title: Ventricular Twisting and Dyssynchrony in Children with Single Left Ventricle Using Three-Dimensional Speckle Tracking Imaging after the Fontan Operation.
abstract: BACKGROUND
  The importance of left ventricular (LV) twisting has been recognized in various types of heart disease, but no studies have investigated twisting of functional single ventricle using echocardiography. This study aimed to evaluate LV twisting and dyssynchrony of children with single left ventricle (SLV) after the Fontan operation and explore the relationship between twisting motion and ventricular contractility using three-dimensional speckle tracking imaging (3DSTI).
  
  
  METHODS
  Thirty-five children with SLV and 35 healthy children (controls) were enrolled. The patients were divided into wide and narrow QRS groups according to the QRS interval. Atrioventricular valve inflow velocity and tissue Doppler imaging velocity were obtained, and the Tei index was calculated. Apical rotation, basal rotation, twist, torsion, time to peak apical rotation, time to peak basal rotation, time to peak twist, apical-basal rotation delay, and the systolic dyssynchrony index (SDI) were measured by 3DSTI.
  
  
  RESULTS
  Patients with SLV had significantly lower apical rotation (2.50 ± 2.25° vs. 4.85 ± 2.68°, P < 0.001), basal rotation (-3.46 ± 3.11° vs. -7.76 ± 2.11°, P < 0.001), twist (5.15 ± 4.75° vs. 12.19 ± 3.65°, P < 0.001), and torsion (1.04 ± 0.99°/cm vs. 2.37 ± 0.77°/cm, P < 0.001) compared to controls. Time to peak basal rotation, apical-basal rotation delay, and time to peak twist were significantly longer in patients. Apical rotation was significantly lower in the wide QRS group but similar in the narrow QRS group as compared to controls. Time to peak twist and apical-basal delay were significantly longer in the wide QRS group in contrast to the similar time in the narrow QRS group compared with controls. Among these twisting parameters, twist and torsion were most significantly correlated with left ventricular ejection fraction (LVEF), the Tei index, and SDI. Twist and age were significantly correlated.
  
  
  CONCLUSIONS
  Twisting is reduced in children with SLV after the Fontan operation. Torsion is a good indicator of LV global function because of good reproducibility and its lack of association with age.
authors.affiliation: Department of Pediatrics, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Shu-Wen
authors.initials: SW
authors.lastname: Zhong
authors.affiliation: Department of Pediatric Cardiology, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Yu-Qi
authors.initials: YQ
authors.lastname: Zhang
authors.affiliation: Department of Pediatric Cardiology, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Chen
authors.affiliation: Department of Pediatrics, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Shan-Shan
authors.initials: SS
authors.lastname: Wang
authors.affiliation: Department of Pediatrics, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Wei-Hua
authors.initials: WH
authors.lastname: Li
authors.affiliation: Department of Pediatric Thoracic and Cardiovascular Surgery, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Sun
mesh_terms: D002648:Child; D002675:Child, Preschool; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D005260:Female; D018729:Fontan Procedure / Q000379:methods*; D006352:Heart Ventricles / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D007223:Infant; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014102:Torsion Abnormality / Q000000981:diagnostic imaging* / Q000209:etiology / Q000517:prevention & control; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology
keywords: single left ventricle; systolic dyssynchrony index; three-dimensional speckle tracking imaging; torsion; twist