Temporal variations in effective orifice area during ejection in patients with valvular aortic stenosis

Area of Science:

• Cardiovascular Physiology
• Medical Imaging
• Biomechanical Engineering

Background:

• Effective orifice area (EOA) is standard for aortic stenosis (AS) severity but is static.
• Dynamic EOA changes during ejection may better reflect hemodynamic severity.
• Current assessment may miss nuances of AS pathophysiology.

Purpose of the Study:

• To investigate dynamic EOA changes during ejection in severe AS versus controls.
• To determine if ejection patterns vary with AS severity.
• To correlate ejection dynamics with AS hemodynamic severity.

Main Methods:

• Compared dynamic EOA changes in severe AS (n=15) and controls (n=15).
• Analyzed ejection patterns across varying AS severity (n=45).
• Measured velocities (V(LVOT), V(AS)) and EOA opening rates during ejection.

Main Results:

• Severe AS showed delayed peak velocities (V(LVOT), V(AS)) and slower EOA opening rates.
• EOA reached maximum later in severe AS, with a prolonged opening phase versus controls.
• EOA opening rate and timing correlated with mean pressure gradient in AS patients.

Conclusions:

• Dynamic EOA changes and ejection timing differ significantly in severe AS.
• These dynamic parameters provide additional insights into hemodynamic severity.
• Ejection dynamics may refine the assessment of AS pathophysiology.