What does it mean when r-22 gauge reads the same on the low and high sides of a heat pump?

It means either the compressor is not running, or if you are certain it is, the compressor valves are bad. You can verify this by taking an amperage reading and comparing what you read to the compressor nameplate. If the valves are bad the reading will be significantly lower than they should be. Also the compressor will feel hot to the touch and will cycle on and off on its internal temperature protection device.