Welcome to HCM
is quite common in boys of your age,so do not worry there is no relation between heart problem and masturbation not even other health problems.it is normal to go for it occasionally .
But excess of everything is bad, during this age take care of your studies and job.
Take care of your diet and exercises.
It is good that no smkoking and alcohol just do not start them some times once you start it becomes difficult to quit.
Take care of yourself
Good Luck to you.