Profound Increase of Lung Airway Resistance in Heart Failure: a Potential Important Contributor for Dyspnea

Dyspnea is a major symptom of heart failure (HF). Here, we have studied the lung remodeling and airway resistance in HF mice. We demonstrated that aortic banding-induced HF caused a dramatic decrease of lung compliance and an increase of lung airway resistance. The decrease of lung compliance was correlated with the increased lung weight in a linear fashion (γ² = 0.824). An HF-induced increase of lung airway resistance and a decrease of lung compliance were almost identical in anesthetized mice and in the isolated lungs from these mice. HF caused profound lung fibrosis in mice with increased lung weight. Moreover, HF patients of NYHA class III-IV showed increased lung density as revealed by high-resolution CT scanning. These data indicate that lung compliance and lung airway resistance may be useful in determining lung remodeling after HF, and lung structure changes may contribute to dyspnea in HF.