Real-time, automated echocardiographic measures of ventricular area and area change: comparison with radionuclide technique.

Echocardiography now permits tracking of the blood-endocardial border and automatic measurement of ventricular area throughout the cardiac cycle. To determine the accuracy of this technique, we compared echocardiographic measurements of area with similar measurements made by radionuclide technique in 19 children, ages 4-24 years (mean 13 years). The blood-endocardial border was tracked from the apical two-chamber view and radionuclide measurements were made from the left anterior oblique view. We measured echocardiographic end-diastolic area, end-systolic area, and fractional area change from the average of five cardiac cycles. The radionuclide area measurements were made from a gated blood pool study incorporating 700-1200 cardiac cycles. Results were compared by bias analysis. The mean differences (+/- 1 S.D.) between left ventricular area measurements were: end-diastole 1.13 +/- 2.3 cm2, end-systole -0.90 +/- 1.33 cm2, and fractional area change 7.4 +/- 9.3 (%). Differences between the measurements were within the limit of agreement (mean +/- 2 S.D.) in 55 of 57 measurements. The area measurements were not free from bias; the mean differences of area measurements were significantly different from zero for end-diastolic area (P < or = 0.05), end-systolic area (P < or = 0.01), and fractional area change (P < or = 0.002). Echocardiography tended to underestimate end-diastolic area and fractional area change and it tended to overestimate end-systolic area. Real-time tracking of the blood-endocardial border is possible and allows accurate measurement of ventricular area.