title: Percentiles for left ventricular rotation: comparison of reference values to paediatric patients with pacemaker-induced dyssynchrony.
abstract: OBJECTIVE
  Left ventricular rotation is an interesting mechanism to investigate patients with heart disease. In children, reference values have to be defined prior to assess pathology.
  
  
  RESULTS
  One hundred and seventy-four healthy individuals (0-20 years) were investigated by two-dimensional speckle tracking echocardiography, percentiles were created addressing the amount and time-to-peak values (TTP) of rotational parameters normalized to percentage of cardiac cycle (cc). Patients with right ventricular (RV) pacemaker stimulation were integrated into percentiles describing their rotational delay. Feasibility was 87.4% in healthy individuals (8.5 ± 6.2 years), 42 patients (13.0 ± 6.6 years, mean RV-stimulation time: 6.1 ± 4.3 years) were enrolled. Apical rotation (Rot(ap)) varied and was higher than basal rotation (Rot(bas)) throughout all ages. Peak torsion (Tor(max)) normalized to left ventricle (LV) length (Tor(maxi)) was elevated in early childhood and decreased until adulthood. TTP values revealed greater dispersion between apical and basal rotation at younger age and a decrease during maturation. Patients with RV pacing had decreased Tor(max) (10.0 ± 6.0 vs. 13.7 ± 6.6°, P < 0.05), Rot(ap) (6.7 ± 4.8 vs. 9.3 ± 5.7°, P < 0.05) and Rot(bas) (-3.3 ± 2.6 vs. -4.5 ± 2.7°, P < 0.05). Patients with impaired ejection fraction (EF) had abnormal delays between Rot(ap) and Rot(bas).
  
  
  CONCLUSIONS
  Percentile illustrations of LV rotation reveal a high amount and dispersion of Rot(ap) and Tor(maxi) in young children as well as a higher rotational delay compared with older ages. Abnormal delays in RV pacing are associated with reduced EF.
authors.affiliation: Center for Congenital Heart Defects, Heart and Diabetes Center Northrhine-Westfalia, Ruhr-University of Bochum, Georgstr.11, Bad Oeynhausen 32545, Germany tlaser@hdz-nrw.de.
authors.forename: Kai T
authors.initials: KT
authors.lastname: Laser
authors.affiliation: Department of Paediatrics, Allgemeines Krankenhaus, Hagen, Germany.
authors.forename: Pia
authors.initials: P
authors.lastname: Hauffe
authors.affiliation: Center for Congenital Heart Defects, Heart and Diabetes Center Northrhine-Westfalia, Ruhr-University of Bochum, Georgstr.11, Bad Oeynhausen 32545, Germany.
authors.forename: Nikolaus A
authors.initials: NA
authors.lastname: Haas
authors.affiliation: Institute for Radiology, Nuclear Medicine and Molecular Imaging Heart and Diabetes Center Northrhine-Westfalia, Ruhr-University of Bochum, Bad Oeynhausen, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Körperich
authors.affiliation: Clinic for Cardiology, Heart and Diabetes Center Northrhine-Westfalia, Ruhr-University of Bochum, Bad Oeynhausen, Germany.
authors.forename: Lothar
authors.initials: L
authors.lastname: Faber
authors.affiliation: Department of Biometry and Medical Informatics, Otto-von-Guericke University, Magdeburg, Germany.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Peters
authors.affiliation: Center for Congenital Heart Defects, Heart and Diabetes Center Northrhine-Westfalia, Ruhr-University of Bochum, Georgstr.11, Bad Oeynhausen 32545, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Fischer
authors.affiliation: Center for Congenital Heart Defects, Heart and Diabetes Center Northrhine-Westfalia, Ruhr-University of Bochum, Georgstr.11, Bad Oeynhausen 32545, Germany.
authors.forename: Deniz
authors.initials: D
authors.lastname: Kececioglu
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012016:Reference Values; D012399:Rotation; D054159:Torsion, Mechanical; D016277:Ventricular Function, Left / Q000502:physiology*; D055815:Young Adult
keywords: Children; Pacemaker; Percentiles; Rotation; STE; Torsion