Right ventricular contractility decreases during exercise in patients
with non-advanced idiopathic pulmonary fibrosis
Abstract
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 ten matched
controls. Transthoracic echocardiography images were acquired at rest
and during a cardiopulmonary exercise test. We assessed 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 worsened, whereas control patients
experienced 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.