In the fall of 1995, the Rev. Ronald P. Pytel had resigned himself to an idle life and early death. At 48, his heart was so damaged that just walking made him winded. His complexion was pallid and his weight a gaunt 140 pounds. His quality of life, he recalls one doctor saying, "wasn't worth a plug nickel."

But the pastor of Holy Rosary Catholic Church in Baltimore, like many of his parishioners, had long been devoted to Faustina Kowalska, a Polish nun and mystic who died in 1938. At a healing service in October 1995, he and a dozen church members were praying to her for his health when the priest fell to the floor and, although conscious, could not get up for 15 minutes. "I could talk, but I couldn't move a muscle," he recalled. "It was as though I was paralyzed." When he finally stood up, he felt so fit he began laughing.

Nowadays, the blond Pytel has the rosy cheeks of a choirboy, weighs a hearty 170 pounds and swims with abandon. His pumping machine is so robust he jokes of having "the heart of a 19-year-old." He and his parishioners call what happened a miracle.

And so does the Catholic Church.

Having concluded that Pytel's heart recovery was so rapid and complete that it could only be a result of Kowalska's heavenly intervention, another of her devotees and fellow Pole, Pope John Paul II, is to canonize her Sunday in Rome.

Pytel, who is of Polish descent, seems pleased but bewildered by his unexpected role in adding a saint to the church's pantheon of more than 4,500 holy people. Two documented miracles are required for elevation to sainthood. Kowalska already was credited with the 1981 cure of a Massachusetts woman. Pytel's made her canonization possible.

"I still ask, 'Why me?' when so many people are praying for health reasons," he said. "Why the Lord chose me I wouldn't know."

Kowalska's canonization is a major event for members of Holy Rosary, whose large Romanesque-style church, built in 1927 by Polish immigrants, stands a few blocks from the waterfront in the Fells Point section of East Baltimore. Every day petitioners come here to intercede with Kowalska, better known as Blessed Faustina, in a small room dedicated to her and the devotion she promoted known as the Divine Mercy.

"I pray to her every day," said Dottie Olszewski, 73, director of the tiny shrine. "She takes care of everything for me now. She's good. She intercedes for you--if what you're asking for is Jesus's will."

Unlike all other female saints who adopted Poland as home, Kowalska will be the first one born in Poland, said the Rev. Seraphim Michalenko, of the National Shrine of the Divine Mercy in Stockbridge, Mass., where 30,000 pilgrims come annually to pray to her. Michalenko, a member of the Marians of the Immaculate Conception, an order of priests and brothers founded in Poland in 1673, is the church official responsible for collecting information in North America about Kowalska's miracles.

Born Helena Kowalska in 1905 near Lodz, she entered the convent at 25, took the name Faustina and served as the cloister's cook, gardener and housekeeper. In 1931, she began having visions of Jesus, who appeared with two rays of light--one red and one white--emanating from his heart. She said he directed her to have a painting done of what she'd seen and write on it, "Jesus, I Trust In You."

In a nearly-700 page diary, Kowalska described her visions and the message of Divine Mercy, a devotion that extols Christ's mercy and urges people to be merciful to others. She died in Krakow at age 33 of tuberculosis.

Because of her limited education, the nun wrote phonetically, often without punctuation or quotation marks. As a result, translations of her diary came out muddled, appearing that she was attributing to herself things Jesus had said of himself, Michalenko said. In 1958, the Vatican banned her writings.

When Cardinal Karol Wojtyla became archbishop of Krakow, the future Pope John Paul II told Rome he had a problem: Many in his flock were calling Kowalska a saint. His superiors advised him to start interviewing people who'd known her and get an exact translation of her diary. Eventually, theologians deemed her writings orthodox and worthy of dissemination. The ban on her diary was lifted April 15, 1978.

