Assessment of right atrial pressure using echocardiography and correlation with catheterization

Right ventricular systolic pressure is crucial for both treatment and prognosis of cardiovascular and pulmonary diseases. The proper measurement of right ventricular systolic pressure depends on an accurate estimation of right atrial pressure (RAP). There is no standard method for estimating RAP noninvasively. The purpose of this study was to compare different noninvasive methods, namely, inferior vena cava (IVC) size and inspiratory collapse, tissue Doppler derived E/E' (TV E/E') for estimating RAP, and their correlation with catheter-based measurements in patients with mitral valve stenosis with atrial fibrillation (AF) or normal sinus rhythm (NSR).

The study group consisted of 39 patients (13 men, mean age 58.9 ± 11.8 years) with rheumatic mitral valve stenosis. We performed cardiac catheterization and transthoracic echocardiography on all patients.

Mean RAP measured by catheterization was 9.7 ± 3.8 mmHg. No correlation was found between RAP and TV E/E' ratio, but there was a significant correlation between RAP and IVC diameter (r = 0.51, p < 0.05). Seventeen patients (43.6%) were in AF and 22 patients (56.4%) were in NSR. There was no correlation between TV E/E' ratio and RAP in patients with AF and in patients with NSR. RAP was correlated with collapsibility index in patients with AF (r = 0.56, p < 0.05). RAP was significantly correlated with IVC diameter (r = 0.62, p < 0.005) and collapsibility index (r = 0.49, p < 0.05) in patients with NSR.

The combination of IVC diameter and collapsibility index is a simple a semiquantitative approach that might provide a better estimation of RAP.