WASHINGTON -- Former Vice President Dick Cheney was admitted to the hospital Friday after experiencing discomfort, the latest health scare for the 69-year-old Republican leader who has a long history of heart disease.

FoxNews.com has learned that the former vice president is expected to be discharged from George Washington University in the next day or two. According to a statement from the Office of the Former Vice President, Cheney's illness was a result of progressive retention of fluid related to his coronary artery disease.  After receiving IV medication, his President is "markedly improved". 

Cheney was not feeling well on Friday and went to see his doctors, and, on their advice, he was admitted to the hospital for further testing.

Cheney's heart attack earlier this year was his fifth since age 37. A heart attack occurs when blood flow to the heart muscle is blocked. In that episode in February, Cheney underwent a stress test and a heart catheterization.

Long said he had no other details about Cheney's condition.

A face of his party for decades, Cheney has remained a prominent voice of opposition to the Obama administration. His public career spanned decades, including service as a lawmaker, defense secretary and White House chief of staff.

Cheney had bypass surgery in 1988, as well as two later angioplasties to clear narrowed coronary arteries.

In 2001, he had a special pacemaker implanted in his chest. In addition, doctors in 2008 restored a normal rhythm to his heart with an electric shock. It was the second time in less than a year that Cheney had experienced and been treated for an atrial fibrillation, an abnormal rhythm involving the upper chambers of the heart.

The Associated Press contributed to this report