QRS Width and T-Peak to T-End Interval Are Prolonged in Preadolescents with Severe Intrauterine Growth Restriction at Birth when Compared to Controls

The aim of this study is to assess how increased globularity and wall thickness resulting from intrauterine growth restriction (IUGR) in preadolescents affects the QRS width, T-peak to T-end and QT intervals, all biomarkers associated with susceptibility to ventricular arrhythmia. 12-lead ECG from 33 subjects who had severe IUGR and 60 control subjects were studied. Spatial principal component analysis was applied to the multilead ECG to emphasize the QRS complex and T-wave, followed by QRS detection and T-wave delineation to derive QRS width, T_{pe}, QT intervals and the ratio T_{pe}/QT. Additionally, we used a computational biventricular model with and without a more globular ventricle structure as observed in IUGR subjects but with no wall thickness modification, where the simulated ECG and its derived intervals were measured and compared with the clinical results. The IUGR subjects showed significantly wider QRS (4 ms), longer T_{pe} intervals (2 ms), and higher T_{pe}/QT ratio (3%) as compared to control group. Simulations did not corroborate those findings suggesting that other cardiac remodeling different from the accounted globularity, as perhaps wall thickness, should be the responsible for the increased QRS width and T_{pe} interval in IUGR, all associated with an increased transmural dispersion and a greater risk of ventricular arrhythmia.