Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Old technology helps find new test for leg artery disease

08.06.2006


Between 8 and 12 million Americans are affected by peripheral arterial disease, or PAD, where the arteries that bring blood to the legs are blocked by atherosclerotic plaque. The incidence of PAD is expected to rise in coming decades as the population ages, one reason it’s vital to develop new methods to diagnose the severity of PAD and develop new drugs to treat it.



By examining the physiology of patients who exercised under a magnetic resonance imaging scanner (MRI), doctors at the University of Virginia Health System have devised a new test to diagnose and follow peripheral arterial disease. This test shows promise in helping drug companies test new PAD medications and, perhaps in the near future, may give doctors the ability to tell which patients are at risk for developing PAD-related complications and require stenting, bypass surgery or even amputation of a leg.

A UVa cardiologist, Dr. Christopher Kramer, and his colleagues, measured how fast the leg muscles of patients with PAD, and people without PAD, recovered a phosphorus substance called phosphocreatine (PCr), the major energy "store" in muscle cells. Tests at UVa on 20 patients with mild to moderate PAD and 14 people without PAD, showed that the median time to recover phosphocreatine at the end of exercise in PAD patients was three times slower, 91 seconds in the PAD group versus 35 seconds in the normal group.


"Not only is this a good test that can discriminate patients with PAD from those without the disease," Kramer said, "but a longer exercise time was a marker of worse outcomes in PAD patients. Those patients with events, including amputations and surgery, had a longer recovery time." Kramer’s findings are published in the June 6 issue of the Journal of the American College of Cardiology found on the web at: http://www.cardiosource.com/jacc/index.asp

What was unusual is that the UVa doctors stepped back in time and used a measurement technique developed in the 1970’s called MR spectroscopy, the forerunner to modern MR imaging. "We were somewhat surprised that of all new tests for PAD that we have been developing, the one that seemed to work the best is spectroscopy. It’s relatively simple and not particularly sexy, but very accurate physiologically," Kramer said.

All of the patients tested exercised to exhaustion on a special push-pedal machine in an MRI scanner. A spectroscopy coil in the MRI then took readings of the phosphocreatine level in the legs every 15 seconds for several minutes afterward. "If the blood flow is poor," Kramer explained, "PCr recovery is slow, because the muscle is not getting the energy sources it needs to restore PCr. It is an energy-dependant process."

Right now, doctors use several tests to measure PAD severity, including measuring blood pressure in the ankles and comparing it to blood pressure in the arms. Doctors can also do an angiogram of the artery, using dye to show where blockages exist. But, Kramer said, "if you are following a patient over weeks and months, you don’t want to do multiple angiograms if you don’t have to, and certainly not x-rays or CT scans because of the radiation and contrast dye involved." Yet another reason this new test may be so valuable.

Kramer said people with peripheral arterial disease often have coronary and cerebrovascular disease as well. The risk factors for PAD include smoking, high blood pressure, high lipids and diabetes. People with PAD generally have pain in the calves when they exercise. Those with severe disease can have pain at rest and tissue loss, including ulcers.

Bob Beard | EurekAlert!
Further information:
http://www.virginia.edu
http://www.cardiosource.com/jacc/index.asp

More articles from Health and Medicine:

nachricht Researchers release the brakes on the immune system
18.10.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht Norovirus evades immune system by hiding out in rare gut cells
12.10.2017 | University of Pennsylvania School of Medicine

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Osaka university researchers make the slipperiest surfaces adhesive

18.10.2017 | Materials Sciences

Space radiation won't stop NASA's human exploration

18.10.2017 | Physics and Astronomy

Los Alamos researchers and supercomputers help interpret the latest LIGO findings

18.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>