BOONE, N.C. (AP) — Evangelist Franklin Graham successfully underwent a specialized heart surgery on Monday to treat a condition which had developed in recent months, a spokesman said.

Mark Barber, a spokesman for North Carolina-based Samaritan’s Purse, said in a news release that Graham underwent the procedure at Mayo Clinic in Rochester, Minnesota.

In recent months, according to the news release, the son of the late evangelist Billy Graham had developed constrictive pericarditis, inflammation, and hardening of the sac around the heart that compresses the heart and prevents it from working properly.

The surgery involved removing the pericardium, the statement said. Graham’s doctors expect a full recovery and assured him that he should be able to return to his normal activity and ministry schedule.

Graham serves as the president of Samaritan’s Purse and of the Billy Graham Evangelistic Association.