Systolic function of a single left ventricle and exercise capacity in adults after Fontan palliation: A preliminary study using exercise echocardiography

Abstract

Background

Patients with functionally single ventricle after Fontan palliation are an increasingly large group in adult congenital heart disease departments. This cohort is also among the most complex to manage. However, many patients face a range of complications. Due to several reasons, patients following Fontan palliation experience significant reductions in exercise capacity. Cardiopulmonary exercise testing (CPET) provides means to assess exercise tolerance with objective parameters.

Objectives

The aim of the study is comparison of Stress Echocardiography (SE) parameters and CPET data in order to discover the potential relationship between them.

Methods

We enrolled 30 patients with a functionally single ventricle of left ventricle morphology who had undergone Fontan palliation and were hospitalized at the Department of Congenital Heart Defects between 2019 and 2021. The study was conducted using a bicycle ergometer in a semi-recumbent position. The parameters measured at rest and at peak exercise included the ejection fraction (EF) of the single ventricle and global longitudinal strain (GLS). The results of the current CPET were also incorporated. Demographic data, previous interventions, pharmacological treatment, and comorbidities were extracted from the patients' medical records.

Results

GLS measured at rest and EF measured at peak exercise correlated with Predicted Peak Oxygen Consumption (pVO2%pred).

Conclusion

GLS of the single left ventricle shows a meaningful association with pVO₂%pred and EF measured at peak exercise during stress echocardiography also correlates with pVO₂%pred, suggesting that both parameters provide complementary insights into the functional capacity and contractile reserve of the single ventricle in Fontan patients.