My cardiologist says i have an innocent left anterior hemiblock. how can left anterior hemiblock be innocent?

Innocent hemiblock: Since you're alarmed, you need to discuss this more fully with your cardiologist and ask specifically what he means. Perhaps you have already been through exams and testing related to this? My guess is that he means it's causing no symptoms or problems with your cardiac function. But it is an abnormality that requires investigation.

It is possible: Assuming you don't have any of the obvious conditions associated with lafb (htn, coronary heart disease, valve disease) then it is possible that you have acquired some calcification or scarring that has affected this part of the electrical system. While lafb is never normal it may not be something that will affect you in any clinically meaningful way.