Radius of proximal isovelocity surface area in the assessment of rheumatic mitral stenosis: Connecting flow to anatomy and hemodynamics

Background: 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). methods and results: 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. conclusion: 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. © 2015 the authors.