Asif, a confidante of Sharif, said doctors have advised the prime miniter to undergo an open-heart surgery, following which he will be staying in the hospital for a week.
"The prime minister will travel after one week, on doctor's permission," he added. Sharif's daughter, Maryam Nawaz, confirmed on twitter that her father will undergo an open-heart surgery on Tuesday.
"Prayers are the most effective and potent medicines. Millions will pray for him so he will be fine," she tweeted.
Maryam then went on to explain her father's medical condition, saying: "In 2011 Nawaz Sharif had a cardiac procedure called 'Atrial Fibrillation Ablation', during which certain complications occurred resulting in perforation of heart which was in turn treated by open heart surgery."
Therefore, Sharif had been visiting his doctor for follow up, she said. "After some recent symptoms a team of cardiologists and cardiac surgeons carried out some scans and tests, following which they decided to go for an open heart surgery," she said.
The prime minister will be on specific medication for the next three days before his surgery on Tuesday, Maryam said.
"The recovery period and hospital stay will be one week. Nawaz Sharif will travel back to Pakistan as soon as the doctors allow." This is Sharif's second trip to London for medical check-up in few weeks' time.
He had gone to London on May 22 for a medical checkup and was supposed to come back in a week. The prime minister had undergone a check-up in Pakistan last month following which he decided to visit London for a proper medical check-up.