Sanchez, a Belen Democrat, had a coronary angioplasty on Thursday at an Albuquerque hospital and is being released Friday. The procedure widens a clogged artery and a stent was inserted to help keep it from narrowing again.
Sanchez's brother, Raymond, said the procedure was a precaution against future heart problems.
Sanchez's chief of staff Lorraine Montoya-Vigil said Friday the Senate leader didn't have a heart attack but hadn't been feeling well. Sanchez also had an angioplasty last year.
Sanchez is expected to return to the Senate early next week.
Sanchez's office issued a statement saying he was in good spirits and expected a full recovery.