Premature Ventricular Contractions...you get extra, out-of-timing beats in your ventricles. Many EPs don't want to tackle these, maybe because their records of success are poor and not improving. Better to not do the procedure if it stands a poor chance of success. Some, comparatively few, of the best EPs can fix these and do it routinely.

Left Bundle Branch Block, meaning the left ventricle's descending branch from the Bundle of His is not working properly, so you get an abnormal heart rhythm. It's not generally serious as many live with it....untreated. However, if it happens to be coincident with another potentially serious problem, it should be taken as a serious matter needing treatment. In your case, it may be that your PVCs are a sign that you need mechanical intervention if anti-arrhythmic drugs are not likely to work or are not indicated in the literature. It may mean a catheter ablation for you in the weeks/months ahead.

I had to google hypermobile interatrial septum. It's the thin wall between the two top chambers of the heart that keeps the two upper pumps closed off from one another and working to force blood through the valves below them. You don't want leaky pumps! In this case, hypermobility means that the septum wall itself moves more than it ought to, maybe because of a genetic abnormality or a random defect that has, with age, begun to be more problematic, or possibly so. It's good they detected it early. I'm sure it can be fixed, but maybe open-hart might be needed for that...again, I don't know.

That these conditions are known is a good sign your team is getting things right for your sake. It won't be fun waiting for your turn to have them addressed, but I think they're all manageable.