Impairments in Pulmonary Function in Fontan Patients: Their Causes and Consequences

Area of Science:

• Cardiopulmonary interactions
• Congenital heart disease
• Respiratory physiology

Background:

• Fontan circulation lacks a sub-pulmonary ventricle, leading to passive pulmonary blood flow.
• Ventilation significantly influences pulmonary blood flow and cardiac output in Fontan patients.
• Abnormalities in lung function, including restrictive patterns and impaired gas transfer, are common.

Purpose of the Study:

• To review cardiopulmonary interactions in Fontan circulation.
• To examine the prevalence and severity of impaired lung and respiratory muscle function.
• To discuss causes, consequences, and potential strategies for improving respiratory function.

Main Methods:

• Review of existing data on cardiopulmonary interactions.
• Analysis of spirometry and diffusing capacity of carbon monoxide measurements.
• Assessment of respiratory muscle function and exercise capacity.

Main Results:

• Restrictive ventilatory patterns and impaired gas transfer are frequently observed.
• Reduced lung volumes are independently associated with decreased survival in adults.
• Skeletal and inspiratory muscle weakness is reported, with potential for improvement via exercise.

Conclusions:

• Impaired lung function significantly impacts exercise capacity and quality of life in Fontan patients.
• Respiratory impairments are linked to reduced survival, particularly in adults.
• Strategies to improve respiratory function may reduce morbidity in this population.