Reference Values of Echocardiographic Measurements of Cardiac Structures and Function among Healthy Infants in Enugu, Nigeria: A Prospective Observational Study

Abstract

Background: There are varying results in reference values of cardiac structures and function in healthy infants in every locality. It is expedient to develop reference values among infants in this locale. Aims: This study sought to evaluate the reference values of  echocardiographic measurements of cardiac structures and function in healthy Igbo infants in Enugu, Nigeria.

Materials and Methods:  This is a prospective study which involved 105 healthy infants who had echocardiographic measurement of  cardiac structure and function over a four-year period.

Results: The mean weight of the subjects was 3.8286 ± 0.498 kg at 95% confidence  interval. The mean gestational age at birth was 38.5 ± 1.265 weeks at 95% confidence interval. Scatter diagram showed the  relationship between cardiac structures and body surface area (BSA). There was a positive association between BSA and mitral valve  (MV), tricuspid valve (TV), aortic valve (AV), and pulmonary valve (PV). The association between MV and BSA is as in the equation, MV =  200 × BSA‑38. The relationship between BSA and other indexed cardiac structures is as in the following equations: TV = 166.7 × BSA‑30.7,  AV = 116.7 × BSA–21.7, PV = 116.7 × BSA–21.7, right pulmonary artery = 116.7 × BSA‑22.7, left pulmonary artery = 133.3 × BSA–26.3, and  main pulmonary artery = 200 × BSA‑42. There was a significant positive correlation between the age of participants and most indexed  cardiac structures, but no significant correlation was seen for gender.

Conclusion: Normative reference values among Igbo infants  derived from echocardiographic assessment of cardiac structural dimension and function are elicited in this study. These reference  values could be a guide and could help the paediatric cardiologist and cardiothoracic surgeon in some clinical and surgical decisions.