Blind Identification of the Central Aortic Pressure Waveform from Multiple Peripheral Arterial Pressure Waveforms

Author(s):  
Gokul Swamy ◽  
Qi Ling ◽  
Tongtong Li ◽  
Ramakrishna Mukkamala
2001 ◽  
Vol 51 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Masaru Sugimachi ◽  
Toshiaki Shishido ◽  
Kunio Miyatake ◽  
Kenji Sunagawa

2020 ◽  
Vol 23 (1) ◽  
pp. 7-11
Author(s):  
P. Nikolov

The PURPUSE of the present study is changes in function and structure of large arteries in individuals with High Normal Arterial Pressure (HNAP) to be established. MATERIAL and METHODS: Structural and functional changes in the large arteries were investigated in 80 individuals with HNAP and in 45 with optimal arterial pressure (OAP). In terms of arterial stiffness, pulse wave velocity (PWV), augmentation index (AI), central aortic pressure (CAP), pulse pressure (PP) were followed up in HNAP group. Intima media thickness (IMT), flow-induced vasodilatation (FMD), ankle-brachial index (ABI) were also studied. RESULTS: Significantly increased values of pulse wave velocity, augmentation index, central aortic pressure, pulse pressure are reported in the HNAP group. In terms of IMT and ABI, being in the reference interval, there is no significant difference between HNAP and OAP groups. The calculated cardiovascular risk (CVR) in both groups is low. CONCLUSION: Significantly higher values of pulse wave velocity, augmentation index, central aortic pressure and pulse pressure in the HNAP group are reported.


2008 ◽  
Vol 294 (6) ◽  
pp. H2535-H2539 ◽  
Author(s):  
David G. Edwards ◽  
Matthew S. Roy ◽  
Raju Y. Prasad

Cardiovascular events are more common in the winter months, possibly because of hemodynamic alterations in response to cold exposure. The purpose of this study was to determine the effect of acute facial cooling on central aortic pressure, arterial stiffness, and wave reflection. Twelve healthy subjects (age 23 ± 3 yr; 6 men, 6 women) underwent supine measurements of carotid-femoral pulse wave velocity (PWV), brachial artery blood pressure, and central aortic pressure (via the synthesis of a central aortic pressure waveform by radial artery applanation tonometry and generalized transfer function) during a control trial (supine rest) and a facial cooling trial (0°C gel pack). Aortic augmentation index (AI), an index of wave reflection, was calculated from the aortic pressure waveform. Measurements were made at baseline, 2 min, and 7 min during each trial. Facial cooling increased ( P < 0.05) peripheral and central diastolic and systolic pressures. Central systolic pressure increased more than peripheral systolic pressure (22 ± 3 vs. 15 ± 2 mmHg; P < 0.05), resulting in decreased pulse pressure amplification ratio. Facial cooling resulted in a robust increase in AI and a modest increase in PWV (AI: −1.4 ± 3.8 vs. 21.2 ± 3.0 and 19.9 ± 3.6%; PWV: 5.6 ± 0.2 vs. 6.5 ± 0.3 and 6.2 ± 0.2 m/s; P < 0.05). Change in mean arterial pressure but not PWV predicted the change in AI, suggesting that facial cooling may increase AI independent of aortic PWV. Facial cooling and the resulting peripheral vasoconstriction are associated with an increase in wave reflection and augmentation of central systolic pressure, potentially explaining ischemia and cardiovascular events in the cold.


2008 ◽  
Vol 10 (4) ◽  
pp. 295-303 ◽  
Author(s):  
Wilmer W. Nichols ◽  
Scott J. Denardo ◽  
Ian B. Wilkinson ◽  
Carmel M. McEniery ◽  
John Cockcroft ◽  
...  

2015 ◽  
Vol 309 (5) ◽  
pp. H969-H976 ◽  
Author(s):  
Samuel Vennin ◽  
Alexia Mayer ◽  
Ye Li ◽  
Henry Fok ◽  
Brian Clapp ◽  
...  

Estimation of aortic and left ventricular (LV) pressure usually requires measurements that are difficult to acquire during the imaging required to obtain concurrent LV dimensions essential for determination of LV mechanical properties. We describe a novel method for deriving aortic pressure from the aortic flow velocity. The target pressure waveform is divided into an early systolic upstroke, determined by the water hammer equation, and a diastolic decay equal to that in the peripheral arterial tree, interposed by a late systolic portion described by a second-order polynomial constrained by conditions of continuity and conservation of mean arterial pressure. Pulse wave velocity (PWV, which can be obtained through imaging), mean arterial pressure, diastolic pressure, and diastolic decay are required inputs for the algorithm. The algorithm was tested using 1) pressure data derived theoretically from prespecified flow waveforms and properties of the arterial tree using a single-tube 1-D model of the arterial tree, and 2) experimental data acquired from a pressure/Doppler flow velocity transducer placed in the ascending aorta in 18 patients (mean ± SD: age 63 ± 11 yr, aortic BP 136 ± 23/73 ± 13 mmHg) at the time of cardiac catheterization. For experimental data, PWV was calculated from measured pressures/flows, and mean and diastolic pressures and diastolic decay were taken from measured pressure (i.e., were assumed to be known). Pressure reconstructed from measured flow agreed well with theoretical pressure: mean ± SD root mean square (RMS) error 0.7 ± 0.1 mmHg. Similarly, for experimental data, pressure reconstructed from measured flow agreed well with measured pressure (mean RMS error 2.4 ± 1.0 mmHg). First systolic shoulder and systolic peak pressures were also accurately rendered (mean ± SD difference 1.4 ± 2.0 mmHg for peak systolic pressure). This is the first noninvasive derivation of aortic pressure based on fluid dynamics (flow and wave speed) in the aorta itself.


2003 ◽  
Vol 105 (2) ◽  
pp. 219-225 ◽  
Author(s):  
Geoffrey C. CLOUD ◽  
Chakravarthi RAJKUMAR ◽  
Jaspal KOONER ◽  
Jonathan COOKE ◽  
Christopher J. BULPITT

Central arterial pressure, measured close to the heart, may be of more patho-physiological importance than conventional non-invasive cuff blood pressure. The technique of applanation tonometry using SphygmoCor® has been proposed as a non-invasive method of estimating central pressure. This relies on mathematically derived generalized transfer functions, which have been previously validated using invasive peripheral pressure measurements. We compared simultaneous estimates of central aortic pressure using this technique with those measured directly during the routine diagnostic cardiac catheterization of 30 subjects (age range 27–84 years), half of whom were aged 65 years or more. This was done by applanating the left radial artery and recording the non-invasive brachial cuff blood pressure to generate a central aortic pressure estimate, using the SphygmoCor® radial transfer function. The comparative results were analysed using Bland—Altman plots of mean difference. SphygmoCor®, on average, underestimated systolic central arterial pressure by 13.3 mmHg and overestimated diastolic pressure by 11.5 mmHg. The results were similar in patients aged under and above 65 years. Furthermore, non-invasively measured brachial pressures were seen to give an overall closer estimate of the central arterial pressure than the SphygmoCor® system. The transfer function has been validated from invasively measured arterial pressures and the current use by the system of non-invasive measures may explain the discrepancies. However, age, drugs and arterial disease would also be expected to play a role.


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