Does Frozen Heart proc Liandry's Passive?

{quoted}

"UNIQUE Passive: Dealing spell damage applies a damage-over-time effect for 3 seconds that deals bonus magic damage equal to 2% of the target's current Health per second. This bonus damage is doubled against movement-impaired units and capped at 100 damage per second vs. monsters."

It's only movement slows, not attack speed slows.

Go in a game and test it then. I'm fairly sure it works with Frozen Heart.

"Movement impaired" includes slows, slows include attack speed slows. That's just how it is. You can test it out yourself, but here are some references:

• http://leagueoflegends.wikia.com/wiki/Oppression_%28Season_Four_Mastery%29

"Warden's Mail and Frozen Heart's passive will count as impairing movement."

• http://www.reddit.com/r/leagueoflegends/comments/2233ey/frozen_heart_aura_doubles_liandrys_passive_damage

"Looking even further back, Riot decided that Attack Speed slows are counted as movement slows." "I had FH/Liandry Ryze use Q on Ancient Golem and then step out of the FH aura range, and then back in. The moment I dipped out of the aura range, the proc damage dropped in half (in this case, 32), and when I went back in, it went to 64. I also tried Liandry's without Frozen Heart on the same target. When I bought Frozen heart, the proc's damage doubled."

• http://cloth5.com/frozen-heart-interactions/

"Now, here’s where the interaction with Frozen Heart comes in. The attack speed reduction aura on Frozen Heart counts as a movement impairment—meaning that as long as you stand within 700 units of your target (think around Caitlyn auto-attack range), they’ll receive the doubled burn damage."