Ankle pressure index
Ankle pressure index (ankle-brachial index, ABI, ankle-brachial pressure index, ABPI, Doppler index, DI) is a non-invasive diagnostic method that gives information about the ratio of arterial pressures on the upper and lower limbs.
This is an easy test to detect asymptomatic atherosclerosis. The sensitivity and specificity of the examination is about 80%, the most reliable for Lower Extremity Peripheral Artery Disease. Decreased values predict further development of angina pectoris, IM, internal heart failure, Lower Extremity Peripheral Artery Disease or Stroke.
False-negative values are usually obtained in patients with diabetes mellitus or mediocalcinosis. For these patients, we choose other methods (eg thumb-arm index, toe-brachial index ).[1]
Calculation[edit | edit source]
We perform the calculation for both lower limbs separately. We divide the measured pressure on the lower limbs by the value of blood pressure on the upper limbs (highest or highest average value)[2].
| Index evaluation ABI | |
|---|---|
| normal value | >0,9 |
| stenosis in the area between the aorta and distal arteries | <0,9 |
| critical ischemia (closure) | <0,5 |
Measurement[edit | edit source]
Perfusion pressures are determined using Doppler ultrasound examination or oscillometric measurements using the ABI system.
The Doppler ABI determination and the oscillometric ABI determination are not interchangeable. 'Oscillometric examination' overestimates low ABI values and underestimates high ABI [3] Oscillometric examination has a high negative predictive value. [4][5][6], it is faster and its results do not depend on the experience of the investigator. It is, therefore, more suitable as an ICHDK screening method in primary care.
Discrepancies between the results increase at the ABI cut-off values (especially in incompressible arteries with calcinosis). In these patients, the method of choice is the Doppler measurement of the ankle pressure.
Refernces[edit | edit source]
Related articles[edit | edit source]
Resources[edit | edit source]
- KARETOVÁ, Debora – STANĚK, František, et al. Angiologie pro praxi. 1. edition. Praha : Maxdorf, 2001. pp. 311. ISBN 80-85912-52-X.
- ŠTEJFA, Miloš. Kardiologie. 3. edition. Praha : Grada, 2007. pp. 722. ISBN 978-80-247-1385-4.
References[edit | edit source]
- ↑ CÍFKOVÁ, Renata. Prevention of cardiovascular diseases [online]. [cit. 2021-01-21]. <https://dl1.cuni.cz/pluginfile.php/877095/mod_resource/content/2/50_nova.pdf>.
- ↑ VOWDEN, Peter – VOWDEN, Kathryn. Doppler assessment and ABPI: Interpretation in the management of leg ulceration [online]. [cit. 2019-04-21]. <http://www.worldwidewounds.com/2001/march/Vowden/Doppler-assessment-and-ABPI.html>.
- ↑ MUDR values. PETR WOHLFAHRT, Ph.D. The relationship between the characteristics of the arteries of the lower limbs and aortic stiffness and their effect on cardiovascular risk . 2014. Also available from: https://is.cuni.cz/webapps/zzp/detail/148371/.1st Faculty of Medicine (1st Faculty of Medicine). Thesis supervisor Prof. MUDr. Renata Cífková, CSc.
- ↑ Beckman JA,Higgins CO, Gerhard-Herman M. Automated oscillometric determination of the ankle-brachial index provides accuracy necessary for office practice. Hypertension 2006;47:35-8
- ↑ Mehlsen J, Wiinberg N, Bruce C. Oscillometric blood pressure measurement: a simple method in screening for peripheral arterial disease. Clin Physiol Funct Imaging 2008;28:426-9.
- ↑ MacDougall AM, Tandon V, Wilson MP, Wilson TW. Oscillometric measurement of ankle-brachial index. Can J Cardiol 2008;24:49-51
