Slight dizziness

Hi
Recently had a two chamber pacemaker Medtronic Azure sure scan for a low heart rate.
I also have persistent AFIB.
Was getting dizziness that almost felt like I'd pass out before surgery.
Since surgery it's better but still have some light dizziness nothing like before but still just don't feel right. Usually when I get up or light exercise.
Have lowered BP medicine BP is excellent.
Have a stress test coming up soon.
Was wondering has anyone experienced this? Any possible suggestions of why this is happening.
Thanks