Frenchman flies to London after New York Red Bulls' game against Real Salt Lake to spend an hour with his former Arsenal team-mate after Bolton midfielder's cardiac arrest
Henry travelled over 3,500 miles from New York to spend time with his former Gunners team-mate and his family at the London Chest Hospital.
The New York Red Bulls forward also revealed that Muamba is able to "talk perfectly" as he continues to recover after collapsing against Tottenham at White Hart Lane on Saturday.
The Frenchman announced on his Twitter feed: "Leaving back to America - Fabrice is getting a lot better which is fantastic. I will let you know more when I'm back in the US.
"Fabrice is in a stable condition and can talk perfectly."
One of Muamba's doctors had ealier revealed that the former England under-21 international had stopped breathing for 78 minutes before finally being revived in hospital.
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