Fairfax County Public School Superintendent Jack D. Dale during a school board meeting on Feb. 9, 2012, in Falls Church. (Mark Gail/The Washington Post)

Fairfax County schools Superintendent Jack D. Dale underwent emergency heart surgery Tuesday evening after he suffered an aortic aneurysm at work, and it is possible he will not return to his job before his planned retirement this summer, according to school officials.

Dale was conscious and resting in the Inova Fairfax Hospital intensive-care unit Wednesday, hospital officials said. Deputy Superintendent Richard Moniuszko will assume the superintendent duties as Dale recovers.

Dale, 64, told colleagues Tuesday that he was not feeling well, and in the evening he was transported by ambulance to the hospital, a short ride from the Fairfax public schools headquarters near Gallows Road.

After arriving at the hospital, Dale had cardiovascular surgery to address the aortic aneurysm, which is a weakening of the wall of the aorta, the main artery that carries blood from the heart to the rest of the body. Aortic aneurysms tend to be treated aggressively because the weakening of the aortic wall can cause it to balloon and possibly rupture, which is often fatal.

“It was a complete surprise,” said Fairfax County School Board Chairman Ilryong Moon (At Large). “Dr. Dale is a very healthy guy.”

“We are all very grateful for the quick medical response and the care that he is being given,” said board member Jane K. Strauss (Dranesville). “Our prayers are with his family.”

Moniuszko said Dale is accustomed to working the long hours that come with running a school system with 181,500 students. Dale is also a licensed pilot and regular golfer. Recently, Moniuszko and Dale played a round of golf together despite rainy weather.

“We’ve got some good people in the leadership team, and they’ll keep the ship running while he’s out,” Moniuszko said. “We’re hoping he’ll be back soon.”

Dale, who is married and has five children and four grandchildren, started his career as a high school math teacher and became Fairfax County’s superintendent in 2004. His nine-year tenure is scheduled to end when he retires at the end of June; the school board hired veteran Texan educator Karen Garza as the next superintendent.