Right ventricular contractility decreases during exercise in patients with non-advanced idiopathic pulmonary fibrosis

Introduction: Early right ventricular dysfunction in non-advanced patients with idiopathic pulmonary fibrosis has not been fully elucidated. Thus, we aimed to assess right ventricular functions in idiopathic pulmonary fibrosis patients and controls by speckle-tracking strain echocardiography at rest and peak exercise. Methods: We conducted a cross-sectional study in 20 idiopathic pulmonary fibrosis patients without oxygen use, blood oxygen saturation levels ≥92% at rest, and modified Medical Research Council score ≤3 and enrolled 10 matched controls. Transthoracic echocardiography images were acquired at rest and during a cardiopulmonary exercise test. We analyzed two-dimensional echocardiographic parameters and right ventricular function using the global longitudinal strain assessed by the two-dimensional speckle-tracking technique. Results: In the control group, we found normal values of global longitudinal strain (GLS) at rest and at peak exercise, the latter being much more negative (-23.6±2.2% and -26.8±3.1%, respectively; p<0.001). By contrast, GLS values in the idiopathic pulmonary fibrosis group increased from -21.1±3.8% at rest to -17.0±4.5% at peak exercise (p<0.001). The exercise revealed a difference between the two groups as the mean GLS values moved during peak exercise in opposite directions. Patients with idiopathic pulmonary fibrosis got worse, whereas control patients presented improved right ventricular contractility. Conclusions: Right ventricular dysfunction was unveiled by speckle-tracking echocardiography during exercise in non-advanced idiopathic pulmonary fibrosis patients. We suggest that this reflects an inadequate right ventricular-arterial coupling decreasing the right ventricular longitudinal contraction during exercise in these patients. This parameter may be useful as an early index of suspected pulmonary hypertension.