Pulse wave velocity

Pulse wave velocity (PWV) is the velocity at which the blood pressure pulse propagates through the circulatory system, usually an artery or a combined length of arteries. PWV is used clinically as a measure of arterial stiffness and can be readily measured non-invasively in humans, with measurement of carotid to femoral PWV (cfPWV) being the recommended method. cfPWV is highly reproducible, and predicts future cardiovascular events and all-cause mortality independent of conventional cardiovascular risk factors. It has been recognized by the European Society of Hypertension as an indicator of target organ damage and a useful additional test in the investigation of hypertension. Pulse wave velocity (PWV) is the velocity at which the blood pressure pulse propagates through the circulatory system, usually an artery or a combined length of arteries. PWV is used clinically as a measure of arterial stiffness and can be readily measured non-invasively in humans, with measurement of carotid to femoral PWV (cfPWV) being the recommended method. cfPWV is highly reproducible, and predicts future cardiovascular events and all-cause mortality independent of conventional cardiovascular risk factors. It has been recognized by the European Society of Hypertension as an indicator of target organ damage and a useful additional test in the investigation of hypertension. The theory of the velocity of the transmission of the pulse through the circulation dates back to 1808 with the work of Thomas Young. The relationship between pulse wave velocity (PWV) and arterial wall stiffness can be derived from Newton's second law of motion ( F = m a {displaystyle F=ma} ) applied to a small fluid element, where the force on the element equals the product of density (the mass per unit volume; ρ {displaystyle ho } ) and the acceleration. The approach for calculating PWV is similar to the calculation of the speed of sound, c 0 {displaystyle {c_{0}}} , in a compressible fluid (e.g. air): c 0 = B / ρ {displaystyle c_{0}={sqrt {B/ ho }}} , where B {displaystyle {B}} is the bulk modulus and ρ {displaystyle { ho }} is the density of the fluid. For an incompressible fluid (blood) in a compressible (elastic) tube (e.g. an artery): P W V = V ⋅ d P / ( ρ ⋅ d V ) {displaystyle PWV={sqrt {Vcdot dP/( ho cdot dV)}}} , where V {displaystyle V} is volume per unit length and P {displaystyle P} is pressure. This is the equation derived by Otto Frank, and John Crighton Bramwell and Archibald Hill.