QT-interval dispersion in malnourished children

Background: Little is known about the electrocardiographic (ECG) QT interval and its variability in malnourished children. Hypothesis: The study of the QT interval and its dispersion in malnourished children was undertaken to determine whether the QT interval and its variability are increased in these children. Methods: In 40 children (20 malnourished and 30 controls) aged 12.2 +/- 14.4 months (23 male) a conventional ECG was performed for computing heart rate, heart rate variability, corrected QT interval, and QT-interval dispersion. A blood sample was obtained for measuring hemoblogin, hematocrit, plasma protein, and plasma electrolytic concentrations. Results: Corrected heart rate, heart rate variability, and QT interval were similar in both groups. When compared with the control group, the malnourished children had greater corrected QT-interval dispersion, and that dispersion was more accentuated in the precordial leads. They also had repolarization abnormalities (flattened or inverted T waves and U waves). Hemoglobin, hematocrit, plasma protein, and plasma electrolytic concentrations were lower in the malnourished children. However, the ECG findings showed no statistically significant relationship with either the blood parameters, the severity or type of malnutrition, and the size or the weight of the children. Conclusions: QT-interval dispersion is increased in malnourished children and the dispersion is more accentuated in the precordial leads.