Establishing Heart Rate Norms in Children with Fontan Palliation Using Holter Monitors

Area of Science:

• Pediatric Cardiology
• Electrophysiology
• Congenital Heart Disease

Background:

• Fontan palliation increases risks of arrhythmias and sinus node dysfunction.
• Annual Holter monitoring is recommended but lacks normative data for Fontan patients.
• Existing data is limited, with only one study on healthy children.

Purpose of the Study:

• Establish normative Holter heart rate data for pediatric Fontan patients.
• Compare Holter data between Fontan patients and healthy children.
• Create a reference dataset for ambulatory ECG screening in Fontan physiology.

Main Methods:

• Retrospective, single-center analysis of 642 Holter monitors from 133 Fontan patients (aged 5-21).
• Exclusion criteria: pacemakers, significant AV valve regurgitation, or depressed ventricular function.
• Comparison of heart rate values with a cohort of 502 healthy controls.

Main Results:

• Fontan patients showed higher minimum HRs in adolescents and lower average HRs in younger children compared to controls.
• Fontan patients universally had lower maximum heart rates.
• Males and digoxin users had lower minimum HRs; heterotaxy correlated with higher minimum/average HRs.

Conclusions:

• This study provides the first normative Holter heart rate data for pediatric Fontan patients.
• Findings indicate Fontan patients do not exhibit significantly lower minimum heart rates.
• The data serves as a valuable reference for clinical assessment, highlighting the need for multicenter studies.