Right atrial size relates to right ventricular end-diastolic pressure in an adult population with congenital heart disease.

AIM: Noninvasive markers of right ventricular (RV) diastolic dysfunction are limited by their lack of reproducibility and accuracy. We tested the hypothesis that right atrial (RA) size measured by echocardiography was correlated to invasive parameters of RV diastolic filling. METHODS AND
RESULTS: We studied 31 consecutive adult patients with congenital heart disease. From 2D echocardiography images, we measured maximal RA long-axis and short-axis lengths, area and volume. We compared each of these measures to right ventricular end-diastolic pressure (RVEDP) and mean right atrial pressure (mRAP) measured by right heart catheterization. RA long-axis, short-axis, area, and volume correlated significantly with RVEDP (r = 0.78, P < 0.001; r = 0.61, P < 0.001; r = 0.79, P < 0.001; and r = 0.75, P < 0.001, respectively) and mRAP (r = 0.66, P < 0.001; r = 0.56, P = 0.002; r = 0.70, P < 0.001; r = 0.68, P < 0.001, respectively). Single cut points for each echocardiographic parameter demonstrated reasonable accuracy to rule-in and rule-out RVEDP ≥ 7 mm Hg (sensitivity = 74%, specificity = 82%, positive LR = 4.1, negative LR = 0.32 for RA long-axis of 49 mm; sensitivity = 89%, specificity = 82%, positive LR = 4.9, negative LR = 0.12 for RA area of 14 cm²; sensitivity = 89%, specificity = 82%, positive LR = 4.9, negative LR = 0.13 for RA volume of 37 mL).
CONCLUSION: RA size measured by echocardiography is strongly correlated to invasive parameters of RV diastolic filling and predicts high RV end-diastolic pressure.