Background: Patients after repair of congenital right heart disease (CRHD) may exhibit left ventricular (LV) dyssynchrony (LVD). However, the diagnosis of LVD is difficult and its reliability limited because current methods do not assess LVD of the whole LV simultaneously. The aim of the study was to assess LVD according to a novel global systolic dyssynchrony index (SDI) derived from real-time 3-dimensional echocardiography in patients after repaired CRHD.
Methods: Two-dimensional echocardiography and real-time 3-dimensional echocardiography were performed in 30 patients after CRHD repair and in 30 matched healthy controls. Real-time 3-dimensional echocardiography data sets provided time-volume curves, and 2 global SDIs were derived from the dispersion of time to reach minimal systolic volume according to a 16- or 17-LV segment model.
Results: Both SDIs were significantly elevated in the patient as compared with the control group (P < .001). A cutoff value for both SDIs was calculated and LVD defined as one of the SDIs exceeding cutoff. Left ventricular dyssynchrony was present in 5 (100%) of 5 patients with a LV ejection fraction (EF) <50% and 13 (52%) of 25 patients with preserved LVEF, thus being diagnosed in a total of 18 (60%) of 30 patients. Moreover, patients with LVD showed a significantly higher degree of pulmonary regurgitation (P = .01) with elevated right ventricular volumes and altered septal motion. Stepwise multivariate analysis identified LVEF (P = .005) and the degree of pulmonary regurgitation (P = .02) as independent predictors of LVD.
Conclusions: Left ventricular dyssynchrony can be detected in about 60% of patients after CRHD repair and is mainly due to significant pulmonary regurgitation resulting in an altered septal motion and systolic LV function.