QRS duration and mechanical dyssynchrony correlations with right ventricular function after fontan procedure

Area of Science:

• Pediatric Cardiology
• Congenital Heart Disease
• Cardiac Electrophysiology

Background:

• Increased QRS duration and mechanical dyssynchrony are linked to reduced ventricular function in adults.
• Hypoplastic left heart syndrome (HLHS) patients undergo the Fontan procedure, altering cardiac physiology.
• The study investigates if these electro-mechanical findings apply to HLHS patients post-Fontan.

Purpose of the Study:

• To test the hypothesis that QRS duration and mechanical dyssynchrony correlate with ventricular function in HLHS patients after the Fontan procedure.
• To evaluate the relationship between electrocardiographic and echocardiographic measures of dyssynchrony and right ventricular (RV) function.

Main Methods:

• Retrospective cross-sectional study of HLHS patients post-Fontan procedure.
• QRS duration measured via 12-lead electrocardiography.
• Mechanical dyssynchrony assessed using Doppler tissue imaging (DTI), including time to peak strain rate (SRs) and modified Yu SRs.
• RV function evaluated through DTI s' wave, RV myocardial performance index, global strain, global SRs, and RV fractional area change.

Main Results:

• Thirty-one echocardiographic studies from 26 HLHS patients (median age 5.3 years) were analyzed.
• QRS duration showed a significant correlation with global SRs (r=0.42).
• Mechanical dyssynchrony measures (time to peak SRs, modified Yu SRs) correlated significantly with RV function parameters (DTI s' wave, global strain, RV fractional area change).

Conclusions:

• Both QRS duration and mechanical dyssynchrony demonstrated weak correlations with RV function in HLHS patients post-Fontan.
• The clinical implications of these correlations require further investigation in larger cohorts.
• These electro-mechanical parameters may offer insights but need validation for guiding treatment in this complex population.