Diastolic ventricular interaction in patients after atrial switch for transposition of the great arteries: A speckle tracking echocardiographic study

Abstract

BackgroundWe tested the hypothesis that diastolic ventricular interaction occurs after atrial switch operation for transposition of the great arteries (TGA) and that subpulmonary LV diastolic function is influenced by septal geometry. MethodsTwenty-nine patients (male 19) after atrial switch operation for TGA aged 20.8±4.1years and 27 healthy controls were studied. Two-dimensional longitudinal systolic strain, systolic (SRs), early diastolic (SRe), and late diastolic (SRa) strain rates of both ventricles were determined using speckle tracking echocardiography. Early diastolic trans-atrioventricular velocity (E) and myocardial early diastolic myocardial velocity (e) at the ventricular free wall–annular junction were measured. Geometry of the morphologic left ventricle was quantified by the diastolic eccentricity index (EI). ResultsIn both systemic and subpulmonary ventricles, SRe and SRa were significantly lower and trans-atrioventricular E/e ratios higher in patients than controls (all p<0.001). In patients, RV SRe correlated with left ventricular (LV) SRe (r=0.49, p=0.008), and RV SRa correlated with LV SRa (r=0.46, p=0.01). Significant leftward shifting of the septum in patients was reflected by the greater LV EI (p<0.001). In patients, LV EI correlated with age- and sex-adjusted z score of LV end-diastolic volume. 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). ConclusionsSystemic RV diastolic dysfunction occurs after atrial switch operation and correlates with subpulmonary LV diastolic dysfunction. The observed diastolic ventricular interaction may potentially be mediated through alteration of septal geometry.