Introduction: Tissue Doppler imaging techniques (pulsed-wave TDI (pwTDI) and color-coded TDI (cTDI)) allow for the assessment of myocardial performance during the cardiac cycle. The application of such techniques in neonatology is sporadic and poorly studied. Objective: The objective of the present study was to determine average values of pwTDI indicators of left ventricular performance (maximum systolic velocity of the mitral annulus (s’), maximum velocity in early diastole (e’) and maximum velocity in late diastole (a’)) and to examine their dynamics in prematurely born newborns in the first week of life. Methods: Prematurely born newborns of postnatal age up to 7 days were divided by gestational age into Group1 (<28 weeks) and Group 2 (≥28 weeks). Standard pwTDI parameters (s’, e’ and a’) were measured, compared between the groups and correlated with gestational and postnatal age, as well as application of respiratory support. Results: Fifty subjects were included (Group 1: 24; Group 2: 26). Average values of parameters s’, e’ and a’ were: Group 1: 4.06 ± 0.78 cm/s, 3.71 ± 0.40 cm/s and 3.98 ± 1.06 cm/s, respectively; Group 2: 4.18 ± 1.22 cm/s, 4.68 ± 1.04 cm/s and 4.12 ± 0.94 cm/s, respectively. Values of parameter e’ differed significantly between groups (p = 0.001) and strongly correlated with gestational age (p = 0, Pearson’s R = 0.88). There was no significant difference between groups for parameters s’ and a’ (p = 0.42 and 0.31, respectively). The values of s’, e’ and a’ did not differ between patients with an without respiratory support. Conclusion: Parameter e’ depends on gestational age, whereas parameters s’ and a’ are independent of gestational age. pwTDI indicators do not change during the first week of life, nor are all robust to hemodynamic circumstances caused by invasive/non-invasive respiratory support.
Keywords: echocardiography; neonatology; premature newborns; pwTDI; tissue Doppler.