Medicinski Glasnik (Aug 2011)
A simplified proximal isovelocity surface area method for mitral valve area calculation in mitral stenosis: not requiring angle correction and calculator
Abstract
Aim To simplify proximal isovelocity surface area (PISA) method for mitral valve area (MVA) calculation that does not necessitate the usage of a calculator and angle correction, and to compare values estimated using this novel method with the values obtained by the conventional PISA, planimetry and pressure half-time (PHT) methods.Methods We evaluated patients with a wide range of mitral stenosis (MS) severity. The MVA was measured by the methods of PHT (MVA PHT), planimetry (MVApl), conventional PISA (MVAC-PISA) and the novel method of simple PISA (MVAS-PISA). Application of simple PISA was performed subsequently by division of the peak mitral inflow velocity by four; measurement of the radius by adjusting the aliasing velocity to this value; square of the radius gives the MVAS-PISA. Results Twenty patients were enrolled in the study. Peak and mean pressure gradients of patients were 20 ± 6 mmHg and 10±4 mmHg,respectively. The average values of MVApl, MVAPHT, MVAC-PISA, and MVA S-PISA were 1,54±0,41, 1,65±0,40, 1,58±0,42, 1,57 ± 0,44 cm2, respectively. MVAS-PISA had a strong correlation with the MVAC-PISA, MVApl and MVAPHT . Furthermore, there was no signi- ficant difference between simple PISA and the other methods. The agreement between planimetry and simple PISA methods for detecting severe mitral stenosis (MVA<1.5 cm2) determined by ROC analysis was very good with a sensitivity and specificity of 100 % and 92%, respectively. Conclusion Simple PISA is a user friendly method which does not take time and gives simple and correct results. If the diagnostic power of the technique is proven by more comprehensive studies, it can supersede the conventional PISA method.
