Niclas Bergfors, another recent acquisition, also scored. He has five goals in seven games since being obtained as part of the Ilya Kovalchuk trade with New Jersey.
"You get a new start when you come to a new team," said Bergfor, who had 13 goals with the Devils this season.
MacArthur was acquired from Buffalo on Wednesday in a trade for two draft choices. Artyukhin came from Anaheim for a minor leaguer and a draft pick Monday.
"I thought that we had instant chemistry with the new guys," Atlanta coach John Anderson said. "That's a hard thing to find. If you score a couple of goals for your new team, it [endears] you right away."
The Thrashers chased Islanders goalie Dwayne Roloson in the first period, scoring three goals on seven shots.
Bergfors got Atlanta started with a goal 5:04 into the game. Then Antropov and MacArthur scored in a 25-second span. The first two Atlanta goals came on feeds from Little, and MacArthur knocked in his own rebound.
"It's always nice to get one early," MacArthur said. "I had a lot of nerves."
Martin Biron didn't fare any better than Roloson when he came in, giving up a goal to Afinogenov on the second shot he faced.
"In that first period, it felt like everything they shot went in," Islanders coach Scott Gordon said.
The Islanders made it 4-1 on their 21st shot of the first period, with Streit beating Hedberg on a power-play blast with 17 seconds left.
Atlanta regained its four-goal advantage on Antropov's power-play goal 10:05 into the second period, and Artykhin scored an unassisted goal on a breakaway with 4:07 remaining in the period.
"I think we feel good about ourselves," Anderson said. "I don't know if it's momentum or confidence or maybe a little bit of both. If we can keep on this role the playoffs are right there."
Schremp scored on a power play for the Islanders with 8:22 remaining in the third period, and Jackman scored with 7:12 left.
The Islanders have won just three of their past 13 games. ... With the addition of MacArthur and Artyukhin, Todd White was among the healthy scratches for Atlanta despite having a goal and an assist Tuesday night in a 4-2 victory over Florida. ... The game was the 800th in franchise history for the Thrashers, who joined the NHL as an expansion team in 1999-2000. The franchise has 301 victories.
Copyright by STATS LLC and The Associated Press
Arena: Philips Arena Location: Atlanta, Georgia
Referees: Greg Kimmerly, Mike Leggo Linesmen: Derek Amell, Brad Kovachik