Objective: We tested the hypothesis that systemic right ventricular (RV) diastolic dysfunction and diastolic ventricular interaction occur after atrial switch operation for transposition of the great arteries (TGA).
Methods: Twenty-nine patients aged 20.8±4.1 years post-atrial switch operation and 27 healthy controls were studied. Two-dimensional longitudinal systolic strain and systolic (SRs), early diastolic (SRe), and late diastolic (SRa) strain rates of both ventricles were determined using tissue speckle echocardiography. Early diastolic trans-atrioventricular velocity (E) and myocardial early diastolic myocardial velocity (e) at ventricular free wall-annular junction were measured. Geometry of the morphologic left ventricle was quantified by the diastolic eccentricity index (EI).
Results: In both systemic and subpulmonic ventricles, SRe and SRa were significantly lower and trans-atrioventricular E/e ratios higher in patients than controls (all p<0.001). Significant leftward bulging of septum in patients was suggested by the greater left ventricular (LV) EI (p <0.001). As a group, LV EI correlated negatively with LV SRe (r=-0.62, p<0.001) and LV SRa (r=-0.51, p<0.001), and positively with mitral E/e ratio (r= 0.33, p= 0.02). In patients, RV SRe correlated with LV SRe (r=0.49, p=0.008), and RV SRa correlated with LV SRa (r=0.46, p=0.01). Furthermore, in patients, the systemic RV SRe correlated with RV SRs (r=0.52, p=0.004) and LV systolic strain (r=0.41, p=0.03).
Conclusion: Systemic RV diastolic dysfunction occurs after atrial switch operation for TGA and correlates with subpulmonic ventricular diastolic dysfunction. The observed diastolic ventricular interaction is probably mediated through alteration of septal geometry.