Criteria to detect mitral prosthetic valve dysfunction via continuous wave Doppler echocardiography

Area of Science:

• Cardiology
• Biomedical Engineering
• Diagnostic Imaging

Background:

• Prosthetic heart valves are crucial for patients with valvular heart disease.
• Accurate diagnosis of prosthetic valve dysfunction is essential for patient management.
• Doppler echocardiography is a key non-invasive tool for assessing cardiac function.

Purpose of the Study:

• To establish diagnostic criteria for mitral prosthetic valve dysfunction using Doppler echocardiography.
• To evaluate the function of St. Jude Medical (SJM) and Björk-Shiley (B-S) mechanical valves.
• To correlate echocardiographic parameters with prosthetic valve performance.

Main Methods:

• Doppler echocardiography was performed on 100 patients post-mitral valve replacement (50 SJM, 50 B-S).
• Mitral Valve Area (MVA) was calculated using the Pressure Half Time (PHT) method (220/PHT).
• Analysis included correlations between MVA, left ventricular function, geometric valve area (GVA), body surface area (BSA), and maximum disc-opening angle (maxOA).

Main Results:

• In SJM valves, MVA correlated with the valve area index (GVA/BSA). The average % area index was 100.2% +/- 12.8%, with no dysfunction observed.
• A % area index below 73% was proposed as a criterion for SJM valve dysfunction.
• For B-S valves, 19 patients had reduced maximum opening angles (<58 degrees), associated with decreased MVA and % area index (<70% if maxOA <50 degrees).

Conclusions:

• The % area index, calculated using Doppler echocardiography, can help diagnose dysfunction in SJM mitral prosthetic valves.
• Reduced maximum opening angles in B-S valves are linked to decreased MVA and % area index, suggesting potential dysfunction.
• Doppler echocardiography provides valuable insights into the functional status of mechanical mitral prosthetic valves.