The 24-year-old midfielder's signing will reportedly be announced imminently by the Scottish Premiership side.
Kitchen, 24, has been without a club since leaving D.C. United upon his contract expiring at the end of the 2015 MLS season in order to explore opportunities in Europe.
The former University of Akron product, who can also play at right-back or centre-half, made 158 regular season appearances for DCU after being selected third overall in the 2011 MLS SuperDraft and established himself as one of the league's top emerging talents, recording 10 goals and 10 assists in the process.
His impressive performances have earned the Indiana native three senior US international caps since his debut in February 2015, while agent Lyle Yorks revealed last May that several teams in Germany were monitoring his client's progress along with Champions League sides from Belgium and Denmark.
A robust and disciplined defensive midfielder with noted leadership qualities, Kitchen would prove a good fit for the Scottish Premiership and should challenge for a starting spot at third placed Hearts from the outset given his success across the Atlantic.
Robbie Neilson’s men moved within six points of second placed Aberdeen with last night’s 2-0 home win over Inverness Caledonian Thistle and the addition of the promising American alongside Prince Buaben in the centre of the park could give them a major boost during the run-in.