According to a statement from Dick Cheney’s office, the Vice president was treated “without complication” Wednesday for an abnormal heartbeat. He underwent a successful procedure to restore his normal rhythm with an electric shock. Last year too, Cheney underwent a procedure to deal with an irregular heartbeat.

The statement noted: “During a visit with his doctors this morning, it was discovered that the vice president is experiencing a recurrence of atrial fibrillation, an abnormal rhythm involving the upper chambers of the heart.”

Sensing a problem early Wednesday, Cheney, 67, saw the White House physician, who discovered the vice president was experiencing a recurrence of the irregular heartbeat. However, Cheney went to George Washington University Hospital for treatment in the afternoon, after completing most of his regular assignments at the White House.

After the recurrence of his heart trouble, the second in less than a year, was officially disclosed, Cheney’s fundraising visit to Illinois for Republican congressional candidate, Martin Ozinga, was cancelled.

Cheney’s press secretary, Megan Mitchell, said that prior to his hospital visit, the Vice President called Ozinga at home where the fundraiser was under way without him, and offered his support for Ozinga’s candidacy.

Cheney, who suffered his first heart attack in 1978, has had quadruple bypass surgery in the past.

Explaining Cheney’s problem of irregular rhythm of heart, Dr. Zayd Eldadah, director of cardiac arrhythmia research at Washington Hospital Center, said: “This kind of rhythm problem generally does keep coming back over time. The natural history of atrial fibrillation in people who have heart disease, and are older, is that it keeps coming back, and generally comes back more frequently.”

The doctor said it is not unusual for Cheney to have another such episode. An estimated 2.8 million Americans have atrial fibrillation, the most common type of irregular heartbeat and one that is not life-threatening in itself.