Accentuated left ventricular lateral wall function compensates for septal dyssynchrony after valve replacement for aortic stenosis

BackgroundThe interventricular septal motion becomes reversed after aortic valve replacement (AVR) for aortic stenosis (AS) despite maintained stroke volume (SV). We hypothesis that left ventricular (LV) lateral wall compensates for such disturbances, in order to secure normal SV.MethodsWe studied 29 severe AS patients (age 63 ± 11 years, 18 males) with normal ejection fraction (EF) before, 6 months and 12 months after AVR and compared them with 29 age- and gender-matched controls, using speckle tracking echocardiography.ResultsIn patients, the LVEF and SV remained unchanged throughout. Before AVR, the septal radial motion, septal and lateral strain were reduced (p < 0.001). Peak septal and lateral displacements, times from QRS to peak displacement were all not different from controls.Six months after AVR, septal radial motion reversed (p < 0.001), lateral strain increased (p < 0.05), peak septal displacement reduced (p < 0.01) while lateral displacement increased (p < 0.05). Time to peak septal displacement delayed (p < 0.01) in contrast to lateral displacement which became early (p < 0.05), resulting in a significant septal-lateral time delay (p < 0.01). The accentuation of LV lateral wall correlated with septal displacement time delay (r = 0.60, p < 0.001) and septal–lateral time delay (r = 0.64, p < 0.001). SV correlated with lateral displacement (r = 0.39, p < 0.05). The systolic strain was correlated with opposite wall displacement (p < 0.05 for both). There was no correlation between these measurements before and 12 month after AVR.ConclusionsAccentuated lateral wall displacement compensates for septal dyssynchrony in order to maintain normal LVEF and SV. The continuing recovery of these disturbances 12 months after complete mass regression suggests an ongoing reverse remodeling.