Hello, Welcome to JustAnswer and thank you for your question.
Yes it is related to the thickness of the heart muscles of this is due to athletes heart.
Because heart in athletes is strong and can pump same amount of blood at a low rate then it does for a person with a weak or non athletic heart.
no i do not think it is getting larger day be day because.
Heart enlarges at max rate at teen age
and this is what happens in HCM
it enlarges in teen age and it very thick by the age of 20 years
You are 39 years
and it is mild hypertrophy
which means it is due to high blood pressure most likely.
and they take a decade to enlarge.
Your heart rate is no an issue.
Once we find something abnormal our brain then tries to see more and more
this is what is happening with you
your heart rate is not an issue even 40/min does not need treatment
if it does not cause symptoms
It is normal to vary heart rate from 60-100/min because this is what we call normal range
you may have never seen a doctor telling you that 72 beats/ minute is the accurate heart rate
because it varies 40 units during our activities
As you have 57 or 55/ min heart rate
so your variation of 40 from 57 is normal
In your case i would say that from 57-97 is your normal range.
If heart rate goes beyond this at rest then it is abnormal.
you have questions ?
Your ECG was normal ?
Did you had a holter test ?
Then it means you are misreading the pulse.
It can vary
If you are sure you are checking it correctly and it is irregular
then it means you need to get a fresh ECG and holter.
Well VT and VF are very fast like 150/min and more
it do not think it is VT or VF
Breathing fast and slow can change the heart rate it is what we call respirophasic variation
To me it is nothing serious like VT or VF
Only thing or test to confirm this is ECG and holter
I will be offline because it is around 11pm here
See you tomorrow Inshallah.