Purpose: This study evaluated the left heart (LH) function such as LA and LV deformation separately using 3DSTE in C, HCM and HCMG+P- patients. To assess pathophysiological consequences of HCM condition on LH , we investigated the impact of the genetic mutations on LH functioning in patients who have no clinical symptoms or structural abnormalities based on 2D echocardiography.
Methods: We enrolled 82 C, 25 HCM and 11 HCMG+P- patients; 20 subjects in HCM group had an obstructive sub-aortic gradient (SUB_AO). 2D and 3DSTE echocardiography were performed sequentially, and for the latters we acquired LA and the corresponding LV, for each subject in the same clip. In the first part of the study we assessed LA and LV mechanical remodeling only in C and HCM, then in the second step we included also HCMG+P-. 3DSTE evaluated the peak and the time to peak of longitudinal (GLS,GLPDS) circumferential (GCS,GCPDS) and radial strain (GRS,GRPDS) during systolic phase for LV and in diastolic phase for LA. GRS was not acquired for LA because his thickness wall is too small. In order to define the correlation among structural remodeling and impaired function, we correlated 2D parameters with 3DSTE.
Results: Concerning 2D parameters we found dilated LAVi, higher LVMASSi and increased E/e' ratio in HCM compared with C; when we included also HCMG+P-, we found the same results. 3DSTE variables showed impaired GLS and GCS in HCM for both LV and LA analysis and GRS only for LV; also GLPDS was increased in HCM subject. At pairwise analysis, GLS and GLPDS were in agreement to demonstrate normal deformation in HCMG+P- (similar with C) (see Figure 1). We also found a correlation among 3DSTE, LVMASSi, E/e' ratio and LAVi (GLS: vs LVMASSi ? 0.381; vs LAVi ? -0.446; vs E/e' ? 0.312; GLPDS: vs LVMASSi ? 0.338), whereas a positive association among 2D parameters and SUB_AO (SUB_AO: vs LVMASSi ? 0.593; vs LAVi ? 0.580; E/e': vs LVMASSi ? 0.513; vs LAVi ? 0.534). Increased LVMASSi might determine poor LV compliance with the development of diastolic dysfunction and finally increased LAVi; on the other hand, the presence of SUB_AO contributed to LH remodeling by determining higher LV pressures. These alterations might impact significantly on LH mechanical properties as detected by impaired 3DSTE parameters and may underline the relation between LH remodeling and reduced 3D strain.
Conclusions: Main findings concern normal LH deformation in HCMG+P-despite the genetic mutations, and impaired deformation in HCM group compared to C; in particular, reduced strain were found both in LA and LV as a marker of worst mechanical remodeling with evidence of correlation with GLS and GCS.