Application of Proximal Isovelocity Surface Area Method to Determine Prosthetic Mitral Valve Area

摘要: Abstract Background. In this study, we investigated the accuracy of orifice area determination prosthetic valve (Biocor) by using proximal isovelocity surface method (PISA). Thirty-two patients (26 women, 6 men; mean age 44 ± 8.1 years) were studied. Eleven in normal sinus rhythm and rest atrial fibrillation. Associated valvular lesions mild aortic regurgitation 12 moderate tricuspid 19 patients. Sizes valves 27 to 31, implantation duration was 4 8 years. Methods Results. We analyzed flow convergence zone with concept a hemispheric model. Mitral (MVA) calculation formulated MVA=2πr 2 × Va/Vm (Vm/Vm – Va), where Vm is maximal mitral velocity Vm/Vm Va correction factor account for flattening isotachs near orifice. MVA calculations PISA compared pressure half-time (PHT), continuity equation (CONT), color (CFA) methods. areas 2.17 0.17 cm , 2.22 0.21 2.19 0.22 2.16 PISA, CFA, PHT, CONT methods, respectively. Values comparison measurements different methods vs r = .86; .77; CONT, .89. Conclusions. The gives reliable estimates large orifices such as valves. Although best correlation seen method, results study also confirmed that can be applied reasonable accuracy. (J Am Soc Echocardiogr 1998;11:1056-63.)