WASHINGTON — Connecticut U.S. Rep. John Larson, who inexplicably stopped speaking during a speech Monday on the House of Representatives floor, said Tuesday night he had suffered a complex partial seizure.

The 76-year-old Democrat, who is serving his 13th term, said the House attending physician referred him for further evaluation following the incident. The diagnosis was determined after a round of tests, according to a news release from Larson’s office.

People who experience such seizures, which can last 30 seconds to two minutes, can appear to be daydreaming or staring blankly. They may also make some movements, such as chewing, according to Cedars-Sinai medical center. During his speech, Larson is speaking normally before he suddenly stops, drops his arm and stares ahead, appearing to make chewing movements.

Larson, whose office on Monday said the incident was likely “an adverse reaction to a new medication,” attributed the complex partial seizure to a heart valve replacement.

“Fifteen years ago, I had a heart valve replacement due to a variation in the shape of my aortic valve that I was born with,” he said in a statement. “Sometimes, people with this condition can later develop symptoms such as the momentary change in speech or movement that was apparent yesterday. ”

Larson said he has been prescribed medication that doctors told him will “greatly reduce the chance of this happening again.” Larson, a member of the House Ways and Means Committee, said he plans to resume his congressional duties on Wednesday.

“I am looking forward to getting back to work for the people of Connecticut’s First District,” Larson said.