Biventricular interaction and aortic function in adult patients with repaired tetralogy of Fallot: a 2D-3D speckle tracking echocardiographic study

In patients late after correction of tetralogy of Fallot(TOF) the combined effects of preoperative hypertrophy and hypoxia, ventricular interdependence, acquired postoperative lesions such as pulmonary or aortic regurgitation, and congenital vasculopathy may result in impaired right ventricular(RV) as well as left ventricular(LV) function. The aim of the present study was to investigate the interventricular interactions in repaired TOF(rTOF) and the impact of aortic function on biventricular performance using two-dimensional(2DSTE) and three-dimensional speckle tracking echocardiography(3DSTE). Twenty-five adult patients with rTOF and twenty-five age- and gender-matched healthy controls were studied. LV and RV volumes were determined by 3DSTE and cardiac magnetic resonance(CMR). LV and RV longitudinal(LVLS, RVLS) and area strains(LVAS, RVAS) and LV twist/rotation were calculated by 3DSTE. Ascending aorta circumferential strain(AAo-CS) was obtained using 2DSTE. LV-3DSTE parameters were decreased in rTOF patients compared to controls even in patients with normal ejection fraction. AAo-CS was decreased(6.7±1.9 vs 10.1±2.6, p=0.003) in rTOF patients compared to controls even in the presence of normal aortic dimensions and correlated with AAo diameter(r=-0.69, p=0.0001), LV twist(r=0.54, p=0.004), LVAS(r=-0.56, p=0.003) and RVLS(r=-0.39, p=0.036). LVAS an AAo-CS were associated with disease severity (peak oxygen consumption, arrhythmia occurrence). Significant improvement in global χ2 value was noted with RV-3DSTE parameters + LVAS + AAo-CS compared to RV dysfunction alone for detecting exercise capacity impairment(from 77.1 to 84.4 to 91.2, p=0.003). Speckle-tracking echocardiography revealed subtle LV and AAo dysfunction in adults with rTOF. A correlation was observed between LV and RV strain changes as well as between AAo strain impairment and LV/RV dysfunction. LV and AAo changes had an incremental value in evaluating disease severity.