Prospective Evaluation of a Method for Estimating Ascending Aortic Pressure From the Radial Artery Pressure Waveform

Abstract

Abstract-Pressure wave reflection in the upper limb causes amplification of the arterial pulse so that radial systolic and pulse pressures are greater than in the ascending aorta. Wave transmission properties in the upper limbs (in contrast to the descending aorta and lower limbs) change little with age, disease, and drug therapy in adult humans. Such consistency has led to use of a generalized transfer function to synthesize the ascending aortic pressure pulse from the radial pulse. Validity of this approach was tested for estimation of aortic systolic, diastolic, pulse, and mean pressures from the radial pressure waveform. Ascending aortic and radial pressure waveforms were recorded simultaneously at cardiac surgery, before initiation of cardiopulmonary bypass, with matched, fluid-filled manometer systems in 62 patients under control conditions and during nitroglycerin infusion. Aortic pressure pulse waves, generated from the radial pulse, showed agreement with the measured aortic pulse waves with respect to systolic, diastolic, pulse, and mean pressures, with mean differences Ͻ1 mm Hg. Control differences in Bland-Altman plots for meanϮSD in mm Hg were systolic, 0.0Ϯ4.4; diastolic, 0.6Ϯ1.7; pulse, Ϫ0.7Ϯ4.2; and mean pressure, Ϫ0.5Ϯ2.0. For nitroglycerin infusion, differences respectively were systolic, Ϫ0.2Ϯ4.3; diastolic, 0.6Ϯ1.7; pulse, Ϫ0.8Ϯ4.1; and mean pressure, Ϫ0.4Ϯ1.8.

Measurement of pulse wave velocity in children and young adults: a comparative study using three different devices

“…29 The applanation tonometry devices PP and SC are invasively validated. 12,27 Both use electrocardiogram-gated sequential tonometric measurements to asses aortic (carotid-femoral) PWV and are widely used in clinical and research practice. [23][24][25] Survival studies in adults indicate that PWV measured by applanation tonometry has a good clinical predictive value.…”

“…[6][7][8][9] In a previous work, including more than 1000 children and teenagers, we provided reference values for pulse wave velocity (PWV), thereby constituting a suitable tool for longitudinal clinical studies assessing subgroups of children who are at long-term risk of cardiovascular disease. 10 A multitude of various methods and techniques have been used to assess PWV in adults such as applanation tonometry, 11,12 ultrasound, 13,14 methods using mechanotransducers 15 and computerized oscillometry; 16 furthermore, a number of comparative studies with diverging results have been published concerning the comparability of the different methods. [17][18][19][20][21] Instruments based on the principle of applanation tonometry (PulsePen (PP) (DiaTecne, Milan, Italy) and Sphygmocor (SC) (AtCor, Sydney, Australia) have been extensively used.…”

“…[22][23][24][25][26] PP and SC devices have been validated invasively in adults. 12,27 It is claimed that, in children, PWV measurements by applanation tonometry may be difficult to carry out as they are time consuming and require some degree of patient cooperation. 9 Thus, manufacturers are promoting new easy-to-use instruments to enter the market as valid tools for measuring aPWV.…”

Comparison of two measuring instruments, B-pro and SphygmoCor system as reference, to evaluate central systolic blood pressure and radial augmentation index

“…[8][9][10] The reference device for estimating these measures is the SphygmoCor system (pulse wave analysis). 7,11 Recently, a new system has been developed that estimates derived aortic pressure using an n-point moving average method (B-Pro device s + A-pulse software). 12 This device has been validated in some sub-populations, particularly in the high-risk hypertensive individuals and in the Asian populations, but it has not been validated to date in healthy Caucasians without drug treatment.…”

Central blood pressure estimation for the masses moves a step closer

“…Although the latter has been the subject of much criticism in the literature, it appears to be accurate when compared against direct ascending aortic invasive pressure measurements. 15,16 Nevertheless, both techniques use a hand-held pizo-electric probe, and some skill is required to obtain good-quality waveforms. This, together with the desire to move central pressure estimation into a more clinical arena, has led to the development of a number of more 'userfriendly', operator-independent devices such as the Arteriograph, Omron HEM9000AI and Vicorder.…”