aortic impedance
The opposition to pulsatile blood flow in the aorta, determined by vessel elasticity, resistance, and wave reflection properties.
Full Definition
Aortic impedance is a measure of the opposition to pulsatile blood flow in the aorta, encompassing both steady-state resistance and the dynamic properties of the arterial system including compliance and wave reflections. It is influenced by factors such as aortic stiffness, diameter, wall thickness, and the presence of branch vessels that create reflection sites. Aortic impedance directly affects cardiac workload and ventricular-arterial coupling. Changes in impedance following aortic surgery, particularly with synthetic graft placement, can significantly impact postoperative cardiac function and long-term outcomes. Understanding impedance characteristics is crucial for optimizing surgical techniques and graft selection.
Usage
Usage note: Complex hemodynamic concept; distinguish from simple resistance or compliance measures.
In Context
- "Postoperative measurement showed increased aortic impedance following synthetic graft placement, contributing to elevated afterload." — hemodynamic assessment
- "The patient's elevated aortic impedance was attributed to extensive atherosclerotic disease and reduced vessel compliance." — cardiac catheterization report