OBJECTIVE Continuity equation to evaluate aortic valve area (AVA(CE)) is critically dependent on accurate measurement of left ventricular outflow tract diameter and velocity. To circumvent these limitations, the present study aimed to generate nomograms for a facilitated estimation of aortic valve area using peak aortic valve pressure gradient (DeltapAv) and left ventricular ejection fraction (LVEF). RESULTS Two hundred and fifty-five subjects with non-invasively and invasively defined aortic valve stenosis (AS) formed the basis of this study. Basis of the nomograms was the correlation analysis between DeltapAv and AVA as estimated by AVA(CE) within different LVEF groups. LVEF differed from 65.6 +/- 1.8% (Group I, LVEF > 60%) to 34.5 +/- 4.3% (Group IV, LVEF > or = 30%). DeltapAv and AVA varied from 85.6 +/- 19.5 mmHg and 0.69 +/- 0.16 cm2 in Group I to 58.5 +/- 15.9 mmHg and 0.73 +/- 0.23 cm2 in Group IV (DeltapAv: P < 0.001). Mean AVA(CE) showed no significant difference between the groups. Correlation between DeltapAv and AVA(CE) was statistically significant with P < 0.001 in all subgroups (R2 between 0.72 and 0.76). Furthermore, a prospective estimation of AVA using the developed nomograms correlated very well with invasively determined AS using the Gorlin formula (R2 = 0.76, SEE = 0.21 cm2, bias 0.04 cm2). CONCLUSIONS The present study has established and confirmed a solid, easy to use nomogram-based method to accurately quantify severe AS.