P860Proximal flow convergence region and vena contracta in mitral regurgitation: presumptions versus truth by RT-3D TEE

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Introduction. Nonconventional PISA method and vena contracta method are based on 2 similar presumptions: 1) constant regurgitant orifice and 2) hemispheric proximal flow convergence region (PFCR), respective round vena contracta (VC) cross-section. Daily practice shows that many regurgitant orifices are not constant and their respective PFCR are not hemispheric and many VC have non-circular cross-section. It might have significant impact to the quantification of mitral regurgitation (MR). The true shape of PFCR and VC as well as their behaviour haven't been finally clarified yet.Aim of the study. To characterize the 3D shape and behaviour of PFCR and 2D shape and behaviour of VC in MR using RT-3D TEE.Methods: 61 consecutive patients with wide variety of mitral regurgitant lesions were investigated using RT-3D TEE modality. They had a total of 65 regurgitant orifices. Full volume RT-3D CFM TEE investigation was carried out using iE33 PHILIPS system. The 3D data sets were analyzed using Qlab program. PFCR and the respective VC were analyzed in early-, mid- and late-systole. Radius r1-3 and seeming length l'1-3 were measured on PFCR, while width w1-3, length l1-3 and area a1-3 were measured on VC cross-section. Using our own program for nonconventional PISA method we also calculated in every systole 3 individual regurgitant orifice areas (ROA) ROA1-3 and 3 individual regurgitant volumes (RV) RV1-3. Statistical analysis of acquired data comprised: relative incidence of the shapes of PFCR, and VC, relative incidence of behaviour (constant versus variable) in PFCR, ROA and VC and also a series of 9 regressions between VC w1-3, l1-3 and a1-3 and the respective ROA1-3 as well as 9 regressions between VC w1-3, l1-3 and a1-3 and the respective RV1-3.Results. PFCR was hemispheric only in 5% and hemiellispoidal in 95%. VC had round crossection in 9% only while elongated in 91%. PFCR was constant in only 14% while variable in 86%. VC was constant in only 17%, while variable in 83%. Regressions between VC dimensions or area and ROA or RV reached best correlation coefficient (0,78, resp. 0,76) for VC area.Conclusions: The shape as well as behaviour of PFCR, ROA and VC are similar. Vast majority of PFCR and VC are non-hemispheric respective non-circular and vast majority of PFCR, ROA and VC are not constant. Conventional PISA method and VC method need extensive revision in order to match the shape and behaviour of regurgitant phenomena and to yield more reliable results.

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