RA function by 3D speckle tracking echocardiography in atrial septal defect

Purpose. The purpose of this study was to examine right atrial (RA) function by two-dimensional (2DSTE) and three-dimensional (3DSTE) speckle-tracking echocardiography in patients with atrial septal defect (ASD) who had implantation of atrial septal devices and developed paroxysmal atrial fibrillation (PAF). Methods. Seventy-three patients with hemodynamically significant secundum ASD were prospectively studied and followed up for six months after occluder insertion and compared with a normal age-matched group(n=73). A subgroup of 17 patients who developed PAF after device implantation was also studied. RA peak global longitudinal strain (PS) was determined using 2DSTE. Standard deviations(SDs) of times to peak strain (TPS) were calculated as indices of dyssynchrony. RA volumes, emptying fraction (EF), and expansion index (EI) were determined using 3DSTE. Results. RA PS, EF, and EI (pre-closure values) were reduced in patients with atrial devices compared with controls, and further reductions were observed in patients with PAF. A moderate positive relationship was found between 2D and 3DSTE techniques for RA-Vmax (r=0.62,p=0.014) and RA-Vmin (r=0.58,p=0.029). The time course of pre-closure RA volumetric and functional parameters on six-months follow-up after device insertion showed that pre-existent atrial dysfunction persisted during the 6-months follow-up in spite of partial reduction of atrial volumes. Pre-closure 3D-RA-EI (r=-0.479, p=0.009) and RA-TPS (r=0.315, p=0.023) were independent predictors of PAF by multivariate analysis after adjustment for age and left atrial dysfunction. The areas under the ROC-curve(AUC) for 3D-RA-EI, RA-PS, RA-TPS (pre-closure values) showed high discriminative values(from 0.76 to 0.85) in predicting PAF. By combining 3D-RA-EI and RA-TPS, the AUC increased to 0.90. Conclusions. Two-dimensional and three-dimensional speckle tracking echocardiography appears clinically helpful in ASD patients in revealing right atrial dilatation and dysfunction pre-existent to device closure and associated with PAF development. Right atrial parameters had a higher association with PAF compared to both the size of the implanted device and left atrial indices. The combination of right atrial volumetric indice s(expansion index) and deformation parameters (time to peak strain) provided stronger estimates of PAF risk compared to other right atrial indices.