Pulmonary factors limiting exercise capacity in patients with heart failure.

Patients with heart failure are frequently limited by exertional dyspnea. The mechanisms underlying dyspnea in these patients remain unclear. In this review, the pathologic changes that occur in the lung as a consequence of chronic pulmonary venous hypertension, pulmonary function test abnormalities, and potential mechanisms for dyspnea including airflow obstruction and/or respiratory muscle dysfunction are discussed.