Muamba fell to the ground in the 42nd minute of the match at White Hart Lane, and medics attending to him for some time on the field as they used CPR and defibrillation in their attempts to revive him.
The former England Under-21 international was eventually stretchered off the field and taken to hospital, with confirmation that the match was abandoned coming a short time afterwards.
The FA, his former clubs, team-mates, friends and fellow professionals were quick to express their hopes that the 23-year-old pulls through on Twitter.
The FA: "Our thoughts and prayers are with Fabrice Muamba and his family right now. A wonderful person."
Arsenal: "The thoughts of everyone at Arsenal Football Club are with Fabrice Muamba and his family"
Birmingham City: "Everybody at Birmingham City would like to send their well wishes to Fabrice Muamba and his family at this time."
Bolton Wanderers midfielder Stuart Holden: "For all those asking, I know as much as you do.. waiting anxiously for updates from teammates. Fab is a fighter! Praying for you Fab @fmuamba .. hope he's ok..Thoughts with him and his family #bwfcfamily"
Justin Hoyte, a former teammate of Muamba's at Arsenal: "I seriously hope my best friend in football @fmuamba is ok. Stay strong bro please please stay strong. God is with u remember tht!!!!!
"please please be ok bro! I love you so much bro.#PrayforMuamba please everyone he is the nicest guy u will ever meet an know!"
Peterborough defender Gabriel Zakuani, who like Muamba was born in Kinshasa, DR Congo, and moved to Britain as a youngster: "I want every single person 2 Retweet #PrayForMuamba that's my family & 1 of the most humble guys around, thoughts with his wife & son Joshua"
Tom Huddlestone, former England Under-21 team-mate: "Thoughts with fab and his family! Feel sick watching this, puts football+everything else into perspective"
James Vaughan, another Under-21 contemporary of Muamba's: "Please please let fab be ok! Honestly one of the nicest people in the world! Please everyone pray for him! Love you bro!! Xx "
Coventry City Gary McSheffrey: "Hope fabrice muamba pulls through, devestated! Played at blues with him, nicest lad u could meet"
Manchester United and England striker Wayne Rooney: "Hope fabrice muamba is ok. Praying for him and his family. Still in shock."
Tottenham Hotspur midfielder Rafael van der Vaart, who looked visibly distressed as he was on the pitch while Muamba was being attended to: "Terrible what happened with Muamba during the game. We're all praying for him."
David Gold, co-owner of West Ham United: "Fabrice Muamba is one of the nicest and most respectful young men I have ever met in football. I'm thinking of you Fab get well soon."
Queens Park Rangers captain Joey Barton: "Just heard the sad news about Fabrice Muamba. My thoughts are with him and his family right now. Puts everything in to perspective"
Former West Ham midfielder Valon Behrami, now at Fiorentina: "C'mom Muamba you're used to fighting in the field now fight for the most important thing!!pray for you.."
Manchester City captain Vincent Kompany: "Desperate for some good news coming from the Bolton camp. Come on Fabrice Muamba!! Too young to die man!!"
Aston Villa's Charles N'Zogbia: "Massive support for Muamba and his family. May God be with them all at this time. Please pray for him, I will be."
Former England captain Gary Lineker: "Everyone in football is with you Fabrice Muamba"
Liverpool midfielder Lucas Leiva: "#PrayForMuamba"