Cardiovascular and Respiratory Interactions in Idiopathic Pulmonary Fibrosis by Extended Partial Directed Coherence:...

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease that can lead to chronic arterial hypoxemia, hypercapnia, and dyspnea. To improve clinical symptoms in IPF patients, supplemental oxygen (SupplO₂) has been prescribed with the aim to maintain SpO₂ level, and consequently to relieve dyspnea, increase physical activity and improve quality of life. In this study, we investigated the effect of disease and short-term SupplO₂ on cardiovascular and respiratory autonomic regulation. Linear and nonlinear indices were extracted from the beat-to-beat variability of heart rate (HR), systolic (SYS) blood pressure and respiration (RESP) in IPF patients and healthy subjects spontaneously breathing ambient air (AA) and during SupplO₂ at 3 L/min. It was found that the effects on autonomic nervous systems (ANS) regulation were better demonstrated by the Granger causality (GC) method. GC was significantly higher (p<0.01) in patients compared to controls for the interactions RESP→SYS and BBI→SYS.Clinical Relevance-Short-term SupplO2 in IPF could adversely affect systolic blood pressure variability in particular. This study may help in the management of SupplO2 administration.