Left ventricular geometry, global function, and dyssynchrony in infants and children with pompe cardiomyopathy undergoing enzyme replacement therapy

Background: Enzyme replacement therapy (ERT) for infantile-onset Pompe disease effectively reduces the left ventricular (LV) mass. This study sought to explore detailed process of LV reverse remodeling after ERT with the use of tissue Doppler and stain rate imaging. Methods and Results: Nine infants and children with Pompe cardiomyopathy undergoing ERT for ≥1 year, as well as 36 healthy control subjects, were studied. Global systolic and diastolic function was evaluated by peak systolic and early-diastolic velocity at mitral annulus. Temporal systolic and diastolic dyssynchrony was evaluated by the coefficient of variation of the time from the QRS complex to peak systolic and early-diastolic strain rate among 12 LV segments. All pre-ERT patients had impaired global systolic and diastolic function as well as increased regional dyssynchrony (P <.001 for each of all). During the regression of LV hypertrophy, all of these functional indices improved (P for trend <.001), with temporal diastolic dyssynchrony being a significant factor linking to LV mass index in multivariate analysis (P <.001). Conclusions: ERT improved global LV function and dyssynchrony in Pompe patients. The relationship between LV mass and temporal diastolic dyssynchrony during reverse remodeling suggested a pathophysiologic role of dyssynchrony in Pompe cardiomyopathy.