A Large Pedigree With Valvuloseptal Defects

dimensions crossing perpendicularly, modeling the left ventricle as a prolate ellipsoid.3 In consequence, the areas outside the postulated ellipse (area with oblique lines in Figure 4) may be underestimated in a distorted left ventricle. The underestimated areas exist at diastole in group B and both at diastole and systole in group C. On the other hand, with the modified Simpson’s rule, the cross-sectional areas of the left ventricles are directly planimetered, so that the accurate measurement of LV volume during both diastole and systole seems to be possible regardless of the existence of LV distortion. Even in the group A patients, some angiographic volumes were underestimated 50% by echocardiography. We think that this large underestimation may be attributed to technical problems of echocardiography or tracing, because LV endocardial surfaces recorded on videotapes were partially unclear in these patients.