Left atrial size - does it matter? How much?

I have been doing a deep dive into left atrial size in relation to afib and how it affects the ablation procedure itself and the outcome. I have learned a few things since and wanted to hear what others have read or experienced.
I have had annual echos for a good 30 years or so and my understanding is that at one time having a severely enlarged left atrium did not bode well for a successful ablation. I just looked at my numbers and the first thing I noticed was that it was measured in terms of volume, not diameter. It seems that volume (LA volume indexed to body surface area) is a far more accurate metric.
I also learned that years ago EPs were less likely to ablate on severely enlarged atriums - was it because it was more complex or resulted in lower success rates? or both?
Also it seems that afib itself can cause the left atrium to enlarge so wouldnt an enlarged atrium be a given for most patients? that would rule almost everybody out at one time.
I found this useful chart and some commentary on Steve Ryan's website:
Left atrial chart
Mary

Thanks for posting this. My understanding is that the enlargement, which can be mildly reversed (not in all patients) over time if ablated successfully, leads to fibrosis and mitral valve prolapse, or compromise of function, both of which greatly complicate, or in some cases preclude, ablation.

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gloaming
Thanks for posting this. My understanding is that the enlargement, which can be mildly reversed (not in all patients) over time if ablated successfully, leads to fibrosis and mitral valve prolapse, or compromise of function, both of which greatly complicate, or in some cases preclude, ablation.

This is my experience: before my ablation with Dr. Natale he told me to get my severe mitral valve regurgitation repaired. I did so and the ablation went ahead without problems. I am hoping that my left atrial size will diminish with time now, though it is only mildly dilated. I don’t know whether the dilation exacerbated the mitral valve problem or perhaps vice versa. It does seem that untreated a fib will cause increased dilation.

I agree that the dilation can reversed but in my case it was quite substantial.I had mitral stenosis so over time that together with afib dilated my left atrium from about 70 ml to 111 ml (normal female atrium tops out at 52) . I had multiple valve replacements in 2016 and in 5 years it was actually in the normal range (35 ml). since then it has fluctuated between normal and moderate. Not sure what to make of that.
Daisy, I always thought that my valve problems led to the dilation but I could be wrong! Will try and get some answers from my cardiologist when I see her tmr.

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NoTrigger
Daisy, I always thought that my valve problems led to the dilation but I could be wrong! Will try and get some answers from my cardiologist when I see her tmr.

It is hard to say though in my case, I developed Afib in 2010 and at that time my mitral valve only was mildly prolapsed with mild regurgitation, so it could well be that Afib was more responsible for the dilation than the mitral valve problem.

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NoTrigger
... since then it has fluctuated between normal and moderate. Not sure what to make of that.
...

It is almost certain to be operator error', or the typical variability from assessor to assessor. In Industrial/Organization Psychology, the field in which I worked, we call it 'interrater reliability'. Not only are there different instruments, which have to be calibrated now and then, but the operators are not the same people, and those reading the results are not always the same people, same training, same overseeing, etc.

Just started researching this after realizing that my pre-ablation echo showed increased left atrial pressure. (No one ever mentioned that).

[pubmed.ncbi.nlm.nih.gov]

This is a good read!

Megan - that is indeed interesting except that I did not find any references to left atrial pressure or measures of LAP anywhere on all my echo reports. A little frustrating. I do see PASP (is that the same?). Further research revealed that LAP is a calculated measure, perhaps that's why. There is a whole bunch of acronyms in the measurements area of the report: LVEDVI, SVESVI, LA A/P, RVOT VTI, etc.
My cardiologist did comment that pressure was about the same as last year but I have no idea what number she was referring to after I scoured the report later. I asked about the left atrial volume and she thought that there might have been a measurement error and would get back to me after measuring it again. I don't think she would have said anything if I hadn't brought it up. That is a little troubling - one wonders how many "measurement errors" there are in my reports.

I find all of it frustrating. I have had a handful of echos, and only the echo that I had at a different facility went into detail on the left atrial pressure. So I do not know if it was a result of the chronic AVT, or if it had been there previously. But that is scary, because the other echo's didn't mention it or pick up on it, and that is a definite indicator of heading towards potential tachycardia induced cardiomyopathy. It was described on my echo under hemodynamics, "Systolic flow blunting noted in pulmonary veins consistent with elevated left
atrial pressure.". But this was the only echo that discussed hemodynamics. I will plan to have future echos there as well, because obviously they are doing a better job. However, my old EP didn't catch it or discuss it.

I feel that we have to be so vigilant.....