CALCULATION OF THE REGURGITATION FRACTION OF MITRAL-INSUFFICIENCY BY DOPPLER-ECHOCARDIOGRAPHIC STUDY OF THE PISA METHOD

The aim of this study was to propose a new method for calculating the regurgitation fraction of mitral insufficiency by the proximal isovelo city surface area (PISA) method and to compare it with the value of th e catheter regurgitation fraction. Thirty-five patients (21 men and 14 women) aged 59 +/- 13 years with isolated mitral insufficiency were s tudied. Analysis of the proximal isovelocity surface area enabled calc ulation of an instantaneous maximum regurgitant flow, surface of the r egurgitant orifice and the regurgitant volume. The regurgitant fractio n was calculated by dividing the regurgitant volume by the sum of the regurgitant volume and aortic stroke volume measured by Doppler echoca rdiography. These parameters were compared with the corresponding cath eter data and the angiographic grade of mitral insufficiency. The echo cardiographic and catheter studies were performed within 1.7 +/- 1.2 d ays. There was a statistically significant correlation between the ins tantaneous maximum regurgitant flow calculated by the PISA method and the catheter regurgitant flow (r = 0.88; p = 0.0001) ; between the reg urgitant volume calculated by the PISA method and the catheter regurgi tant volume (r = 0.85; p = 0.0001) and the regurgitation fraction calc ulated by the PISA method and the catheter regurgitant fraction (r = 0 .82; p = 0.0001). A regurgitant fraction by the PISA method of > 45 % corresponded to severe mitral regurgitation (greater than or equal to angiographic grade 3 and/or a catheter regurgitant fraction greater th an or equal to SO %) with a sensitivity of 88 % and a specificity of 1 00 %. The PISA method should form part or routine quantification of mi tral insufficiency.