title: Selective echocardiographic analysis of epicardial and endocardial left ventricular rotational mechanics in an animal model of pericardial adhesions.
abstract: OBJECTIVE
  Diagnosis of pericardial adhesions is challenging. Twisting of the left ventricle (LV) is essential for normal LV functioning. We experimentally characterized the impact of pericardial adhesions on epicardial and endocardial LV rotational mechanics with velocity vector imaging (VVI).
  
  
  RESULTS
  In nine open-chest pigs, the heart was exposed while preserving the pericardium. Early-stage pericardial adhesions were simulated by instilling tissue glue to pericardial space. Using VVI, LV rotational mechanics was quantitatively assessed endocardially and epicardially along with haemodynamic data at baseline and following the experimental intervention. End-diastolic volume, ejection fraction, stroke volume, late diastolic filling velocity, and LV endocardial torsion decreased significantly. LV epicardial torsion showed only a trend towards decrease (P = 0.141). Endocardial twist and torsion decreased significantly (P = 0.007) from 8.6 +/- 2.2 degree and 1.497 +/- 0.397 degree/cm to 5.3 +/- 1.8 degree and 0.97 +/- 0.38 degree/cm, respectively; epicardial twist showed a trend towards a decrease in its magnitude. Gradients of endocardial/epicardial twist and torsion did not significantly change.
  
  
  CONCLUSIONS
  The model suggests that early-stage pericardial adhesions reduce both epicardial and endocardial LV twist and torsion without a significant alteration in their transmural gradient. Selective endocardial/epicardial analysis of LV twisting mechanics may have a diagnostic role in detection of early formation of pericardial adhesions.
authors.affiliation: Translational Ultrasound Research Laboratory, Division of Cardiovascular Diseases, College of Medicine, Mayo Clinic, Scottsdale, AZ, USA.
authors.forename: Mohsen S
authors.initials: MS
authors.lastname: Alharthi
authors.forename: Panupong
authors.initials: P
authors.lastname: Jiamsripong
authors.forename: Anna
authors.initials: A
authors.lastname: Calleja
authors.forename: Partho P
authors.initials: PP
authors.lastname: Sengupta
authors.forename: Eileen M
authors.initials: EM
authors.lastname: McMahon
authors.forename: Bijoy
authors.initials: B
authors.lastname: Khandheria
authors.forename: A Jamil
authors.initials: AJ
authors.lastname: Tajik
authors.forename: Marek
authors.initials: M
authors.lastname: Belohlavek
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D004195:Disease Models, Animal; D004452:Echocardiography / Q000379:methods*; D004699:Endocardium / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006439:Hemodynamics; D010496:Pericardium / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D012399:Rotation; D013552:Swine; D000267:Tissue Adhesions / Q000000981:diagnostic imaging / Q000503:physiopathology; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*