WASHINGTON — Vice President Dick Cheney has had his heart returned to normal rhythm after experiencing an abnormal heartbeat.

The vice president underwent an outpatient procedure this afternoon that restored the heart's normal rhythm.

A spokeswoman says the procedure — an electric shock administered at the hospital — went smoothly and without complication. Cheney spent the morning at the White House before the procedure and is now home and ready to resume his normal schedule.

Cheney has had four heart attacks, starting when he was 37 years old, and many related doctor and hospital visits over the years since. He has had quadruple bypass surgery and two artery-clearing angioplasties. In 2001, he had a special pacemaker implanted in his chest. The pacemaker's battery was replaced last year, and then the entire device was replaced.

In 2005, he had surgery to repair an arterial aneurysm on the back of each knee.

In his checkup in July, doctors said Cheney's heart was beating normally for a man of his age and health history.

The campaign event Cheney will miss is for Marty Ozinga, a wealthy suburban concrete company owner. Ozinga is running for the House against Democrat Debbie Halvorson, a high-ranking Illinois state senator.