P.s., since they said the issue is with the top part of his heart this probably means they aren't seeing any P waves which implicates the Sinus node. The 30 bpm is probably something called "escape rhythm". The ventricles start to beat on their own if the sinus node beat doesn't arrive in time. It's a backup system, but escape rhythm is much slower than the heart's normal pacemaker the sinus node.
The only way I'm aware to fix a low heart beat is with a pacemaker. That is, if the low heart rate is symptomatic like your son's. If it's not symptomatic, if it were me, I'd just leave it alone. It sounds like he might have "sick sinus syndrome", which if bad enough he would benefit from a pacemaker.
We are not doctors here and are not medically trained to give such advice but it sounds to me like he needs it. There is some sort of issue in the atria blocking the signal or slowing it down enough that he is passing out and that isn't good. Passing out is dangerous so a pacemaker seems like the logical choice in this instance. If you are unsure and this something that happens seldom, meaning it comes and goes, you can go seek a second opinion but a rate in the 30s is super low and most doctors try to avoid pacemaker implantation unless they feel it is absolutely necessary so it seems like a wise choice but get a second opinion if you want peace of mind. I hope your son feels better soon.