title: Mechanical effects of left ventricular midwall fibrosis in non-ischemic cardiomyopathy.
abstract: BACKGROUND
  Left ventricular (LV) mid-wall fibrosis (MWF), which occurs in about a quarter of patients with non-ischemic cardiomyopathy (NICM), is associated with high risk of pump failure. The mid LV wall is the site of circumferential myocardial fibers. We sought to determine the effect of MWF on LV myocardial mechanics.
  
  
  METHODS
  Patients with NICM (n = 116; age: 62.8 ± 13.2 years; 67% male) underwent late gadolinium enhancement cardiovascular magnetic resonance (CMR) and were categorized according to the presence (+) or absence (-) of MWF. Feature tracking (FT) CMR was used to assess myocardial deformation.
  
  
  RESULTS
  Despite a similar LVEF (24.3 vs. 27.5%, p = 0.20), patients with MWF (32 [24%]) had lower global circumferential strain (Ɛcc: -6.6% vs. -9.4 %, P = 0.004), but similar longitudinal (Ɛll: -7.6 % vs. -9.4 %, p = 0.053) and radial (Ɛrr: 14.6% vs. 17.8% p = 0.18) strain. Compared with - MWF, + MWF was associated with reduced LV systolic, circumferential strain rate (-0.38 ± 0.1 vs. -0.56 ± 0.3 s(-1), p = 0.005) and peak LV twist (4.65 vs. 6.31°, p = 0.004), as well as rigid LV body rotation (64 % vs. 28 %, P <0.001). In addition, +MWF was associated with reduced LV diastolic strain rates (DSRcc: 0.34 vs. 0.46 s(-1); DSRll: 0.38 vs. 0.50s(-1); DSRrr: -0.55 vs. -0.75 s(-1); all p <0.05).
  
  
  CONCLUSIONS
  MWF is associated with reduced LV global circumferential strain, strain rate and torsion. In addition, MWF is associated with rigid LV body rotation and reduced diastolic strain rates. These systolic and diastolic disturbances may be related to the increased risk of pump failure observed in patients with NICM and MWF.
authors.affiliation: Centre for Cardiovascular Sciences, University of Birmingham, Birmingham, UK. robinjamestaylor@gmail.com.|Department of Cardiology, The Queen Elizabeth Hospital Birmingham, Mindelsohn Way, Edgbaston, Birmingham, B15 2WB, UK. robinjamestaylor@gmail.com.
authors.forename: Robin J
authors.initials: RJ
authors.lastname: Taylor
authors.affiliation: Centre for Cardiovascular Sciences, University of Birmingham, Birmingham, UK. frazumar@gmail.com.|Department of Cardiology, The Queen Elizabeth Hospital Birmingham, Mindelsohn Way, Edgbaston, Birmingham, B15 2WB, UK. frazumar@gmail.com.
authors.forename: Fraz
authors.initials: F
authors.lastname: Umar
authors.affiliation: Centre for Cardiovascular Sciences, University of Birmingham, Birmingham, UK. erica.lin@uhb.nhs.uk.
authors.forename: Erica L S
authors.initials: EL
authors.lastname: Lin
authors.affiliation: Centre for Cardiovascular Sciences, University of Birmingham, Birmingham, UK. amar.ahmed@uhb.nhs.uk.
authors.forename: Amar
authors.initials: A
authors.lastname: Ahmed
authors.affiliation: Centre for Cardiovascular Sciences, University of Birmingham, Birmingham, UK. william.moody@uhb.nhs.uk.|Department of Cardiology, The Queen Elizabeth Hospital Birmingham, Mindelsohn Way, Edgbaston, Birmingham, B15 2WB, UK. william.moody@uhb.nhs.uk.
authors.forename: William E
authors.initials: WE
authors.lastname: Moody
authors.affiliation: The Christ Hospital Heart and Vascular Center, Cincinnati, OH, USA. mazurw@ohioheart.org.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Mazur
authors.affiliation: Bakken Research Centre, Medtronic Inc, Maastricht, The Netherlands. berthold.stegemann@medtronic.com.
authors.forename: Berthold
authors.initials: B
authors.lastname: Stegemann
authors.affiliation: Centre for Cardiovascular Sciences, University of Birmingham, Birmingham, UK. john.townend@uhb.nhs.uk.|Department of Cardiology, The Queen Elizabeth Hospital Birmingham, Mindelsohn Way, Edgbaston, Birmingham, B15 2WB, UK. john.townend@uhb.nhs.uk.
authors.forename: Jonathan N
authors.initials: JN
authors.lastname: Townend
authors.affiliation: Centre for Cardiovascular Sciences, University of Birmingham, Birmingham, UK. rick.steeds@uhb.nhs.uk.|Department of Cardiology, The Queen Elizabeth Hospital Birmingham, Mindelsohn Way, Edgbaston, Birmingham, B15 2WB, UK. rick.steeds@uhb.nhs.uk.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Steeds
authors.affiliation: Department of Cardiology, The Queen Elizabeth Hospital Birmingham, Mindelsohn Way, Edgbaston, Birmingham, B15 2WB, UK. f.leyva@aston.ac.uk.|Aston Medical Research Institute, Aston Medical School, University of Aston, Birmingham, UK. f.leyva@aston.ac.uk.
authors.forename: Francisco
authors.initials: F
authors.lastname: Leyva
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D009202:Cardiomyopathies / Q000150:complications / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D003287:Contrast Media; D003971:Diastole; D004739:England; D005260:Female; D005355:Fibrosis; D019786:Gadolinium DTPA; D006333:Heart Failure / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D006352:Heart Ventricles / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D011237:Predictive Value of Tests; D013314:Stress, Mechanical; D013599:Systole; D054159:Torsion, Mechanical; D016277:Ventricular Function, Left
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA