Objective: We sought to test the hypothesis that myocardial deformation is abnormal in children with isolated left ventricular (LV) noncompaction.
Methods: Longitudinal and circumferential myocardial deformation was determined using speckle tracking echocardiography in 9 patients aged 5.6±5.5 years and compared with those of 9 age-matched controls. Their LV ejection fraction and systolic dyssynchrony index (SDI) were assessed by 3-dimensional echocardiography. Relationships between myocardial deformation and LV dyssynchrony with LV ejection fraction were further determined in patients.
Results: Noncompaction involved both LV apex and mid lateral wall in 8 patients, and LV apex alone in 1. Compared with controls, patients had lower LV global longitudinal systolic strain (p=0.007), systolic strain rate (SR) (p=0.041), and early diastolic SR (p<0.001), and global circumferential strain (p=0.033), systolic SR (p=0.17), and early diastolic SR (p=0.043), but similar RV longitudinal myocardial deformation parameters (all p>0.05). Regionally, the longitudinal systolic strain of the basal (p=0.009), mid (p=0.005), and apical (p=0.086) segments of LV lateral wall, and basal (p=0.015), mid (p=0.016) and apical (p=0.13) septum was lower in patients than controls. Three (33%) patients exhibited LV mechanical dyssynchrony (SDI> 4.9%). In patients, LV ejection fraction correlated significantly with SDI (r=-0.98, p<0.001), global LV longitudinal systolic strain (r=0.70, p=0.035) and SR (r=0.78, p=0.013), and global LV circumferential strain (r=0.92, p<0.001) and SR (r=0.83, p=0.006).
Conclusions: Abnormal myocardial deformation of the left ventricles extends beyond the noncompacted regions and contributes probably to global LV systolic dysfunction and mechanical dyssynchrony.