Vice President Dick Cheney was recovering at home Monday night after being treated for an irregular heart beat, found Monday morning during a checkup for lingering cold symptoms, Cheney's office said.

Doctors found atrial fibrillation, an abnormal rhythm involving the upper chambers of the heart.

Cheney was treated at George Washington University Hospital in Washington, D.C., undergoing cardioversion — delivery of an electric impulse to the heart, which is a standard treatment for atrial fibrillation.

The treatment is performed as an outpatient procedure, and Cheney returned home Monday night.

Cheney has a history of heart conditions. In 1978 he had his first heart attack, after which he stopped smoking. He had three more heart attack — after the third heart attack in 1988, he underwent quadruple bypass surgery.

Cheney has been diagnosed with irregular heartbeats and other problems on several occasions since his last heart attack in 2000, and most recently was hospitalized in March for deep venous thrombosis, resulting in a blood clot in Cheney's left leg. Doctors intended to treat him with blood thinners at the time.