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 endures 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 only 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 against 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.