Heart surgeon Dr. Samuel Hunter, of Mendota Heights, helped pave the way for modern pacemaker technology.

Hunter, whose work revealed that a pacemaker could be a permanent solution to shore up aging hearts, died Oct. 22 in St. Paul. Hunter, who had suffered from coronary artery disease, was 86.

He and electrical engineer Norman Roth of Medtronic developed an improved electrode for use with an existing external pacemaker.

Hunter tried the pacemakers on dogs, and it worked. In 1959, the device was attached to a 72-year-old patient at Bethesda Hospital in St. Paul. He lived for seven years more.

Until then, external pacemakers had only been used on children and for very short periods.

"Sam's idea to use a pacemaker on an adult was a big breakthrough," said Earl Bakken, inventor of the first battery-powered pacemaker and a co-founder of Medtronic.

Hunter was a "wonderful man," Bakken said. "He was very kind to patients."

Implantable pacemakers came on the scene in 1960.

Dr. Donald Swenson, of Mound, a retired internist, worked with Hunter for decades. "He was innovative," Swenson said. "He was fearless, and he tried things that other surgeons were reluctant to do."

Born in Belfast, Ireland, Hunter grew up in Staten Island, a borough of New York City. The student athlete played baseball and basketball at Cornell University in Ithaca, N.Y., earning a bachelor's degree in 1943.

At the University of Rochester medical school in New York, he played professional basketball to pay for medical school. The school's dean frowned on that, fearing that Hunter wouldn't have time for both, and persuaded him to drop out of basketball. He also arranged for a scholarship for Hunter.

Hunter came to the University of Minnesota for his residency in cardiothoracic surgery in 1947.

During the Korean War, he served as an Army doctor. When he returned to civilian life, he completed his studies and joined a private practice in St. Paul.

In the late 1950s, he suspended private practice for more than a year to conduct research with pioneering open-heart surgeon Dr. C. Walton Lillehei at the University of Minnesota.

He enjoyed the arts, golf and annual canoe-camping trips to the Boundary Waters Canoe Area Wilderness. He was a trustee of numerous arts and professional organizations, such as the St. Paul Chamber Orchestra, and active in Physicians for Social Responsibility.

He retired more than 15 years ago.

In addition to his wife of 64 years, Thelma, he is survived by five sons, David, of Minneapolis, Robert, of Tucson, Ariz., Stephen, of Mendota Heights, James, of White Bear Lake, and John, of Chicago, and nine grandchildren

Services will be held at 2 p.m. Nov. 23 at Westminster Presbyterian Church, 1200 Marquette Av., Minneapolis.