Background Very preterm newborn infants often need cardiovascular support. More knowledge about myocardial function and factors that influence the immature myocardium may be helpful for optimising cardiovascular support in these infants.

Objective Serial assessment of global myocardial function by means of colour tissue Doppler imaging (cTDI) in very and extremely preterm infants during the first 24 h of life.

Study design One-centre, prospective, observational longitudinal cohort study in a third level Neonatal Intensive Care Unit. Sixty-five infants with median (range) gestational age (GA) 27 (24–31) weeks and birth weight (BW) 1049 (484–1620) g underwent echocardiographic examinations including cTDI at 5, 12 and 24 h after birth.

Main outcome measures Peak systolic and peak diastolic annular velocity and peak annular displacement of the left and right ventricle.

Results There was a significant reduction in systolic and diastolic velocities and displacement of both ventricles from 5 to 12 h age. From 12 to 24 h, there was a non-significant increase in myocardial velocities and displacement. At 5 h, babies with haemodynamically significant patent ductus arteriosus (PDA) had significantly higher systolic and diastolic velocities in both ventricles than those with non-significant PDA.

Conclusions Myocardial tissue velocities decrease significantly from 5 to 12 h after birth in very preterm infants. Further studies are needed to confirm these results and to determine their clinical implications.