Evil wizard, cavern, immortal, heart, fantasy movie

It's fantasy movie from 60's, 70's or 80's. I am almost sure that was in Russian Language. My friend saw it in 80's. The main character is a man (perhaps a young boy). His main enemy is an evil wizard. The wizard lives in a cave and keeps his heart. He doesn't leave a cavern. He is immortal (probably).I think that main weakness of the wizard was his heart and it was reason that wizard keeps own heart. At the end, the main character destroy his heart, when a wizard leaves a grotto. The wizard rides and falls from horse and die (something like heart attack).

It's similar thread like "Captain Sindbad" (1963), but it isn't. It was something like "Кащей Бессмертный" (1944), but it isn't too.

What is name of this film ? Help me, please. заранее спасибо.