Repolarization Patterns in Congenital Heart Disease.

Area of Science:

• Cardiology
• Pediatrics
• Electrophysiology

Background:

• Congenital heart diseases (CHDs) can affect myocardial repolarization.
• Prolonged QT interval (QTc) is a marker for ventricular arrhythmia risk.
• Understanding repolarization patterns in pediatric CHDs is crucial for risk stratification.

Purpose of the Study:

• To investigate repolarization patterns, specifically QT interval and early repolarization, in pediatric patients with cyanotic and acyanotic congenital heart diseases.
• To identify associations between repolarization abnormalities and clinical parameters in these patients.

Main Methods:

• A cross-sectional case-control study involving 100 pediatric patients with CHDs (50 cyanotic, 50 acyanotic) and 50 healthy controls.
• Measurements included oxygen saturation, echocardiography, and 12-lead electrocardiogram (ECG) to determine corrected QT (QTc) interval.
• Statistical analysis was performed to compare groups and identify significant associations.

Main Results:

• Mean QTc was significantly higher in acyanotic CHDs with volume overload compared to controls (0.426s vs 0.4s).
• Increased left ventricular end-diastolic dimension was significantly associated with QTc prolongation (p=0.01).
• Early repolarization was more prevalent in patients with CHDs (18% acyanotic, 48% cyanotic) than controls (6%).
• Decreased oxygen saturation was significantly associated with early repolarization (p=0.01).

Conclusions:

• Acyanotic congenital heart diseases with volume overload and increased left ventricular end-diastolic dimension are associated with prolonged QTc.
• Decreased oxygen saturation is linked to early repolarization in pediatric patients with congenital heart disease.
• These findings highlight the importance of monitoring repolarization in pediatric CHD patients for arrhythmia risk assessment.