pacemaker would not cause these symptoms. I agree that an appointment with your cardiologist is a very good idea.
I hope this helps Gina.