title: Tissue Doppler imaging in the left ventricle and right ventricle in healthy children: normal age-related peak systolic velocities, timings, and time differences.
abstract: OBJECTIVE
  Tissue Doppler imaging (TDI) enables assessment of velocities and timings within the left (LV) and the right (RV) ventricle with high temporal resolution. Knowledge on normal age-related values of peak systolic velocities and timings in healthy children may optimize the benefit of device-based therapies in paediatric patients with heart failure.
  
  
  RESULTS
  A total of 123 healthy children (from 1 month to 18 years old) underwent TDI evaluation of the RV and LV. Peak systolic velocity and time to peak systolic velocity were assessed at the basal LV lateral wall, inter-ventricular septum (IVS), RV free wall (RVFW), and at the RV outflow tract (RVOT). Intra-ventricular time differences were calculated. Regression analysis was performed to assess the age dependency of the ventricular mechanics. Median peak velocities were: LV lateral wall: 6.3 cm/s (inter-quartile range (IQR): 5.1-7.9 cm/s); IVS: 6.0 cm/s (5.4-6.7 cm/s); RVFW: 10.2 cm/s (8.9-11.3 cm/s); RVOT: 7.2 cm/s (6.0-8.2 cm/s). Timings of peak systolic velocities were: LV lateral wall: 101 ms (91-112 ms); IVS: 114 ms (100-128 ms); RVFW: 177 ms (157-194 ms); RVOT: 100 ms (88-113 ms). Timings and peak velocities significantly increased with age at both ventricles. No relevant time difference was observed within the LV, whereas a considerable time delay was observed within the RV between the RVFW and the IVS (62 ms, IQR: 45-74 ms) and between the RVFW and the RVOT (74 ms, IQR: 59-93 ms).
  
  
  CONCLUSIONS
  The present evaluation provides TDI-derived physiological values on normal LV and RV mechanics of healthy children. Within the LV, no relevant time difference was observed, whereas a considerable mechanical delay is observed within the healthy RV.
authors: Division of Pediatric Cardiology, Department of Pediatrics, J6-S Leiden University Medical Center, Albinusdreef 2, PO Box 9600, 2300 RC Leiden, The Netherlands. a.e.van_der_hulst@lumc.nl
authors: Annelies E
authors: AE
authors: van der Hulst
authors: Victoria
authors: V
authors: Delgado
authors: Arend D J
authors: AD
authors: Ten Harkel
authors: Liselotte M
authors: LM
authors: Klitsie
authors: Luc H P M
authors: LH
authors: Filippini
authors: Jeroen J
authors: JJ
authors: Bax
authors: Nico A
authors: NA
authors: Blom
authors: Arno A W
authors: AA
authors: Roest
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016014:Linear Models; D008297:Male; D010372:Pediatrics; D011446:Prospective Studies; D012016:Reference Values; D013599:Systole; D013997:Time Factors; D018608:Ultrasonography, Doppler / Q000379:methods*