Jump racing's best-known horse Sprinter Sacre was dramatically pulled up halfway through his comeback outing in the Desert Orchid Chase at Kempton with what veterinary advice diagnosed to be an irregular heartbeat.

Nicky Henderson postponed the gelding's reappearance after ruling out the Tingle Creek Chase at Sandown earlier in the month when Sprinter Sacre had returned an unsatisfactory scope test, but he had been gleaming with health in the paddock and all had been developing according to plan in the early stages.

Simply unbeatable in 10 previous outings over fences, Sprinter Sacre produced a long and flamboyant leap at the fifth but just two fences later jockey Barry Geraghty suddenly applied the brakes and trotted back anti-clockwise around half a circuit before dismounting in front of Henderson and concerned connections.

On stamina-sapping ground, the 2-9 favourite was set for a tricky reintroduction against the Tingle Creek winner Sire De Grugy (4-1), who was left to stave off the challenge of Oiseau De Nuit by four lengths.

Henderson gave an initial debrief before the seven-year-old was taken off for testing, and as he left for his Lambourn stable an hour and a half later he said: "We are still on the heart monitoring side of it, and it's still irregular.

"We were thinking of taking him to Newmarket straight away but I think the horse has had a lot of stress today and I'd rather take him home tonight.

Denman is a recent case of a top National Hunt horse recovering from what is often known as atrial fibrillation.