MI Remodeling Timeline and Echo EF variance

66 year old male, fairly athletic, good lipids now and all biomarkers.

Broadly asymptomatic even when exercising, now 10 months past original MI, exercise very day, went through cardiac rehab.

I had an MI in the LCX between OM1 and OM2 10 months ago, did not act upon the symptoms quickly at the time since it was not very painful, so very likely to have dead myocardial tissue corresponding to a 12K tropinin level in the ER.

Over the past 10 months, I have had maybe 6 episodes of AFib, some of short durations (2 hours) and others longer (10 days) that self terminate. Typical not runaway at around 85 bpm.

In the interest of determining if perhaps post MI remodeling, I got another echo done at the 10 months point to compare to the echo 20 days after the original MI. The goal was to determine if left ventricle damage due to scar tissue and less contractility, was causing upstream left atrium dilation -- which can be source of AFib.

The results were not what I expected based on how I feel and perform, reduced EF and more left ventricle and atrium dilation.

I do recognize that results can vary between readers and based on image quality ... some specify as much as 20 percent.s perform, reduced EF and more left ventricle and atrium dilation.

I do recognize that results can vary between readers and based on image quality ... some specify as much as 20 percent.

Recent echo showed a reduction of EF to 45 - 50 at the 10 month point, from 55 to 60 percent at 20 days after my MI - 10 point swing.

Full text description of left ventricle/atrium from my most recent echo is as follows:

Left Ventricle: Mildly reduced left ventricular systolic function with a visually estimated EF of 45 - 50%. EF by 2DSimpsons Biplane is 49%. Left ventricle is mildly dilated. Mildly increased wall thickness. Mild hypokinesis of thefollowing segments: basal inferolateral and mid inferolateral. Global longitudinal strain is normal. Global longitudinalstrain is -17.5%. Grade II diastolic dysfunction with increased LAP. E/E' Ratio (Averaged) is 10.21
Left Atrium: Left atrium is moderately dilated. LA Volume Index BP is 53 ml/m2.

The description of the hypokinesis directly maps to the location in the LCX where my MI occurred ... so that is clearly the scar tissue that is acting more stiff. The 2 sections are 5 and 11 on the 17-point cardiac map.

I understand the heart will dilate to maintain stroke output in response to less kinetic behavior .. and that seems evident in the echo results.

My questions are as follows:

1. How much variance can be expected in echo results in terms of EF and other important parameters?

2. What is the typical adverse remodeling timeline, meaning how many months post MI is it expected to reach a completed state, presumably where the scaring/remodeling is complete? At 10 months post MI, is most of not all of adverse remodeling complete? My concern is that my EF may be worse in the future if this process is not yet complete.

3. Does the description of my left ventricle and atrium provided in the latest echo listed above (e.g. "LA Volume Index at 53") fall into the category of minimal, intermediate, or grave concern?

I am trying to determine if I headed towards heart failure ... even if I really feel ok ... but then apparently I have a high pain threshold.

Any thoughts on experiences or insight on this would be appreciated.