Echocardiographic assessment of patient-prosthesis mismatch

Echocardiographic assessment of patient-prosthesis mismatch Patient-prosthesis mismatch is present when the effective prosthetic valve area is less than that of the normal human valve [1]. The reduction in valve area is usually mild to moderate and may not be off immediate clinical significance. Occasionally, it can be severe and patients may be hemodynamically and symptomatically worse after valve replacement. This typically occurs after aortic valve replacement for aortic stenosis as the aortic annulus is not dilated and permits insertion of only a smaller prosthetic valve compared to that in aortic regurgitation. Similar situation can be there after mitral valve replacement for mitral stenosis. Patient prosthesis-mismatch is an important cause of increased transvalvar gradient detected by Doppler echocardiography. Effective orifice area of an aortic prosthetic valve may be too small in relation to patient’s body surface area and can result in abnormally high gradients [2]. Indexing of calculated valve area with respect to body surface area is usually done to assess patient prosthesis mismatch. Indexed effective orifice area of an aortic prosthetic valve should be more than 0.85 cm2/m2 to avoid significant gradient at rest and exercise [3]. This corresponds to the concept that in moderate stenosis of native aortic valve, the indexed effective orifice area is <0.90 cm2/m2. An indexed effective orifice area ≤0.60 cm2/m2 will correspond to severe stenosis and requi...
Source: Cardiophile MD - Category: Cardiology Authors: Tags: Echocardiography Source Type: blogs