Pulse wave analysis and arterial stiffness.
Assessment of the pulse character is one of the earliest recorded medical skills, but objective recordings of the pulse waveform--sphygmography--emerged only in the nineteenth century. This technique fell into disuse with the advent of the sphygmomanometer, but interest has recently been rekindled with the introduction of computer technology and applanation tonometry. Pulse wave analysis (PWA) is a technique that allows the accurate recording of peripheral pressure waveforms and generation of the corresponding central waveform, from which the augmentation index and central pressure can be derived. In clinical studies, we have shown that PWA is a highly reproducible technique and easy to apply. Together with ECG-gated assessment of pulse wave velocity, also using PWA, these measures provide important information about arterial stiffness. Stiffness may be partly under the functional control of the endothelium, which releases a number of vasoactive mediators, as well as being structurally determined. Increased stiffness is associated with most cardiovascular risk factors and established atherosclerosis. However, increased stiffness may be more than a marker for occult atheroma. It may be involved in the pathogenesis of cardiovascular disease by a number of mechanisms. Assessment of stiffness, perhaps using PWA, may therefore provide better risk assessment and allow treatment to be targeted to those most in need.