title: Left ventricular torsion shear angle volume analysis in patients with hypertension: a global approach for LV diastolic function.
abstract: BACKGROUND
  Torsion shear angle φ is an important measure of left ventricular (LV) systolic and diastolic functions. Here we provide a novel index utilizing LV normalized torsion shear angle φ ^ volume V ^ loop to assess LV diastolic functional properties. We defined the area within φ ^ V ^ loop as torsion hysteresis area, and hypothesized that it may be an important global parameter of diastolic function. We evaluated the φ ^ changes to increased V ^ during early diastole - d φ ^ / d V ^ as a potential measure of LV suction.
  
  
  METHODS
  Sixty resistant hypertension patients (HTN), forty control volunteers were studied using cardiovascular magnetic resonance with tissue tagging. Volumetric and torsional parameters were evaluated.
  
  
  RESULTS
  HTN demonstrated concentric remodeling with preserved ejection fraction. HTN had significantly decreased normalized early filling rate, early diastolic mitral annulus velocity and E/A (1.33 ± 1.13 vs. 2.19 ± 1.07, P < 0.0001) vs. control. Torsion hysteresis area was greater (0.11 ± 0.07 vs. 0.079 ± 0.045, P < 0.001) and peak - d φ ^ / d V ^ at early diastole was higher (10.46 ± 8.51 vs. 6.29 ± 3.85, P = 0.002) than control. Torsion hysteresis area was significantly correlated with E/A (r = -0.23, P = 0.025). Thirteen HTN patients had both E/A ratio < 1.12 (Control mean E/A-1SD) and torsion hysteresis area > 0.12 (Control mean torsion hysteresis area + 1SD).
  
  
  CONCLUSIONS
  Torsion hysteresis area and peak early diastolic - d φ ^ / d V ^ were significantly increased in hypertensive concentric remodeling. The φ ^ V ^ loop takes into account the active and passive recoil processes of LV diastolic and systolic phases, therefore provides a new global description of LV diastolic function.
authors.forename: Chun G
authors.initials: CG
authors.lastname: Schiros
authors.forename: Ravi V
authors.initials: RV
authors.lastname: Desai
authors.forename: Bharath Ambale
authors.initials: BA
authors.lastname: Venkatesh
authors.forename: Krishna K
authors.initials: KK
authors.lastname: Gaddam
authors.forename: Shilpi
authors.initials: S
authors.lastname: Agarwal
authors.forename: Steven G
authors.initials: SG
authors.lastname: Lloyd
authors.forename: David A
authors.initials: DA
authors.lastname: Calhoun
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Denney
authors.forename: Louis J
authors.initials: LJ
authors.lastname: Dell'italia
authors.forename: Himanshu
authors.initials: H
authors.lastname: Gupta
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D003971:Diastole; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications*; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D054159:Torsion, Mechanical; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling