NONINVASIVE VARIANT OF GORLIN FORMULA CAN BE USED TO IDENTIFY SEVERE AORTIC-STENOSIS

In recent years the continuity equation has been established as a valu able non-invasive method for calculating aortic valve area. The contin uity equation cannot be used if there is calcification or sub-valvular stenosis in the left ventricle-outflow tract, because the area of the outflow trace is not circular in those cases. The authors have tested the value of a non-invasive variant of the Gorlin formula, as an alte rnative method of identifying severe aortic stenosis. They examined 32 consecutive patients with aortic stenosis with both methods. Seventee n patients had severe stenosis (valve area less than or equal to 0.7 c m(2)), calculated by the continuity equation. The other 15 patients ha d moderate stenosis (valve area 0.7-1.0 cm(2)). Using the non-invasive variant of the Gorlin formula, the authors were able to identify 16 o f the 17 cases with severe stenosis, thus showing that the method is u seful for identifying severe aortic stenosis. (P < 0.001 by chi(2)-tes t).