title: Right ventricular mechanics in hypertrophic cardiomyopathy using feature tracking.
abstract: OBJECTIVE
  Right ventricular (RV) mechanics in hypertrophic cardiomyopathy (HCM) are poorly understood. We investigate global and regional deformation of the RV in HCM and its relationship to LV phenotype, using 2D strain vector velocity imaging (VVI).
  
  
  METHODS
  100 HCM patients (42% females, 41 ± 19 years) and 30 control patients were studied using VVI. Longitudinal peak systolic strain (ϵsys), strain rate (SR), time to peak (ϵ) (TTP), displacement of RV free wall (RVFW) and septal wall were analyzed. Similar parameters were quantified in LV septal, lateral, anterior and inferior segments. Intra-V-delay was defined as SD of TTP. Inter-V-delay was estimated from TTP difference between the most delayed LV segment & RVFW.
  
  
  RESULTS
  ϵsys and SR of both RV & LV, showed loss of base to apex gradient and significant decline in HCM (p < 0.001). Deformation variables estimated from RVFW were strongly correlated with each other (r = 0.93, p < 0.0001). Both were directly related to LV ϵsys, SRsys, SRe, ejection fraction (EF)%, RVFW displacement (P < 0.001) and inversely related to age, positive family history (p < 0.004, 0.005), RV wall thickness, maximum wall thickness (MWT), intra-V-delay, LA volume (P < 0.0001), LVOT gradient (p < 0.02, 0.005) respectively. ROC curves were constructed to explore the cut-off point that discriminates RV dysfunction. Global and RVFW ϵsys: - 19.5% shows 77, 70% sensitivity & 97% specificity, SRsys: - 1.3s(- 1) shows 82, 70% sensitivity & 30% specificity. Multivariate analyses revealed that RVFW displacement (β = - 0.9, p < 0.0001) and global LV SRsys (β = 5.9, p < 0.0001) are independent predictors of global RV deformation.
  
  
  CONCLUSIONS
  Impairment of RV deformation is evident in HCM using feature tracking. It is independently influenced by LV mechanics and correlated to the severity of LV phenotype. RVFW deformation analysis and global RV assessment are comparable.
authors.affiliation: Cardiology Department, Menoufiya University, Egypt.
authors.forename: Hala Mahfouz
authors.initials: HM
authors.lastname: Badran
authors.affiliation: Cardiology Department, Menoufiya University, Egypt.
authors.forename: Mahmood
authors.initials: M
authors.lastname: Soliman
authors.affiliation: Cardiology Department, Menoufiya University, Egypt.
authors.forename: Hesham
authors.initials: H
authors.lastname: Hassan
authors.affiliation: Cardiology Department, Menoufiya University, Egypt.
authors.forename: Raed
authors.initials: R
authors.lastname: Abdelfatah
authors.affiliation: Cardiology Department, Menoufiya University, Egypt.
authors.forename: Haythem
authors.initials: H
authors.lastname: Saadan
authors.forename: Magdi
authors.initials: M
authors.lastname: Yacoub
keywords: feature tracking; hypertrophic cardiomyopathy; right ventricular deformation