The 24-year-old has moved to Tynecastle Park until the end of the season as a replacement for the injured Josh Ginnelly.
Hearts made their move for Kastaneer over the weekend after Ginnelly was ruled out until the end of the campaign with a ruptured hamstring.
The new arrival is quick and direct and can play on either flank. He is 6ft 1ins tall and is also able to operate as a central striker.
Kastaneer’s former clubs include the Dutch sides Dordrecht, ADO Den Haag, FC Eindhoven and NAC Breda, plus Kaiserslautern in Germany.
Hearts manager Robbie Neilson told the club’s website: “I’m pleased that we’ve been able to get Gervane signed up so quickly.
“He’s got a great pedigree, having played top-flight football in Holland and in the English Championship and also at a big German club in Kaiserslautern.
“There’s strength in his play, he’s physically imposing but is pacey and very direct.
“The injury to Josh Ginnelly was a blow but with Gervane here we’re now equipped once again on the wings and I’m looking forward to seeing what he can do as we push towards the title.”
Hearts intend to do more business before the transfer window closes tonight. They are in the market for a central midfielder and, if possible, a right-back to compete with Michael Smith.
The Edinburgh club also hope to move a couple of fringe players out if they can find new teams.