Right heart assessment by echocardiography: gender and body size matters.

BACKGROUND

Published reference values for echocardiographic measurements of right-heart dimensions and function do not stratify for gender and body size. The aim of this study was therefore to assess the impact of gender and biometric characteristics on right-heart dimensions and function.

METHODS

From the echocardiography database at a tertiary care center, 1,625 subjects (mean age, 44 ± 14 years; 47% men) with normal echocardiographic findings between 2000 and 2009 were identified. Gender differences and association with body surface area were assessed retrospectively for right atrial long-axis and short-axis dimensions, right ventricular short-axis dimension, end-diastolic and end-systolic right ventricular area, right ventricular fractional area change, and tricuspid annular plane systolic excursion. The impact of normal values stratified for gender and body surface area was tested in 24 patients with moderate-sized to large atrial septal defects.

RESULTS

All dimensional right-heart measurements were significantly lower in women. Differences became smaller when measurements were indexed for body surface area, but significant differences persisted, particularly for right ventricular end-diastolic area (7.9 ± 1.6 vs 8.7 ± 1.8 cm(2)/m(2), P < .001) and right ventricular end-systolic area (4.0 ± 1.2 vs 4.7 ± 1.4 cm(2)/m(2), P < .001). Fractional area change and tricuspid annular plane systolic excursion indexed to body surface area were significantly higher in women (50 ± 7% vs 46 ± 9% and 14 ± 3 vs 12 ± 2 mm/m(2), respectively, P < .001 for both comparisons). The use of upper reference ranges for end-diastolic right ventricular area stratified for gender and body surface area improved the detection of enlarged right ventricles in patients with moderate-sized to large atrial septal defects (92% vs 54%, P < .007).

CONCLUSIONS

Gender and body surface area are important determinants of right ventricular dimensions and systolic function as measured on two-dimensional echocardiography. The investigators thus propose the use of measurements indexed to body surface area, with upper and lower reference ranges stratified for gender.