Even with electron guns, my 10-year old Panasonic CRT has survived an average of 6-8 hours daily gaming on my old PS and PS2, and up to 18 hours on weekends. It still works fine now, no IR. And I was playing only Gran Turismo for 6 months straight during one stretch, no movies, no regular tv, only GT... and still no IR.

Probably has less to do with scan lines and more to do with power surging maybe?