Are there any artificial satellites that are in a stable elliptical orbit?

Elliptical orbits are in fact stable ones. It's a constant trade between gravitational potential energy and kinetic energy. Getting close to the sun doesn't mean the earth should fall in, it means it will speed up which will propell it back to its highest point in orbit again, slowing it back down. There is a common misconception that gravity acts like a drain, always pointing downwad. Objects that accelerate toward a gravitational force, however, will also decelerate when passing it, leaving a balance. The only difference however is when you actually strike the suface of a gravitational object. But that's a completely different force, called friction. Anything that is drawn to a gravitational field is exchanging potential gravitational energy for kenetic energy. Kenetic energy will also be exchanged for potential energy as the object moves away from the gravitational field.

Russia had 4 TV satellites that circled the poles in highly elliptical orbits.

They swung close to the south pole then up above the north pole slowing as they climbed,turned on at the right time and transmitted up and down then shut off as they sped up,this gave continuous TV reception to the north that couldn't be done from a stationary orbit.

Yes