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[Measurements of intracoronary pressure and blood flow velocity]
C Seiler1, M Fleisch, U Kaufmann
1Department Innere Medizin, Kardiologie, Inselspital, Universität Bern.
Insights
New guidewires offer functional assessment of coronary artery stenosis, evaluating hemodynamic relevance. This improves diagnosis of coronary artery disease by measuring pressure gradients and blood flow velocities.
Area of Science:
- Cardiology
- Medical Devices
- Hemodynamics
Context:
- Current methods like quantitative coronary angiography lack functional assessment capabilities for coronary artery stenosis.
- Functional characterization is crucial to determine if stenosis impacts myocardial perfusion during stress, indicating hemodynamic relevance.
Purpose:
- To introduce novel miniaturized pressure- and Doppler-guidewires for functional assessment of coronary artery stenosis.
- To provide a valuable alternative to traditional non-invasive methods for evaluating coronary artery disease.
Summary:
- Miniaturized guidewires (1/3 mm) enable measurement of trans-stenotic pressure gradients and post-stenotic blood flow velocities.
- Key parameters include coronary flow velocity reserve (hyperemic to resting flow velocity ratio) and fractional flow reserve (hyperemic post-stenotic to aortic pressure ratio).
- These tools also allow quantitative assessment of collateral circulation through pressure and flow velocity measurements during stenosis occlusion.
Impact:
- Enables precise functional assessment of coronary artery stenosis, complementing anatomical imaging.
- Facilitates better understanding of hemodynamic significance and myocardial perfusion compromise.
- Advances the diagnosis and management of coronary artery disease.
Abstract:
Quantitative coronary angiography and new intracoronary imaging devices are not able to provide functional data for the assessment of the severity of coronary artery stenotic lesions. The functional characterization of coronary artery stenosis gives insight into whether it compromises myocardial perfusion under conditions of pharmacologic or physical stress, i.e., whether the stenosis has hemodynamic relevance. The measurement of trans-stenotic pressure gradients and/or post-stenotic blood flow velocities using very recently developed, miniaturized pressure- and Doppler-angioplasty guidewires (1/3 mm in diameter) provides a valuable alternative to traditional, non-invasive means for the functional assessment of coronary artery disease. The most widely employed parameters for the functional characterization of coronary artery stenoses are the ratio between flow velocities during pharmacologically induced hyperemia and at resting conditions (coronary flow velocity reserve), and the pressure-derived fractional flow reserve, i.e., the ratio of mean poststenotic to mean aortic pressure during hyperemia. Furthermore, poststenotic pressure and flow velocity measurements during and after occlusion of stenosis can be used for the quantitative assessment of collateral circulation among different vascular regions.