Extra systollis and heart block

last year i had a pacemaker (set at 60bpm)  fitted after i was diagnosed with 2nd degree heart block. the heart block doesnt appear to be happening any more during regular ecg tests.  
I have suffered from extra systollis for 30 year or more.  Recently a few times when having exercise my heart rate dropped from the 120-130 range to about 75 and stayed there, but very strong beats. My bp was 125-70 when this happened. I feel that my heart electrics are beginning to fail.
In addition my pacemaker seems to jump in when my systollis happns and then my heart seems to beat very irregularly. Its very annoying
Any comments or similarities?

[Jerry_NJ]

Do I read correctly that your HR drops when you begin to exercise?  120 at rest, 75 when exercising?  This seems very strange, but if true I have no comment/experience.

There are several members of this Community on pacemakers, perhaps one will yet be able to relate to your post.

[kpitts]

My normal heart beat is 72, when i do aerobic exercise i get it up to 130 but twice during the exercise and aftere approximately 25 minutes it had suddenly dropped from the 130 to about 75, quite regular though at 75, it happened once whilst bending and once doing crunches. Pacemaker is set at 60 so thats not in play. Both times i have stopped the exercise and gone into cool down mode.