English to Italian Medical Medical: Cardiology Mechanical heart valves,

A defect in a mechanical heart valve:

"Prosthetic valve dysfunction is defined as any change in valve performance which results from intrinsic or extrinsic abnormalities that cause stenosis or regurgitation. Prosthetic valve dysfunction can be classified as structural deterioration, nonstructural dysfunction, or paravalvular leak.
a. Structural Valve Deterioration
Structural valve deterioration is any change in function of the prosthesis which results from an intrinsic abnormality that causes stenosis or regurgitation. The diagnosis should be based on an examination of the explanted or damaged valve. Examples include excessive wear, leaflet escape, leaflet fracture, housing crack, leaflet pitting, or sewing ring deterioration. Excluded from this category is structural deterioration which results from endocarditis, paravalvular leak, and thrombosis."