Interpretation of left ventricular dimensions of neonates obtained from echocardiographic examinations during the early neonatal period

Abstract

In neonates without physiological pulmonary hypertension, left ventricular end-diastolic dimensions (LVDd) are determined with two-dimensional echocardiography and formulated equations. However, there has not been discussed the meanings of dimensions in early neonatal periods, although the short-axis view of the left ventricle is not round at this age. The objective of this study was to assess LVDd in neonates during early neonatal periods. The study group consisted of 460 full-term neonates (230 boys; 230 girls) without congenital heart disease. The iE33 apparatus was employed to examine and measure the LVDds and the longest and shortest dimensions in the short-axis view. A significant difference was observed between the real LVDds and the estimated normal dimensions that were calculated from the formula; LVDd(mm) = 0.352 × Ht(cm)+1.86), (P = 0.020). The mean LVDds were estimated to be 97% of the normal LVDds. The real LVDds were influenced by the angle formed by the real LVDds and the longest dimension. The real LVDds were shorter than normal LVDds. These findings establish normal values for LVDds in the early neonatal period.