Washington - US Vice President Dick Cheney underwent treatment Wednesday after doctors found an abnormal rhythm in his heart, the White House said.

Cheney cancelled plans to attend a campaign event in Illinois and went to George Washington University Hospital in the capital for the outpatient procedure, involving an electrical impulse to restore a normal rhythm in his heart's upper chamber, Cheney spokeswoman Megan Mitchell said.

Cheney, 67, has a history of heart problems and suffered four heart attacks beginning in his 30s. The most recent attack occurred in 2000.

Cheney was diagnosed with a similar problem in November 2007 and received an electronic jolt to correct the rhythm. He has carried a pacemaker since 2000 and is regularly monitored by cardiac specialists.