According to a statement from Cheney's cardiologist, Jonathan Samuel Reiner, MD, the procedure at a local medical center is to determine the vice president's risk of developing a persistent, abnormal heart rhythm. The decision to proceed with the testing, known as an electrophysiology study, followed the discovery of four short, but painless episodes of "abnormally fast heartbeats."
The statement says that the monitoring was done two weeks ago by a device called a Holter monitor that the vice president wore for a period of time in order to get a constant reading of his heart rate. During a White House news conference, the vice president told reporters he now expects the upcoming test will lead to the implantation of a high-tech pacemaker.
"The docs had recommended that I [undergo the monitoring two weeks ago]. I postponed it for several weeks until I had a weekend when I was going to be home. It was easy to do. There was no sense of urgency ... I'm asymptomatic. I didn't even feel [the abnormal rhythms]," said Cheney.
Cheney, known for carrying a heavy workload in the Bush administration, has suffered from heart disease for some 25 years, and this will be the 60-year-old's third hospitalization since the election. He had quadruple bypass surgery in 1988.
Just what will the doctors be looking for when they insert a tube through the artery in Cheney's leg then into his heart? Instead of a balloon to unblock a vessel, the catheter will have a bundle of wires that can detect abnormal rhythms. In fact, the doctors can even turn on the dangerous rhythms, then turn them off.
It may be that Cheney simply has a relatively mild problem like an atrial fibrillation, a form of irregular heartbeat that involves the upper chambers of the heart. Of greater concern would be a ventricular tachycardia, which might affect the heart's ability to pump blood. Such a condition could prove fatal.
Given Cheney's situation, his doctor's say they are considering putting a pager sized device known as an implantable cardioverter defibrillator, or ICD, near his heart. An ICD has the ability to read a heart rhythm and can deliver a shock if it senses an abnormal rhythm. It can respond to a variety of problems up to the worst-case scenario.
"Some people are just barely aware of [the ICD], and others feel like they got kicked in the chest [when it discharges] ... Sometimes [ICDs] actually function as a pacemaker and try to organize the electrical activity of the heart by pacing it," Ira Nash, MD, assistant professor of cardiology at Mount Sinai Medical Center in New York, tells WebMD.
Nash also says that Cheney's heart condition isn't necessarily stress related, and White House spokesman Ari Fleischer says President Bush has "full faith" that Dick Cheney will be back on the job soon.
Sen. Bill Frist (R-Tenn.), himself a transplant surgeon, says the tests on Cheney are "done routinely" as a protective measure.