VATICAN CITY - Pope John Paul II suffered heart failure and is in "very grave" condition, the Vatican said Friday, but it said he was lucid and spent the morning celebrating Mass and receiving top aides, asking one to read him the biblical account of Christ's crucifixion and burial. Spokesman Joaquin Navarro-Valls choked up with tears as he told reporters about the pope's worsening condition. He said the 84-year-old pontiff had been "informed of the gravity of his situation" and decided to remain in his apartment overlooking St. Peter's Square, where thousands of pilgrims gathered to pray for him. John Paul participated in Mass and received some top aides Friday morning, Navarro-Valls said. "The pope is still lucid, fully conscious and extraordinarily serene," Navarro-Valls said. He said the pope had unstable blood pressure and remained in "very grave" condition. Among the top church officials who gathered at his bedside was Archbishop Paolo Sardi, the Vatican vice chamberlain who runs the Holy See between the death of a pope and the election of a new one. Thousands stood vigil on the square outside, many tearfully gazing up at his third-floor window, and millions more around the world paused to pray for him. In Wadowice, Poland, people left school and work early and headed to church to pray for their native son. "I want him to hold on, but it is all in God's hands now," said 64-year-old Elzbieta Galuszko at the church where the pope was baptized in Wadowice, southern Poland. "We can only pray for him so he can pull through these difficult moments." In the Philippines, tears streamed down the face of Linda Nicol as she and her husband asked God to grant John Paul "a longer life." Muslims in France were praying for the pontiff because he was a "man of peace," said Dalil Boubakeur, president of the French Council of the Muslim Faith. Navarro-Valls said John Paul asked aides to read him the biblical passage describing the final stage of the Way of the Cross, the path that Christ took to his crucifixion. In that stage, according to the Bible, Christ's body was taken down from the cross, wrapped in a linen shroud and placed in his tomb. Navarro-Valls said the pope followed attentively and made the sign of the cross. "This is surely an image I have never seen in these 26 years," Navarro-Valls said. Choking up, he walked out of the room. John Paul's health declined sharply Thursday when he developed a high fever brought on by the infection. On Thursday afternoon, the pope suffered heart failure and a condition called "septic shock" during treatment for the infection, the Vatican said Friday, but it denied an Italian news report that he was in a coma. The pope received the sacrament for the sick and dying on Thursday evening. Formerly called the last rites, the sacrament is often misunderstood as signaling imminent death. It is performed both for patients at the point of death and for those who are very sick — and it may be repeated. The Rome daily La Repubblica reported Friday that the sacrament was administered by John Paul's closest aide, Polish Archbishop Stanislaw Dziwisz, who serves as his private secretary. Dziwisz had given the pontiff the same sacrament on Feb. 24 just before the pope underwent a tracheotomy to insert a breathing tube in his throat at the Gemelli Polyclinic hospital, the newspaper said. Italy's Apcom news agency reported Friday morning that the pontiff had fallen into a coma, but the Vatican dismissed the report. Among the aides John Paul received Friday were Secretary of State Cardinal Angelo Sodano, the Vatican's No. 2 official; Undersecretary of State Archbishop Leonardo Sandri; the pope's vicar for Rome, Cardinal Camillo Ruini; his doctrinal chief, Cardinal Joseph Ratzinger; the Vatican foreign minister, Archbishop Giovanni Lajolo; and American Cardinal Edmund Szoka, the governor of Vatican City. The pontiff was attended to in his apartment by the Vatican medical team, and provided with "all the appropriate therapeutic provisions and cardio-respiratory assistance," the Holy See said. It said the pope was being helped by his personal doctor, two intensive care doctors, a cardiologist, an ear, nose and throat specialist and two nurses. Heart failure occurs when the heart no longer has the strength to pump blood through the body, and is a sign that the body's cardiac system is failing. Dr. Paolo Nardini, a Rome physician who is not part of the pope's team, said a heart attack affects only the heart, while heart failure signals a "breakdown of the entire system, basically uncurable." Dr. Peter Weissberg, medical director of the British Heart Foundation, said septic shock "puts a phenomenal strain on the heart." In a statement Friday, Weissberg said that "those already suffering from heart disease — including those with heart failure — are even more susceptible to septic shock. Infection triggers a profound loss of blood pressure, depriving organs around the body of their vital blood supply and putting an enormous strain on the heart." Even the fittest patients need special care and medicine to survive, he said. Ruini said he visited John Paul early Friday and found him "profoundly serene and fully lucid." "I prayed with him for a moment which profoundly moved me. Certainly the pope has completely left himself in God's hands. I invite all Romans and Italians to intensify prayers for him in this moment," Ruini told private TG5 television. He asked Italians to pray for John Paul, and said a special Mass for the pope would be held at 7 p.m. at the basilica of St. John Lateran in Rome. The patriarch of Venice, Cardinal Angelo Scola, also planned a Mass in St. Mark Basilica at the same time. Hospitalized twice last month following two breathing crises, and fitted with a breathing tube and a feeding tube, John Paul has become a picture of suffering. His 26-year papacy has been marked by its call to value the aged and to respect the sick, subjects the pope has turned to as he battles Parkinson's disease and crippling knee and hip ailments. It is not clear who would be empowered to make medical decisions for an unconscious pope. The Vatican has officially declined to comment whether John Paul has left written instructions. Reprinted from yahoo.com