Non-invasive estimation of aortic blood pressures: a close look at current devices and methods.

While for years clinicians have used cuff pressure to assess patients' cardiovascular risk, recent evidences has shown that aortic pressure, or more specifically aortic systolic and aortic pulse pressures, have a better prognostic value to predict cardiovascular events and mortality. This led to the emergence of multiple methods and devices to assess aortic pressure non-invasively. Some use scaled waveforms measured at the carotid level with tonometry, or ultrasounds. Others use transfer function or mathematical modelling from radial or brachial traces acquired from volume plethsymography or applanation tonometry. Not all these techniques are equivalent and most of them have the major flaw of using brachial cuff pressure to scale their results. The purpose of this review is to present the strengths and weaknesses of techniques and various commercial devices to estimate aortic systolic pressure.