Measurement of right ventricular mechanical synchrony in children using tissue Doppler velocity and two-dimensional strain imaging.
BACKGROUND
Right ventricular (RV) mechanical dyssynchrony may be associated with RV dysfunction. The aim of this study was to investigate the feasibility of measuring RV synchrony in normal children using Doppler tissue imaging and two-dimensional speckle tracking.


METHODS
The RV delay (difference in time to peak velocity or two-dimensional strain between the RV lateral wall and the interventricular septum) and standard deviation of time to peak velocity or strain were measured and corrected for heart rate. Intraobserver and interobserver reliabilities were analyzed.


RESULTS
One hundred three children were studied. RV delay analysis was feasible in 95% by Doppler tissue imaging and in 63% by two-dimensional speckle tracking (99% and 84% when imaging was adequate). The mean ± 2 standard deviations RV delay by either method was <70 msec or <8% of the cardiac cycle in systole and <65 msec or <7% of the cardiac cycle in diastole. Intraobserver and interobserver variability showed small absolute differences but high variability because delays were either positive or negative.


CONCLUSIONS
This study establishes the feasibility of the measurement of RV mechanical synchrony in normal children aged 3 to 18 years.
Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, Toronto, Canada.
Wei
W
Hui
Cameron
C
Slorach
Timothy J
TJ
Bradley
Edgar T
ET
Jaeggi
Luc
L
Mertens
Mark K
MK
Friedberg
D000293:Adolescent; D001696:Biomechanical Phenomena; D002648:Child; D002675:Child, Preschool; D003971:Diastole / Q000502:physiology; D004452:Echocardiography / Q000379:methods*; D015150:Echocardiography, Doppler / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006346:Heart Septum / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D015588:Observer Variation; D012016:Reference Values; D012984:Software; D013599:Systole / Q000502:physiology; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D016278:Ventricular Function, Right / Q000502:physiology*; D055815:Young Adult