Comprehensive echocardiographic assessment of right ventricular function, pulmonary arterial elastic properties and ventricular-vascular coupling in adult patients with repaired tetralogy of fallot: clinical significance of 3D derived indices.

We aimed to comprehensively analyze by three-dimensional speckle-tracking echocardiography (3DSTE) and Doppler echocardiography right ventricular (RV) performance, pulmonary arterial (PA) elastic properties and right ventricular-pulmonary artery coupling (RVPAC) in patients with repaired tetralogy of Fallot (rTOF) and assess the feasibility and clinical utility of related echocardiographic indices. Twenty-four adult patients with rTOF and twenty-four controls were studied. RV end-diastolic volume(3D-RVEDV), RV end-systolic volume(3D-RVESV), RV ejection fraction(3D-RVEF), RV longitudinal strain(3D-RVLS) and RV area strain(3D-RVAS) were calculated by 3DSTE. RV end-systolic area (RVESA) was obtained by planimetry. Pulmonary regurgitation (PR) was assessed as trivial/mild or significant by cardiac magnetic resonance (CMR) and color-Doppler. Pulmonary artery (PA) elastic properties were determined using two-dimensional/Doppler echocardiography. RV systolic pressure (RVSP) was measured using standard Doppler methods. RVPAC was assessed using various 3DSTE-derived parameters (3DRVAS/RVSP, 3DRVLS/RVESA, 3DRVAS/RVESV). Overall, 3DRVEF and 3DRVAS were impaired in rTOF patients compared with controls. PA pulsatility and capacitance were reduced (p = 0.003) and PA elastance was higher (p = 0.0007) compared to controls. PA elastance had a positive correlation with 3DRVEDV (r = 0.64, p = 0.002) and 3DRVAS (r = 0.51, p = 0.02). By ROC (receiver operating characteristics) analysis, 3DRVAS/RVESV, 3DRVAS/RVSP and 3DRVLS/RVESA cutoff values of 0.31%/mmHg, 0.57%/mmHg and 0.86%/mmHg, respectively, had 91%, 88% and 88% sensitivity and 81%, 81% and 79% specificity in identifying exercise capacity impairment. In rTOF patients increased 3DSTE-derived RV volumes and impaired RV ejection fraction and strain are associated with reduced PA pulsatility and capacitance and increased PA elastance. 3DSTE-derived RVPAC parameters using different afterload-markers are accurate indices of exercise capacity.