I had been lifting longer too, but it really did almost nothing for my heart rate. Ya know, obvious overlap, but the heart is a muscle and those are different muscles.
For me, I did the whole trainer thing and got a program with a goal of increasing my cardiovascular health. Mostly running and cycling, but after a few months, I could be going all out and my monitor would show me maxing out in the 140s. If you feel like you're progressing though, it might be fine.
Do you feel like there's been improvements in your resting heart rate since you started doing more cardio?