RVR stands for rapid ventricular rate, so all it means is your afib comes with a fast heart beat. That's extremely common and there's nothing particularly bad about it. It just means you're probably more symptomatic than someone without RVR. It also means you need to take rate control drugs such as atenolol and diltiazem.
The immediate treatment is keeping that rapid heart rate under control, and that's what the atenolol and diltiazem are for. Not sure why he switched you, but either drug should work. I'm sure he had you stop the atenolol before the Holter because he wanted to see your heart beat without having the rate suppressed. And yes, stopping the atenolol had a lot to do with your heart going crazy. You're probably in afib more often than you think, but the atenolol was keeping the rate down so you didn't experience many symptoms. Without it, you did.
You made no mention of an anticoagulant. Are you taking one? Whether or not you should be depends on your CHADS-Vasc score. You can calculate your score by clicking
here. The purpose of an anticoagulant is to prevent stroke, which is the primary danger of afib, and if your score is higher than 2, you probably should be taking one.
As long as your heart rate doesn't remain above 100 for prolonged periods of time and your stroke risk is controlled, there really aren't any other dangers to afib. People with afib live just as long as people without.
Unless you have other cardiology issues, there's really no reason to keep two cardiologists. We like to think of general cardiologists as the plumbers of the cardiology world and electrophysiologists (EPs) as the electricians. Afib is an electrical problem, not a plumbing problem, so you really only need an EP unless there's more going on.
As far as long-term treatment goes, you have four choices:
1. Drug therapy. This involves taking a daily antiarrhythmic drug, of which there are several, and probably also a rate control drug like diltiazem or atenolol (metoprolol is more common).
2. Ablation. Current guidelines state that ablation is the accepted front line therapy for most patients.
3. Maze procedure. This is a surgical procedure, so it involves a lot more risk and recovery time than an ablation, and it may also require an ablation anyway.
4. Do nothing. Just take a rate control drug and an anticoagulant and live with it for life.