Unravelling early sinus node dysfunction after pediatric cardiac surgery: a pre-existing arrhythmogenic substrate

Area of Science:

• Pediatric Cardiology
• Cardiac Electrophysiology
• Congenital Heart Disease

Background:

• Early post-operative sinus node dysfunction (SND) frequently affects pediatric patients after surgical correction of congenital heart defects (CHD).
• The underlying pathophysiology of these arrhythmias remains poorly understood.

Purpose of the Study:

• To investigate the electrophysiological mechanisms contributing to early post-operative SND in pediatric CHD patients.
• To identify potential predisposing factors for SND in this population.

Main Methods:

• A case series approach was employed.
• Intraoperative epicardial mapping was performed in three pediatric patients who developed early post-operative SND.
• Analysis of sinoatrial node (SAN) exit sites and atrial conduction patterns.

Main Results:

• All three patients exhibited either an inferior or multiple SAN exit sites.
• Extensive conduction disorders were observed in both superior and inferior regions of the right atrium.
• These findings suggest a link between SAN exit site abnormalities and atrial conduction disturbances.

Conclusions:

• Pre-existing alterations in SAN exit sites, coupled with atrial conduction disorders, may predispose pediatric CHD patients to early post-operative SND.
• Understanding these arrhythmogenic mechanisms is vital for identifying high-risk patients.
• This research contributes to the hypothesis that complex electrophysiological substrates underlie SND in this cohort.