The date is noteworthy to Michalenko, who observed that "six months to the day, on October 15, 1978, that bishop was elected pope." Whether Kowalska had a hand in that momentous development or not, Michalenko finds the timing fortuitous. If the ban had not been lifted before he became pope, it would have been difficult to do it later, Michalenko said, "because people would say he's partisan."

In 1992, the Vatican declared Kowalska responsible for the miraculous cure of Maureen Digan, of Lee, Mass. Digan testified that, after praying at Kowalska's tomb in Krakow in 1981, she was cured of Milroy's disease, a hereditary form of lymphedema that had already cost Digan one leg. That miracle led to Kowalska's beatification as Blessed Faustina in 1993.

Two years later in June 1995, Pytel went to cardiologist Nicholas Fortuin, a professor of medicine at Johns Hopkins University, because he was having difficulty breathing.

"He was in profound heart failure," Fortuin said in an interview, explaining that the outflow valve of Pytel's heart, normally the size of a half-dollar, was no bigger than a pinhole, obstructing blood flow. Because his heart had been forced to work extra hard to keep blood moving, its left ventricle was badly damaged.

Fortuin immediately scheduled Pytel for an aortic valve replacement with Johns Hopkins surgeon Peter S. Greene. The operation would fix the blood flow but not repair the left ventricle. As a result, "he would not likely return to the lifestyle of a parish priest, which is a very energetic and time-consuming lifestyle," Fortuin said. "I told him that frankly."

That was Pytel's situation when he returned to Holy Rosary after the operation. In August, parishioner Olszewski went on a pilgrimage to Kowalska's tomb. Before leaving, she recalled, "I knelt at her grave and promised that if she got Jesus to get Father Pytel healed, I would spend the rest of my life promoting the Divine Mercy devotion."

On Kowalska's feast day, Oct. 5, the parish held a day of prayer that included the healing service. Although Pytel immediately felt better after it, he did not know his heart had fully recovered until a routine checkup with Fortuin in November.

When the doctor observed Pytel's heart with an echocardiogram, which produces an image of internal organs using sonar, he was taken aback.

"Lo and behold, the heart function had returned to normal," Fortuin recalled.

Some patients with Pytel's condition who have valve replacements show marginal improvement in their damaged hearts after several years. But in the priest's case, his once-enlarged heart was back to normal size and "the movement of the walls, which formerly had . . . poor contraction," Fortuin said, "now had returned to normal contraction.

"I was very surprised, maybe astounded," he added. "I didn't expect the left ventricle muscle to come back to its normal state. But it did. That was extremely unusual."

Would he call it a miracle?

"I don't use those terms," Fortuin said. "First of all, I'm a Protestant, second I'm a doctor and third I'm a scientist."

When he testified under oath before church officials investigating Pytel's recovery, Fortuin said he told them: "If you want to call it a miracle, I would not dispute that. That is not the jargon in my world, but . . . this was rather dramatic."

The Right Rev. Jeremiah F. Kenney, chief judge of the Baltimore Archdiocese's Office of Tribunal, supervised the investigation into Pytel's recovery that included sworn testimony from eight witnesses, including physicians Fortuin and Greene. It sent 800 pages of evidence to Rome, which announced its conclusion in December.

"The degree of the cure and the rapidity with which it took place," said Kenney, "are the basis for the judgment that there was indeed a miracle." And Kowalska's canonization means Pytel's recovery was "an extraordinary event beyond the scope of nature [that] came about by inexplicable means."

Pytel and several members of his church will be at the canonization ceremony in Rome, as will Fortuin, who was invited as a guest of the church. At Holy Rosary, meanwhile, they will be adding a special touch to the mural showing Kowalska kneeling before the image of Jesus she saw in her visions: A halo will be painted over her head after April 30, Pytel said.

Even before the Vatican spoke, the priest said, "I knew in my heart that it was a miracle because it was just too sudden of a change."

Still, he admits to occasionally having all-too-human doubts.

"Sometimes," he said, "I wake up in the morning and say, to myself, 'Did I have a four-year dream?' "