I think it runs out eventually, even when maxxed.
I think it runs out eventually, even when maxxed.
It lasts for less than the cooldowns, I know that much.
Off the top of my head I'd say 30 seconds. But I'll find a training Hall later and confirm.
Maxed heart attack lasts 25 seconds.
I think it last as long as the target is alive. Its like a perma-curse.