Limb plethysmography
Definition
Limb plethysmography is a test that compares blood pressure in the legs and arms. It is usually done to check for blood flow blockages in the legs.
Alternative Names
Plethysmography - limb
How the Test is Performed
This test may be done in the health care provider's office or in a hospital. You will be asked to lie in a partially propped-up position.
Three blood pressure cuffs are wrapped snugly around your arm and leg. The health care provider inflates the cuffs and a machine called a plethysmograph measures the pulses from each cuff. The test records the maximum pressure produced when the heart contracts (systolic blood pressure).
Any differences between the pulses are noted. If there is there is a decrease in the pulse between the arm and leg, it may indicate a blockage.
When the test is complete, the blood pressure cuffs are removed.
How to Prepare for the Test
Do not smoke for at least 30 minutes before the test. You will be asked to remove all clothing from the arm and leg being tested.
How the Test Will Feel
You should not have much discomfort with this test. You should only feel the pressure of the blood pressure cuff.
Why the Test is Performed
The test is done to help rule out blocked arteries in the arms or legs.
Normal Results
There should be less than 20 mmHg difference in the systolic blood pressure of the leg compared with that of the arm.
What Abnormal Results Mean
Abnormal results may be due to:
- Arterial occlusive disease
- Blood clots
- Blood vessel changes due to diabetes
- Injury to an artery
- Other blood vessel disease (vascular disease)
Other conditions under which the test may be performed:
Risks
There are no risks.
Considerations
The test is not as accurate as an arteriography. Plethysmography may be done for very ill patients who cannot travel to the arteriography lab. This test can be used to screen for vascular disease or to follow up earlier abnormal tests.
References
Gerhard-Herman M. Guidelines for noninvasive vascular laboratory testing: a report from the American Society of Echocardiography and the Society of Vascular Medicine and Biology. J Am Soc Echocardiogr. 01 Aug 2006; 19(8): 955-72.
Reviewed By: Robert A. Cowles, M.D., Assistant Professor of Surgery, Columbia University College of Physicians and Surgeons, New York, NY. Review provided by VeriMed Healthcare Network.
