AIMS: Myocardial deformation imaging is now used to assess regional ventricular function in infants but their small size presents particular technical challenges. We therefore investigated the determinants of reproducibility of myocardial longitudinal strain (ε) in term and preterm infants, in order to determine optimal technical settings. METHODS AND RESULTS: Repeated longitudinal ε measurements of the mid-segments of the septum, and the left and right ventricular free walls, were performed using five different computation distances (CDs; also called strain length) in 20 infants. The coefficients of variation (CV) were calculated for each CD. Overall, ε measurements were most reproducible with a CD of 6 mm (CV 11.7%). In preterm infants (<34 weeks gestation; mean ± SD diastolic LV length, 20.3 ± 3.5 mm), ε measurements were most reproducible with CD of 6 mm (CV 7.2%); in term infants (>37 weeks gestation; mean ± SD diastolic LV length, 29.6 ± 3.0 mm), ε measurements were most reproducible with CD of 10 mm (CV 13.2%). The reproducibility of measuring ε increased with higher frame rates, from CV of 17.3% at frame rates <180 per s to 11.7% for frame rates >180 per s and 9.6% for rates >248 per s. CONCLUSION: In newborn infants, tissue Doppler loops should be acquired at frame rates above 180 per s. Myocardial deformation analysis of preterm infants should be performed using a CD of 6 mm, whereas a CD of 10 mm is more reproducible in term infants.
AIMS: Myocardial deformation imaging is now used to assess regional ventricular function in infants but their small size presents particular technical challenges. We therefore investigated the determinants of reproducibility of myocardial longitudinal strain (ε) in term and preterm infants, in order to determine optimal technical settings. METHODS AND RESULTS: Repeated longitudinal ε measurements of the mid-segments of the septum, and the left and right ventricular free walls, were performed using five different computation distances (CDs; also called strain length) in 20 infants. The coefficients of variation (CV) were calculated for each CD. Overall, ε measurements were most reproducible with a CD of 6 mm (CV 11.7%). In preterm infants (<34 weeks gestation; mean ± SD diastolic LV length, 20.3 ± 3.5 mm), ε measurements were most reproducible with CD of 6 mm (CV 7.2%); in term infants (>37 weeks gestation; mean ± SD diastolic LV length, 29.6 ± 3.0 mm), ε measurements were most reproducible with CD of 10 mm (CV 13.2%). The reproducibility of measuring ε increased with higher frame rates, from CV of 17.3% at frame rates <180 per s to 11.7% for frame rates >180 per s and 9.6% for rates >248 per s. CONCLUSION: In newborn infants, tissue Doppler loops should be acquired at frame rates above 180 per s. Myocardial deformation analysis of preterm infants should be performed using a CD of 6 mm, whereas a CD of 10 mm is more reproducible in term infants.
Authors: Philip Thaler Levy; Mark R Holland; Timothy J Sekarski; Aaron Hamvas; Gautam K Singh Journal: J Am Soc Echocardiogr Date: 2013-07-20 Impact factor: 5.251
Authors: Willem P de Boode; Yogen Singh; Samir Gupta; Topun Austin; Kajsa Bohlin; Eugene Dempsey; Alan Groves; Beate Horsberg Eriksen; David van Laere; Zoltan Molnar; Eirik Nestaas; Sheryle Rogerson; Ulf Schubert; Cécile Tissot; Robin van der Lee; Bart van Overmeire; Afif El-Khuffash Journal: Pediatr Res Date: 2016-06-08 Impact factor: 3.756