Pathophysiology and cardiorespiratory consequences of interstitial lung disease--review and clinical implications: a special communication.

The purpose of this special communication is to review the pathophysiology of interstitial lung disease (ILD) and its cardiorespiratory consequences at rest and during exercise. Patients with ILD tend to have a resting and disproportionate exercise tachycardia; resting or exercise-induced arterial desaturation; a rapid shallow breathing pattern; and in more severe cases an increase in pulmonary arterial pressure with an associated increase in right ventricular work. Although the acute exercise responses of patients with ILD have been documented, studies on their responses to exercise training are lacking. We, therefore, discuss some of the physiologic consequences of ILD and the clinical measures available to assess these patients at rest and during exercise. We present the implications of these changes for functional ability and propose that modified endurance training is important to the patient with ILD. Potential directions for clinical research in exercise training of patients with ILD are presented.