Abstract 16895: Relationship of Activity Energy Expenditure With Autonomic Balance and Liver Congestion in Patients With Fontan Circulation
Background: CVP increases with physical activity (PA) in Fontan circulation; therefore, excessive PA can be deleterious as it causes organ congestion. Contrarily, moderate exercise has beneficial effects in patients with heart failure, including improvement in autonomic nerve balance, resulting in better prognosis. However, no data are available regarding whether and how the intensity of PA affects the pathophysiology of Fontan patients. To our knowledge, this is the first study that assessed the effects of daily PA on hepatic congestion and autonomic balance in patients with Fontan circulation and determined the ideal intensity of PA for them.
Methods: Daily PA was assessed by activity energy expenditure (AEE) in 37 Fontan patients (3.8-42 years) who wore a high-accuracy accelerometer (Actical®) continuously for 2 weeks. We examined the relationship of the AEE values with γ-GTP, as an indicator of hepatic congestion, and heart rate variability (HRV), as an indicator of autonomic balance. Additionally, AEE/cardiac output (CO) was calculated as an index to assess whether the AEE and CO of the patients matched.
Results: Patients were divided into 4 groups based on the median values of γ-GTP and high-frequency power (HF) obtained through the HRV analysis. AEE was the highest in the “low HF-high γ-GTP” group, which is considered to have the worst prognosis, and was significantly higher than that of the “high HF-high γ-GTP” group (p<0.05). Furthermore, AEE/CO of the “low HF-high γ-GTP” group was significantly higher than that of the other groups, suggesting that patients with unfavorable autonomic balance and congestive liver performed excessive PA that did not match the level of CO. The group with the lowest AEE was the “low HF-low γ-GTP” group, suggesting that minimum activity was beneficial for liver function, but deleterious for autonomic balance. The AEE/CO of the “high HF-low γ-GTP” group (78.5±34.5), which is considered to have the best prognosis, was very close to the average AEE/CO values of all patients, suggesting that the PA performed by the patients in this group matched their CO.
Conclusion: Daily PA improves autonomic balance but causes hepatic congestion in Fontan patients. Customized AEE needs to be determined for each Fontan patient to improve prognosis.
Author Disclosures: A. Yana: None.
- © 2016 by American Heart Association, Inc.