As she sat last week at her dining room table, Rozalija Gannon searched for a sympathy card that serves as a lasting testimonial to her late husband's influence.

Dr. Paul Gannon was a heart surgeon in the Twin Cities for 40 years and worked among some of the region's biggest names in medicine, at a time when doctors here helped develop cardiac pacemakers and other innovations that changed the way physicians around the world care for heart patients.

No less significant, though, is the sympathy card on Rozalija Gannon's table, which her daughter Mary Ann Heine retrieved to show a visitor.

It conveyed thanks from the relatives of a man who underwent emergency heart valve replacement in 1985. Gannon successfully performed the operation, the card explained, and the procedure granted the man another 31 years with his family plus a lasting connection with his doctor.

"He would stick with the patients, and stay with them and sit down — he would talk with them and get to know them," Heine said. "He wanted people to live."

Gannon, 89, of Golden Valley, died this month following a heart surgery career in which he helped the wonder of open-heart surgery transition into a new standard of medical care.

He was born in New Jersey. After attending medical school at Marquette University in Milwaukee, his training ultimately culminated in 1963 at the University of Minnesota, where he earned his Ph.D. about five years later.

Minnesota was the world's hotbed for heart surgery, said Dr. Rosemary Kelly, chief of cardiothoracic surgery at University of Minnesota Health.

One of the first open-heart surgeries happened at the U in 1952, Kelly said, and it was followed by a series of lifesaving breakthroughs over the next 15 years. For Gannon, it must have been exhilarating, she said.

"He was a pioneer in cardiothoracic surgery in our community, at a time when it was just beginning," Kelly said. "They had to build the resources and the expertise. And so most of these surgeons took care of every moment for their patients. … Every surgery was very high-risk, because it just hadn't been done before in a routine fashion."

During his career, Gannon operated at the old Metropolitan Medical Center in Minneapolis and other hospitals. He helped establish in the 1970s a Twin Cities medical society focused on thoracic and cardiovascular surgery, and he created a program to aid 25 Tanzanian children who needed operations.

"He wasn't a headline-maker — he was just a doer," said Timothy Scanlan of St. Paul-based Scanlan International, a medical products company that worked with Gannon.

From the late 1960s through 1995, Gannon held positions as instructor, assistant and associate professor of surgery at the U. Two years ago, his son, Dr. James Gannon, funded an annual lecture in his father's name at the U.

Paul Gannon loved classical music, history, philosophy and travel, said Rozalija Gannon, his wife of 63 years. He started playing the violin at age 5 and continued throughout his life. In later years, he played concerts alongside granddaughter Caroline Heine for friends and family in his home.

A few years ago, Gannon published a book that chronicled Minnesota's prominent role in the history of heart surgery. It includes photos of Gannon with giants like Dr. C. Walton Lillehei, the U physician who was called the "father of open heart surgery."

"He was learning from the fellows who first started it — who did the original open hearts," said Dr. Thomas Kersten, a retired heart surgeon who trained at the U a few years after Gannon finished. "He represented a unique era."

Services have been held.

Christopher Snowbeck • 612-673-4744 Twitter: @chrissnowbeck