What Causes Burning Sensation In Chest After Undergoing CABG?

Hello - I'm almost 6 weeks post CABG, but still have symptoms I had when I first went into the doctor ...much less often,not as intense. Starts with burning sensation in chest, moves to left arm (achy), sometimes into left jaw. Any ideas? My doctors/rehab nurses are stumped. Stress test showed nothing unusual, have been going to cardiac rehab three times per week for two weeks. Right leg has been tingling for two full days now as well. Could this be related to regeneration of nerves where vein was taken from? These symptoms are getting discouraging...