@gloaming I had ventricular Tachycardia and had a pacemaker with a difibulator. My main problem was a rapid heartbeat which would go up to 220 at times. I was commenting on your statement that pacemakers were primary to speed increase a slow heart rate. So I was trying to explain that pacemakers are also used to correct a fast heart rate. When my heart would go up over say 160 and above my pacemaker would actually speed up my heart even more to bring it back into regular rhythm so I wanted to let you know its not only for bradycardia but also used for Tachycardia .
'Yes I know if they use a pacemaker to eliminate the AV node then its doing all the pacing but my AV node was intact. So Pacemakers can also treat a fast heartbeat using a technique to kind of reset it by forcing it higher. Strange I know, but it works. now in my case it would attempt these a few times and if it did not slow the heart down I would receive a shock.