Errors in pressure gradient measurement by continuous wave Doppler ultrasound: Type, size and age effects in bioprosthetic aortic valves
Autor: | Sandy F.C. Stewart, Richard E. Clark, Michael Proschan, Edward P. Nast, Thomas L. Talbot, Francisco A. Arabia |
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Rok vydání: | 1991 |
Předmět: |
Aortic valve
Hemodynamics Prosthesis Design Bernoulli's principle symbols.namesake Transducers Pressure medicine Humans Pressure gradient Bioprosthesis business.industry Ultrasound Models Cardiovascular Signal Processing Computer-Assisted Anatomy Pressure sensor Echocardiography Doppler Models Structural medicine.anatomical_structure Evaluation Studies as Topic Aortic Valve Heart Valve Prosthesis symbols Continuous wave Cardiology and Cardiovascular Medicine business Doppler effect Biomedical engineering |
Zdroj: | Journal of the American College of Cardiology. 18:769-779 |
ISSN: | 0735-1097 |
Popis: | The accuracy of continuous wave Doppler ultrasound in deriving pressure gradients across bioprosthetic heart valves was evaluated in an in vitro pulse duplicator. Simultaneous pressure transducer and Doppler measurements were made in new and explanted aortic bioprosthetic valves of several sizes and four types: Carpentier-Edwards, Ionescu-Shiley, Hancock standard and Hancock modified. The mean and peak gradients calculated by the modified Bernoulli equation from Doppler velocity measurements were always greater than those measured manometrically, despite corrections for location dependence of the manometric gradient (or pressure recovery). The relation between manometric and ultrasonically determined gradient was found to be statistically dependent on the valve type (mean gradient p less than 0.0001; peak gradient p = 0.0003) and size (mean gradient p = 0.0089; peak gradient p = 0.0107). Effects of implantation were observed, but were not shown to be significant. It is concluded that the continuous wave Doppler velocity data overestimated prosthetic valve pressure gradient in all cases, even when pressure recovery was taken into account. Clinicians should be wary of Doppler data when making major diagnostic or therapeutic decisions. |
Databáze: | OpenAIRE |
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