17. Global and regional left ventricular function after arterial switch operation: A speckle tracking echocardiography study

The arterial switch operation (ASO) is now days the standard procedure for transposition of the great arteries (d-TGA) repair. Nonetheless, reduced exercise capacity, coronary artery abnormalities, decreased coronary artery vaso-reactivity, reduced coronary flow reserve, proximal intimal proliferation, and reversible myocardial perfusion defects have been demonstrated in ASO patients. Despite of this, indices of systolic function, as assessed by standard echocardiography are within the normal range in ASO patients. Speckle-tracking echocardiography (STE), can detect early subclinical myocardial abnormalities in several diseases even in presence of normal left ventricular (LV) ejection fraction (EF). Aim to assess LV myocardial deformation and torsion in asymptomatic ASO patients with normal LV EF (⩾55%) by using two-dimensionally derived STE. Methods We studied: (a) Sixty-two asymptomatic patients (26 female) who have undergone 1-stage ASO for simple d-TGA, aged 8.5 ± 5.7 years, with a normal LV EF (⩾55%); (b) Thirty-two age and sex comparable controls (14 female), aged 7.9 ± 4.9 years. Results In ASO patients, global LV longitudinal strain was significantly lower than in controls (−19.2 ± 2.9% vs −22.7 ± 2.4%, respectively, p p  = 0.06) and LV torsion (12.1 ± 4.8° vs 13.1 ± 5.4°, respectively, p  = 0.351) were similar to those measured in controls. Conclusions To the best of our knowledge this is the largest study on ASO patients by using STE. We demonstrated that in asymptomatic ASO patients despite a normal LV EF (⩾55%) there is a significant reduction in longitudinal myocardial deformation while circumferential deformation and LV torsion are preserved, in order to maintain a normal LV EF.