Right ventricular anatomical and functional parameters in healthy Mexican term newborns

Rocío L. Pedraza-Melchor, Department of Neonatology, Hospital Español de México, Mexico City; Postgraduate Department, School of Medicine Universidad La Salle México, Mexico City; Mexico Rodrigo Hernández-Benítez, Department of Pediatrics, Hospital Español de México, Mexico City, Mexico José Iglesias-Leboreiro, Department of Neonatology, Hospital Español de México, Mexico City, Mexico Désireé Vidaña-Pérez, Department of Neonatology, Hospital Español de México, Mexico City, Mexico Isabel Bernardez-Zapata, Department of Neonatology, Hospital Español de México, Mexico City, Mexico Yogen Singh, Department of Neonatology, Cambridge University Hospitals NHS Foundation Trust and University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom

Objective: Right ventricle (RV) function plays an important role during fetal and neonatal transitional circulation. Despite the published echocardiography guidelines in children including neonates, there is scare evidence on RV assessment using echocardiography in Mexican neonates. This study was aimed at assessing RV function and anatomical measures in healthy term newborns and defines normal values in this cohort of patients. Methods: A prospective study involving healthy term newborns in a single center were enrolled in the study to assess RV, all patients were recruited within 24-72 h after birth. The right ventricular assessment was performed as per American Society of Echocardiography’s guidelines. Results: Seventy healthy term newborns with a median gestational age of 38 (38.5 ± 2.7) weeks had RV function assessment and anatomical structures measures with a predefined ten echocardiographic parameters protocol. The mean values for: tricuspid valve diameter was 13 mm ± 1.8, basal diameter of the RV 16.7 mm ± 2, RV length 27.8 mm ± 2.2, mid cavity diameter 14.3 mm ± 1.7, RV-anteroinferior basal diameter 21.5 mm ± 2.5, tricuspid regurgitation gradient 13.3 mmHg ± 5.9, tricuspid annular plane systolic excursion 8.7 mm, right ventricular fractional area change (RVFAC) 4 chamber (%) 40.6 ± 7.5, tricuspid E/A 0.7 ± 0.5, myocardial velocities (cm/s) E´ 8 ± 2.7, A´ 9.6 ± 2.4, S´ 6.9 ± 1.2, myocardial performance index 0.5 ± 0.1, RVFAC 3 chamber (%) 37.8 ± 15.8, and pulmonary acceleration time mean value 58.8 ± 14.9. Flattening of interventricular septum was seen in 13% infants. Conclusions: This study describes echocardiographic parameters for anatomical structures and assessment of RV function in healthy term newborns during transitional circulation. We reported novel anatomical measures of the RV; this information can provide normal reference range values and be referenced while assessing RV function in normal and sick newborns during transitional circulation.

Keywords: Neonates. Right ventricular function. Normal parameters.