aortic valve effective orifice area
The functional cross-sectional area available for blood flow through the aortic valve during systole. Key parameter for assessing aortic stenosis severity and prosthetic valve performance.
Full Definition
The aortic valve effective orifice area (EOA) represents the functional cross-sectional area through which blood flows during systole, accounting for the three-dimensional geometry of the valve opening and flow convergence effects. This measurement is more physiologically relevant than anatomical orifice area because it reflects the actual hemodynamic performance of the valve. EOA is typically calculated using the continuity equation, which incorporates stroke volume and peak velocity measurements. In aortic stenosis, EOA less than 1.0 cm² indicates severe stenosis, while values between 1.0-1.5 cm² suggest moderate stenosis. For prosthetic valves, EOA determines the degree of patient-prosthesis mismatch and influences long-term outcomes.
Usage
Usage note: Distinguish from anatomical measurements; specify calculation method when reporting.
In Context
- "The calculated effective orifice area of 0.7 cm² confirmed severe aortic stenosis." — Echocardiography report
- "Post-operative EOA measurements suggested mild patient-prosthesis mismatch." — Postoperative assessment