I don't believe a pacemaker is used to control AFib. Perhaps your father has other heart problems. The most common use for a pacemaker is to keep the heart from beating too slow, or stopping. Some times a PM is used when the heart electrical system has to be totally shut down, in which case there would be no AFib or other arrhythmia, but this is not done to my knowledge, to control AFib.
My cardio turn off the AF suppression for me when my A-Fib occured. Originally, this pacemaker is a security/insurance for in case one day I got AF. Sound not match what he did and implanted that pacemaker.
Now this pacer uses to pace out any AF occures (pace Atrial and sense Ventricle - DDDR mode). If one day it is not successful then he'll change to VVIR mode (permanently paces Ventricle) and totally ignore the Atrial. Will leave my Atrial fib to dead! Permanently paces Ventricle is not a good choice. It can cause heart failure. I don't understand the pacemaker therapy for AF.............. What's good?