Maryland Speaker of the House Michael E. Busch (D-Anne Arundel) arrives for a news conference in Suitland, Maryland on Aug. 23, 2018. (Michael Robinson Chavez/The Washington Post)

Maryland House Speaker Michael E. Busch (D-Anne Arundel) underwent heart bypass surgery Wednesday night after experiencing shortness of breath during a routine test at a hospital, an aide said Thursday.

Busch, 71, a member of the House since 1987, had a liver transplant in June 2017. He returned to work that August.

His chief of staff, Alexandra Hughes, said Busch was at the University of Maryland Medical Center undergoing a routine test when doctors recommended additional testing to determine the cause of his difficulty breathing. Based on the results, Busch underwent bypass surgery.

“He is awake, alert and is expected to make a full recovery,” Hughes said in a statement. “He will return to work and the campaign trail in the next few weeks.”