Clinical Investigations in Children
Normalizing Echocardiographic Measurements in Children and Neonates
A Comprehensive Echocardiographic Protocol for Assessing Neonatal Right Ventricular Dimensions and Function in the Transitional Period: Normative Data and Z Scores

https://doi.org/10.1016/j.echo.2014.08.018Get rights and content

Background

There is a paucity of echocardiographic data describing right ventricular (RV) dimensions and function in the early transitional newborn period.

Methods

Fifty healthy term newborns underwent serial echocardiography at a mean of 15 ± 2 and 35 ± 2 hours of age. RV dimensions and functional indices were measured as recommended in the American Society of Echocardiography’s recent guidelines. Additional novel parameters included RV anteroinferior basal diameter, fractional area change (FAC) from the apical three-chamber view, and speckle-tracking echocardiography–derived peak longitudinal strain in the RV lateral (apical four-chamber view) and inferior (apical three-chamber view) walls. Results obtained at both time points were compared.

Results

Linear dimensions and tissue Doppler velocities were highly reproducible, while time intervals and FAC measurements were more variable. Three-chamber FAC was higher than four-chamber FAC (36 ± 5% vs. 24 ± 7%, P < .001). Lateral wall peak longitudinal strain was similar to the value for the inferior wall (22 ± 4% vs 18 ± 5%, P > .05). A small increase in RV dimensions was noted on day 2 of life (midcavity diameter, 1.71 ± 0.19 vs 1.55 ± 0.19 cm, P < .01; RV anteroinferior basal diameter, 2.24 ± 0.29 vs 2.06 ± 0.24 cm, P < .01; end-diastolic-area in the apical four-chamber view, 4.32 ± 0.64 vs 4.10 ± 0.69 cm2, P = .04), while no changes occurred in functional indices. RV dimensions and FAC showed moderate linear correlations with birth weight. Z scores could be computed for the majority of measured indices.

Conclusions

Using conventional and novel indices, the investigators describe a comprehensive echocardiographic protocol for neonatal RV imaging, establish reference ranges, and describe the effect of physiologic postnatal transition on RV dimensions and function. This will facilitate future investigations of RV dysfunction in neonatal cardiopulmonary disorders.

Section snippets

Study Design

For this prospective observational study, we recruited 50 healthy term neonates between December 2011 and September 2012 from the Mother and Baby Unit (Mount Sinai Hospital, Toronto, Ontario, Canada). The health records of all infants receiving routine postnatal care were screened, and eligible families were approached within 12 hours of birth. The institutional research ethics board approved the study, and written informed consent was obtained from all parents.

Inclusion and Exclusion Criteria

All healthy, term (gestational

Results

Fifty neonates (17 male) with a mean gestational age of 39.7 ± 1.2 weeks were included. Twelve neonates were delivered by cesarean section. The mean cord pH was 7.23 ± 0.07, and the median Apgar score at 5 min was 9 (range, 8–9). Two infants were noted to have premature atrial contractions during echocardiography that were confirmed by 12-lead electrocardiography. The mean time interval between the two scans was 19.9 ± 1.8 hours. Table 1 summarizes clinical and echocardiographic characteristics

Clinical Significance

In this study we describe a comprehensive echocardiographic protocol for imaging the right ventricle in neonates and establish normal values for various RV dimensions and functional parameters. Preservation of RV function is recognized as a critical prognostic factor in the management of cardiopulmonary disorders of adults, particularly in pulmonary hypertension.11, 12 Cardiopulmonary disorders are not uncommon during the newborn period. Acute pulmonary hypertension has been reported as a

Conclusions

A comprehensive quantitative RV appraisal using 2D echocardiography is feasible in neonates and should include measurements of RV dimensions and function using multiple 2D views. We propose that a practical echocardiographic protocol should include the measurement of posterior basal diameter in addition to the conventional apical RV-4C view–derived linear dimensions. Furthermore, RV functional assessment should include the following parameters, which demonstrated the least interobserver

References (29)

  • N.F. Voelkel et al.

    Right ventricular function and failure: Report of a national heart, lung, and blood institute working group on cellular and molecular mechanisms of right heart failure

    Circulation

    (2006)
  • M. Koestenberger et al.

    Right ventricular performance in preterm and term neonates: reference values of the tricuspid annular peak systolic velocity measured by tissue Doppler imaging

    Neonatology

    (2013)
  • M. Koestenberger et al.

    Systolic right ventricular function in preterm and term neonates: reference values of the tricuspid annular plane systolic excursion (TAPSE) in 258 patients and calculation of Z-score values

    Neonatology

    (2011)
  • L.L. Mertens et al.

    Imaging the right ventricle—current state of the art

    Nat Rev Cardiol

    (2010)
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    This work was funded by the Canadian Institutes of Health Research (MOP #93596 and 84290 to Dr Jankov). Dr Jain is supported by a Sick Kids Research Training Centre Clinician Scientist Training Program Doctoral Award. Dr Dallaire is a member of the Fonds de Recherche Santé Québec–funded Centre de Recherche Clinique Étienne-Le Bel.

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