I know a retired professor who only found out his heart had been in flutter for an unknown length of time when he went in for something unrelated to his heart. He had been an active hiker, kayaker, and cyclist, both he and his wife.

When I had my second bout of atrial fibrillation, around six or seven weeks after the first, and had gone to the ER on both occasions because it was symptomatic and obvious, and because it was novel and frightening, I couldn't get my breath. Only that one time. On all other occasions of entering AF, they being many over the next four years, I never felt breathless. Just the thumping and heaving in my left chest wall.

I agree with you, for what it's worth, that you are unlikely to have a heart problem THAT CAUSES YOU TO FALL OR TO FAINT. I'm going by what you have revealed. You lose your balance, you're not faint, you are conscious of the fall, and you don't faint upon impact with the floor. You just fall. That's not your heart.
However, I have not seen your Holter Monitor or an EKG that might show a problem with your heart. That may still be a concern for your cardiologist. I don't see it, but he/she might. You need to pin this suggestion down, that you need a pacemaker.

I don't know squat about Meniere's, but I do know of it. That expert should know of literature that describes any relationship Meniere's might have with sudden falls. Whatever he/she suggests is what I would try. Loooonnnggg before a pacemaker.