The fact that you had Thrombolytic measures speaks of blockages, and blockages with a resulting
heart attack usually means that some
heart muscle died. Around the dead tissue one usually has weakened heart muscle tissue, and that is what you want to make healthy again, and with good drug regimens like Coreg, Altace, etc, coupled with exercise, you can strengthen your heart and increase the EF.
I find definitions of heart trouble rather intimidating.