February 05, 2008

GPS Devices Measure Severity of Peripheral Artery Disease

TUESDAY, Feb. 5 (HealthDay News) -- The same device that keeps you from getting lost while driving in your car might also give doctors a way to determine the severity of peripheral artery disease (PAD) in patients, French researchers suggest.

People with PAD have clogged leg arteries that cause them severe pain when they walk. In this study, the researchers used Global Positioning System (GPS) devices and a computer spreadsheet to trace and analyze the maximal walking distance (MWD) of 24 PAD patients as they strolled through a public park. MWD is the maximum distance a PAD patient can walk at a normal pace on a flat surface before leg pain forces them to stop.

Currently, a treadmill test is the standard method of determining MWD. However, treadmill assessments are time-consuming, have to be done in vascular laboratories, and may not provide an accurate estimation of MWD or PAD-related disability.

"We found that MWD obtained at a person's usual pace is largely superior to the MWD measured on a treadmill. GPS may allow for a more objective measurement of walking capacity in patients with PAD," study senior author Dr. Pierre Abraham, a physician at the vascular investigation laboratory at University Hospital in Angers, France, said in a prepared statement.

"Patients often report their walking capacity varies from one day to another and also varies from one moment to another within a single stroll," Abraham said.

"GPS allows for the analysis of the distanced walked, of course, but also the speed, duration of resting, and the number of walking bouts over a prolonged recording period," he noted.

However, GPS can't entirely replace treadmills for measuring MWD, Abraham added. That's because treadmill tests are standardized and simultaneously record multiple measurements, such as blood pressure, oxygen consumption and heart rate. In addition, not all PAD patients can do the outdoor GPS test.

PAD affects about 8 million Americans, and people with the vessel disease face a four to five times greater risk of dying from cardiovascular disease.

The study is published in the current issue of Circulation.

More information

The Society for Vascular Surgery has more about peripheral artery disease.

-- Robert Preidt
SOURCE: American Heart Association, news release, Feb. 4, 2008
id=612388