Does low birth weight affect P-wave and QT dispersion in childhood?

Abstract

Background: The aim of our study is to investigate the effects of low birth weight (LBW) on atrial conduction and ventricular repolarization in children by using P-wave dispersion (Pw-d) and QT dispersion (QT-d) analyses. These effects have not yet been studied in detail in LBW children.

Methods: Fifty LBW children and 70 normal birth weight (NBW) children were enrolled in this cross-sectional controlled study. The Pw-d and QT-d of the LBW and NBW children were investigated. Independent Student's t-test, Mann-Whitney U test, and χ(2) test were performed to compare these two groups. Stepwise multiple regression analysis was performed to investigate whether there was a relationship between P-wave indices, QT derivatives, anthropometric and clinical features, and echocardiographic parameters.

Results: Age, gender, body mass index, waist circumferences, systolic and diastolic blood pressure, and echocardiographic measurements were similar between the LBW group and the NBW group (all P values > 0.05). The following findings were recorded for the LBW and NBW groups, respectively: the Pw-d (30 [10-50] ms vs 30 [10-50] ms, P = 0.977), QT-d (20 [10-50] ms vs 30 [15-50] ms, P = 0.561), and QTc-d (26 [14-54] ms vs 33 [17-62] ms, P = 0.866). No significant difference was found in Pw-d, QT-d, and QTc-d in comparison between the groups (all P values > 0.05). Pw-d was related to left atrial diameter and QTc-d was associated with left ventricle mass index even though they were within the normal range.

Conclusion: Compared with the NBW group, no significant difference was found in both atrial conduction and ventricular repolarization features in LBW children.

Keywords: P-wave indices; QT interval; childhood; low birth weight.