Q-T interval in congenital complete heart block

Area of Science:

• Pediatric Cardiology
• Electrophysiology
• Congenital Heart Disease

Background:

• Congenital complete heart block (CCHB) is a serious condition in children.
• The rate-corrected Q-T interval (Q-Tc) is a measure of ventricular repolarization.
• Understanding prognostic markers in CCHB is vital for patient management.

Purpose of the Study:

• To investigate the prognostic significance of prolonged Q-Tc in children with CCHB.
• To correlate Q-Tc interval with symptoms and outcomes in this population.
• To assess the relationship between Q-Tc, ventricular rate, and clinical presentation.

Main Methods:

• Retrospective analysis of 273 children diagnosed with congenital complete heart block.
• Measurement and analysis of rate-corrected Q-T interval (Q-Tc).
• Comparison of Q-Tc intervals and ventricular rates between patients and age-matched controls.

Main Results:

• Fifty-nine out of 273 children had a prolonged Q-Tc, with 50 experiencing symptoms.
• Children with prolonged Q-Tc had a significantly lower ventricular rate (VR) compared to controls.
• A prolonged Q-Tc was associated with a worse outcome, especially when combined with a low VR.

Conclusions:

• Prolonged Q-Tc in children with CCHB is a significant indicator of poor prognosis.
• Elevated Q-Tc may precede symptomatic presentation by over a month.
• Q-Tc interval assessment is valuable for risk stratification in pediatric congenital heart block.