Announcing this yesterday on television, Blair also said that while he would contest for a third term as Prime Minister, he would step down before the fourth.
His office described the "heart procedure" as a catheter ablation to restore his heart's rhythm to normal. He will be sedated during the 2½ hour procedure, and will stay overnight at the hospital.
The prime minister, who required electro-cardiac treatment after suffering from an irregular heartbeat a year ago, is expected to be back at his desk on Monday and go ahead with a trip to Africa next week, his office said.
Dr Punit Ramakhra, who treated the Prime Minister last year, described the problem as a 'sort of short circuit' in the heart, which makes it beat faster or irregularly.
"It's not particularly alarming but it's something that you should get fixed," Blair told the BBC. " It's a routine procedure. I've had it for the last couple of months and it has not impeded me doing my work and feeling fine but it is as well to get it done."
As for his political future, "The decision, of course,
"I want to put myself forward for a third term and if elected I would serve that full term. But then I think it is sensible to say I would not then stand for a further term beyond that." His condition had not made him consider giving up the job, and his family endorsed his decision, he said. "I am not going on and on and on."
According to Dr Ramakhra, the procedure involves pushing catheters through the skin into large veins and advanced under X-ray control until the tip of the catheter lies inside the heart chambers.
"First, electrical sensors at the catheter tip allow the cardiologist performing the procedure to locate the exact site of the short circuit. Secondly, the catheter delivers pulses of energy which actually destroy (ablate) the short circuit," he said.
"It is not a surgical procedure there is no surgical incision and the chest cavity is not opened. As soon as the ablation is carried out, the heart's normal, regular rhythm is restored and the heart's pumping action returns to full efficiency.
"The recovery time is short, with patients able to return to work and undertake full activities within two to three days."
