Terminology for the definition of arterial elastic properties

A profusion of terminology for the description of arterial elastic properties can be found in the literature. This can cause confusion and make comparisons between studies and between different research groups problematical. The multitude of definitions--including "lay" terms--for indices like "compliance" and "distensibility" is highlighted, and it is proposed that a rapidly expanding field such as that studying arterial biophysical properties in vivo will not receive the respect it deserves if fundamental terms can have a multitude of different definitions, absolute values and units. It is also demonstrated that the beta stiffness index, quite widely quoted as a blood pressure corrected index, does nevertheless exhibit considerable blood pressure dependence--especially in patients with cardiovascular risk factors and/or disease. It is questioned whether all of the 24 indices identified for this review really are needed. Furthermore it is suggested that while a number of the parameters may provide complimentary information--depending on which aspects of the vasculature are to be described--there is a very real need for some form of consensus or agreement about terminology for the definition of arterial biophysical properties.