Ventilation and cardiac/perfusion related impedance changes of the lung determined by Electrical Impedance Tomography in cystic fibrosis

Abstract

Electrical impedance tomography (EIT) has the potential to measure ventilation and perfusion related impedance changes in the lung. Ventilation heterogeneity has already been confirmed by EIT in patients with obstructive lung diseases, such as chronic obstructive pulmonary disease (COPD) or cystic fibrosis (CF). In the present study, ventilation and cardiac/perfusion associated impedance changes (∆IV and ∆IC) were investigated in 12 CF patients. Differences in ∆IV and ∆IC ratios over the course of inspiration and expiration during normal tidal breathing were analyzed. Significant differences in ∆IV/∆IC within the expiration were determined (p < 0.01), whereas there were no significant differences in ∆I V/∆IC during inspiration. Differences in ΔIV/ΔIC during the expiration seemed to be mainly caused by variations in the cardiac/perfusion related impedance signal, which might possibly be induced by an impaired lung function in CF.