Results:

There was no correlation between age and TA geometry parameters (r < 0.30). All TA geometry parameters showed significant correlations with body size measures (body surface area [BSA], r = 0.5-0.6; height, r = 0.4-0.5). Women had larger indexed TA perimeter and longer long-axis dimensions compared with men. The longest 3DE TA dimension was significantly longer than diameters measured from both 2DE and 3D multiplanar reconstruction. 3DE TA area, perimeter, and dimensions were largest in late-diastole and smallest at mid-systole/end-systole. Normal tricuspid valve parameters in end-diastole were 8.6 ± 2.0 cm² for area; 10.5 ± 1.2 cm for perimeter; 36 ± 4 mm and 30 ± 4 mm for longest and shortest dimensions, respectively; and 0.83 ± 0.10 for circularity. 3DE TA area, perimeter, and dimensions correlated with both right atrial and right ventricular volumes, suggesting that both chambers may be determinants of TA size. TA fractional area change was 35 ± 10%. Fractional changes in both perimeter and dimensions were >20%. Computed tomography (CT)- and 3DE-obtained perimeter and area measurements correlated highly (r = 0.91 and 0.94, respectively). CT-derived TA perimeter and area, as expected, were larger than those obtained from 3DE by 1.9 ± 0.7 cm and 3.8 ± 1.7 cm², respectively.