The Neonatal QRS Complex and Its Association with Left Ventricular Mass.

Area of Science:

• Neonatal cardiology
• Pediatric electrophysiology
• Cardiac imaging

Background:

• Left ventricular mass index (LVMI) is a key indicator of cardiac health in neonates.
• Electrocardiography (ECG) features, particularly QRS complex characteristics, may offer insights into neonatal cardiac development.
• Understanding the relationship between ECG and LVMI is crucial for early detection of cardiac abnormalities.

Purpose of the Study:

• To assess the evolution of QRS complex features in neonates during their first month of life.
• To investigate the association between ECG parameters and echocardiographic measurements of LVMI in neonates.
• To determine the diagnostic value of ECG features in identifying neonates with LVMI outliers.

Main Methods:

• A prospective cohort study involving 17,450 neonates.
• Electrocardiography (ECG) and echocardiography were performed within the first month of life.
• Correlation analysis between various ECG markers and LVMI, with a focus on identifying LVMI outliers (≥98th percentile).

Main Results:

• A gradual increase in QRS duration and LVMI was observed during the first month of life (p < 0.001).
• All analyzed ECG features demonstrated low correlation with LVMI, exhibiting low sensitivity (0-9.0%) but high specificity (97.2-98.1%) for identifying LVMI outliers.
• The area under the curve values for ECG features in predicting LVMI outliers were close to the identity line (0.49-0.61).

Conclusions:

• The neonatal QRS complex undergoes developmental changes in the first month of life.
• ECG features show a poor correlation with LVMI, indicating limited diagnostic value for detecting LVMI outliers in neonates.
• Current ECG parameters are insufficient for reliably identifying neonates with elevated left ventricular mass.