Purpose .– Right atrial (RA) strain (ε, %) analysis by two-dimensional speckle tracking (2DST) may represent a new tool to evaluate RA function. The aim of our study was to analyze RA ε in a population of patients with idiopathic or associated pulmonary arterial hypertension (PAH) and to correlate its value with other echocardiographic parameters of RA and right ventricular function.

Methods .– Twenty-five subjects (age = 49,4 years; gr1 = 12 healthy, gr2 = 13 with PAH) underwent a complete echocardiography with estimation of systolic pulmonary artery pressure by maximal tricuspid regurgitation (TR max) velocity, measurements of RA surface, TAPSE, RV myocardial performance index (RV MPI) and maximal S velocity in the basal RV free wall (S max) with pulsed DTI. We used 2DST to measure RA ε from cine loops centered on the RA free wall. The cycle reference point was set at the beginning of the P wave, which enabled the measurement of peak negative ε (neg ε), representative of RA contractile function, and peak positive ε (pos ε), corresponding to RA conduit function. As the software automatically divided the walls in 3 different segments, we used the mean of those 3 values for analysis. RA total strain was calculated as the sum of absolute values of pos ε + neg ε and is considered as representative of RA reservoir function. All measurements were averaged on at least 3 consecutive cycles. Spearman’s correlations coefficients between RA ε values and other echographic parameters were calculated. Results: There was no significant difference for neg ε (gr1 = −23.75 ± 11.24 vs gr2 = −20.22 ± 5.93, P = 0.331) between both groups, but pos ε and tot ε were significantly different (pos ε: gr1 = 31.99 ± 17.22 vs gr2 = 17.45 ± 11.19, P = 0.019; tot ε: gr1 = 55.74 ± 11.09: vs gr2 = 37.67 ± 14.13: P = 0.002), as were also TR max, TAPSE, RV MPI, S max and RA surface. There were no correlation between ε neg and any other echographic parameter. Both pos ε and tot ε were significantly correlated with TR max (respectively r = 0.585 P = 0.004; r = 0.725, P = 0.001), TAPSE (respectively r = −0.530, P = 0.006; r = −0.660, P = ∼0.001), S max (respectively r = −0.535, P = 0.006; r = −0.663 P = ∼0.001) and RA surface (respectively r = 0.352, P = 0.08; r = 0.504, P = 0.01).

Conclusions .– The 2DST derived strain is a new tool for RA function assessment. RA conduit and reservoir functions are impaired in patients with PAH but contractile function remains preserved. This is probably an adaptative phenomenon of RA to increased RV preload and decreased RV function induced by PAH as suggested by the correlation of RA strain with TR max, RA area and other echocardiographic parameters of RV function.