Résumé
Echocardiographic assessment of left atrial pressure [LAP] in mitral stenosis [MS] is controversial. We sought to examine the role of the radius of the proximal isovelocity surface area [PISA-r] in the assessment of the hemodynamic status of MS after fixing the aliasing velocity [Val]. We studied 42 candidates of balloon mitral valvuloplasty [BMV], for whom pre-BMV echocardiography was done and LAP invasively measured before dilatation. PISA-r was calculated after fixing aliasing velocity to 33 cm/s. In addition, the ratio IVRT/Te'-E was also measured, where IVRT was isovolumic relaxation time, and Te'-E was the time difference between the onset of mitral flow E-wave and mitral annular early diastolic velocity. IVRT/Te'-E and PISA-r showed a strong correlation with LAP [r= -0.715 and -0.637, all p < 0.001] and with right-sided pressures. In addition, PISA-r correlated with mitral valve area by planimetry method [MVA] and with left ventricular outflow tract stroke volume [r = 0.66 and 0.71, all p < 0.001]. Receiver operator characteristic curve [ROC-curve] showed that PISA-r was not inferior to IVRT/Te'-E in differentiating LAP >/=25 from <25 mmHg. Provided that Val is set to a constant of 33 cm/s, PISA-r can assess the hemodynamic status of MS, and seems a simple alternative to the tedious IVRT/Te'-E for estimation of LAP