frequent svt episodes despite etoprolol

Sadly, your story is not uncommon. I share the same history. As they doped me up with increased dosages of metoprolol, I would often find myself in bradycardia when my heart was behaving because of that heavy dose. And, like you, the events happened with increased frequency. My heart rate was often nearer 180, and it once went all the way up to 300 BPM.
When I learned that electrophysiologists perform catheter ablations to stop the signals from making the heart beat erratically, it was all I wanted. Since then, the EP faculty have decided that catheter ablation is the gold standard of care for patients who have AF. My first ablation was not successful. I was in the sad 25% of ablations that are not successful. The EP agreed to try again, and this time it worked. Note that if 25% of index ablations (first time ablations) are unsuccessful, it means about 75% of all ablations ARE successful. And the rate rises for second and third attempts. So, if you are highly symptomatic, or if you're just worried silly and anxious, and don't want to live with this slow deterioration, seek out a highly accomplished electrophysiologist and get a consultation.

Very helpful. I am likely to proceed with ablation but earliest appointment I could get with my cardiologist at Northwestern was beginning of October. (Waitlisted for earlier time.)
Many thanks for sharing your experience.