Persistently Elevated Right Ventricular Index of Myocardial Performance in Preterm Infants with Incipient Bronchopulmonary Dysplasia

Abstract

ObjectivesElevated pulmonary vascular resistance occurs during the first days after birth in all newborn infants and persists in infants at risk for bronchopulmonary dysplasia (BPD).It is difficult to measure in a non-invasive fashion. We assessed the usefulness of the right ventricular index of myocardial performance (RIMP) to estimate pulmonary vascular resistance in very low birth weight infants.Study DesignProspective echocardiography on day of life (DOL) 2, 7, 14, and 28 in 121 preterm infants (median [quartiles] gestational age 28 [26]–[29] weeks, birth weight 998 [743–1225] g) of whom 36 developed BPD (oxygen supplementation at 36 postmenstrual weeks).ResultsRIMP derived by conventional pulsed Doppler technique was unrelated to heart rate or mean blood pressure. RIMP on DOL 2 was similar in infants who subsequently did (0.39 [0.33–0.55]) and did not develop BPD (0.39 [0.28–0.51], p = 0.467). RIMP declined steadily in non-BPD infants but not in BPD infants (DOL 7: 0.31[0.22–0.39] vs. 0.35[0.29–0.48], p = 0.014; DOL 14: 0.23[0.17–0.30] vs. 0.35[0.25–0.43], p<0.001; DOL 28: 0.21[0.15–0.28] vs. 0.31 [0.21–0.35], p = 0.015).ConclusionsIn preterm infants, a decline in RIMP after birth was not observed in those with incipient BPD. The pattern of RIMP measured in preterm infants is commensurate with that of pulmonary vascular resistance.

Myocardial performance index (Tei index) in term and preterm neonates during the neonatal period

“…These values are lower compared to those obtained in our study (RVMPI = 0.47 ± 0.23). Nevertheless, we confirmed the results obtained by Czernik et al [2] after PDA closure (RVMPI = 0.32 ± 0.08 on the 7 th DOL), and those obtained on the 28 th DOL (RVMPI = 0.31 ± 0.10). Similarly to Czernik et al [2], we observed increased RVMPI (0.31 ± 0.1) values on the 28 th DOL in BPD sufferers diagnosed at 36 weeks PCA, compared to the mild BPD (0.22 ± 0.06) and healthy term neonates (0.23 ± 0.1).…”

“…Nevertheless, we confirmed the results obtained by Czernik et al [2] after PDA closure (RVMPI = 0.32 ± 0.08 on the 7 th DOL), and those obtained on the 28 th DOL (RVMPI = 0.31 ± 0.10). Similarly to Czernik et al [2], we observed increased RVMPI (0.31 ± 0.1) values on the 28 th DOL in BPD sufferers diagnosed at 36 weeks PCA, compared to the mild BPD (0.22 ± 0.06) and healthy term neonates (0.23 ± 0.1). Such elevated RVMPI values in children with severe BPD reflect a persistently elevated pressure in the pulmonary circulation, resulting from a lower number of blood vessels surrounding the pulmonary alveoli, hypertrophy of the vessel media, muscularisation of small peripheral vessels, and inappropriate vasoreactivity [2].…”

“…Similarly to Czernik et al [2], we observed increased RVMPI (0.31 ± 0.1) values on the 28 th DOL in BPD sufferers diagnosed at 36 weeks PCA, compared to the mild BPD (0.22 ± 0.06) and healthy term neonates (0.23 ± 0.1). Such elevated RVMPI values in children with severe BPD reflect a persistently elevated pressure in the pulmonary circulation, resulting from a lower number of blood vessels surrounding the pulmonary alveoli, hypertrophy of the vessel media, muscularisation of small peripheral vessels, and inappropriate vasoreactivity [2]. Although the authors are aware of the limitations of the study, the aim was to present the dynamics of the changes in the mean values of LVMPI and RVMPI in different groups of neonates depending on their maturity.…”

“…For example, impairment of myocardial systolic and diastolic function accompanies intrauterine and secondary infections, and affects preterm neonates with bronchopulmonary dysplasia (BPD), hypoxia, and intrauterine growth retardation [1][2][3][4][5]. Conventional methods of evaluation of myocardial function have limitations in adults, which become even more problematic in the immature myocardium of the preterm neonate.…”

Pulmonary Hypertension in Preterm Infants with Bronchopulmonary Dysplasia

“…The myocardial performance index (or Tei index), a marker of ventricular dysfunction consisting of the sum of isovolumetric contraction and relaxation times divided by the ejection time, is elevated in primary PH, may be elevated in preterm infants with BPD, and may correlate with BPD severity. [79][80][81][82] More recently, tissue Doppler measurements have been found to correlate with elevated end diastolic pressure in adults. The ratio of the early Doppler inflow velocity to the early myocardial tissue Doppler velocity (E/E¢) has been shown to correlate with the severity of BPD, but requires further study to determine if it will be a useful marker of disease.…”