Myron E. Resnick, 89, a Delaware County cardiologist who routinely saw patients newly admitted to the hospital at all hours of the day and night, died Dec. 7 in the nursing home at Beaumont at Bryn Mawr. He had developed pneumonia after testing positive for COVID-19.

Earlier in his career, he had been been co-chief of medicine at Haverford Hospital, which later closed. Even after his second retirement, he continued to volunteer at a clinic in Chester, his daughter, Rosalind Resnick, said.

In 1968, he founded Marple Medical Associates in Broomall, which provided internal medicine and cardiology care. Dr. Resnick started practice as an internal medicine physician, but made the unusual decision to switch to cardiology years later. He had touched a patient’s beating heart during a medical lecture, and it made a lasting impression. “He was so moved by that experience that that’s one of the reasons he became a cardiologist,” his daughter said.

He started working in solo practice before most patients had medical insurance. He was sometimes paid with fruit baskets and cookies. After long days at the office, neighbors would ask him to examine their sick children. “He never said no,” said his daughter, who described her father as a “completely hands-on, old-school doctor.”

Even as the practice became more established, Dr. Resnick insisted on seeing all of his patients when they were admitted to the hospital, said Julian Gladstone, who joined the group in 1974. “We would go in for every admission, day or night,” he said. Dr. Resnick lived near the hospital and would sometimes hitchhike in during snowstorms.

Gladstone described Dr. Resnick as a “very, very responsible” doctor who could be counted on to take care of Gladstone’s patients when he went on vacation. “If you asked him to do something when you left, it was done,” he said.

Myron Resnick’s wife of 64 years, Phoebe Resnick, a public relations executive, died on Sept. 25 at 85. The couple met at Camp Birch Knoll in Stevens Point, Wis., when she was 18 and he was 23. He was a medical student looking for a cheap place to stay, which he found at the camp owned by a distant relative. She was the swimming counselor.

“They met neck deep in water in a lake,” Rosalind Resnick said.

It was love at first sight, but a long-distance one sustained for three years by letters as she attended Wellesley College and he finished school at what was then Hahnemann Medical College and is now Drexel University College of Medicine. They married after her junior year of college, because he joined the Navy.

Dr. Resnick, who grew up in West Philadelphia and attended Overbrook High School, served as a doctor on the USS General H.W. Butner, a troop carrier, from 1957 to 1959. He then returned to Philadelphia and worked briefly at the Philadelphia VA Medical Center.

Rosalind Resnick said her father was proud of his diagnostic skills. “He was a huge fan of Sherlock Holmes and detective novels,” she said. “That’s how he saw himself as a doctor.”

He was also a straight shooter who felt strongly about cigarettes because of the damage they did to his patients’ hearts.

Rosalind Resnick sometimes accompanied her father on rounds. She remembered watching his reaction to seeing a pack of cigarettes on the nightstand of a patient who was recuperating from heart surgery. Her father sat down and looked the patient in the eye. “If you continue to smoke cigarettes, you are going to die,” she remembered him saying. “When my dad talked to patients like that, it was like the voice of God.”

Gladstone also saw that tough approach. “He was a no-nonsense doctor,” he said. “He would tell patients to stop smoking and, if they didn’t stop smoking, he’d say, ‘I won’t be your doctor.’”

He officially retired in 2007, but quickly returned to the practice part time. Around 10 years ago, he retired again, but then began volunteering at a free clinic.

He was also a sports fan and an avid traveler.

In addition to his daughter, Dr. Resnick is survived by his sons, Bruce and Dave, and eight grandchildren.

Contributions in his name may be made to Temple Sholom, 55 Church Lane, Broomall, Pa. 19008.