Doppler echocardiography in normally functioning replacement aortic valves: a review of 129 studies

Area of Science:

• Cardiology
• Biomedical Engineering
• Medical Imaging

Background:

• Echocardiography is crucial for evaluating prosthetic aortic valves.
• Valve hemodynamics are influenced by design and size.
• Published data up to 2005 was reviewed.

Purpose of the Study:

• To review and compare the hemodynamic obstruction of various aortic valve replacement types.
• To identify trends in valve obstructiveness based on design and material.

Main Methods:

• Literature review of published studies on aortic valve replacement hemodynamics.
• Comparative analysis of valve obstructiveness based on reported data.
• Derivation of guide thresholds for obstruction.

Main Results:

• Caged-ball valves were the most obstructive.
• Stented porcine and single tilting-disc valves showed significant obstruction.
• Stented bovine pericardial and intra-annular bileaflet mechanical valves were less obstructive.
• Stentless valves and reduced-cuff mechanical bileaflet valves were even less obstructive.
• Homografts demonstrated the least obstruction.

Conclusions:

• Valve design significantly impacts hemodynamic function and obstruction.
• A hierarchy of obstructiveness exists among different prosthetic aortic valve types.
• Guide thresholds for identifying obstruction were established.