Cheney has a history of heart problems and has a pacemaker. Cheney has had four heart attacks [current as of Feb. 22, 2010], starting when he was 37. 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 in 2008, and then the entire device was replaced.

A summary of Vice President Dick Cheney's heart problems:

- 1978: Cheney's first heart attack. A spokesperson for Vice President Cheney tells FOX the VP stopped smoking after his first heart attack, contrary to preliminary reports.

- 1984: His second heart attack.

- 1988: After suffering his third heart attack, Cheney had quadruple bypass surgery in August to clear clogged arteries.

- Nov. 22, 2000: Cheney suffered what doctors called a "very slight" heart attack - his fourth. He underwent an angioplasty that day to open a clogged artery.

- March 5, 2001: Cheney went to George Washington University Hospital after feeling chest pains. Doctors performed another angioplasty to reopen the artery that had been opened in November. They implanted a stent, a little metal scaffolding, to prop open the almost completely blocked artery.

- June 29, 2001: Cheney disclosed he had been experiencing irregular heart rhythms and would check into a hospital on June 30 for tests that may lead to the implant of a pacemaker to restore normal rhythm. Since the heart attack in November 2000, Cheney said he regularly exercised for 30 minutes on a treadmill and watches his diet. He was taking medication to lower his cholesterol.

- November 13, 2004: Cheney underwent three hours of tests after experiencing shortness of breath. His wife said Cheney had nothing more than a bad cold and his heart was fine.

- Sept. 24, 2005: Cheney underwent successful, elective, minimally invasive, endovascular repair of arterial aneurysms behind his right and left knees. Small aneurysms were identified behind both knees during the Vice President's annual physical examination in July.

- Jan. 9, 2006: Cheney was hospitalized for four and a half hours due to shortness of breath. Doctors found his EKG unchanged, and determined Cheney was retaining fluid because of medication he was taking for a foot problem.

- March 5, 2007: An ultrasound revealed a deep venous thrombosis (DVT) or blood clot in Cheney's left lower leg. His doctors planned to treat him with blood thinning medication for several months.

- November 26, 2007: Cheney went to his doctors complaining of a lingering cough, but during the checkup they determined that he was experiencing atrial fibrillation, an abnormal rhythm involving the upper chambers of the heart. His medical team sent the vice president to George Washington University Hospital for further tests, where it was decided that the electrical impulse was needed to restore a regular heartbeat. "The procedure went smoothly and without complication," the vice president's office said in a statement issued by the White House.

- Oct. 15, 2008 -- Cheney was treated "without complication" for an abnormal heartbeat, his office said, making a short visit to a hospital to restore his normal rhythm with an electric shock. It was the second time in less than a year that Cheney, then 67, had experienced and been treated for an atrial fibrillation, an abnormal rhythm involving the upper chambers of the heart. He went to George Washington University Hospital in the afternoon for treatment. The process took nearly two hours.

- Nov.8, 2008 -- Doctors scanned Cheney's legs on to evaluate arthritis in his knees.

- Feb. 17, 2009 -- Cheney underwent elective back surgery. He underwent the operation at George Washington University Hospital to deal with lumbar spinal stenosis, a common cause of lower back pain in older adults. Spinal stenosis is a narrowing of the spinal canal -- the passage for the spinal cord -- which in turn puts pressure on nerves, causing pain. Surgery is done to widen the passage and ease that pressure, typically by removing a bit of the vertebra. Dr. Anthony Caputy, chairman of the hospital's neurosurgery department, performed the operation.

- September 17, 2009: Cheney went to The George Washington University Hospital for elective surgery to deal with lumbar spinal stenosis. Dr. Anthony Caputy, Chairman of the Department of Neurosurgery, was scheduled to perform the operation.

- Feb. 22, 2010 -- Cheney was hospitalized after experiencing chest pains. The next day his office disclosed that lab testing had revealed evidence of a mild heart attack. He underwent a stress test and a heart catheterization. He was said to be feeling good and was expecting to be discharged in one or two days.