For the second time in less than a year, Vice President Dick Cheney will undergo a procedure at George Washington University Hospital to restore his normal heart rhythm.

Cheney, 67, experienced an abnormal heart rhythm Wednesday morning during a visit with his doctors.

“It was discovered that the vice president is experiencing a recurrence of atrial fibrillation, an abnormal rhythm involving the upper chambers of the heart," said Megan Mitchell, a spokeswoman for the vice president.

In November 2007, doctors had to administer an electrical shock to Cheney's heart to restore it to a normal rhythm. That irregular heartbeat, like this one, was determined to be atrial fibrillation. At that time, White House doctors discovered the irregular heartbeat when they were treating him for a lingering cough from a cold.

The disorder can be found in about 2.2 million Americans, according to the American Heart Association. When a person suffers from atrial fibrillation, the heart's two small upper chambers (the atria) do not beat effectively. Blood isn't pumped out completely and may pool or clot. This is where things can take a dangerous turn.

“In atrial fibrillation, the atria starts beating very, very fast and the rhythms become chaotic and bombard the atria with a much faster heartbeat, said Dr. Virender Sethi, associate chief of the Division of Cardiology and section chief of the Cardiac Catheterization Laboratory at Hackensack University Medical Center.

“The blood stagnates in the atria leaving the danger of clot formation which can give someone a stroke if left untreated,” Sethi told FOXNews.com.

Just like the procedure last November, doctors will administer an electrical shock to Cheney’s heart to bring the heartbeat back to normal.

“The procedure, called cardioversion, entails sedating so the patient doesn’t feel the electrical shock,” Sethi said. “Two paddles are then applied to the chest and a shock is given.”

And while Sethi said Cheney should be able to return home today, there are still obstacles his doctors need to look out for.

“The challenge is to keep the heartbeat normal and in order to do that sometimes additional medication is given -- so the patient doesn’t go back into atrial fibrillation.”

The likelihood of developing this condition increases with age. Three to five percent of people over 65 suffer from the condition.

Cheney has a history of heart problems. He's had a total of four heart attacks — the first one in 1978 when he was only 37-years-old, and the most recent in 2000. He's undergone quadruple bypass surgery, two angioplasties, and an operation to implant a special pacemaker in his chest. He was also put on blood thinners in March 2007.

Click here to view a timeline of Cheney’s health.

The Associated Press contributed to this report.