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 (MVA(pl)), conventional PISA (MVA(C-PISA)) and the novel method of simple PISA (MVA(S-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 MVA(S-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 MVA(pl), MVA(PHT), MVA(C-PISA) and MVA (S-PISA) were 1,54 +/- 0,41, 1,65 +/- 0,40, 1,58 +/- 0,42, 1,57 +/- 0,44 cm(2), respectively. MVA(S-PISA) had a strong correlation with the MVA(C-PISA), MVA(pl), and MVA(PHT). Furthermore, there was no significant difference between simple PISA and the other methods. The agreement between planimetry and simple PISA methods for detecting severe mitral stenosis (MVA<1.5 cm(2)) 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.