Heart rate variability in children with Fontan circulation.

Area of Science:

• Cardiology
• Pediatric Cardiology
• Autonomic Function Testing

Background:

• Heart rate variability (HRV) assesses cardiovascular autonomic control.
• Fontan circulation is a surgical procedure for single-ventricle congenital heart defects.
• Understanding HRV changes in Fontan patients is crucial for monitoring their long-term health.

Purpose of the Study:

• To investigate heart rate variability (HRV) in children with Fontan circulation.
• To analyze the changes in HRV over time in this patient group.
• To compare HRV parameters between Fontan patients and healthy controls.

Main Methods:

• Study included 34 children: 10 with Fontan circulation (Group A) and 24 healthy controls (Group B).
• Evaluations involved echocardiography and 24-hour ambulatory electrocardiogram to analyze HRV.
• Participants were analyzed in subgroups based on age (younger and older than 10 years).

Main Results:

• No significant overall differences in HRV parameters between all Fontan patients and controls.
• Children with Fontan circulation younger than 10 years showed significant differences in two HRV parameters compared to controls.
• Patients older than 10 years exhibited significantly reduced HRV, with eight parameters affected, particularly in low and high-frequency ranges (p < 0.008).

Conclusions:

• Patients with Fontan circulation demonstrate reduced HRV, confirming previous findings.
• A progressive reduction in HRV over time is indicated in children with Fontan circulation.
• Age-related decline in autonomic function is evident in Fontan survivors.