change in ef and norma cath. reports

Initial reports of echo.
Lvef=49 % mild global hypokinseia
trivial MR trivial TR
no PE,CLOTS
Normal chambers size

Catherization reports are small

After six months echo reports are
lvef=75%
no tr mr
no hypokinseia
nothing...

why is there sudden change anything to worry?

my age is 20...65 kg weight height 5'8'