Anna C. O'Riordan, 86, of Old City, a pediatric cardiologist in Philadelphia for 50 years, died Wednesday, Aug. 22, of an infection at Lankenau Medical Center.

Dr. O'Riordan not only became a physician, she also married one.

She and Joseph P. O'Riordan met in her first year at Hahnemann Medical College and were married in 1956, her junior year. He became an ear, nose, and throat surgeon at Nazareth and Holy Redeemer Hospitals; she became a cardiologist at St. Christopher's Hospital for Children.

"She was one of the first 200 people to be certified in pediatric cardiology," said Nandini Madan, an attending cardiologist at St. Christopher's. "She was one of the pioneers of the sub-specialty in the country. She had intellectual curiosity and knew how to deal with children — she had six of her own."

Known to her patients and medical colleagues at St. Christopher's as "Dr. O," she loved medicine and teaching, said her daughter, Catherine A. O'Riordan. "They both went by Dr. O. People would call the house asking for Dr. O, and we'd have to say: 'Which one?' "

Born in Philadelphia, she was the daughter of George D. and Juliet A. Connor. She graduated from Cecilian Academy in Mount Airy and Chestnut Hill College with a degree in chemistry.

In June 1957, she received a medical degree from Hahnemann, now the Drexel University School of Medicine. Her post-graduate work included an internship at Nazareth Hospital, and a residency in pediatrics and fellowship in pediatric cardiology at St. Christopher's Hospital.

She completed a master's degree in pediatrics from Temple University in 1962 and was certified by the American Board of Pediatrics the same year.  She was certified for pediatric cardiology in 1963.

She served as an associate professor of pediatrics at Temple University, Allegheny University of the Health Sciences, MCP/Hahnemann University, and Drexel University School of Medicine.

For over 30 years, she was also an instructor of pediatric advanced life support, or how medical professionals respond to very sick children in emergencies.

She served on the boards of many professional organizations, lectured frequently, and wrote for the Journal of Pediatrics from 1968 to 1994.

While her husband, a Navy surgeon, was stationed at the Naval Hospital on Guam from 1964 to 1967, doing reconstructive work for those injured in Vietnam, she served as the hospital's chief for maternal and child health and disabled children's services. She also was acting director of the Guam Department of Public Health.

She received many professional awards, including election to Alpha Omega Alpha, the medical school equivalent of Phi Beta Kappa, and was named the 1957 Philadelphia Woman Medical Student of the Year by the American Medical Women's Association.

She was cited as among the Outstanding Young Women of America in 1966 by the organization of the same name. She was a fellow of the American College of Cardiology, the American Academy of Pediatrics, and the Irish and American Pediatric Society.

During her time on Guam, Dr. O'Riordan traveled with her husband throughout Asia. She also enjoyed touring the United States and France, often on family visits.

She retired in March 2017.

Maggie McMahon, a friend and fellow sailor, knew Dr. O'Riordan from the Liberty Sailing Club in Philadelphia. Dr. O'Riordan was a founding member in 1988 and sailed until frailty intervened in December 2017.

"She hated to give it up," McMahon said. "Once, she had fallen and fractured her wrist. She went sailing with a cast on. That's gumption."

She enjoyed racing on the Delaware River as well as cruising in the Chesapeake Bay, the Caribbean, the Greek islands, Croatia, the San Juan Islands in Washington state, and off the coast of France.

McMahon said Dr. O'Riordan could talk to anyone, had a good sense of humor, and enjoyed the rituals that go with sailing.

"Once you anchor, you sit down and have an evening drink and chat, and go over the day's sail," McMahon said.

The O'Riordans raised their six children in Warminster. Her husband died in 1986 at age 54.

In addition to her daughter, she is survived by sons John F., Joseph P.  and Michael D.; daughters Patricia Singer and Mary Margaret Millhouse; 16 grandchildren; a great-grandchild; and a sister.

A visitation at 10 a.m. Wednesday, Aug. 29, will be followed by an 11 a.m. Funeral Mass at Our Lady of Good Counsel Church, 611 Knowles Ave., Southampton. Burial is in Resurrection Cemetery in Bensalem.

Memorial donations may be made to the Joseph. P and Anna C. O'Riordan Scholarship Fund at Drexel University Office of Institutional Advancement, Box 8215, Philadelphia, Pa. 19101.