Cardiac fibrosis

Hi 👋 1st time posting…
A quick background of my symptoms;
I’ve had episodes of SVT, NSVT,PVCs and Bijemny . Only on propanalol medication.
A recent increase in these Arrhythmias took me back for more tests;
ECG - showing Bijemny
7 day continuous heart monitor - showed above arrhythmias
Ctca - normal
MRI - normal - apart from Is the nonspecific pattern of mild intensity linear mid wall LGE/ fibrosis in the basal septum…
Now my cardiologist has said this is just part of the aging process. I’m not so sure. Yes, I googled it and it says it’s a marker for DCM and sudden cardiac death…
Now I was terrified of my ongoing symptoms, but this has taken me to another level of anxiety 😥
Has anyone been diagnosed with this type of fibrosis before? And what could cause it?
I’m now on 10 mg of bisoprolol daily
Any advice would be greatly appreciated TIA 😊