Aims: Myocardial velocity imaging has been validated in adults for assessment of ventricular function and indirect indices of pulmonary arterial pressure. To establish whether it could also be used in infants, we investigated the reproducibility of myocardial velocities and deformation indices in term and preterm neonates.
Methods and results: Myocardial velocity loops acquired from 16 infants were analysed by four observers for inter-observer variability, and re-analysed after 6 months by one observer for intra-observer variability. For myocardial velocities, the coefficients of variation (CVs) for the left ventricle (LV) were 10-11 (intra-observer) and 14-20% (inter-observer) and for the right ventricle (RV) 15-19 and 18-24%, respectively. Reproducibility for annular displacements was <13% (intra-observer) and <18% (inter-observer). CVs for LV strain were 14-17 (intra-observer) and 36-43% (inter-observer) and for RV 19-24 and 25-37%. CVs for isovolumic acceleration were in general >40%. In comparison, the CVs for blood pool indices were 3-15%.
Conclusion: Intra-observer reproducibility for myocardial velocity and deformation indices in neonates is adequate for these parameters to be used in clinical research. Inter-observer reproducibility is sub-optimal suggesting that these measurements should be used in clinical practice with caution. Myocardial acceleration, a marker of contractile function, was poorly reproducible.