I work in Cardiology as a Cardiac Physiologist specialising in Pacing.
Your Cardiologist suggested a Pacemaker, if you do go down that route, they are amazing..there are several types depends on your clinical needs.
The modern ones are Bluetooth so they can be monitored from home. Last about 15 years depending on how much demand it needs. Only takes about half a day in hospital.
Can I suggest you look up Pacing on British Heart foundation Web site where they have lots of information, and explains everything.
You have nothing to be concerned about, only very few people have problems but it tends to be more a medication issue, or just after implant but picked up and sorted. You will hear horror stories from folk but the vast majority are all happy.
I would never hesitate in having one.
Good luck and keep safe